The value of three-dimensional computed tomography in diagnosis and management of Jacob's disease.

This study reports a case of Jacob's disease characterized with limited mouth opening due to bilateral coronoid hyperplasia forming pseudojoints with zygomatic arches. Magnetic resonance (MR) examination of temporomandibular joint (TMJ) is usually the imaging method chosen in patients with such symptoms. However, the coronoid processes can not be displayed because they are not included in field of view in MR imaging of TMJ. For that reason, these patients may be treated for a misdiagnosis of TMJ disorders. In this study, the aetiology and diagnostic methods of Jacob's disease, the pre-operative/post-operative role of three-dimensional computed tomography and some measurements used in diagnosis were evaluated.