Endoscopically assisted removal of unilateral coronoid process hyperplasia.

Coronoid process hyperplasia (CPH) is an uncommon disorder characterized by an enlarged coronoid process impinging against the posterior aspect of the zygomatic arch. Young male adults are usually affected, presenting with limited mouth opening, which is typically painless and progressive in nature. The diagnosis of true CPH is established by the findings of (1) uniform coronoid enlargement on radiographic examination and (2) normal bone structure on histopathological examination (i.e., the specimen should be free of any neoplastic growth, such as the previously reported cases of coronoid osteomas, osteochondromas, or exostoses). The treatment is mainly surgical, by means of a coronoidectomy. An intraoral approach is mostly preferred for this procedure to avoid an external scar. However, to avoid the drawbacks of this approach, such as limited exposure and the risk of hematoma and subsequent fibrosis, an extraoral approach may be indicated. This report describes a case of true unilateral CPH in a 17-year-old boy who presented with progressive limited mouth opening in the absence of any pain. Computed tomography (CT) demonstrated a uniformly enlarged right coronoid process. A coronoidectomy was performed with the aid of endoscopic systems, approaching via two short incisions in the temporal scalp. Histopathological examination of the specimen demonstrated essentially a normal bony structure with no evidence of a neoplasm. The authors present the endoscopically assisted technique of coronoid process excision as an alternative method of surgical treatment of CPH and any mass of the coronoid process in general. With this method, the incision is much shorter than a conventional coronal incision and thus morbidity is diminished considerably.