Effect of gene dispersion on estimates of components of generation means and variances. The components of generation means that measure gene action and interaction at homozygous loci have expectations that depend on the degree of association or dispersion of alleles of like effect at different loci. With anything less than complete association, estimates of these components do not necessarily reflect the relative directions, magnitudes or kinds of gene action or interaction present. To illustrate these expected consequences, the F1, F2 and backcross generation of two contrasting crosses between pairs of inbred lines of Nicotiana rustica have been raised in which the same alleles are segregating at the same loci but for loci contributing to variation in final height the alleles of like effect are predominantly associated in one cross and predominantly dispersed in the other. The simultaneous analysis of the data from the two crosses show all the expected effects of the differences in the degree of association or dispersion. In the dispersion cross the effects of gene action at homozygous loci are underestimated and the interaction between homozygous loci is not detected at all. The large directional dominance component that is common to both crosses is in fact no greater than the additive component once the deflating effect of dispersion is removed, thus ruling out the presence of overdominance. No effects of association or dispersion on the components of variation could be detected nor would any be expected unless there were differences in the predominant linkage phase between the two crosses. Large and predictable effects on estimates of the number of effective factors are, however, demonstrable.


7-Hydroxymethotrexate as a urinary metabolite in human subjects and rhesus monkeys receiving high dose methotrexate. Human subjects and rhesus monkeys receiving the antitumor agent methotrexate at the high dose levels recently introduced into clinical use (greater than 50 mg/kg) excrete significant amounts of the metabolite 7-hydroxymethotrexate. The metabolite is not detected in these species after methotrexate therapy at conventional dose levels. The evidence indicates that in primates, the in vivo conversion of methotrexate to 7-hydroxymethotrexate is a dose-dependent phenomenon, with the enzyme system(s) catalyzing the reaction having a low affinity for the drug.


The effect of periodontal dressings on the healthy periodontium. Twenty-seven proprietory periodontal dressings were applied to the lower labial segments of 18 subjects showing low levels of gingival inflammation when assessed by the Gingival Index system at the time of application. Specimens of each dressing type were subsequently removed at intervals ranging from 3 h to 5 days. The material adhering to the deep surface of the dressing was examined by light, transmission and scanning electron microscopy and was shown to be a complex heterogeneous structure consisting of large intact epithelial cell sheets and oral bacteria in a proteinaceous matrix. Possible mechanisms which could contribute the epithelial cell and protein components to this structure were discussed. It was concluded that the dressings themselves caused little damage to the normal periodontium but could be associated with increased levels of inflammation at longer time intervals because of bacterial growth. The significance of these findings to current clinical practice is discussed.


Osteogenic sarcoma arising in an old burn scar. An osteogenic sarcoma arising in an old burn scar on the right thigh of a 70-year-old woman is described. Salient features of this rare cutaneous tumor were: a large pinkish exophytic mass, spindle and oval cells, multiple foci or osteoid formation, atypical osteoblasts and multinucleated giant cells.


Collagenolytic activity of crevicular fluid from pericoronal gingival flaps. Fluids from normal and inflamed gingival flap tissues, overlying partially erupted lower third molars, were incubated on reconstituted collagen gels and examined for collagenase activity. Collagenase activity was observed only in fluids originating from tissues with pericoronitis. However, when fluids from clinically normal tissues were treated with NaSCN, some also showed collagenase activity. Only the fluids from normal-looking tissues with a history of pericoronitis showed collagenase activity after NSCN treatment. No enzyme activity was observed in treated or untreated fluids from normal tissue from patients with no history of pericoronitis. It was concluded that the fluid collagenase activity originated from the adjacent gingival tissue because (1) the activity of the untreated fluid observed in this study seemed to parallel the acitivity of the adjacent gingival tissue, based on our observations in a previous study; (2) NaSCN affected the fluid collagenase in the same way that others found it to affect gingival tissue collagenase; and (3) the disc gel electrophoretic pattern of the breakdown products of collagen produced by the GCF enzyme was similar to that produced by gingival tissue collagenase and differed from that produced by a bacterial collagenase reported to exist in human gingival fluid.


Study on the composition of bovine gingival lipids. The lipids in bovine gingival tissue were characterized qualitatively and quantitatively. The total lipid content was 2.35% on wet weight. The total nonpolar lipids and total polar lipids were 70.69 and 29.31% of the total lipids, respectively. Cholesterol esters, free fatty acids, and triglycerides were the major nonpolar lipids. Polar lipids were predominantly phosphatidyl choline, phosphatidyl ethanolamine, and sphingomyelin. Traces of glycolipids, lysophosphatidyl choline, phosphatidyl inositol, phosphatidyl serine, and prostaglandins were present. Oleic, palmitic, and stearic acids were found to be the major fatty acids in all lipid classes. Cholesterol esters, total polar lipids, and free fatty acids were more unsaturated than glycerides. Linolenic and arachidonic acid contents were highest in cholesterol esters and total polar lipids.


Detection of prostaglandins in bovine gingival tissue. It has been characterized earlier that bovine gingival lipids contain a fairly high level of arachidonic acid, a potential precursor of prostaglandin biosynthesis. The purpose of the present study was to investigate whether prostaglandins are natural components of bovine gingival tissues. Qualitative analysis of the lipid extract by a combination of thin-layer chromatography on plain and silver nitrate-impregnated silical gel plates and ultraviolet absorption spectroscopy strongly indicate the presence of PGE1, PGE2, and PGF2. There was also an indication for the occurrence of other prostaglandins, such as PGB, PGE3, PGF1, and PGF3.


Cusp size sexual dimorphism, and the heritability of maxillary molar cusp size in twins. The data given on the cusp size of maxillary first permanent and second primary molars support the following conclusions. The qualitative literature on cusp size hierarchy requires revision because the quantitative data suggest that the mesiolingual cusp is largest, the distobuccal cusp second largest, the mesiobuccal cusp third largest, and the distolingual cusp smallest. Sexual dimorphism is apparent only when reflected as a collective measure of total occlusal area, a summation of cusp and ridge sizes. Antimere variations are random for individual cusps and collective measures of total occlusal areas mask observable right-side, left-side cuspal variations. Similarly, cross-twin and co-twin analyses of cusp size heritability indicate a low level of hereditary variability.


Studies of the mechanism of sucrose-associated colonization of Streptococcus mutans on teeth of conventional rats. The mechanism of the colonization of S mutans strain 6715 on teeth in the presence of sucrose has been investigated using conventional Sprague-Dawley rats. Experiments were performed using rats fed diets with 56% sucrose or 56% glucose; oral inoculations with sucrose-grown, extracellular glucan-coated cells and glucose-grown, uncoated cells; and teeth treated with dextran 2000 via its incorportation in the diet, or teeth left untreated. In all instances, sucrose was required for satisfactory colonization of the test strain. Preformed extracellular glucan, whether associated with the bacterial cell or with the tooth surface, did not facilitate bacterial colonization when compared with cells or teeth devoid of extracellular glucan under the conditions used. The evidence suggests that glucan-mediated attachment of S mutans strain 6715 in the presence of sucrose involves an initial phase in which the cells are relatively weakly associated with the tooth surface and a subsequent phase during which firmer attachment occurs via new glucan synthesis.


An apparatus for measuring the rheological properties of dental materials. An indirect extrusion capillary viscometer has been developed. This has been tested for nonsetting Newtonian fluids and was found to give results close to, but slightly lower than the actual viscosity. The same apparatus has been successfully applied to a non-Newtonian fluid to determine the dependence of viscosity on shear rate. The technique described should meet the requirements for assessing the rheological characteristics important in the mixing and setting of dental materials. The developed viscometer must be coupled with a sensitive mechanical testing machine capable of an adequate range of crosshead speeds that can be changed rapidly. By obtaining force vs time curves at different shear rates for setting materials, viscosity can be calculated as a function of time. Also, the viscosity at any given time during the setting process can be calculated as a function of shear rate. This chould be of aid in the interpretation of changes in rheological properties during setting of dental materials.


Evaluation of instructional materials for teaching psychomotor skills. An investigation was conducted to determine the effectiveness of self-instructional materials for a cavity preparation procedure using two types of dental auxiliaries under assisted and unassisted instructional conditions. Results showed significant pretest to posttest performance gains, with the instruction proving equally effective across both types of auxiliaries and instructional conditions.


Experimental carcinogenesis in duct-artery ligated rat submandibular gland. In an attempt to shorten tumor induction time and alter tumor anaplasticity, ductal metaplasia was induced in the submandibular gland of 30 rats by ligation of the duct and artery followed by the implanation of 4-mg pellets of pure DMBA. Control groups consisted of 19-ligated and 15-DMBA implanted rats. The ligate controls showed degeneration and atrophy of the affected gland and replacement of glandular tissue by scar tissue. The DMBA controls followed the expected pattern, with all rats eventually developing well-differentiated squamous cell carcinoma. The CMBA-ligated rats showed a combination of the two processes, each acting separately from the other. There was no difference either in induction time or tumor anaplasticity between the DMBA control rats and the DMBA-ligated rats. It seems that only factors relating to a change in the immunologic response of the host affect the latent period of tumor induction time in submandibular gland carcinogenesis.


