The effect of occlusal disorder on the thickness of temporomandibular joint disc / 实用口腔医学杂志

ABSTRACT

Objectives: To investigate the effects of cent ra l disordered occlusion on the thickness of TMJ disc. Methods:The thickness of temporomandibular joint disc was measured in 5 cadavers with centr al disordered occlusion, including secondary malocclusion caused by loss of post erior tooth for a comparable long time with collapse of neighbor teeth and supra -eruption of its antagonized tooth, the supra-erupted third molar resulted fro m lack of antagonized tooth for a comparable long time and individual posterior tooth cross bite or reverse cross bite asymmetrically. Other 7 cadavers without central disordered occlusion served as controls. All samples were examined histo logically for the TMJ disc thickness. Out of 18 New Zealand rabbits, aged 5 mont hs, 9 were treated orthodontically to pull the first premolar move medially, occ luding with its opposite un-coincidently, central disordered occlusion was grad ually induced. The other 9 rabbits served as blank controls. The TMJs were sampl ed 3 months after beginning of the experiments, stained with HE and observed und er microscope. Results: In both cadavers and animals, the TMJ di sc was found much thicker in central disordered occlusion group than that in the control group (P