Differences in Temporomandibular Joint Pain and Age Distribution Between Marrow Edema and Osteonecrosis in the Mandibular Condyle

Abstract

This study investigated the differences of age distribution and temporomandibular joint (TMJ) pain between marrow edema and osteonecrosis in the mandibular condyle. Subjects consisted of 35 TMJs in 35 patients with abnormal bone marrow on MR images who were selected from a consecutive series of 527 patients with TMJ disorders. Proton density and T2-weighted MR images taken in the oblique sagittal and coronal planes were used to diagnose condylar marrow abnormalities and divide them into either edema or osteonecrosis. The differences in TMJ pain and age distribution for these two abnormalities were assessed with the one-sided Wilcoxon rank sum test with 0.05 alpha level.The degree of pain was higher in joints with marrow edema than in joints with osteonecrosis (p=0.033). The mean age was higher in joints with osteonecrosis (p<0.001). Our results suggest that there is more severe pain in TMJs with marrow edema of the mandibular condyle than in those with osteonecrosis. Since the patients with marrow edema have lower age, it also appears that marrow edema may be a precursor condition for osteonecrosis of the TMJ.

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Notes on contributors

Tsukasa Sano

Dr. Tsukasa Sano received his D.D.S. degree from Showa University, Tokyo, Japan in 1987 and his Ph.D. degree from the same university in 1991. He was a visiting assistant professor in the Department of Radiology, University of Rochester Medical Center, Rochester, New York. Currently, he is a professor and chairman of Oral and Maxillofacial Radiology, Tokyo Dental College in Chiba, Japan

Per-Lennart Westesson

Dr. Per-Lennart Westesson is a professor and Director of Neuroradiology, University of Rochester, New York. He has been working on temporomandibular joint imaging since the late 1970s. He developed double contrast arthrography and has contributed scientific articles on imaging and pathophysiology of the joint.

Mika Yamamoto

Dr. Mika Yamamoto received her D.D.S. degree from Nagasaki University, Nagasaki, Japan in 1995 and her Ph.D. degree from Showa University, Tokyo, Japan in 2003. She was a research fellow in the Department of Radiology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston and is an instructor of radiology, Showa University School of Dentistry.

Tomohiro Okano

Dr. Tomohiro Okano received his D.D.S. degree from Tokyo Dental and Medical University, Tokyo, Japan in 1973 and his Ph.D. degree from the same university in 1977. He was a visiting fellow of the National Institutes of Dental Research, Bethesda, Maryland from 1979 to 1981. Currently, Dr. Okano is a professor and chairman of radiology, Showa University School of Dentistry in Tokyo.