ameloblastic fibro - odontoma ( afo ) is defined as a benign odontogenic tumor with slow growing behavior .
afo is characterized by histologic features of ameloblastic fibroma ( af ) with the formation of enamel and dentine .
this is a case report of afo accompanied with a number of impacted deciduous teeth and its management in a 4-year old boy .
examination of oral cavity revealed an extensive swelling from midline to left deciduous maxillary first molar , covered with normal mucosa .
radiographic examination showed a well - defined mixed radiolucent - radiopaque lesion that extended horizontally from midline to mesial border of the left maxillary primary first molar and vertically from alveolar crest to the floor of nose .
ameloblastic fibro - odontoma ( afo ) is defined as a mixed odontogenic tumor in which both odontogenic epithelium and ectomesenchyme are proliferated and dental hard tissue formation can be seen as its consequence .
prevalence of afo is relatively rare , about 3.1% of all odontogenic tumors ( 1 , 2 ) .
affected patients are generally between 8 to 12 years , and no tendency to gender or anatomic position was reported , although some articles report a slight tendency for posterior mandible involvement ( 2 , 3 ) .
most cases defined as painless swelling may be detected to be the result of tooth eruption failure ( 4 , 5 ) .
radiographic view of afo consists of a well - defined unilocular or multilocular radiolucent lesion that contains part of irregular radiopaque particles ( 6 ) . because of these large mineralized parts , it is impossible to differentiate the afo from complex odontoma through radiographic examination ( 7 ) .
histopathologic feature of afo is characterized by cords , strands and islands of odontogenic epithelium submerged in embryonic connective tissue that simulate rudimentary dental pulp ( 2 , 4 ) . for treatment of afo conservative enucleation followed by curettage
is recommended ( 8) . generally , the prognosis of afo is reported as excellent ( 9 ) .
the purpose of this article is to describe a case of afo that affected the left maxillary region of a patient that was treated with surgical approach without any sign of alteration or recurrence after 12 months of follow - up .
the parents of a 4-year - old boy referred to the pediatric dentistry , school of dentistry , tehran university of medical sciences , on june 2014 complaining of missing teeth . according to patient
s mother , since she noticed the swelling , her son was visited immediately by a dentist who referred him to the dental school . the patient s past medical history was unremarkable .
he had healthy parents and there was no history of systemic diseases in his family .
a general physical examination showed no abnormality and his mother did nt mention any history of trauma .
extra - oral examination showed a painless swelling on the left anterior maxilla , with firm consistency on the palpation , which caused little facial asymmetry .
intra - oral examination revealed a vestibular , non - tender and firm consistency swelling and expansion of buccal cortical plate that was covered with normal mucosa .
the panoramic radiograph and ct scan ( axial section ) revealed an expansile , mixed radiolucent - radiopaque lesion with well - defined corticated border .
there was a radiolucent rim and scattered foci of calcified particles which contained several radiopaque bodies of varying sizes and shapes with density similar to enamel or dentin in the left anterior maxilla .
the lesion extended horizontally from midline to mesial border of left maxillary primary first molar and vertically from alveolar crest to the floor of the nose ( figure 1 a ) .
excisional biopsy and careful curettage of surgical cavity and removal of impacted left primary central and lateral incisors was performed .
the specimens fixed in formalin and submitted for histopathological assessment consisted of 2 pieces of bony tissue , each one having rhomboid - shape measuring 3  2  1 cm and one paper - tiny piece measuring 2  3 cm ( figure 1 b ) .
there was myxoid matrix in some spaces which contained odontogenic epithelial cells ( figure 1 c ) .
after 4 months , the patient received a nance esthetic appliance ( figure 2 a ) . during the 12 month
follow up period no sign of recurrence was detected and soft tissue healing was uneventful .
complete bone healing and normal tooth eruption pattern of permanent central and lateral incisors can be seen on last follow - up radiographs ( figure 2 b ) .
afo is a benign tumor composed of odontogenic epithelium proliferation embedded in a ectomesenchymal tissue that resembles dental papilla , with dentin and enamel formation as a result of inductive properties of this tissue ( 8 - 10 ) .
usually , this lesion is discovered trough routine radiographs for determining the reason of failure in tooth eruption ( 2 ) .
afo is generally asymptomatic and expansion of involved hard tissue can be seen in clinical examination ( 4 ) .
