The odontoma is a hamartomatous lesion consisting of enamel, dentin, pul and cementum. They are observed in the form of a tooth or as a mass of agglomerated teeth. Most of these occur during the period of development of normal teeth and grow to some extent. The fused tooth was the developmental abnormality of the teeth and the hard tissues of the adjacent teeth were combined. In general, these two lesions are not related, but two problems can occur together with systemic or local causes in the morphological differentiation period. We report a case of a 6 - year - old boy who visited our clinic for the eruption of a calcified mass in the mouth. The patient was diagnosed by the fusion of a odontoma and a mandibular permanent anterior tooth. And then, fused odontoma was removed surgically and the mandibular permanent anterior was restored by using composite resin. Calcified material was diagnosed as a composite tooth. After 6 months, the permannant teeth was satisfactory eruption and did not show any pathological problems in periapical radiography.

Ameloblastic fibrosarcoma (AFS) is an extremely rare malignant odontogenic tumor characterized with benign ameloblastic cells islands and malignant mesenchymal component. While two-thirds of AFS seem to arise de novo, but one-third develops from recurrent ameloblastic fibroma (AF) or ameloblastic fibro-odontomas (AFO). Pathological distinction of malignant transformation is essential for appropriate treatment. The patient was a 28 years old man. Since the primary tumor was excised, the mass recurred 2 years later. The recurrent tumor was diagnosed as AFS. Chief complaint was pain in the right mandible. Computer tomography finding revealed multilocular intrabony lesion with radiopaque substance in the primary lesion. In the recurrent lesion cortical bone destruction was found. Microscopically, both the primary and recurrent lesions showed benign ameloblastic follicles with myxoid or highly cellular mesenchymal proliferation. The histological difference between primary and recurrent lesions were that foci of dental hard tissue composed of enamel and dentin were found only in the primary lesion, whereas nuclear pleomorphism was aggrevated in the recurrent lesion. The histological criteria determining malignancy were discussed.

A nineteen years old male patient showed a cystic lesion in left maxillary canine to premolar area (#23-#25). This lesion was asymptomatic, and found during his routine radiological check in local clinic. In the radiological observation the cystic lesion showed round radiolucent image containing many calcified bodies which were usually small but irregular in shape, expanding tumorously and resulted in the displacement of canine and second premolar in the absence of first premolar. The lesion was surgically enucleated, and a cystic fibrous tissue containing abnormal teeth was removed and examined pathologically. With the histological observation of tumorous odontogenic epithelium including many ghost cells, which were closely associated with abortive teeth, the lesion was finally diagnosed as CCOT associated with complex odontoma. The ghost cells of CCOT was strongly positive for β-catenin, GADD45, and LC3, and slightly positive for MMP-9, while they were rarely positive for BCL2, Wnt1, HSP-70, and p38. Therefore, it was presumed that the ghost cells of CCOT might undergo dormant cell state through altered cytodifferentiation stimulated by severe growth arrest, DNA damage signaling, and abundant autophage formation.

The purpose of this case report was describe the management of impacted and dilacerated mandibular secondary primary molar with cystic formation associated with odontoma. A four-year-old male patient was presented unerupted mandibular left secondary primary molar. Radiographic examination revealed radiopaque mass on left posterior mandible, an impacted and dilacerated mandibular secondary primary molar, and a well defined osteolytic lesion surrounding crown of the impacted tooth. Under local anesthesia, the patient was treated by surgical removal of the odontoma and marsupialization of the cystic cavity. After 14 months, the secondary primary molar had erupted and there was no recurrence.

Odontomas are mixed odontogenic tumors in which both the epithelial and mesenchymal components have undergone functional differentiation. Two types of odonotma are histomorphologically recognized: complex and compound. Complex odontomas have little or no morphologic similarity to normal tooth formation, and they commonly found in the posterior mandible. They are typically asymptomatic, and the most common presenting symptom is usually lack of eruption of a permanent tooth. The recommended treatment for an odontoma is conservative surgical excision. No tendency for recurrence has been noted. An eight-year-old girl was presented with swollen mouth floor. Radiographically, there were radiopaque mass on anterior mandible with impacted lower left central incisor. Under midazolam intraoral sedation and N2O-O2 inhalation sedation, the odontomas were surgically removed. The diagnosis was complex odontoma. After follow-up of 28 months period, there was no recurrence. The impacted tooth erupted spontaneously and the space for the erupted tooth was regained orthodontically.