Role of sucrose in colonization of Streptococcus mutans in conventional Sprague-Dawley rats. The role of sucrose in the colonization of S mutans strain 6715 in conventional Sprague-Dawley rats was studied. A diet with 56% sucrose favored the oral colonization of the test strain compared to diets with 56% glucose or fructose or to laboratory chow as determined by recoveries from extracted teeth ground in tissue grinders. S mutans strain 6715 cells became well established in all rats fed a high sucrose diet with cell inoculums ranging from 10(8) to the lowest effective dose of 10(5) CFU once orally administered; in rats on nonsucrose diets, inoculation with even the highest dose only infrequently resulted in the establishment of S mutans strain 6715. Sucrose- and glucose- grown cells appeared to behave similarly. Colonization of S mutans strain 6715 occurred in all rats fed diets with a sucrose content ranging from 56 to as low as 1%. The establishment of S mutans strain 6715 on the teeth of rats fed diets with a sucrose concentration of 0.1 or 0.01% was impaired and comparable to the diet containing 56% glucose. In rats fed a high glucose diet, uniform establishment and persistence of the test strain occurred after frequent inoculations with about 5 X 10(8) CFU. The colonization under these conditions appeared to be independent of the intestinal canal as a bacterial cell source. These data suggest the possibility that S mutans can establish itself in the human mouth in the absence of dietary sucrose. In rats fed a high glucose diet and inoculated with 10(7) CFU or less, the cells gradually disappeared from the teeth; in contrast, the test strain implanted well in rats fed the sucrose favors firmer attachment of initially weakly attached cells via in situ new glucan synthesis. S mutans strain 6715 also appeared to have some affinity for teeth in the absence of dietary sucrose that may be of ecological significance. Once firmly established in rats fed a high sucrose diet, S mutans strain 6715 maintained itself in high numbers on the teeth after a switch to a high glucose diet during a 14-week period.


Cementum regeneration in replanted teeth with differing pulp treatment. Cementum regeneration on exposed dentinal root surfaces of replanted teeth not subjected to replantation. The implication was that secondary reattachment of replanted teeth was largely dependent on the status of supporting alveolar tissues. The role of the replant appeared essentially passive, reacting as a substrate for cementum deposition that may be more or less acceptable to the regenerating periodontal tissues as dictated by the extraoral history. Although the pattern of cementum deposition was unaltered by replantation, the quantity of new cementum deposited on exposed dentin did appear to be affected by pulpal treatment; thus, an indication was given that survival of replanted teeth may be influenced by pulpal procedures.


Continuous culture studies on the growth and physiology of Streptococcus mutans. We examined the effects of nutritional limitations on the production of lactic acid by Streptococcus mutans grown at low growth rates in continuous culture. Lactic acid production was greater in nitrogen- and phosphate-limited continuous cultures than in glucose-limited conditions. These results are correlated with the release of calcium from enamel in cellfree broths from various fermentations.


Working time of polymeric restorative materials. The validity of determining the working times of polymeric restorative materials with the use of rheologic methods in the laboratory has been investigated by measuring the adaptation of polymeric restorative materials to artificial cavities when inserted at 30-second time intervals during their setting reactions. There was significant deterioration in adaptation during the working times which suggests that small changes in viscosity early in the setting reactions radically affect the materials' mobility.


Influence of amalgam, alloy, and mercury on the in vitro growth of Streptococcus mutans: I. Biological test system. A procedure is presented for the in vitro growth of Streptococcus mutans in a dextrose-beef extract medium. Growth was estimated spectrophotometrically. The amount of amalgam, alloy, or mercury that was added to the sealed test tube influenced the rate and extent of growth.


Aging changes in the articular disk of the temporomandibular joint in the guinea pig. The development of cartilage cells was investigated in the articular disks of the temporomandibular joint (TMJ disk) from two groups of guinea pigs age 1 month and 2 years old. There is strong evidence that the presence of chondrocytes in the TMJ disks of the older group of guinea pigs is the result of a biological aging phenomenon and is not related to pathologically induced changes.


Potential use of one-phase (methyl methacrylate) in dental implants. Three techniques were studied to control the porosity and the pore size of the one-phase PMMA matrix, namely light sintering and the use of hydroxyapatite- or NaCl-filler. These techniques alleviate the problems of residual monomer inherent in the two-phase PMMA system. A two-step light sintering technique with a solid polymer core and porous outer layer showed improvement in the overall mechanical properties and good potential for anatomical implants. The NaCl-filled PMMA was found to give the best overall mechanical properties and control of porosity. The mechanical properties of the filled, water-equilibrated composites were close to literature values of dry PMMA systems except for a noticeable drop in their modulus. In the instance of hydroxyapatite, the 20 wt %-filled PMMA composites with 35-mesh particle size suffered a substantial loss in their mechanical properties and physical integrity after soaking for one week in water. Polymer-filler particle size ratio should be taken into consideration in compounding in order to obtain the desired filler distribution (either random or network).


Plasmid DNA satellite bands seen in lysates of Streptococcus mutans that form insoluble extracellular polysaccharides. A satellite band of plasmid DNA was seen in cell lysates prepared from two strains of S mutans using buoyant-density equilibrium centrifugation. Mutants, defective in their ability to synthesize insoluble extracellular polysaccharides, showed no detectable satellite DNA band when prepared by the same procedure. These mutants were induced by treatment with EB, acridine orange, or SDS, which are known to be effective agents for the elimination of extrachromosomal genetic inheritance. The derived mutants produced more soluble polysaccharides from sucrose than their parent strains. The decreased ability to synthesize insoluble polysaccharides was related to both glucan and fructan formation. These findings suggest that the plasmid DNA of the S mutans strains genetically controls formation or activity of the enzymes responsible for synthesis of extracellular insoluble glucan or fructan.


Gold-nickel alloys in dental prostheses. A gold-nickel master alloy was prepared by arc melting in an inert atmosphere and from it, mechanical test specimens and dental prostheses were made by centrifugal casting. The cast alloy had a yield strength of about 7,400 kg/cm2, with an elongation of 12%. The alloy was clinically tested in the form of partial dentures and crown and bridge materials. For the 32-month period these prostheses have been in use, no tissue reaction, tarnish, or corrosion had been observed.


Clinical studies of dental cements: V. Recall evaluation and a zinc phosphate cement. Patients with restorations cemented with a reinforced zinc oxide-eugenol cement and a zinc phosphate cement were recalled after a four- to seven-year interval. No significant differences in clinical success were observed between restoration luted with the two cements. No significant difference in the incidence of caries at the restoration margins was noted between the cements.


Zinc polycarboxylate cements: a chemical study of erosion and its relationship to molecular structure. Experimental results show that the rate of elution of Zn2+ and Mg2+ ions from polycarboxylate cements decrease with the cement's age. This phenomenon is explained by the setting reaction in which these cations are liberated from the oxide powder by an exchange with protons from the polyacid and in this state are vulnerable to water leaching. Subsequently, these cations become bound to the polyanion chain and become more resistant to water leaching. Magnesium ions are more easily hydrolyzed than zinc ions because they are less strongly bound to the polyanion chain. Zinc ions are apparently more strongly bound to a polyacid which is a copolymer of acrylic and itaconic acids, than to the homopolymer of acrylic acid. The pattern of elution of ions differs between the different cements, so that measurements after 24 hours cannot be used to predict long-term durability on a comparative basis. This coupled with the slow but continuous loss of ions makes a 24-hour test of doubtful validity. Polycarboxylate cements absorb water that is present in the matrix in loosely bound and tightly bound forms. The ionization of the polyacid to a polyanion during the course of the reaction apparently creates a demand for water, and the cement where the COOH:C ratio in the polyacid is highest absorbs the most water.


Barriers to identification and motivation of minority group members for dentistry. The barriers preventing dental students from pursuing dental careers are formidable, and the lack of commitment is really the major one. Before future students can become informed and motivated and can commit themselves to a career in dentistry, they must see the full sustained and honest commitment of those who teach and advise them, as well as of those who practice the profession. Once assured of this, they can proceed together with the profession to dismantle the other barriers.


Utilizing learning theory to promote effectiveness of instruction in preclinical operative dentistry. In comparing two methods of instruction, one must be cautious about forming conclusions because of certain variables which can influence results. Such variables are differences in populations, in instructor effectiveness, and in availability of instructional aids. The comparison does, however, demonstrate differences between the two groups. The fact that the entire class taught by the modified course passed the proficiency examination after nine trials, compared to 12 for those from the traditional course, is not in itself significant. The impressive fact is that in the early trials the rate of students who qualified for clinical practice was nearly doubled in the learning theory group. This might imply that the learning theory group demonstrated a greater degree of problem-solving ability because of opportunities for discovery learning within the course. Since both classes were given the proficiency examination approximately two-and-a-half months after they had completed the preclinical course, it would seem that the learning theory design resulted in retention of the objectives of the course by a significant number of students. Consequently, it is the authors' opinion that the learning theory design provided a more effective method of instruction. Clinical operative dentistry consists of highly intricate procedures which for their successful completion require complex psychomotor responses in the operator. Therefore a program of instruction in operative dentistry must be highly effective. When such a program is organized, utilization of learning theory principles, especially those of skill learning, may aid in achieving this goal.


Trial State Boards as a teaching technique. Trial State Boards call upon the dental hygiene student to pull together all the skills and knowledge accumulated during the course of studies before facing the actual Board of Dental Examiners. It has been the experience of many in the field of dental hygiene education that the anxiety created in a testing situation is largely a result of unknowns. At the Ohio State University, the Trial State Board is viewed as an effective means of eliminating some of the anxiety (by eliminating some of the unknowns) and thereby of helping the student to be more relaxed and to emerge with a more accurate evaluation of his or her abilities in terms of taking the licensing examination. Although this process is time consuming, the results seem well worth the time. For the clinical faculty the review by dentists, who do not normally see the students in the clinic, is of great value. Once the testing is over and the dentists have completed their evaluations and comments, these are reviewed by the members of the clinical faculty. A specialized program can be worked out for each student needing additional help to correct any deficiency before graduation. For some the idea of holding a Trial State Board will be a new concept in the traiing of dental hygiene students. For others it may already be part of the training program. For all involved in the education of members of the health professions it is worth considering as both a teaching tool and a learning experience.