this lesion is commonly found in the molar area , with significant tendency to mandible , affects mainly individuals under 20 years old ( 1 , 4 ) . in a review of literature ,
philipsen et al . ( 11 ) found only 1 case of afo being > 20 years old among 86 cases that they reviewed .
the average age of afo cases at the time of diagnosis was 9 ( ranging from 1 to 22 ) years , with a male / female ratio of 1.4/1 .
commonly , afo was found in the posterior area of mandible , with a mandibular / maxillary ratio of 2.4 , while in our case report , lesion affected the anterior portion of maxilla in a 4-years - old boy .
radiographically , the afo can be seen as a uni- or multilocular radiolucent lesion with a well - defined border commonly associated with a radiopaque margin ( 11 ) .
the ratio of radiopaque to radiolucent zones was different in each particular case ; with domination of calcified structures . the lesion sometimes mimics a complex odontoma appearance ( 10 ) .
surgical procedure showed a well - circumscribed tumoral mass that contains several amounts of small irregular calcified masses . because of benign behavior of this tumor conservative and careful surgical approach is appropriate ( 4 , 6 , 12 ) . sometimes , the differentiation between afo and developing complex odontoma is impossible .
however , the presence of great amount of dental hard tissue consisting of enamel , dentin , and cementum - like components organized in a haphazard pattern favors diagnosis of a complex odontoma .
in addition , the differential diagnosis between afo and odontoameloblastoma is critical . in this lesion ,
the epithelial component is typical of ameloblastoma and the fibrous stroma shows cellular myxoid tissue adjacent to the dental calcified tissues ( 1 ) .
based on the amount of histologic differentiation , ameloblastic fibrodentinoma ( afd ) is defined by some researchers as a stage between the ameloblastic fibroma ( af ) and afo ( 13 ) .
the difference is that the afo is specified by both enamel matrix producation and osteodentin or dentin - like deposits ( 7 , 11 ) .
in contrast to afo , af has no signs of dental hard tissues formation ( 2 ) and potential for recurrence and malignancy exists ( 3 , 14 ) . for evaluating the nature and behavior of lesions , age of the patient and tumor s size
are the most important factors that must be considered at initial detection phase . in our case ,
histopathologic assessment showed typical specification of both ectomesenchymal and epithelial components which led to diagnosis of afo .
recurrence of afo is rare , and most recurrences are related to incomplete surgical removal ( 16 ) .
a recent case of afo was treated with enucleation and impacted lower left first permanent molar was preserved and complete eruption was reported without any sign of recurrence ( 17 ) .
another report , confirmed that a conservative enucleation and curettage in conjunction with copious irrigation was successful to prevent recurrences ( 16 ) . due to possible increased rate of recurrence
, there is no consensus regards to tooth maintaining after afo removal ( 12 ) .
however , some clinical reports achieve success without dental management followed by tooth eruption with no sign of recurrence ( 17 ) . in summary
, we report a case of an afo affecting a 4-year - old boy involving the left anterior side of maxilla . in this case ,
 introductionameloblastic fibro - odontoma ( afo ) is defined as a benign odontogenic tumor with slow growing behavior . 
 its prevalence is rare . 
 afo is characterized by histologic features of ameloblastic fibroma ( af ) with the formation of enamel and dentine . 
 case presentationthis is a case report of afo accompanied with a number of impacted deciduous teeth and its management in a 4-year old boy . 
 examination of oral cavity revealed an extensive swelling from midline to left deciduous maxillary first molar , covered with normal mucosa . 
 radiographic examination showed a well - defined mixed radiolucent - radiopaque lesion that extended horizontally from midline to mesial border of the left maxillary primary first molar and vertically from alveolar crest to the floor of nose . 
 the differential diagnosis was odontoma ( ameloblastic fibro - odontoma , complex odontoma ) . 
 surgical enucleation and curettage was performed under general anesthesia . 
 histopathologic sections show bone trabeculae in marrow spaces . 
 there was myxoid matrix in some spaces which contained odontogenic epithelial cells . 
 these findings led to diagnosis of afo . 
 no sign of recurrence has been observed during the 12-month follow - up period.conclusionalthough afo is a rare tumor , it is more prevalent in childrens jaw . 
 conservative surgical treatment allowed the normal development of teeth . 
Introduction
Case Presentation
Conclusion
1. Introduction
2. Case Presentation
3. Discussion