The shape of the condyle and position of the meniscus in temporomandibular joint dysfunction

The position of the meniscus seems to be significant in the natural history of temporomandibular joint dysfunction. It can be identified on MRI and arthrography but generally its displacement is referred to only in the sagittal plane. Little consideration is given to the shape and size of the condyle which could have great influence upon the position which the meniscus takes up. This paper reports the findings in 105 TM joints which have had arthrotomy for meniscoplasty (meniscopexy) and menisectomy over an 8-year period. Only 30% of the condyles had a normal size and shape; 24% were excavated on the medial side, 15% had lost the anterior surface of the condyle and were oblique in shape, 15% were small and round, while 12.5% were flattened, two having no discernable condyle at all. The meniscus was found to be displaced anteromedially most commonly, with the anterior position, to which reference is so frequently made, being rare; the medial position was more common. The significance of these findings is discussed with particular reference to imaging.