Abstract
The temporalis muscle in man is a broad radiating muscle situated in the temporal fossa. This muscle has a complex morphology and is composed of main portion and some additional bundles. Rarely, aberrant muscle bundles are also observed directly beneath the fan-shaped main part of the temporalis. These muscle bundles were studied extensively in comparative anatomy for many years, but become a new topic in the clinical anatomy with the recent advances in the modern imaging procedures and plastic reconstruction in the maxillo-facial region. An intriguing case of unusual muscle was observed in the lateral surface of the skull of a male cadaver at a routine anatomical dissection. The aberrant muscle was composed of two well-defined portions: superior and inferior. The superior portion extended from the temporalis muscle superficially and inserted into the internal surface of the zygomatic arch. The inferior portion originated from the zygomatic arch and inserted onto the lateral surface of the coronoid processus of the mandible. The reported muscle is probably a result of an abnormal division of the masticatory muscles anlage and may have clinical significance in diagnostics and surgery.