Telangiectatic osteosarcoma(TAEOS) is a rare subtype of osteosarcoma(OS) composed of blood-filled or empty cystic architecture simulating aneurysmal bone cyst. TAEOSs account for 2-12% of all OSs. TAEOSs mostly develop around knee and proximal humerus, but TAEOSs of the jaws are rare. To the best of my knowledge, this is the fourth case of primary TAEOS affecting the jaws. A 36-year-old female who had been previously diagnosed osteosarcoma by biopsy reported with a chief complaint of throbbing and swelling of the right mandible. The patient received neoadjuvant chemotherapy followed by hemi-mandibulectomy. After surgery, patient received adjuvant chemotherapy. The patient is free of disease for 6 months after surgery. TAEOSs are mimicking other benign entities, such as aneurysmal bone cyst and central giant cell granuloma. Thus, careful diagnosis through thorough radiographic and histopathologic evaluation is important to establish a treatment plan, prognosis, prediction and management strategy.

Sarcomatous transformation of fibrous dysplasia (FD) is rare and can occur in patients with McCune-Albright syndrome (MAS). To date, there have been several cases of malignant transformation of FD in the craniofacial area of patients with MAS. Here, we report an additional case of secondary osteosarcoma arising from FD in the mandible of a 41-year-old woman with MAS. The patient complained of rapid swelling in the right facial area, which was initially misdiagnosed as soft tissue sarcoma at another hospital. After neoadjuvant concurrent chemoradiotherapy resulting in poor response, the lesion was surgically resected in our hospital, and the final diagnosis of secondary osteosarcoma was rendered. Currently, post-operative adjuvant chemotherapy is in progress. As a result of our review of 17 reported cases showing malignant transformation in FD/MAS, the M/F ratio was 1:1.1, and the median age at onset of malignancy was 28.6 years. The most commonly affected site was the craniofacial bones (n=13; 76%), and the most common histopathologic type of malignancy was osteosarcoma (n=14; 82%). More than half of the patients (8/15; 53.3%) died within 1 year, mainly due to lung metastasis (6/8; 75%). Taken together, since MAS patients with malignant transformation of FD have a relatively poor prognosis, accurate diagnosis based on histopathologic findings as well as clinical and radiographic information is important to select optimal treatment.

Intraosseous hemangioma of the jaws is a rare disease as compared to other skeletal and soft tissue hemangiomas. Preoperative differential diagnosis is critical in that severe bleeding can cause both intra and postoperative complications. Surgical excision of the intraosseous hemangioma can be performed with the use of steroid injection or sclerosing agent into the lesion before the surgical approach. However, even with the embolization of the blood vessels before surgical excision, there still exists a risk of massive hemorrhage during the procedure for the larger lesions. In this report, we present a case of which first tentatively diagnosed as ameloblastoma thus the use of sclerosing agents or vascular embolization was not considered before the surgery. Although there was a strong tendency to intraoperative bleeding, delicate hemostasis was achieved with surgicel(Ethicon SARL, Johnson and Johnson, Switzerland), bosmin(Jeil Pharm, Republic of Korea), and electrocautery. The final histopathological examination confirmed an intraosseous hemangioma of the mandible. The patient is undertaken for follow-up period of 1 year and the prognosis is under favorable condition.

Orthokeratienized odontogenic cyst (OOC) is a comparatively unusual developmental odontogenic cyst arising from odontogenic epithelium. Recurrence has rarely been noted, and has been reported in less than 2% of cases. Epidermoid cyst (EDC) is a benign cystic lesion, which is lined by stratified squamous epithelium and includes keratin debris. They can present anywhere in the body but are rare in the head and neck areas. In this report, we present an uncommon case of simultaneous occurrence of OOC in mandible and EDC around the areas of both ears in a patient who has no history of genetic syndrome.

Dentigerous cyst is considered one of the representative cystic lesions, which accounts for approximately 15%-30% of the odontogenic cysts. Although its recurrence rate is low, a small proportion of dentigerous cysts converted into ameloblastomas, squamous cell carcinomas, and mucoepidermoid carcinomas. Here we present an uncommon case characterized by histopathological transformation from a dentigerous cyst to an ameloblastoma, and further investigate the factors contributing to its conversion.

Parosteal osteosarcoma, a subtype of juxtacortical osteosarcoma, has a better prognosis compared to central osteosarcoma with a relatively low risk for recurrence and metastasis. Rarely, it can arise synchronously with other malignant tumors. Synchronous malignancies are defined as the occurrence of a second primary malignancy within 6 months of the appearance of the first malignancy. Here in, we introduce a 64-year-old woman who visited the Department of Oral & Maxillofacial Surgery, Yonsei University Dental Hospital with a 2 year history of a whitish verrucous lesion on the palate. She presented an exophytic mass on mandible during the following visits. Histopathologic evaluation revealed a synchronous parosteal osteosarcoma and squamous cell on right mandible and a precancerous verrucous leukoplakia on the palate.