Modulus of elasticity and strength properties of dental cements. The modulus of elasticity of commercial dental cements was determined by an optical strain gauge method. Values of compressive and tensile strengths also were measured. Of the cements of primary consistency tested, a noneugenol zinc oxide cement had the lowest mechanical properties. A zinc phosphate cement had the highest value of compressive strength and modulus, but a zinc polyacrylate cement had the highest tensile strength. A zinc polyacrylate cement base had the highest tensile strength, but a zinc phosphate cement base had the highest compressive strength and modulus of elasticity. A calcium hydroxide liner had higher mechanical properties than an unmodified ZOE liner.


Comparison of posterior teeth.

Comparison of posterior teeth. Patients compared the mechanical efficiency of certain types of posterior teeth. Patients, allowed to choose the denture that was most comfortable and the most stable, and that performed the best, all selected the nonanatomic tooth form. Women selected the dentures with the flat occlusal posterior teeth and men preferred the posterior teeth with metal inserts. On the basis of this small sampling of patients treated with anatomic and nonanatomic posterior teeth, I suggest that favorable results would be obtained if nonanatomical teeth were used to construct dentures for all age groups. If, in addition to good function, we can provide an esthetically pleasing,nonanatomic type posterior tooth, we will have achieved our goal in the construction of fine dentures.


Squamous cell carcinoma of the oral soft tissues: a statistical analysis of 14,253 cases by age, sex, and race of patients. Squamous cell carcinoma is the most frequently occurring malignant tumor of the oral structures, accounting for about 90% of the total number of malignant oral lesions. Among 14,253 cases of soft tissue squamous cell carcinomas of the oral area in the files of the Armed Forces Institute of Pathology, the most common locations are the lower lip (38% of the cases) and the tongue (21%). In the past few years, however, the number of carcinomas of the floor of mouth has been increasing. Our material also shows a definite trend of the carcinomas to develop in patients of an age group 10 years younger than has been previously reported.


Two-year clinical evaluation of a pit and fissure sealant. Part II. Caries initiation and progression. For the study, 479 paired permanent teeth and 20 paired deciduous teeth were coated under controlled clinical conditions with Nuva-Seal. A red dye was added to assist in placement and subsequent evaluation over a two-year period. Eighty-four children (ages 10 to 14) participated in the study. Caries was evaluated 3, 6, 12, and 24 months later with the same rating scale used at the baseline examination (0, caries free, to 4, severe caries), except when the sealant was found completely present and intact; then caries evaluation was limited to visual inspection through the sealant. The caries rate for control teeth was 6.9% at 3 months, 16.1% at 6 months, 26.4% at 12 months, and 37.6% at 24 months. Corresponding percent effectiveness figures for the sealant were 63.6%, 66.6%, 61.7%, and 54.6%, respectively. At 24 months, effectiveness rates for all types of teeth were at least 52% with the exception of the maxillary second molars (only 27% sealant effectiveness). Overall, caries protection as reflected by percent effectiveness was higher for mandibular teeth and premolars than for maxillary teeth and molars. There was significant effect on the incidence of dental caries when the sealant remained completely intact. Percentage effectiveness rates in this case were 90.7% at 12 months and 90.9% at 24 months. There was little gain or loss in caries protection when the sealant was partially or completely missing. Twenty-four percent of the children had a positive net gain or treatment effect at three months. This increased to 52% at 6 months, 62% at 12 months, and 70% at 24 months. With the use of half-mouth caries rates, the corresponding figures for positive treatment effects were slightly higher (30%, 64%, 70%, and 80% respectively).


Computerized placement in dentistry: the Minnesota experience. In response to identified manpower information and service requirements, the Minnesota Dental Association, the board of dentistry, and the University of Minnesota School of Dentistry established the Dental Information Service Center in 1972. One major effort of the center was to develop a computerized placement service for dentistry in the state. This service was recently subjected to a user evaluation. Of 1,030 delivered questionnaires, 431 were returned in response to a single mailing. The respondents included 216 employers and 215 employees, including dentists seeking positions. Dental employers generally found the system to be their most successful strategy in the search for employees; from the perspective of employees, other sources such as personal contact competed with the computerized system as the most successful source of information. Evidence from this evaluation indicates that the computerized placement experience in Minnesota has been quite positive. Dentists have relied on the service somewhat more heavily than other dental occupational groups, possibly because alternate sources of information traditionally have not served the health professions. Overall satisfaction ran quite high, and an overwhelming majority of the respondents thought that the service should be continued and expanded to either a regional or a national level.


Recurrent ameloblastoma of the mandible. Ameloblastoma is by nature an invasive tumour and the full extent of the infiltration is not always appreciated when the lesion is being excised. Included in a series of 40 cases are 7 recurrent lesions. Pertinent clinical features of the 7 recurrent cases are discussed. A close study has been made of the recurrent tumours in the hope that some explanation could be found for the unsuccessful primary treatment. The investigation considered a number of aspects of the behavior of this growth and from this certain facts have emerged. Definitive treatment should not be embarked on before the diagnosis has been established. Only then can an overall plan of management be devised. It is noteworthy that the rate of growth of the lesion is more rapid in the younger age group. Ameloblastoma varies in it's clinical and radiological presentation. Primary treatment is influenced by the size and site of the particular lesion. The management of the recurrent lesion depends on the mode of presentation of the particular growth.


Results of radical treatment of cancer of the parotid gland. Twenty-five patients with different histological variants of malignant tumours of the parotid gland have been treated by parotidectomy combined with interstitial radiotherapy with delayed afterloading and dose fractionation during the operation. The indications for this therapeutic approach and the techniques used are described. The follow-up of the patients ranging from one to over five years showed only two local recurrences, although most of the patients were in an advanced stage locally. Complications due to the irradiation have not been observed.


Problems in the reconstruction of the inner canthus and the lacrimal duct. The problems of reconstruction of the destructed mesial lid angle are discussed. Correct evaluation of the lesion is very important. Depending on whether primary or secondary reconstruction has to be done, different technical approaches are recommended. A personal technique of reconstruction of the lacrimal duct is described. This technique has given very satisfactory results.


Logopaedic findings following advancement of the maxilla. From 1972 to 1974, the authors carried out logopaedic examinations of over 100 patients with retrodisplaced maxillae at the Clinic for Maxillo-Facial Surgery at the University of Zurich (Director: Prof. H. Obwegeser, M.D., D.M.D.). From this clinical material, 40 cases which were fully documented in respect of medical history, surgical treatment and speech behavior were selected, and the effect of the advancement of the maxilla on the individual ability to articulate was studied.


Drug treatment of trigeminal neuralgia with sympatho- and parasympatholytics. Exciting factors in trigeminal neuralgia known to date are reviewed, and the involvement of the vegetative system in the development of neuralgic pain is documented by clinical observations. Studies of free fatty acids (ffs) and free glycerin (FGly) conducted to assess sympathetic and vegal involvement revealed a sympathetic component to be active in attacks along the distribution of the first and second trigeminal branches, while pain originating from the third branch appears to be mediated by vagal stimuli. Sy,patho- and parasympatholytic therapy is discussed and its effect reviewed in a large group of cases. More than 50% of cases were found to be improved.


Orthodontically induced eruption of the permanent canine combined with alveolar cleft osteoplasty: a new procedure illustrated by a case with stereophotogrammetric reconstructions. A new technique is suggested which will allow secondary bone grafting to be carried out at approximately 10 years of age when some potential of active tooth eruption and maxillary alveolar growth remains. Surgery is followed during the healing phase by orthodontic traction of the unerupted canine through the bone graft. This allows the reconstruction of the dental arch, while the bone graft is maintained by the osteogenic influence of the canine root. The technique is detailed and illustrated and a case report presented. A stereophotogrammetric reconstruction demonstrates the improvement in integumental contour following the technique described.


Sarcoma arising in irradiated jawbones. Possible relationship with previous non-malignant bone lesions. Report of 6 cases and review of the literature. Thirty-seven cases of radiation-induced sarcoma of the jaw are reviewed from the literature and six new cases are reported. It appears that irradiation seems to play a significant role in the development of jaw sarcoma: 10% of jaw sarcomas arise in irradiated bone. The initial lesion, however, that required irradiation appears to be equally important: 46% of the cases were found to have fibrous dysplasia as the initial lesion, whereas 18% of the remaining cases included diverse bone lesions. The bone was assumed to be normal in only 36% of the cases where irradiation was administered to adjacent tissue lesions. It seems that the association between irradiation and a pre-existing bone lesion has a definite oncologic effect.


Effect of adrenalectomy on the synthesis of cholinesterases. Adrenalectomy decreased the rate of regeneration of brain and striated muscle acetylcholinesterase (EC 3.1.1.7) in mice after sublethal poisoning with diisopropylphosphofluoridate (DFP). This may explain similar findings in previous experiments in hypophysectomized animals.


Immune reactivity in vitro to spontaneous canine oral tumors. In vitro reactivity of autochthonous lymphocytes to tumor cells from progressively growing oral tumors in dogs was studied. Tumors were collected during surgery or before necropsy and prepared for tissue culture. Only viable, glass-adherent tumor cells were used. The cells were first incubated either with culture medium or with canine serum, and then they were mixed with lymphocytes. The cultured tumor cells were destroyed by high numbers of lymphocytes, but the reactivity was blocked for tumor cells that had been incubated with autologous serum. Tumor cell growth was stimulated by low numbers of lymphocytes. These results point out the complexity of tumor enhancement in vivo.


Evaluation of an automated direct fluorometric method for determination of total estrogens in pregnancy urine. The value of urinary estriol as a measure of placental function has been previously established. The authors have modified to total automation a previously published method. The method operates at an analytical rate of 30 samples per hour. Results are expressed as mg. estrogen/gm. creatinine (E/C). In normal pregnancy values rise from a mean of 18 at 31 weeks gestation of 43 at term.


