the prosthetic rehabilitation for maxillectomy patients aims at separation of oral and nasal cavities to allow adequate deglutition and articulation , to restore the midfacial contour and to provide acceptable esthetic results .
lack of support , retention and stability are common problems associated with patients who have undergone maxillectomy .
the retention of an obturator depends on various factors such as : direct and indirect retention provided by the remaining teeth , defect size , tissue undercuts available around the cavity and development of muscular control .
the presence of teeth facilitate prosthetic rehabilitation , however , fabrication of prosthesis for an edentulous patient with maxillectomy defect is challenging even to the most experienced clinician .
this clinical case report describes the prosthodontic management of an edentulous patient who had undergone partial maxillectomy due to mucormycosis .
osseointegrated dental implants and magnet attachments were used to achieve a retentive and stable , large sized definitive obturator .
a 52-year - old ex - serviceman reported to the department of oral and maxillofacial surgery with chief complaints of foul breath and ulcer since 2 months .
medical history revealed that he was an uncontrolled type ii diabetic for the past 13 years .
intraoral examination revealed a raw , 4 cm  2 cm aramany 's class i type of left maxillectomy defect .
mandibular movements were within the normal range ; tongue function was normal and speech was inarticulate .
for the interim prosthesis , irreversible hydrocolloid ( plastalgin , septodont , france ) impression was made and casts were prepared in type iii dental stone ( kalstone , kalabhai , india ) .
functional border molding of the tissues was carried out and the defect area was impressioned using high fusing impression compound ( pinnacle , dpi , india ) and light body silicone impression material ( aquasil , dentsply , germany ) .
the patient used the prosthesis for 03 months during , which multiple adjustments and relining with a resilient tissue conditioning material ( gc reline soft , gc , japan ) were carried out .
the retention was a major concern , patient being edentulous . in the process of planning for an implant supported definitive prosthesis ,
radiographic evaluation revealed adequate height and width of the residual ridge with d3 type maxillary bone for implant placement .
an implant supported definitive prosthesis was therefore planned , which would enhance the compromised retention for this case of  edentulous  maxillectomy defect .
a diagnostic maxillary impression was made with an irreversible hydrocolloid using a stock metal tray .
the impression was poured in type iii dental stone for designing of the definitive obturator and planning for placement of dental implants .
three two stage osseointegrated dental implants ( mis ; confident system ) were placed in the residual right maxilla : ( diameter : 3.75 mm , length : 11 mm ) in the right maxillary first molar site ; ( diameter : 3.75 mm , length : 13 mm ) in the right maxillary canine site and ( diameter : 3.75 mm , length : 11 mm ) in the right maxillary incisor region [ figure 2 ] .
post - operative orthopantomogram was carried out to check the implants placement after achieving clinical primary stability [ figure 3 ] .
three implants placed in residual maxilla post - operative opg showing implants in position the second stage surgery was performed after 08 months .
after the implants were checked for clinical success they were exposed and gingival formers were placed .
abutments were milled and screwed ; transfer copings were placed over the implants and an open tray impression was made with medium body silicone material ( aquasil , dentsply caulk , germany ) .
magnetic keepers were placed over the abutments on the cast and wax patterns for the copings were fabricated .
the modified copings were cast in nickel chrome alloy ( bellabond , bego , germany ) . after polishing ,
in addition , surveying and designing procedures of master cast were carried out for the fabrication of metal denture base framework .
copings of magnetic keeper cemented over implants a custom impression tray was fabricated on the metal framework using autopolymerizing resin and adjusted for proper extension in patient 's mouth .
border molding was performed for the residual maxilla and the defect was recorded using the addition silicone soft putty ( aquasil , denstply , germany ) and definitive impression was made using light body silicone impression material ( aquasil ultra lv , denstply caulk , germany ) .
conventional prosthodontic protocols of boxing and pouring the impression with american dental association type iii dental stone were followed to fabricate a definitive cast .
after adapting a layer of modeling wax ( cavex outline , netherlands ) , the definitive cast was flasked and processed in the customary manner to fabricate a hollow bulb using heat - activated methyl methacrylate ( lucitone 199 ; dentsply ) .
the processed record base was evaluated intraorally for extensions and occlusal rim was fabricated using modeling wax .