Mucormycosis is an aggressive opportunistic fungal infection that can be found in the oral cavity. The fungus usually affects the immunocompromised patients and tends to invade and block blood vessels, resulting in significant tissue necrosis and invasive mucormycosis. However, a non-invasive form of mucormycosis is mostly asymptomatic and found accidentally in the immunocompetent normal hosts, manifested by localized overgrowth of the fungus. Here, we report a rare case of asymptomatic non-invasive mucormycosis of the mandible that was incidentally diagnosed in wide resection specimen of liver transplant patient who had previously underwent surgery of excision and simultaneous alloplastic bone graft due to mandibular ameloblastoma. Histopathological examination of the specimen revealed that there was neither vasculitis nor tissue necrosis, but numerous fungal hyphae were located only within the alloplastic graft materials in decalcified tissue sections. Awareness of the possibility of life-threatening mucormycosis in immunocompromised patients should be emphasized because it can be inactive or reactivated depending on the immune state of patients.

Recently, a number of recent reports have reported cases of bone marrow defect (BMD) in the mandible. Among the diseases seen by BMD in radiographs, focal osteoporotic bone marrow defect(FOBMD) is asymptomatic, which is discovered incidentally and localized radiolucency. Because it varies in size, shape, trabeculae and border definition, it needs to biopsy to differential diagnose other intraosseous lesions that show radiological bone marrow defects. This cases report discusses the pre-operation considerations in patients planning to implant the mandible and suspected to have FOBMD in radiographs. The following 4 cases in Dental Hospital of Wonkwang University were taken in panoramic and Cone beam computed tomography(CBCT). In all cases, there were radiolucent lesion diagnosed with FOBMD under radiologic differential diagnosis. In three of cases the implant were placed without treatment plan change and one case changed the treatment plan with removable partial denture. BMD is anatomical state that can affect primary stability of implant fixture. During implant placement, it can lead to unexpected results that fixture is fallen into BMD and the nerve may be damaged after implant fixture removal to cause hyperesthesia. Preoperative diagnosis of these lesions by differential diagnosis with panoramic and CBCT can prevent the complications by changing the treatment plan or paying attention to the manipulation during surgery.

Myelolipoma is a benign tumor consists of mature adipocyte and hematopoietic elements. Mostly, this tumor locates in adrenal gland and it also can be found in extra-adrenal area. However, intraosseous myelolipoma is extremely rare. The etiology of this tumor is unclear but some hypothesis proposed that altered mesenchymal stem cell functioning and hormonal events act together in the pathogenesis of myelolipoma. With radiographic view, myelolipoma shows similar characteristics of other fat-containing tumors. The histopathologic examination is necessary for the definite diagnosis. This case report includes a patient with intraosseous myelolipoma of maxilla and mandible and literature review about the clinical, histopathologic, and radiologic features of myelolipoma.

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive variant of squamous cell carcinoma arising in various anatomical sites. This article describes a case history of BSCC of the floor of mouth with mandibular involvement, and further discusses the appropriate management of such case with reference to the literature review. A 52-year-old male patient was referred to our clinic from another university hospital. Segmental mandibulectomy with supraomohyoid neck dissection and mandible reconstruction with left fibular free flap under general anesthesia was performed, followed by radiotherapy. Histopathological examination on the tumor lesion revealed features of squamous cell carcinoma with comedo-type necrosis. A diagnosis of BSCC was given by the oral pathology specialist. Basaloid squamous cell carcinoma (BSCC) is a biphasic variant of SCC with both basaloid and squamous cell histology. A recent report showed that there is no significant difference in the prognosis. Due to the lack of accumulated research, close follow-up and continuous research are deemed necessary. Treatment that focuses on the stage of the tumor is appropriate. A periodic follow-up observation is also very important due to the occurrence of distant metastasis to the lungs.

Benign fibro-osseous lesions are demonstrated as a group of conditions, which normal bone is replaced by a connective tissue matrix that gradually develops cemento-osseous tissue and include developmental lesion, reactive lesion, dysplasia and tumor. Cemento-osseous dysplasia is one of benign fibro-osseous lesions, which is non-neoplastic process. Histologic features of cemento-osseous dysplasia are admixtures of bone and cementoid materials in a fibrous stroma. Cemento-osseous dysplasia associated with traumatic bone cysts has infrequently been reported. Traumatic bone cyst is a pseudocyst that may befound in both the jaws and the long bones. Though blockage of interstitial fluid drainage orvenous obstruction may be the cause of traumatic bone cyst, the exact pathogenesis of traumatic bone cysts is unknown. Melrose et al. was the first to report association of cemento-osseous dysplasia and traumatic bone cystsin their series. It is assumed that different mechanism is involved in cyst formation in these cases. This report presents review of literature and describes a case of focal cemento-osseous dysplasia associated with traumatic bone cyst of the mandible and its surgical treatment.