Calcifying cystic odontogenic tumor (CCOT), also known as calcifying odontogenic cyst or Gorin cyst is a rare developmental lesion which arises from odontogenic epithelium. It has been classified as a benign odontogenic neoplasm related to odontogenic apparatus by the World Health Organization. CCOT may be associated with other odontogenic tumors, most frequently odontoma, a finding that is a rare event in other types of odontogenic cysts or tumors. This report describes a case of hybrid odontogenic tumor composed of CCOT and ameloblastic fibroma-odontoma of the impacted right maxillary canine region that occurred in a 14-year-old female.

Ameloblastic fibro-odontoma has been defined as a lesion similar to ameloblastic fibroma by WHO, as it shows inductive changes which forms enamel and dentin. Ameloblastic fibro-odontoma is a very rare mixed dentition tumor in children, and the symptom shows indolent edema in maxillary and mandibular molar area. The prevalence is two times higher in male than in female, and two times higher in maxilla than in mandible. Radiologically, it shows clear border and characteristics of both fibroma and odontoma histologically. This review reports a case that a 4-year old female visited in dental clinic of this school for edema as chief complaint in Feb, 2012. Emergency surgical curettage was performed right after initial diagnosis as odontoma, then confirmed diagnosis as Ameloblastic fibro- odontoma after biopsy. Currently, after 6 month, no sign of recurrence can be seen. Ameloblastic fibro-odontoma is very rare mixed dentition tumor. Moreover, as it is the case of female maxilla, this case is worth of publishing. Furthermore, accurate diagnosis of Ameloblastic fibro-odontoma is difficult. This review is published for accurate diagnosis through differential diagnosis of several important mixed dentition tumors.

This is a case reporL of a ra re mi xed odontogenic tumo r, amelob lastic fibro-odontoma in the poste1'ior of r ight ma nd tlbe A 2-year - olcl ma le pa ti enL was referred to our department ['or large tumorous lesion 011 ri ght mandible Radiograph ic examination s howed la rge radi opaque and rad iolu cent lesion with impacted and unerupted tooth, #44‘ #45 , #46 #85 , AJ'Ler s urgi cal enuclea Li on & cu rettage of t he mass , the tumor was confirmed to ameloblastic fibro-odontoma. lt was composed with c1 enta l orga ns a ncl is la nd of odontogeni c epithelium embedded in a cell - ri ch mesenchymal s troma, AIso‘ we ca rri ed out an immunohi stochemical study. The resul ts s howed positive CK7 staining. and showed weekly positi ve for Bcl - 2‘ Ki - 67 s Laining, while CEA, CK8‘ CKl2, CKl6 showed l1egative, Follow-up studies have shown no tumot recurrence for 2 yea rs ,

Odontomas are the most common benign tumors of odontogenic origin characterized by their‘ slow growth, and a re cons ider ed to be developmental a nomalIes They consist of enamel, dentine, cementum and pulpal tissue and cons titue about 22% of all odontogeni c tumors The purpose of this study was to value clinicopathologic features of this kind 01 tumors‘ and to apply these results to make a pa ln of diagnosis and treatment in future, The 20 cases of odontomas between 1991 a nd 2004 subrn.i tted to Dept , of Oral Pathology of Dankook Univ, Dental Hos pital were used We analyzed theil‘ prev a lence‘ di s tributi on in gender , age of the pat ients , anatornic location. clinical manifestations and histopa thologic fea rtures Cli nical symptoms s howed delayed eruption(n=3) of either the deciduous or permanent tooth‘ mtra- 01 extraoral swelli ng(n =9). pain(n =2) , Of a ll the odontomas, 45% in the Mn & 55% in the Mx was seen There were 55% in the anter iosuperier sector & 25% i n the pos ter ioi nferior zone. while the rest in the upper molar region, COO showed 18,5 year s(r ange 6,4) , 60% 0[' diagnosed odontomas, incisor / canine area of mx, smaller(5-30mm) & unilocular. and mu l tip le radiopaque mini teeth s urroun따d by defined radiolucency, whi le CXO showed 30, 1 years(range 14 , 5) ‘ 40% of diagnosed odon tomas ‘ 1s t and 2nd molar of the mn, la rger(1O-60mrn) & unilocular undistinguished radiopaque mass and surrounded by ra di 이 uc e nt zo ne & a di s tin ct ra di opaque border, Both showed reduced enamel epithelium, enamel. dentin and cementum‘ di s play ing s ph eri al calcificat ions. and fibrous capsule as background , A.nd ghost cells were seen in 2 cases COO s howed hig hly orga nization & differenti ation, resembling a minitooth Each tooth was contained with co n nective tissuc sac CXO s howed haphazard organization, and was domi nated by dentin , displaying no resemblance a tooth, Through the definitive diagnos is of odonotmas on the basis of the clinicopath이 ogi c results, we should establish a plan in diagnosis and t rea tment of odontomas