Wound healing and the amniotic membrane. The successful clinical application of the amniotic membrane as a surgical dressing is discussed as to the mode of healing. The amniotic membrane does not appear to be a permanent structure when used as an allograft.


The metabolism of estradiol by perfused livers and liver slices of normal and cirrhotic rats. The metabolism of estradiol- 17 beta and cirrhotic (CC14 -induced) rat livers was studied in isolated perfused livers and in incubations of liver slices. In these experiments the cirrhotic livers show a reduced clearance of estradiol, an accumulation of extractable metabolites and a delayed transformation to non-extractable metabolites. It is concluded that these changes in the metabolism of estradiol are caused not only by an altered circulation of the blood through intrahepatic shunts, but also by disturbances in the uptake and/or metabolism of the estrogens by the liver cells.


Scavenging of dental anesthetic gases.

Scavenging of dental anesthetic gases. Results of recent surveys suggest that there are significant health hazards involved with chronic exposure to waste anesthetic gases. While results of these surveys were significant, they did not prove a cause-effect relationship. Considerable evidence in experimental animals suggests such a relationship; it is reasonable to assume that this applies to the clinical situation. An anesthetic technique that uses a circle-system absorber with a scavenging trap and non-recirculating exhaust duct has been described. This system was combined with use of a closed-cell rubber sponge for an oropharyngeal pack that was impermeable to air or anesthetic gases. In addition, a tight-fitting nasal mask or sealed nasopharyngeal tube was used. Ventilation of room air also was improved. These changes produced a 93.3% reduction in halothane and 91.2% reduction in nitrous oxide in the dental operating room.


Experimental osteogenesis at fracture sites and gaps. One hundred and twenty male albino rats were used to study the regenerative potential of periosteum, and the effects of the size of discontinuity defects on bone repair. The clinical, radiologic, and histological studies disclosed new bone formation and remodeling of fibular fractures and gaps in the presence of periosteum or bone contact, or both. Small and large fibular fracture gaps without periosteum resulted in nonunion, interposition of fibrous tissue, and no new bone formation. It was concluded from the current experimental studies that bone contact is more important than periosteum for normal bone healing. Where contact is not possible, the presence of periosteum assumes a more essential role.


Distribution of glands in the mucosa of the hard palate and its relation to carcinoma. Carcinoma of the hard palate in women who practice reverse smoking is very common in Visakhapatnam. This carcinoma usually occurs in the middle of the posterior half of the hard palate and not in the soft palate or in the anterior half of hard palate. The volume of the glandular tissue in the mucosa of the hard palate is maximum to the right or left half of the midline in the posterior half in both fetuses and adults. The localization of the carcinoma of the hard palate in reverse smokers corresponds to the glandular area of the mucosa of the hard palate.


Cryosurgery for oral cancer--a six-year retrospective study. In a review of 50 patients with oral cancer treated by cryosurgery, local control of the tumor for more than two years was achieved in 90%. In only 4 of 25 instances where the tumor had superficially invaded bone, or was adjacent to it, was resection necessary. Cryosurgery was effective in controlling benign and premalignant lesions also. The treatment is often palliative and sometimes curative when patients refuse other recommended care.


Radionuclide bone scanning in the diagnosis of lesions of the maxillofacial region. Radionuclide scanning is a safe, simple, sensitive technique for demonstrating lesions of the skeletal system. It has proved to be valuable in the early detection and differential diagnoses of lesions involving the maxillofacial region. Abnormal uptake of a bone scanning agent relies on a disturbance of the mineral metabolism of bone. These changes in the pathophysiology of bone are detected earlier on radioisotope bone scans than on radiographs. Bone scanning is a superior technique for diagnosis when compared to radiographic examination. A positive scan is not pathognomonic of any specific disease, but with the clinical, laboratory, and radiographic findings, it can differentiate many lesions and contribute invaluable information concerning a particular lesion or condition so that treatment can be more effectively planned.


Palisaded, encapsulated neuroma of the lip. A case of palisaded, encapsulated neuroma of the lower lip has been presented. To the best of our knowledge, this is the first reported instance in the dental literature. The lesion characteristically occurs on the skin of the face near the oral, nasal, and orbital mucocutaneous junctions and, therefore, is readily visible to the oral diagnostician. It occurs most often in middle-aged individuals and, although it may clinically mimic other lesions, the operative finding of an easily enucleated mass near a mucocutaneous junction should suggest this lesion in the differential diagnosis. Histologically, the lesion is characterized by three distinct zones--an outer compressed fibrous connective tissue capsule, an inner myxomatous zone, and a central zone of proliferating Schwann's cells arranged in interlacing fascicles with areas of palisaded cells and organoid structures. The lesion is treated by enucleation or excision and has no tendency to recur.


Sequelae of dental extraction during quinine-induced thrombocytopenia. The pathogenesis and treatment of quinine-induced thrombocytopenia is discussed. The case presented involved the sequelae of a dental extraction performed during an episode of acute thrombocytopenia. A complete medical history and knowledge of current medications and their possible side effects are of paramount importance before any patient is treated.


Emotional response to intravenous delta9tetrahydrocannabinol during oral surgery. The administration of delta9THC intravenously as a premedicant to oral surgery resulted in acute pronounced elevations in anxiety states, a predominance of dysphoria over euphoria, and varying degrees of psychotic-like paranoiac thought. Neural effects that appeared to promote these effects included distortions of perception with sensory delusions, and heightened sensory receptiveness including antalgesic impressions of surgery; autonomic and visceral arousal greater than control or placebo levels; lack of overt behavioral signals of distress due to depersonalization; and time disintegration leading to fear-inducing misinformation about real surgical events. Introverted subjects who generally were inclined to rely on drug solutions to their problems tended to respond poorly to surgical pain and anxiety with delta9THC. These results, obtained from subjects considered to  have levels of presurgical apprehension that were average or below average, suggest that the environment in which high doses of cannabinols are experienced is a potent factor in determining the quality of the emotional response. A surgical environment containing even the mild stress of outpatient oral surgery appears to have the potential to precipitate undesirable emotional responses among cannabinol-intoxicated patients. There is continued high-level social use of cannabinols inour society, with an estimate of 40% to 55% among the college-age group seen frequently by oral surgeons. Results of this study suggest that clinicians should be prepared to detect the subtle signs of marijuana intoxication to protect their patients from further psychophysiologic complications during surgery.


Reimplantation of freeze-treated and saline-treated mandibular bone. Mandibular bone devitalized by freezing after removal from the body and subsequently reimplanted was observed for its potential to reunite and grow in comparison to a similar saline-treated section of bone from the same animal. After a year, there were no significant discernible clinical or histological differences between the slaine-treated and the frozen bone. Approximately the same amount of histologically indistinguishable bone formed in either instance. The results suggest that a partially resected mandible subjected to freezing maintains the same capacity to act as an autogenous graft as does bone partially devitalized by immersion in saline solution.


Middle-third facial osteotomies: their use in the correction of congenital dentofacial and craniofacial deformities. Several congenital abnormalities result in dentofacial and craniofacial deformities in the middle third of the face. Each of these deformities presents unique problems with multiple coexisting anomalies of the entire dentofacial and craniofacial region. Those engaged in the habilitation of patients with congenital facial deformities must be cognizant of the fact that, unlike in individuals with developmental dentofacial deformities there are unique ophthalmological, otolaryngological, neurological, dental, speech, and psychological problems coexisting with these conditions. Multiple procedures, either performed simultaneously or staged, are frequently necessary to achieve optimum esthetic and functional results. With a comprehensive multidisciplinary approach, acceptable habilitation of many of these individuals can be achieved.


Surgical treatment of mandibular hypomobility. Mandibular hypomobility may be the result of a number of intra- and extra-articular conditions. Its treatment, predicated on an accurate diagnosis, varies from minor manipulative maneuvers to several surgical procedures. The applicability of coronoidectomy, in certain conditions, has become increasingly important.


Antibiotic therapy in oral and maxillofacial surgery. Too frequently, antibiotics are used unnecessarily for routine dental procedures. Good surgical techniques, immaculate postoperative oral hygiene, and close follow-up are sufficient in many situations. In infectious processes, culture and snesitivity testing should be used to determine the cause of infection before surgical or antibiotic therapy is given. A conservative approach should provide adequate care and minimize the gross overuse of antibiotics.


Mandibular fracture resulting from dog bite: report of a case. The diagnosis and management of a fractured mandible of a 4-year old child has been presented. A brief review of the literature is given. The remarkable aspect of the case is its reported cause of dog bite. The patient was managed conservatively by closed reduction, and use of Oliver loops. The maxillomandibular fixation was lost on the 11th postoperative day. At that time, no mandibular deviation or limitation of movement was noted. Further immobilization was not deemed necessary. During a three-month follow-up period, no complications occurred.


The three-dimensional mandibular bone plate. A new type of mandibular bone plate implant has been described that immobilizes the mandible more ridigly than do previous bone appliances. Because of this characteristic, maxillomandibular fixation may be eliminated in a large percentage of fractured mandibles, or the time for immobilization is, at least, reduced.


Treatment of mandibular prognathism in an acromegalic patient. A 41-year-old man with acromegaly underwent cryosurgery for a pituitary adenoma. Although soft tissue regression is possible after pituitary ablation, bony changes are permanent. Thus, bilateral vertical osteotomies and bilateral coronoidotomies were performed for correction of the mandibular prognathism. The postoperative occlusion and facial profile were very acceptable. Unfortunately, the patient died of a myocardial infarction eight days postoperatively.


Experimental foreign body reactions to toothpaste abrasives. Some clinical oral foreign body reactions have been reviewed. The testing of the foreign body potential of substances used as abrasives in toothpastes has shown a number to be capable of this. The clinical implications are briefly discussed. The initial studies were conducted when the author was on the faculty of the School of Dentistry, University of Birmingham, England.


Periodontal emotional stress syndrome.