maxillomandibular jaw relations were recorded and transferred to an articulator ( hanau h2 ; teledyne technologies , los angeles ) using a whipmix self - centered springbow type of facebow . denture teeth ( cosmo hxl , dentsply , china )
were arranged and evaluated intraorally for dentolabial relation and lip support and horizontal and vertical jaw relations were verified . upon the patient 's approval for phonetics and esthetics , waxing and festooning of the gingival and palatal portions of the obturator
were completed , the processed base was reinvested and the prosthesis was processed into heat - activated methyl methacrylate .
after necessary adjustments , each magnet ( cobalt - samarium , ambica co. , india ) was centered on the magnetic keeper coping with a thin ( 0.001 inch ) cellophane separating sheet interposed to prevent acrylic resin from locking onto the abutment .
a small amount of acrylic resin was added on the intaglio surface of the denture where magnets were to be secured .
the denture was inserted intraorally and seated to pick up the magnets [ figure 5 ] .
pressure indicating paste was used to determine any undue pressure placed on the surrounding tissues . finished prosthesis with magnets in place
the obturator prosthesis was inserted [ figure 6 ] and phonetics and esthetics was re - evaluated .
post - insertion instructions were given to the patient and follow - up was carried out every 03 weeks .
the last follow - up of the patient was 6 months following the insertion of the new prosthesis .
the patient had been using the new obturator prosthesis satisfactorily and no signs of failure associated with implants were detected .
the retention was a major concern , patient being edentulous . in the process of planning for an implant supported definitive prosthesis , radiographic evaluation revealed adequate height and width of the residual ridge with d3 type maxillary bone for implant placement .
an implant supported definitive prosthesis was therefore planned , which would enhance the compromised retention for this case of  edentulous  maxillectomy defect .
a diagnostic maxillary impression was made with an irreversible hydrocolloid using a stock metal tray .
the impression was poured in type iii dental stone for designing of the definitive obturator and planning for placement of dental implants .
three two stage osseointegrated dental implants ( mis ; confident system ) were placed in the residual right maxilla : ( diameter : 3.75 mm , length : 11 mm ) in the right maxillary first molar site ; ( diameter : 3.75 mm , length : 13 mm ) in the right maxillary canine site and ( diameter : 3.75 mm , length : 11 mm ) in the right maxillary incisor region [ figure 2 ] .
post - operative orthopantomogram was carried out to check the implants placement after achieving clinical primary stability [ figure 3 ] .
three implants placed in residual maxilla post - operative opg showing implants in position the second stage surgery was performed after 08 months .
after the implants were checked for clinical success they were exposed and gingival formers were placed .
abutments were milled and screwed ; transfer copings were placed over the implants and an open tray impression was made with medium body silicone material ( aquasil , dentsply caulk , germany ) .
magnetic keepers were placed over the abutments on the cast and wax patterns for the copings were fabricated .
the modified copings were cast in nickel chrome alloy ( bellabond , bego , germany ) . after polishing ,
copings were cemented to the superior surface of the abutment with resin cement ( variolink n , ivoclar , liechtenstein ) [ figure 4 ] .
in addition , surveying and designing procedures of master cast were carried out for the fabrication of metal denture base framework .
copings of magnetic keeper cemented over implants a custom impression tray was fabricated on the metal framework using autopolymerizing resin and adjusted for proper extension in patient 's mouth .
border molding was performed for the residual maxilla and the defect was recorded using the addition silicone soft putty ( aquasil , denstply , germany ) and definitive impression was made using light body silicone impression material ( aquasil ultra lv , denstply caulk , germany ) .
conventional prosthodontic protocols of boxing and pouring the impression with american dental association type iii dental stone were followed to fabricate a definitive cast . after adapting a layer of modeling wax ( cavex outline , netherlands ) ,
the definitive cast was flasked and processed in the customary manner to fabricate a hollow bulb using heat - activated methyl methacrylate ( lucitone 199 ; dentsply ) .
the processed record base was evaluated intraorally for extensions and occlusal rim was fabricated using modeling wax .
maxillomandibular jaw relations were recorded and transferred to an articulator ( hanau h2 ; teledyne technologies , los angeles ) using a whipmix self - centered springbow type of facebow .
