Korean Journal of Oral and Maxillofacial Radiology 2005; 35 : 231-4.English.

The diagnosis of coronoid impingement using computed tomography.

Baik JS, Huh KH,Park KS, Park MS, Heo MS, Lee SS, Choi SC.

*Department of Oral and Maxillofacial Radiology, BK21, and Dental Research Institute, College of Dentistry, Seoul National University **Department of Oral and Maxillofacial Surgery, Sanggye Paik Hospital, College of medicine, Inje University ***Department of Oral and Maxillofacial Radiology, College of Dentistry, Seoul National University Korea.

Coronoid impingement can cause limitation of mouth opening. In many cases, it appears to be related to the
coronoid hyperplasia. We present a case of mouth opening limitation caused by coronoid impingement on the
posterior surface of the zygomatic bone without coronoid hyperplasia. The bony changes in coronoid and zygoma including surface irregularity and discontinuity of the cortex and sclerotic change of inner medullary space were noted on computed tomography (CT) scans in different level of axial planes. Through another CT scans in open mouth position could demonstrate that those bony changes were caused by the contact of both surfaces against each other. In case coronoid impingement is suspected of the many possible causes, the open mouth CT scans will be needed to reveal the direct impingement of coronoid on zygoma even without coronoid hyperplasia. (Korean J Oral Maxillofac Radiol 2005; 35 : 231-4)
KEY WORDS : Coronoid Impingement; Trismus; Tomography Scanners, X-ray Computed