MANDIBULAR HEIGHT ASYMMETRY FOLLOWING EXPERIMENTALLY-INDUCED TEMPOROMANDIBULAR-JOINT DISK DISPLACEMENT IN RABBITS

Objective. The purpose of this study was to test the hypothesis that n onreducing disk displacement of the temporomandibular joint causes man dibular asymmetry Study design. Unilateral anterior temporomandibular joint disk displacement with intact posterior disk attachment was surg ically created in the right joints of seven growing rabbits. In each o f seven sham animals, the right temporomandibular joint was surgically opened without any disk manipulation. Seven animals served as referen ces. For identification of ramal growth and inferior growth at the man dibular base, tantalum implants were inserted into the mandibular body . Lateral cephalograms were exposed repeatedly throughout the 3-month investigation period. Kruskal-Wallis one-way analysis of variance was used to compare the groups. Results. Compared with the sham and refere nce groups, the experimental group exhibited a deviant growth pattern, with inferiorly directed growth along the mandibular base and in the genial area. The ramal height was significantly shorter on the side wi th disk displacement. No significant Side difference was present in th e sham and reference groups. Conclusions. Disk displacement can cause mandibular asymmetry in growing rabbits, including shortening of the m andibular ramus and excessive inferiorly directed bone growth along th e lower border of the mandible.