Periodontal emotional stress syndrome. Eleven cases are presented which demonstrated severe periodontal bone loss especially in the posterior segments of the mouth in a group of young men, ages 22 to 32, unexplained by other local etiologic factors. The only common denominator in all cases was severe emotional stress associated with active duty in Viet Nam. The name "periodontal emotional stress syndrome (PESS)"is suggested as a possible term to be included in the nomenclature of the classification of periodontal disease.


Plaque, gingivitis and dental aptitude test scores of dental students. In general, plaque and gingivitis scores were correlated negatively with the manual parameters and positively with the academic and mental parameters studied. Plaque showed significant negative correlations with the manual average and the carving test. Gingivitis also demonstrated a negative correlation, just short of significance, with the manual average, but virtually no correlation existed between gingivitis and the carving test. Gingivitis displayed a significant positive correlation with the academic average, and plaque exhibited a nonsignificant positive correlation with the academic average. Relationships between these parameters may help determine what segments of the population are more susceptible to plaque accumulation and gingivitis and may suggest possible new approaches to the adoption of preventive measures. Finally, in view of the statistically significant but relatively low correlation found between manual dexterity and oral health, further investigations are indicated to establish the validity of the relationship.


Clinical evaluation of a newly designed contoured tooth-brush. A newly designed contoured toothbrush was tested against the Oral B toothbrush in a single blind crossover study over a 6-month period using 78 patients. The findings were: (1) The contoured toothbrush was significantly better (P less  than 0.01) than the Oral B brush for gingival index scores; (2) Plaque scores were lower for the contoured brush (P = 0.10); (3) No significant differences were observed with respect to calculus scores.


The role of alveolar bone in the noneruption of molar teeth in grey lethal mice. The in utero and neonatal development of the molar teeth in osteopetrotic grey lethal mice and normal litter mates was observed in timed embryos which were obtained by caeserian section, and in neonatal litters which were sacrificed on the day of birth and each day thereafter until day 7. Serial coronal and sagittal sections through the heads were prepared. The earliest disturbances in the alveolar bone-tooth germ complex were seen at day 19 in utero. At birth, the grey lethal first molar germs are severely distorted by encroaching alveolar bone. The abnormalities become progressively more marked until day 7. The failure in alveolar bone remodeling is the factor which prevents tooth eruption in grey lethal mice.


Histoplasmosis of the gingiva. Report of a case. A 71-year-old white man presented with a large ulcerated lesion which extended to the facial and palatal aspects of the maxillary left first and second bicuspids. A biopsy was made because the lesion appeared to be carcinomatous. It proved to be benign but it was positive for histoplasmosis. Although the patient had a 9 month history of weight loss, fatigue, frequent nausea, night sweats, respiratory symptoms, and other symptoms compatible with a diagnosis of histoplasmosis, skin tests and complement fixation tests had been consistently negative. After the diagnosis was made and the organism was cultured from the oral lesion, therapy (amphotericin B) was initiated and the patient responded favorably. Within 12 months, the symptoms regressed, the oral lesions healed, and the patient regained 25 lb.


Gingival status during prolonged fasting for weight loss. Nineteen obese patients were observed during a prolonged period of fasting for weight loss. The period of fasting ranged from 15 to 71 days. The patients consumed a dose of certain vitamins and minerals with 2 liters of water per day. No effort was made to alter the patient at the beginning and termination of the fasting period. At the time of original recording the Plaque and Gingival Index correlated directly. As the fasting period lengthened, there was a decrease in the Plaque Index scores but the Ginival Index scores increased considerably. This is an opposite correlation to what one would expect in individuals maintained on an adequate diet.


Plaque-neutrophil interaction in monoinfected rats as visualized by transmission electron microscopy. Rats monoinfected with Actinomyces naeslundii contain massive interdental bacterial plaques which are partically covered by a concentration of PMNLS. The neutrophils are massed in the form of a pseudoepithelial barrier several cell layers thick with narrow intercellular spaces. The PMNL barrier appears to prevent bacterial invasion of the underlying gingiva. Phagocytosis and killing of bacteria occurs at the interface between the plaque and the PMNL barrier. The protective as well as possible detrimental effects of PMNL concentrations are discussed in terms of tissue destruction in periodontal disease.


A survey of factors possibly associated with cervical abrasion of tooth surfaces. The study indicates that cervical abrasion is related in some way to a factor or factors associated with the initial stages of the tooth-brushing procedure. The evidence, furthermore, demonstrates that an excessive use of dentifrice habitually placed, undiluted, on the same area of the mouth, may produce the abrasion. In view of this evidence, it would seem prudent to advise patients to use decreased quantities of dentifrice and to initiate the brushing procedure on the occlusal surfaces of the teeth to effect a dilution of the dentrifrice. The same effect might be accomplished by alternating the initial placement of the brush between the quadrants to more evenly distribute the abrasive effect. The high percentage of these lesions found in this young age group demonstrates a higher prevalence of the lesion in a younger age group than was previously suspected. We can further conclude that cervical abrasion is related to age and gingival recession. Furthermore, the study indicates that patients who exhibit cervical abrasion have less plaque and the lower bleeding scores than those who do not.


The effect of topical application of dextran on the gingiva of the beagle dog. Dextrans derived from Leuconostoc mesenteroides were placed on clinically healthy gingiva of Beagle dogs once a day for 21 days. Control gingival tissues received saline. Both healthy controls and dextran-treated tissues were brushed daily. Inflamed control tissues were obtained by allowing plaque to accumulate for 21 days. Tissues receiving daily application of dextran solutions developed chronic gingival inflammation but displayed no clinical signs of gingivitis. Healthy control gingival tissues showed no clinical signs of gingivitis and minor histologic inflammatory changes. Tissues exposed to dental plaque showed the typical clinical and histological inflammatory changes of gingivitis. Thus dextran, a substance similar to the extracellular polysaccharide found in dental plaque, was able to penetrate the sulcular epithelium, enter healthy gingival connective tissue and cause chronic inflammation. This connective tissue inflammation occurred without inducing any of the clinical signs of gingivitis. Therefore, it is concluded that dextran produced one component of the gingivitis response, chronic histologic inflammation, independent of another major component of the disease, clinical inflammation.


The use of auxiliaries in prosthodontic graduate programs. There is a need for more dental services, and the use of auxiliaries can help the dentist meet this need. Dental educators and the government are encouraging programs and research in the expanded use and management of dental auxiliaries. Advanced prosthetic programs have special needs. The dentist-patient relationship for this highly personal service, usually accompanied by difficult clinical and technical problems, requires a dentist with special skills. No advanced program should use auxiliaries to the extent that the student does not develop these special skills in diagnostic, clinical, and technical areas. Expanded duties to demonstrate how much an auxiliary can do could be harmful. The program director and the faculty should judge the level of assistance each student should have in an advanced program.


Prosthetic teachers: number and qualifications for undergraduate education. A proposal has been made regarding the number and qualifications of undergraduate educators. To place this proposal in the proper perspective, certain philosophies, objectives, and methodologies of the teaching-learning experience were identified. These, of course, are partially unproven, conceptual innovations. The need exists to better qualify students in prosthodontics before they are graduated from a dental school. Unfortunately, schools seem to be taking a negative position on this problem. What better way to control a group than to govern the education of the individuals concerned.


Teaching prosthodontics in general dentistry. Because of the projected increase in the demand for high-quality prosthodontic services in the future, it will be necessary to upgrade undergraduate prosthodontics and to provide, in addition, improved prosthodontic training in the general dentistry residencies. The Federation of Prosthodontic Organizations is the unified voice of our specialty and must stand at the forefront to provide and direct this training. Every accredited program should be required to offer training in prosthodontics. We cannot expect graduate students to specialize in prosthodontics if we allow it to be downgraded, reduced in scope in our dental schools, and excluded from general dentistry residencies.


Prosthodontics in a general practice program of advanced dental education. The problems involved in teaching prosthodontics in a general practice program outwardly appear to be due to the lack of sufficient basic prosthodontic training dispensed by the dental schools. This lack of sufficient training is not the fault of dental school faculties. The students are not learning what they are taught. What they need is more repetition, which means more time. The problems are not insurmountable. We just must find the route.


Limitation of clinical practice to prosthodontics. Limitation of practice implies specialization and the delivery of services by a specialist who has been recognized for his expertise through formal advanced education, experience, and/or examination. Prosthodontists in limited practice are currently influenced by problems related to patient referrals, third-party payment for services, and competence certification. Perhaps the most significant problem in prosthodontics today is the need to succinctly define the parameters of prosthodontic practice in order to provide guidelines for assuring that such practices are limited to the defined specialty.


Combating the illegal practice of dentistry. (1) Problems concerning the illegal practice of dentistry are increasing. (2) The Canadian experience has had an effect (3) In recent years, nearly one third of our states have experienced some threat by illegal dentistry. (4) Economics is a major factor. (5) Responsibility for a successful program must be continuous from all levels - national, state, and local. (6) For a program to be successful, it must reach the dentist at the grass-roots level. (7) This in an area where the FPO can show real leadership.


Classification of occlusal carvings.

Classification of occlusal carvings. Laboratory fees associated with the use of fully adjustable articulators are for the time and skill the technicians employ in harmonizing the occlusion to condylar paths of movement and are not based on the instrument used. The classification of occlusal carvings presented in this article for alloy and porcelain restorations aids in establishing accurate communications between the dentist and the laboratory. This classification enables the dentist to accurately specify to the technician the amount of time and skill the dentist wants the laboratory to expend (which affects the laboratory fee) to fabricate the prescribed occlusion.