Clear cell odontogenic carcinoma (CCOC) is an extremely rare odontogenic neoplasm; Only a few cases have been reported in the English literatures. It displays a propensity for the mandible, most commonly presenting in the fifth to seventh decades, with a female predilection. The clinical and radiological manifestations are multiple and the diagnosis is histological. Histological feature is of large islands and strands of uniform cells with round or ovoid nuclei and clear cytoplasm. Clinically, painless swelling is the most common symptom, followed by pain, teeth mobility, and paresthesia. CCOC has a good prognosis after surgery. This case report presents the histopathological and clinical features of CCOC excised from the mandible.

The case of an intraosseous leiomyoma in a 22-year-old man is presented. The tumor was incidentally discovered during dental radiographic examination for endodontic treatment of mandibular first molar. Radiographic examination revealed a well-defined unilocular radiolucency between the roots of mandibular left canine-first premolar, measuring approximately 1.9 x 1.8 cm and perforation of the buccal cortical plate. Histological and immunohistochemical examination was diagnostic of intraosseous solid leiomyoma. Here, we report a rare case of leiomyoma of the mandible, together with conventional histopathologic and immunohistochemical findings.

Calcifying Epithelial OdontogenicTumor(CEOT), also known as Pindborg tumor is a rare lesion comprising about 1% of all odontogenic tumors mostly rising in the posterior of the mandible. It generally occurs in patients between 30-60 years old. This paper describes a case of CEOT in a 17 year-old female affecting the right mandible. Histopathologic findings showed sheets of polygonal tumor cells and pools of amorphous, eosinophilic amyloids with calcifications. 1 year after resection of the tumor, no clinical and radiographic signs of recurrence were observed.

Myofibroma is a benign tumor composed of fibroblasts and myofibroblasts, occasionally occurring most commonly as a solitary lesion of soft tissue, skin, or bone in children younger than 3 years of age. Solitary lesion of myofibroma is exceedingly rare in adult jaws. This report describes a rare case of myofibroma in the mandible that occurred in a 41-year-old Korean woman.

The mandible character of the Lucanidae is vary by considering of developmental difference in male individual specimen. Especially, species of Genus Cyclommatus Parry, 1862 presents strong mandibular allometry. In this research, The species group which related to Cyclommatus montanellus Möllenkamp, 1904 has been evaluated for the first time in this research with inner teeth composition and positioning to establish clear taxonomic key to each species.

Osteoblastoma(OB) is a rare tumor of bone representing less than 1 % of all tumors of the maxillofacial region. The lesion usually appears in vertebral column, sacrum, long bones but rare in mandible or maxilla. The lesion occurs most commonly at age from 3 to 78 years with the mean age of 22-23 years. In this article, we report one case of OB occurred in mandible. With clinical examination and radiological diagnosis, preliminary diagnosis was made as Fibro-osseous lesion, osteomyelitis or cementoblastoma. Under general anesthesia, associated tooth was extracted and excisional biopsy was done. After microscopic examination, it was diagnosed as OB. The patients which we presented did not complain any specific complications, and showed good prognosis.

Central odontogenic fibroma(COF) is an extremely rare benign tumor that accounts for 0.1% of all odontogenic tumor. COF is regarded by the World Health Organization(WHO) as a benign odontogenic neoplasm derived from mesenchymal odontogenic tissue. The lesion occurs most commonly in the mandible and patients ranging in age from11 to 80years with mean age of 34years. In this article, we report two case of COF. Case I was associated odontoma and impacted tooth. Odontoma and impacted tooth was removal under general anesthesia. After microscopic examination, finally we diagnosis this lesion as COF. Patients of case II showed radiolucent lesion at the mandible. Lesion was enucleated under general anesthesia. After microscopic examination, finally we diagnosis this lesion as COF. The patients which we presented did not complain any specific complications, showed good prognosis.

This study aimed to compare the mandible inferior cortical bone thickness before and after orthognathic surgery on panoramic radiographs. Among 1092 orthognathic surgery patients, 37(12male, 25 female, average age 23.8 yrs± 4.4) were selected who underwent mandible inferior cortex contouring. The total mandible sides which underwent inferior cortex contouring were 62. The mandible inferior cortical bone thickness was measured below the mesial root of the first molar tooth. The mandible inferior cortical bone thickness was 3.49mm± 0.6mm before orthognathis surgery and 1.92 mm± 0.88 mm after surgery, with statistically significant difference between the two(p<.05). The mean contouring amount was 1.57 mm± 0.8 mm. Mandible inferior cortex contouring are often included in orthognathic surgery.