Abstract
To understand the relationship between anterior disc displacement of the temporomandibular joint (TMJ) and condylar guidance inclination, condylar movements during protrusive movement were analyzed in 780utpatients (63 females and 15 males;mean age, 35.4±14.1y) having anteriorly displaced disc confirmed on magnetic resonance images. Thirty outpatients (18 females and 12 males; mean age, 37.8±14.5y) without disc displacement were also enroIled as a control group. Mandibular movement was recorded with a six-degree-of-freedom jaw tracking device, to obtain every 1-mm change in condylar guidance inclination during protrusive movement guided by anterior teeth.
Since inclinations of the condylar path were significantly larger in the disc displaced group (36.7±12.6°) than in the control group (33.1±11.6°)(P<0.05;t-test), steep inclinations of the condylar path could be a contributing factor of anterior disc displacement of the TMJ. However, there was no statistical significance in the inclinations of the condylar path between disc displacement with reduction and without reduction. The results show that condylar guidance inclination has little association with disc reduction status.
