Orthokeratinized odontogenic cyst (OOC) is a relatively rare odontogenic cyst, distinct from odontogenic keratocyst (OKC). In the 4th edition of WHO Classification of Head and Neck Tumors (2017), OOC has been included as a separate entity in the category of developmental odontogenic cysts. It presents as a unilocular radiolucent lesion in the posterior mandible and is frequently related to impacted teeth, thus mimicking dentigerous cyst. Due to low local aggressiveness and no association with nevoid basal cell carcinoma syndrome, it does not show tendency to recur. When compared to OKC, OOC exhibits substantial number of differences with respect to clinical, pathological and behavioral features and treatment modalities. Hence, recognizing OOC as unique lesion is mandatory to avoid unnecessary overtreatment. This paper aims to report a rare case of OOC associated with impacted tooth, showing calcifications and emphasizes its differences from OKC. Furthermore, the recent concepts about OKC and OOC are discussed.

Peripheral odontogenic myxoma is a rare odontogenic tumor representing an extra osseous counterpart of central odontogenic myxoma. It is commonly seen in gingiva between the 3rd and 4th decades of life and appears predominantly in females. Compared to central odontogenic myxoma, it is a less aggressive, slow-growing lesion with a low recurrence rate. However, close postoperative follow-up is required because of the unlimited growth potential of incompletely removed lesions. It shares many features with other soft tissue myxoid proliferations occurring in the oral cavity and hence needs to be differentiated from them. Very few cases of peripheral odontogenic myxomas have been reported and, to the best of our knowledge, no case has been reported in a pediatric patient. We present an unusual case of peripheral odontogenic myxoma occurring in a 12-year-old girl located in the anterior mandibular gingiva, with an emphasis on differential diagnosis.

Human actinomycosis is a rare soft tissue infection caused by Gram-positive, anaerobic bacteria Actinomyces israelii, a commensal of the oral cavity. The major clinical forms of actinomycosis are cervicofacial, thoracic, abdominal and pelvic forms. The cervicofacial region is most commonly affected. Actinomycosis is sometimes difficult to diagnose and it should be borne in mind in the differential diagnosis of numerous infectious and non-infectious diseases. We report a patient who came with tooth pain and extra-oral swelling which later on presented as multiple draining sinuses. Our initial suspicion was dento-alveolar abscess or osteomyelitis. However, a culture of the discharge and subsequent biopsy revealed actinomycetes, confirming cervicofacial actinomycosis, but presenting itself not as the typical 'lumpy jaw'. The patient was successfully treated conservatively with a short but intensive antibiotic course.

Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic malignancy with a female predilection, typically presenting as swelling in anterior region of mandible. CCOC was classified as a malignant neoplasm of odontogenic origin by the WHO in 2005 as it exhibits an aggressive growth pattern, local recurrence, and tendency of distant metastasis. Histologically, CCOC is characterized by sheets and islands of vacuolated/clear cells. Since clear cells are present in few odontogenic tumors, salivary gland neoplasms, and metastatic tumors to the jaws; presence of clear cells in a lesion of head and neck area poses a diagnostic challenge. Knowledge about the clinical course, histopathologic pattern, and immunoprofile of CCOC aids in differentiating it from other clear cell tumors. Herein, we present a case of CCOC in anterior mandibular region of 60-year-old female patient with an emphasis on its differential diagnosis from other clear cell lesions of the jaws.

No abstract