Evaluation of the effects of the Twin-blok appliance on the temporomandibular joint

The purpose of this study was to predict the effect of Twin-blok functional appliance used by patients with CL II div 1 malocclusion on the dentofacial structures and Temporomandibular joint using SAM Axiograph, SAM MPI and conventional sephalometrics. The study material consisted of lateral sephalograms, hand wrist radiographs, TMJ panoramic radiographs, SAM axiograph and MPI records taken at the beginning of the study the treatment groups skeletal age was 1 1,52 years while the age of the control group was 1 1,91 years. Maximum mouth opening and protrusion movements were recorded using SAM axiograph device for right and left TMJ's separately after the prediction of the centric relation and centric occlusion in the area of TMJ and insizal tooth using MPI: The control group patients were observed for 6 months without any orthodontic or orthopedic treatment. Twin-blok and conquord face bow were used by the treatment group for 6 months. After six months, the records and films were evaluated. In the results the Twin-block system has improved the growth of the lower jaw and inhibited the growth of the upper jaw. The convexity of the face, over jet and overbite has reduced. The retrusion of maxillary incisors and protrusion of123 mandibular incisors was improved. The sella angle, effective length of mandible, lower face, anterior and posterior face, face length were increased. Twin-block system had no effect on the maximum clinical opening. The right protrusion inclination and the mean inclination of the left protrusion of the condyle were decreased. A decrease was observed in the value of Ah and AL.