Giant Osteoma of Zygoma Mimicking Pseudo-Temporo-Mandibular Joint Ankylosis: A Case Report.

Giant osteoma is a rare entity in the head and neck region when compared to long bones. Even in the head and neck region, the paranasal sinuses are commonly associated, but the involvement of jaw bones is very rare. The lesions are usually asymptomatic and so remain undiagnosed for years. In the reported case, the distinct presentation with reduced mouth opening made it more confusing to diagnose as it became somewhat similar to symptoms of temporo-mandibular joint disorder. The involvement of the zygomatic bone with its extension into the mandibular ramus region made it more unique in its presentation. The objective of the current article is to present an unusual case of giant osteoma of zygoma causing reduced mouth opening, misdiagnosed as a true intra-articular temporo-mandibular joint ankylosis previously. This was then diagnosed correctly with help of a computed tomography scan and histopathology and treated with surgical excision.