Exostosis of the mandibular coronoid process

Abnormal enlargement of one or both mandibular coronoid processes may lead to a limited mandibular excursion. A case of unilateral coronoid process exostosis severely limiting mandibular function is described. A review of the literature pertinent to this uncommon abnormality is presented. The various entities of coronoid process osteochondroma, osteoma, exostosis, hypertrophy and developmental anomaly, all producing a similar picture of coronoid process enlargement are discussed. The proper use of the available radiographic techniques simplifies the diagnosis of these uncommon maladies, as long as a coronoid process abnormality is considered in the differential diagnosis of restricted mandibular movement.