Psychophysical investigations of the preferred vertical dimension of occlusion in edentulous patients. Two psychophysical methods were tested to obtain information on the long-term accuracy and stability of the vertical relation of occlusion as determined by the technique described by Lytle and Timmer (PVDO). One method (Békésy) was unsatisfactory. The other method (forced-choice) produced stable results. The data collected showed that, over a brief period of time, all test subjects could define their PVDO within a margin of less than 1 mm. Some subjects were unable to determine a precisely defined PVDO. These subjects also showed considerable variations in the PVDO over longer periods. Other subjects were able to establish a constant and remarkably stable value for the PVDO over many weeks. For these types of patients, precise determination of the vertical relation of occlusion is of the utmost importance.


A method for the control of galvanism.

A method for the control of galvanism. A simple method has been described for controlling the galvanic pain that occasionally follows the placement of amalgam restorations. The use of silver nitrate appears to be immediately effective in eliminating this annoying occasional problem.


Tooth loading and cuspal guidance in canine and group-function occlusions. (1) Tooth loading with cuspal guidance in canine and group-function occlusions has been discussed. (2) Canine guidance and group-function guidance occlusions are considered normal; the latter occurs naturally due to occlusal wear. (3) When an entire occlusion is to be restored, either occlusal scheme will serve adequately. (4) Where only a portion of the occlusion is to be restored, the restoration must be consistent with the existing occlusal scheme. (5) Regardless of which occlusal scheme is used, the dentist must maintain it during regular postoperative appointments.


Intraoral infrared color photography of radiotherapy patients. A clinical screening study was performed in which head-and-neck radiotherapy patients were photographed intraorally using infrared "false color" film and Ektachrome color film. These photographs were compared to determine if differences existed in appearance between the intraoral tissues within the field of radiation and those intraoral tissues not in the field of radiation. No differences could be detected with either the "false color" film or with Ektachrome color film. Further investigations in the use of infrared color photography as applied to the radiotherapy patient could be undertaken by using a light source that transmits infrared rays only and a lens filter that passes only infrared rays. This method would produce a film that shows only the reflected infrared rays. Both color and black-and-white film should be used in this study.


Application of "cusp writer" findings to practical and theoretical occlusal problems. Part II. The cusp writer is a teaching aid to facilitate understanding of the correlation between cusp angulations and the various occlusal determinants. The cusp writer provides graphic evidence that the occlusal determinants which influence configurations (i.e., incisal guidance, condylar guidance, plane [curve] of occlusion, curve of Spee [compensating curve], and plane of motion) are reciprocal, one tempering the value of the other. Cusp writings demonstrate the following: (1) The angle of the plane (curve) of occlusion to the plane of motion in concert with the other occlusal infuluence determines the optimal height and angulation of the cusps. (2) Cusps appear to be steep or shallow relative to each other, to the plane of occlusion, and to the plane of motion. (3) The steepness of the curve of Spee determines the relative cusp height and angulation of one tooth to another, from an anterior to a posterior direction in the dental arch. (4) The angle of the tangent to any segment of the curve of Spee to the plane of motion determines the optimal height and angulation of the cusps of the segment. (5) The graphs show that the flatter the curve of Spee, the more uniform the cusp height and angulations are from anterior to posterior teeth. The steeper the curve of Spee, the more irregular the cusp height and angulations are with steeper anterior cusps and flatter posterior cusps. (6) The steeper the curve of Spee, the flatter the molar cusp angulations must be to avoid deflective and/or interceptive occlusal contacts on the balancing side. (7) With the syndrome of a steepening curve of Spee due to the loss of one or more lower posterior teeth, the cusps of the remaining opposing teeth must be constantly flattened by wear or selective grinding and reshaping to avoid traumatic occlusion, unless the drifting is interrupted by restorative dentistry. (8) Cusp angulation of artificial teeth should be chosen to harmonize with the angle of incidence of the compensating curve tangents to the plane of motion. (9) Condylar guidance has less influence on cusp angulation in comparison to incisal guidance and the other occlusal determinants. (10) Changing the hinge axis location 1/2 inch (12.5 mm.) distally and/or superiorly has very little effect on the influence of the above occlusal determinants on cusp configuration, if the vertical dimension of occlusion remains constant.


Hinge-axis location and face-bow transfer for edentulous patients. There are distinct advantages to locating the hinge axis for the edentulous patient by use of the modified Loma Linda hinge-axis locator. These include: (1) alteration of the vertical dimension of occlusion on the articulator may be accomplished since the opening or closing takes place around the patient's terminal hinge axis; (2) valid and verified centric and eccentric relation records may be obtained at an increased vertical dimension of occlusion that is in harmony with the patient's terminal hinge axis; (3) cusp-form posterior teeth can be articulated and verified in the mouth with minimal occlusal correction by use of a terminal hinge axis. Some disadvantages to the procedure may include: (1) the additional procedure of making a modeling compound clutch for hinge-axis location; (2) the initial modification of the edentulous trays to accommodate the recording device; and (3) the technique is used with the Whip-Mix articulator; however, it can be modified for use with other articulators.


Cast chromium alloy surgical splints.

Cast chromium alloy surgical splints. A cast chromium alloy surgical splint can be fabricated in less than 6 hours. This splint has the advantages of being well fitted, smooth, rigid, and less bulky than prefabricated splints. Other metals can be utilized in a similar manner to fabricate cast surgical splints.


Posterior accessory foramina of the human mandible. A study was performed on 150 dry, adult, human mandibles from cadavers of unspecified sex and unknown ethnic background, which had been imported from India. These mandibles were placed in the "standard basal position" and topographically divided into 11 bilateral areas posterior to the second bicuspid teeth. The accessory foramina in these areas were studied to determine their mean diameter, incidence of occurrence, and the areas in which they occurred. The medical surfaces of the mandibles exhibited foramina more frequently and in greater numbers than did the lateral surfaces. The right and left halves of the mandibles showed remarkable similarity. Much of the data obtained correlated with previous investigations, indicating that neurovascular components enter and leave the body on the mandible in the posterior region. Foramina 0.4 mm. or larger in diameter were evaluated separately. These larger foramina occur most often in the superior and middle thirds on the medial surface of the ramus (areas 6 and 7). They also occur fairly frequently in the retromolar area (area 11). This information can be usefully applied to future dissection studies concerning the soft-tissue components of these foramina. The data obtained reveal that these foramina occur frequently and in approximately the same locations. This suggests that these foramina are functionally important in supplying neural and/or vascular components to the mandible.


Registrations for relating the mandibular cast to the maxillary cast based on Kennedy's classification system. Accurate registrations of centric relation are mandatory for many aspects of diagnosis and treatment. Registrations can be obtained with a variety of techniques. However, each technique must give consideration to such factors as: the character and location of tooth support, the quantity and quality of soft-tissue support, the location of dentulous and edentulous regions, the neuromuscular control of the patient, and the physical characteristics of the registering material. Kennedy's classification system provides a guide to the selection of the method of registration.


A method of measuring pressures against tissues supporting functioning complete dentures. A metod for measuring pressures exerted by denture bases against the supporting tissues during mastication which yields valid quantitative results was developed. Use of a specially designed diaphragm pressure transducer overcomes the disadvantages of a cantilever-beam arrangement which gave inaccurate results in earlier studies. On going research using this method was described. Several suggestions for additional applications of this method for prosthodontic research were presented.


Using electromyographic biofeedback in treating orofacial dyskinesia. Electromyographic biofeedback can be used to help patients learn to control muscle contractions resulting from orofacial dyskinesia. The size of the electronic equipment and the simplicity of its use make this form of therapy practical for use by patients. The technique for treatment was described.


Physical properties of dental amalgam containing metal pins. No type of pin inclusion investigated in this study produced consistent increases or decreases in the strength of amalgam specimens under a variety of loading conditions and specimen ages. However, comparison of relative values for specimens tested under the same conditions showed that the highest fracture loads were found more often for specimens containing threaded gold pins than for any other type of specimen.


Excessive crown contours facilitate endemic plaque niches. Facial and lingual surfaces of teeth restored with complete metal and porcelain-fused-to-metal crowns exhibited greater mean plaque accumulation than did the contralateral teeth. This cross-sectional study showed greater facial-lingual width and plaque indices for restored teeth than for natural or unrestored teeth. This relationship between plaque and excessive contours must not be considered wholly dependent and conclusive. The multifactorial phenomenon influencing plaque accumulation no doubt could contribute to the findings of this study. However, until demonstrated otherwise, the creation of artificial crown contours that are greater than natural tooth convexities must be considered another parameter promoting endemic plaque niches. Sound application of principles with respect to the form of teeth and supporting tissue can preclude contouring of restorations beneficial to the accumulation of dental plaque.


The use of an intraoral training aid in the speech rehabilitation of laryngectomy patients. This study was undertaken to determine whether the speech of poorly rated esophageal speakers could be improved with the aid of a structured palatal prosthesis. Palatograms testing certain speech sounds critical to the plosive-injection technique for air intake showed that improvement resulted after one week of wearing the training prosthesis. All subjects showed some improvement in speech after wearing the prosthesis for one week. Eight out of 10 subjects showed marked improvement in speech. It is suggested that a physiologically structured palatal prosthesis can assist some esophageal speakers to improve their speech.


Pseudogingival prosthesis following periodontal surgery. A technique for replacing interdental papillae with a prosthesis is described. Emphasis on the accuracy of the master impression is essential to a satisfactory result. Good oral hygiene and removal of the prosthesis at night are of paramount importance.


Induction of malignant bone tumors in rats by 1-(2-hydroxyethyl)-1-nitrosourea. Forty male MRC-W rats were treated chronically with 1-(2-hydroxyethyl)-1-nitrosourea in drinking water (total dose, 330 mg/rat). Fifteen rats (38%) developed osteogenic osteosarcomas or chondrosarcomas of the lower vertebrae. This was the first time that an orally administered organic compound induced a high incidence of these tumors.


