Cemento-ossifying fibroma is a benign fibrous lesion with an unknown cause, mostly asymptomatic, painless swelling of the affected jaw. This is a case report on a cystic lesion found on radiographic examination in a patient with an extraction of mandibular left tooth. A 29-year-old female was referred to Pusan National University Dental Hospital due to a radiopaque lesion in the left mandible. On the medical history examination, the left lower mandibular tooth had been extracted 4 years ago, and there were no specific findings in the general medical history. According to histopathologic findings, along with proliferation of spindle cells, cementum-like substances were observed along with irregularly shaped osseous calcified substances containing osteocytes in the cellular fibrous connective tissue. In this study, we report a case that showed cystic changes due to tooth extraction, which made it complicated to determine the differential diagnosis from the existing fibrous-osseous lesion.

Ameloblastoma is a benign odontogenic tumour of epithelial origin and comprises 1% of maxillomandibular tumors or cysts. The incidence of pathological changes such as ameloblastoma from the follicle of impacted third molar was reported to have low incidence. However, there are many reports that asymptomatic third molars are related with various pathological conditions. A case of ameloblastoma secondary to third molar extraction and subsequent sagittal split ramus osteotomy (SSRO) had not been reported. At the right ramus area, radiolucent lesion had been noted at 6 years after the surgical extraction of the third molar followed by SSRO for the mandibular prognathism. The lesion was proved to be the basal cell type ameloblastoma. There had been no significant bony lesion before or 1 year after the SSRO. The tumour was successfully removed and there was no evident recurrence at 4 year of the follow up after the removal of the ameloblastoma. There are some reports suggesting the pathologic potential of the pericoronal tissues of impacted third molars to develop odontogenic keratocysts and ameloblastomas. The current case reports a rare possibility of ameloblastic change at the site of uneventful healing after third molar extraction and orthognathic surgery.

There are many case reports about cysts within the bones of the jaws associated with impacted third molars. When osmotic pressure is introduced into a cyst, the cyst expands and displaces the third molar. If continuity of cyst wall is lost, cystic expansion cannot occur, and the cyst cannot displace the third molar. This study analyzed four cases of pathologic migration of the third molar in ruptured cystic lesions that had formed bone tunnels and intraoral fistulas to identify the causes and factors contributing to this migration. Authors hypothesized that closure of fistulas repeated generation of pressure, it may temporarily increase the osmotic pressure within a cyst that has lost its continuity, causing displacement of the third molar. A cyst that has lost its continuity due to fistula formation within the oral cavity can cause ectopic displacement of the adjacent impacted teeth.

The presence of the microorganisms of untreated canals is one of the main reasons of the failure in the endodontic treatment. The knowledge of variations in the canal systems of the tooth is important for the successful endodontic treatment. In the maxillary molars, the presence of the two separate palatal roots is very rare variations. Although there have been several case reports of maxillary first and second molars, the case reports of maxillary third molars are very few. This case report presents the endodontic treatment of a maxillary third molar with two separate palatal roots. It is important to notice the clinical signs and analyze the radiographs carefully. The use of a microscope is helpful for the visualization of pulpal chamber, and pulpal chamber floor should be investigated thoroughly with endodontic explorer. The straight-line access for all the canal orifices is important for the success in the endodontic trea