denture teeth ( cosmo hxl , dentsply , china ) were arranged and evaluated intraorally for dentolabial relation and lip support and horizontal and vertical jaw relations were verified . upon the patient 's approval for phonetics and esthetics , waxing and festooning of the gingival and palatal portions of the obturator
were completed , the processed base was reinvested and the prosthesis was processed into heat - activated methyl methacrylate .
the completed prosthesis was fitted intraorally and remounted to equilibrate occlusion . after necessary adjustments , each magnet ( cobalt - samarium , ambica co. , india ) was centered on the magnetic keeper coping with a thin ( 0.001 inch ) cellophane separating sheet interposed to prevent acrylic resin from locking onto the abutment .
a small amount of acrylic resin was added on the intaglio surface of the denture where magnets were to be secured .
the denture was inserted intraorally and seated to pick up the magnets [ figure 5 ] .
pressure indicating paste was used to determine any undue pressure placed on the surrounding tissues . finished prosthesis with magnets in place the obturator prosthesis was inserted [ figure 6 ] and phonetics and esthetics was re - evaluated .
post - insertion instructions were given to the patient and follow - up was carried out every 03 weeks .
the last follow - up of the patient was 6 months following the insertion of the new prosthesis .
the patient had been using the new obturator prosthesis satisfactorily and no signs of failure associated with implants were detected .
edentulous patients with maxillectomy defects present a significant challenge for prosthetic rehabilitation and the adaptive capabilities of the patient as retention is highly compromised . the only option for retaining prosthesis in such cases , besides implants , is optimum engagement of the available soft - tissue undercuts found within the defect space and the non - affected side . the ability to fully engage these undercuts
is further limited by the path of insertion for the prosthesis and the restricted mouth opening .
hence , the option of using endosseous implants to increase obturator retention has been introduced in the present case . the overall survival rate for implants supporting maxillofacial prosthesis
although magnets may not result in adequate denture retention in every case , it is apparent that the nature of the magnetic force in controlling vertical displacement of the denture is likely to result in an improvement in retention .
magnetic retention units in the form of cobalt samarium magnets can be embodied conveniently in the conventional obturators .
the technique is simple to use , particularly when compared with other retention procedures , which can be both complicated and time consuming . in this
patient magnets were preferred over the conventional bar and clip design because of space constraints .
moreover , magnets avoid lateral stresses which are essential for long - term implant success .
magnets have the disadvantages of low corrosion resistance and possible cytotoxic effects , which may limit their use in the oral cavity , but studies have revealed that no such - tissue damaging effects have been observed clinically for cobalt samarium magnets . surgical reconstruction of the palate using a free tissue transfer may provide a stable permanent partition between oral and nasal cavities .
however , it gives way to gravity , distorting palatal contours and preventing access into the defect for support and retention of the prosthesis .
surgically reconstructed defects may or may not improve the treatment outcome when compared with conventional prosthetic rehabilitation of the defect .
zygomatic implants that provide remote anchorage have also been proposed in the rehabilitation of maxillary defects , but this option was eliminated because of the lack of available bone .
meticulous oral hygiene measures and regular follow - up needs to be instituted for a patient using implant supported obturator prosthesis .
it is advised that the patient wears the prosthesis at night as sinus secretions and saliva can not be managed without it .
prosthetic rehabilitation is often difficult to achieve due to the absence of teeth , lack of favorable tissue undercuts and presence of non - keratinized nasal mucosa .
obturator prostheses should recreate a partition between the oral and nasal cavities to restore oral function and esthetics .
implants with magnetic units offer a practical method of improving the retention of obturators provided acceptable prosthetic protocols are followed for the rehabilitation .
 edentulous patients with maxillectomy defects present a significant challenge for prosthetic rehabilitation and the adaptive capabilities of the patient as retention is highly compromised . 
 hence , the option of using endosseous implants to increase obturator retention has been used . 
 a patient of mucormycosis of the left maxilla was treated with surgical excision . 
 after satisfactory healing , definitive implant supported magnet retained prosthesis was fabricated for the patient . 
 implants with magnetic units offer a practical method of improving the retention of obturators provided acceptable prosthetic protocols are followed for the rehabilitation . 
Introduction
Case Report
Definitive prosthesis
Discussion
Conclusion