Karyotope and survival in human acute leukemia. Of 111 patients presenting with acute forms of leukemia, 44% had a chromosomally abnormal cell line in the bone marrow at diagnosis. In each of the acute leukemia forms (myeloid, lymphatic, stem-cell), patients with karyotypic abnormalities showed mean and median survival times like those with normal chromosomes. Both groups showed a wide range of survival times. The mean and median survival times of patients with mixed populations of chromosomally normal and abnormal cells did not differ from those of patients with exclusively abnormal cells in the bone marrow. The karyotypic abnormalities associated with acute leukemia, as well as having no etiologic significance, probably do not determine the subsequent course of the leukemia.


Human myelogenous (Ph+) leukemia cell line: transplantation into athymic mice. Chronic myelogenous leukemia (CML) cells from line K-562, containing the Philadelphia (Ph1) chromosome, were transplanted into nude mice and grew as solid vascularized tumors containing cells like those seen in the patient and in the cultures. Cells taken from the tumors were near triphoid and retained all human chromosome markers in culture.


Alteration of biologic behavior of a rat leukemia by different routes of passage. Two clonal leukemia cell lines exhibiting diploidy or tetraploidy were isolated separately from a mother cell population of rat myelogenous leukemia DBLA-6 (induced by 1-butyl-1-nitrosourea), and their biologic characteristics altered during serial iv or ip passages in Donryu rats were examined. In early generations after the establishment of the clones, leukemia-inducing capacities were clearly demonstrated only in the diploid clone and were characterized as follows: a) release of leukemia cells into the peripheral blood after inoculation, and b) infiltration, and growth of leukemia cells in the bone marrow and spleen. After repeated iv passages, however, leukemia-inducing capacity was greater not only in the diploid but also in the tetraploid clone. By serial ip passages, this capacity was never acquired but was gradually lost even in the diploid clone. Cell electrophoretic mobility, cell size, or susceptibility to chemotherapeutic agents were also modified. There was a strong correlation between the routes of passage and the direction of the changes: The iv route enhanced or the ip route suppressed the leukemia-inducing capacity. Chromosome constitutions were also changed.


In vitro erythroid colony formation in acute myelogenous leukemia in the rat. Erythroid colonies were grown in vitro in plasma clot cultures. Normal adult rat bone marrow responded to exogenous erythropoietin with the formation of an average of 2 colonies/10(3) cells plated. No erythroid colonies were observed in cultured normal spleen preparations. Shay chloro-leukemia cells administered iv induced an acute myelogenous leukemia. During the progressive stages of the disease, the numbers of erythrocyte colony forming units (CFU-E) in the marrow decreased; concomitantly, these progenitors appeared in leukemic spleen cultures. Paralleling changes in CFU-E, the numbers of nucleated red blood cells in the marrow declined but increased in the leukemic spleen. However, compensatory spleen erythropoiesis was transient, due to continued leukemia cell colonization. The loss of erythroid progenitor cells from the bone marrow played a significant role in the anemia associated with this leukemia.


[Pharmakokinetics of hydroxy-urea. Therapy of acute myeoblastic leukemias using synchronization and recruitment effects (author' transl)]. By a plasma-concentration of hydroxy-urea (HU) higher than 0.5-2.2x10(-4)M the DNA-synthesis in leukemia cells was blocked reversibly in 9 patients. The plasma half-time of HU varied between 120 and 198 min. To synchronize leukemic cell populations the DNS-synthesis was blocked over a period of 36 hours by maintaining the HU-concentration above the critical lower level. In a second phase-specific therapeutic step cytosine-arabinoside (AraC) was given 4 times in a dose of 1 mg/kg each. A recruitment after the application of AarC made more cells available for the next following synchronization step. 4 acute myeloblastic leukemias with high peripheral cell counts were treated according to this schedule. One patient is still in complete remission for now 14 month. This synchronization/recruitment schedule seems to be successful in acute myeloblastic leukemias with high proliferation rates measured by biochemical and cytokinetic methods.


[Effects of administration of gastric mucoprotein and vitamin B 12 on rats fed Hauk's and Osers standard diet and Wynn's cariogenic diet]. An increase in dental decay of 48.89% over controls fed with a cariogenic diet was noted when gastric mucoprotein and vitamin B12 were administered to rats receiving a standard diet.


[Nerve block in the treatment of cranio-facial pain]. The purpose of antalgic nervous block is described and the reasons why a patient suffering from pain syndrome should be examined at the same time by a multidisclipinary team (whos composition will vary depending on the site of the pain) are explained. Such a team will also include the anaesthetist, maxillofacial surgeon, neurologist, neurosurgeon, orthopaedist, radiophysiothherapist, non-medical psychalagist and neurologist. 2436 antalgic nervous blocks undertaken between 17-3-1963 and 31-5-1974 on the head and neck are reviewed. They are analysed in relation to the site of the block, the pathology, the anaesthetic used, and complications. Long-term results are mentioned in brief.


[Primary osteosarcoma of the skull--a case report (author's transl)]. A case of primary osteosarcoma of the skull is reported in this paper. The patient was a 41-year-old male, who complained of painless swelling of the left upper eyelid and became unable to open his left eye. He was admitted to our hospital on March 27, 1972. A bony hard tumor, fingertip in size, was palpable subcutaneously at the left superior orbital margin. The tumor was inmovable and not tender. Ophthalmological examinations of the left eye revealed disturbance of upward ocular movement without exophthalmos. The ocular fundus showed slight dilatation of the retinal veins and the normal disc. The visual acuity and the visual field appeared intact. X-ray films of the skull showed irregular osteolytic changes in the left orbital roof and the superior orbital margin. Left carotid angiogram showed abnormal vessels forming pools and arterio-venuous fistulae in the osteolytic lesion. An April 5, 1972, surgical removal of the tumor was performed successfully and the dura attached to the tumor was also excised. After operation, chemotherapy and radiation therapy were applied. Histological examination showed osteosarcoma invading the dura. At present, two years and seven months after surgical treatment, the patient is doing well without evidences of recurrence of this disease.


Congenital dislocation of the hip an evaluation of neonatal diagnosis. A survey of 23443 live births in the North Canterbury area has shown that the incidence of uncomplicated congenital dislocation of the hip was 2.65 per 1000 live births. That a positive family history and breech delivery are important factors in identifying the infant at risk was confirmed. In spite of the fact that routine neonatal examination of 5158 of the infants detected dislocation or instability of the hip in the neonatal period four times as frequently as in the remainder of the group, no evidence can be found to suggest that this achieved a reduction in the frequency of late diagnosed or missed cases.


Cot deaths in Southland.

Cot deaths in Southland. Cot deaths in Southland, New Zealand, were studied over a five-year period, from 1968 to 1972. The epidemiological and pathological features of the 40 deaths are reviewed and are found to be similar to most other studies. The possible relationship between selenium deficiency and cot deaths is discussed. Comparisons are made with the results of an Auckland study.


Further studies on the effects of infant feeding on speech quality. A previous speech survey (Broad, 1972) has been extended to include similar children in schools on the West Coast of the South Island, making a total of 319 for the two surveys. Both surveys were retrospective. The West Coast study has extended the findings of the earlier project. The combined studies showed that: 1. Breast feeding is associated strongly with improved speech clarity in the male child and the tendency for breast feeding to be associated with improved tonal quality is sustained. 2. Reading ability is associated with breast feeding for the entire group, boys showing the effect more clearly than girls. 3. A high degree of association was found between reading ability and speech clarity. 4. There is an association between breast feeding and confidence. There is evidence that the feeding effect is different for both sexes and that differences exist between the two regions.


Streptococci and viruses in association with rheumatic fever in Wairoa. An analysis of 398 viral cultures from 151 children belonging to 101 families carried out in the Wairoa area in 1963: with an analysis of 169 throat swabs taken from the same group of 50 patients for the months of May, June, July and August 1974, and the incidence of the haemolytic streptococcus as found from the Wairoa Hospital laboratory cultures for 1974 is reported.


Conservative treatment of digit amputations. A conservative regime for distal digit amputations allowing healing under vaseline gauze has much to recommend it, being simple and allowing rapid healing with few complications. Secondary distal amputations for gangrene and sepsis also heal rapidly if left open. A consecutive series of 55 amputations treated in this way is described.


Changes in radioiodine uptake in New Zealand. The radioiodine uptakes of 965 patients presenting at Dunedin, over the period January 1959 to January 1970 have been examined. A small change toward lower values of uptake was noted, however, the change was much less than the changes reported in the USA.


The content of histamine and fish food poisoning. The histamine content of various fish samples that were involved in food poisoning incidents was determined. There was an elevated level of histamine and this is discussed in terms of fish spoilage. The histamine level could be helpful in gauging the degree of spoilage of commercially canned fish.


The role of the counsellor in a medical centre. The counsellor is one member of the para-medical team being used more and more frequently by doctors. His role is allied to, but distinct from the doctor. He is not an authority figure who diagnoses and prescribes, but acts so as to help the patient diagnose the nature of his own dysfunction and assist him to draw on his own resources for growth and change. The methods the counsellor uses vary, but his goal harmonises with the doctor--the removal of disease from the psychosomatic unity of the patient.


Natural family planning.

Natural family planning. A personal series of 600 private patients using natural family planning techniques is presented. The total failure rate was 4.7 pregnancies per 100 woman-years. The advantages of this method over conventional contraceptive techniques are stressed.


A clinical study of hyperuricaemic men.

A clinical study of hyperuricaemic men. A group of 43 hyperuricaemic men discovered during the 1967 Rangiora diabetic and metabolic survey was examined clinically in 1968 and their blood chemistry repeated. They were then compared with a control group matched for age. No significant differences were found in the two groups either in physical findings or in biochemical measurements apart from the known differences in serum uric acid and the presence of gout in hyperuricaemics. When the study was repeated on the same group in 1973 still no significant difference was found which could be attributed to the hyperuricaemia.


