Effect of Twin-block appliance on condylar process location during mandible forward positioning: Quantitative measurements / 中国组织工程研究

ABSTRACT

BACKGROUND:Using Twin-block appliance to treat mandibular retrusion,the mandible position changes greatly.The influence of this change on temporomadibular joint and the effect of Twin-block appliance on condylar growth remain unclear.OBJECTIVE:To observe the effect of Twin-block appliance on condylar process location during mandible forward positioning.PARTICIPANTS:A total of 20 patients with mandible retraction (Angel Ⅱ) malocclusion were selected from Department of Stomatology,First Sanatorium of Qingdao,Jinan Military Area Command of Chinese PLA,comprising 13 males and 7 females,aged 10.8 years (range 9-13 years).All patients were treated with Twin-block appliance.Four median joint pantomograms were taken before treatment,1 week after treatment,1 week and 1 year after treatment finish to measure the condylar process location.RESULTS AND CONCLUSION:In all cases,neutroclusion were obtained.No clicking,pain or other temporomadibular joint symptoms were observed.The condylar process position altered significantly.The anterior space distance was decreased,the superior space distance was increased,and posterior space was enlarged (P<0.05-0.01),i.e.condylar process moved downward and forward.The condylar process position was consistent with preoperative,and joint superior,anterior and posterior space distributed balancedly.Twin-block appliance could restore normal and harmonious process-fossa relationship through growth remodeling,but maintenance is necessary till the remodeling accomplish.