Coronoid Hyperplasia

髁突增生或者bifid condyle临床遇到过，但是喙突（冠状突）增生还没有遇到过。

Coronal cone beam computed tomography and three-dimensional reconstruction showing elongation of the coronoid processes. (from Color Atlas of Oral and Maxillofacial Diseases)

Hyperplasia of the coronoid process of the mandible is an uncommon bony anomaly that limits the ability to open the mouth. As the jaw translates forward when the patient tries to open the mouth, the elongated coronoid process impinges on the body or arch of the zygomatic bone. Coronoid hyperplasia is diagnosed most frequently in teenagers, although some examples have been documented in newborns and older adults. The mean age at diagnosis is 23 to 25 years of age. Bilateral cases are four to five times more common than unilateral examples. Coronoid hyperplasia also is three to five times more common in males than in females, which suggests that there could be an endocrine influence. Heredity also may play a role because cases have been noted in siblings.
Bilateral coronoid hyperplasia presents with a progressively worsening ability to open the mouth, which typically develops over a period of several years. In unilateral examples, the mandible may deviate toward the affected side. Radiographic examination will reveal elongation of the coronoid process(es), which is often best demonstrated on CT imaging. Treatment consists of coronoidectomy or coronoidotomy, which usually is accomplished via an intraoral approach. Postoperative physiotherapy plays an important role in trying to preserve the increased oral opening.