Present and future of isolation systems in Auckland. The present and possible future facilities for the management of infectious diseases at Auckland Hospital have been reviewed. Geographical integration of infectious cases with adult medical cases on the one hand and general paediatric cases on the other is recommended, with close co-operation between paediatricians, clinical microbiologists and physicians in other branches of medicine. Details are given of currently available facilities and techniques for the infectious diseases department.


A case of carcinoid.

A case of carcinoid. A patient is described with a malignant carcinoid tumour of the ileum with nodal secondaries causing mesenteric vessel occlusion and ileal infarction.


Antibiotic sensitivity in hand infections. A survey of patients presenting for primary treatment of infected lesions on their hands was carried out. Eight-nine lesions were cultured from which 116 organisms were isolated. The main organisms were coagulase-positive staphylococci. In 24 cases these were acting in concert with group A beta-haemolytic streptococci. Of the coagulase-positive staphylococci isolated, 19 percent were resistant to sulphonamides, and only 45 percent were resistant to penicillin.


Chromium, manganese, copper, zinc and cadmium content, of New Zealand foods. The concentrations of chromium, manganese, cooper, zinc and cadmium are reported for 130 different New Zealand foods, along with water content and the ratio of the edible portion to the as purchased portion. The range of trace element concentrations for the major food groups were almost always within those reported by other investigators.


Psychiatric aspects of murder and attempted murder. The clinical data and forensic aspects of 28 individuals charged with murder and 10 charged with attempted murder examined over the last 35 years are recorded. The majority of those aged 40 years or over were criminally insane. A positive family history of psychiatric illness was present in the majority of the criminally insane group. Murder and attempted murder in the setting of a stable marriage was almost invariably the result of serious psychiatric illness. After the clearcut cases of schizophrenia and depressive illness were separated there were left a mixed paranoid group and a large group of individuals with severe personality disorders. Of the forensic aspects a case is made for the wider use of "unfitness to plead" in the severely psychotic. The follow-up of cases strongly suggested that those found not guilty on psychiatric grounds were likely to be held for longer periods than those treated as criminals. The author suggests that the public would be better protected if the Crown sought an insanity verdict in some cases rather than oppose it.


Peritoneal osteosarcoma following irradiation therapy of ovarian cancer. A peritoneal osteosarcoma occurring after irradiation therapy for cystadenocarcinoma of ovary is described. Only 6 cases of postradiation extraosseous osteosarcomas have been reported and none of them have arisen within the peritoneum. The clinical presentation and histopathology of this unusual tumor is presented with a review of the literature.


Postoperative sequelae after anterior segmental osteotomies. Reported are the results of a clinical study evaluating the postoperative sequelae of maxillary and mandibular segmental osteotomies. Sixteen patients were evaluated for postoperative pulp vitality, tissue viability, neuropathies, segment stability, and patient response. The findings support the use of this modality when accurate diagnosis and treatment planning are followed by competent surgical procedures.


Effects of lavage techniques with third molar surgery. A comparison study of 206 mandibular third-molar surgical sites, half of which were irrigated with high volumes of isotonic normal saline solution with a conventional hand syringe and half of which were irrigated with high volumes of isotonic normal saline solution by means of a mechanical pulsating lavage instrument, revealed the following: 1. No cases of localized osteitis occurred with the use of mechanical irrigation in 103 surgical sites (0%). 2. One case of localized osteitis occurred with regular irrigation in 103 surgical sites (0.97%). 3. The over-all incidence of localized osteitis was one case in 206 surgical sites (0.49%). 4. One case of infection occurred with mechanical lavage (0.97%). 5. Two cases of infection occurred with conventional lavage (1.96%). 6. The over-all incidence of infection was three cases in 206 surgical sites (1.45%). 7. No significant differences occurred at the 0.95 level of confidence when the two groups' 3- and 5-day healing were compared. 8. A fairly even distribution of postoperative infections and/or localized osteitis was noted among the cases handled by the three surgeons directly involved in the performance of the operations. 9. Three hundred fifty milliliters of isotonic normal saline solution under pressure (whether electrical or conventional) appreciably reduced the reported incidence of localized osteitis without the use of antibiotics. 10. The mechanical irrigator was less cumbersome and faster (30 seconds for 350 ml.) than the conventional hand syringe (4 to 5 minutes for 350 ml.). 11. The sterilization procedure was more complicated for the mechanical irrigator (gas autoclave) than for the conventional hand syringe (presterilized disposable type). 12. Loose (unattached) soft tissue and bony spicules were thoroughly removed by 350 ml. of irrigation.


Treatment of chronic mandibular dislocation. Report of a case. The procedure described in this article achieves the desired objective, but without the use of foreign bodies or any additional operation to obtain grafting material. Unlike many surgical approaches in use for treating chronic dislocation, there is no capsular violation. Six operations have been performed with this technique, and all have been successful.


Intraoral psoriasis associated with widespread dermal psoriasis. A case believed to represent true intraoral psoriasis has been presented and documented with clinicopathologic material. Intraoral lesions in patients with cutaneous psoriasis should be investigated to determine whether these lesions represent psoriasis or another coexisting entity.


Sialochemistry in Sjögren's syndrome.

Sialochemistry in Sjögren's syndrome. The value of sialochemistry in the study of Sjögren's syndrome was explored by comparative examination of a spectrum of parotid components in twelve subjects with a positive diagnosis of the disease and twelve control subjects with normal gland function. The subjects with Sjögren's syndrome all exhibited a marked reduction in flow rate and phosphate concentration and a marked elevation in sodium and chloride concentration. The concentration of IgA was somewhat elevated (commensurate with reduced flow rate); the levels of IgG, IgM, and albumin were normal. The major functional abnormality in the parotid gland in Sjögren's syndrome appears to be luminal transport in the ductal region; leakage of serum components is minimal. Sialochemistry can be helpful in differentiating Sjögren's disease from other diseases of the salivary gland and in assessing degree of pathologic change.


Salivary studies in alcoholic cirrhosis. Eighteen patients with alcoholic cirrhosis were examined, and parotid saliva was collected. Enlargements of the parotid glands were seen in eleven of the eighteen patients (61%). This percentage is in accord with the data previously reported. The salivary findings of increased flow rate, protein, and amylase levels indicate that hypertrophy and increased acinar function may be a component of the parotid enlargement and that, furthermore, a fatty replacement of functional gland tissue is probably not involved. In addition, the salivary electrolyte changes found, increased potassium with effectively decreased sodium excretion, suggest that the elevated aldosterone level commonly found in cirrhotic patients affects salivary secretions in these patients in much the same way as it does in patients with hypertension.


Structural changes in odontodysplasia.

Structural changes in odontodysplasia. Report is made of a histologic and scanning electron microscopic (SEM) study of teeth affected by odontodysplasia. The enamel was found to be thinner than normal, and the entire surface showed numerous depressions. The prismatic orientation, diameter, and density were found to be normal. Although the mantle dentin remained normal, the rest of this tissue showed a tendency to globular formation. The orientation, density, size, and shape of the dentinal tubules appeared to be normal. The cementum, in general, was normal, but in some instances appeared to be scalloped or globular. The pulp consisted of normal tissue but was found to be larger than normal. The presence of denticles was an outstanding feature.


Studies on oral submucous fibrosis. III. Epithelial changes. The literature on the epithelial changes in oral submucous fibrosis is reviewed. The epithelial changes seen in thirty-eight biopsy specimens from thirty-eight patients with oral submucous fibrosis are presented in detail. It was seen that in submucous fibrosis there is a tendency toward epithelial atrophy associated with hyperothokeratosis and pyknotic changes in the nuclei of the basal-cell layer. Hyperplasia of the epithelium usually associated with hyperparakeratosis was also noticed. A striking feature in this study was the absence of glycogen from most of the Grade III (severe) cases. Vacuolization of prickle-cell layer, increased mitotic activity, and epithelial atypia were also noticed in a few cases. The significance of submucous fibrosis as a possible precancerous lesion is emphasized, with reference to the recent reports in the literature.


Histopathologic findings in third molar opercula. This review of 130 opercula revealed the following findings: 1. In nine cases, salivary gland tissue was present in variable amounts. 2. The oral epithelium was unremarkable, except for eleven cases of atypia, most likely benign atypia resulting from trauma and inflammation. 3. Odontogenic-type epithelium was found in sixty cases. None showed unusual proliferation, but two cases were of a clear-cell type. 4. The lining epithelium was variably present and was either simple squamous, cuboidal, columnar, or stratified squamous in type. 5. Fifty-four cases were found which showed either bone, dentin, osteoid, or focal odontodysplasia in the tissue, including one case that showed a structure identical to a periodontal membrane encircling it. 6. The lining epithelium on the ISO was often completely absent. This was true with almost no inflammation as well as with marked inflammation present. The soft-tissue overlying erupting third molar teeth contains a host of different tissues. Many of these have the propensity to undergo proliferation, neoplastic change, or cause postoperative complications and delay healing. Therefore, it is my opinion that all such tissue removed be subjected to histopathologic review. Furthermore, surgeons should be aware of the possible neoplastic potential and the detrimental healing effects of these various tissues if an operculum is used for primary closure.


Experimental in vitro lesions adjacent to composite restorations in etched cavities. Class V cavities and wedge-shaped cavities simulating erosions were prepared in thirty extracted, permanent human teeth. After being etched for 2 minutes with the pertinent cleanser, the wedge-shaped cavities were restored with Enamelite or Restodent. The Class V cavities were etched with 50% phosphoric acid and restored with HL-72. Artificial lesions around the fillings were produced by immersing the teeth in an acid-gelatin system. Ground sections of the teeth with the fillings in situ were studied by polarized light microscopy and microradiography. All the teeth showed "outer lesions," whereas the occurrence of a "wall lesion" was a rare exception.