OBJECTIVETo discuss the diagnosis and treatment of condylar resorption of unknown reason.

METHODSThe clinical data including the records of history, physical examination, radiography and laboratory of ten patients were studied. Ten patients consisted of 8 females and 2 males (mean age 24.1 years, range 19-31 years) had common clinical features including anterior open bite, posterior occlusal prematurities and Class II malocclusion. Images demonstrated a small and short condyle with abnormal shape, usually accompanied by the developmental insufficiency of the ramus and condyle. The condylar, even the ramus, showed the black marrow signal on MRI images. Four patients were treated by condylar reconstruction with costochondral graft after condylectomy under the supervision of endoscope. Two patients were treated by reduction and repair of disk. Four patients didn't accept any treatment.

RESULTSFour patients treated by condylar reconstruction with costochondral graft showed structures with the size and shape morphologically similar to normal joint and achieved a stable occlusion after follow-up of 6-18 months. Two patients treated by reduction and repair of disk didn't show significant change of open bite and remodeling of condyle after follow-up of 4-6 months.

CONCLUSIONThe diagnosis of condylar resorption of unknown reason can be achieved based on the physical examination and radiographical images. The condylar reconstruction with costochondral graft after condylectomy is feasible.