Effect of modified twin block appliance used for distoclusion treatment on stomatognathic system

Aim. Study of the effect of modified twin block activator used for distoclusion treatment on stomatognathic system and its improvement.

Methods. 55 patients with skeletal distoclusion were examined. Out of them 28 patients treated orthodontically comprised the study group and 27 non-treated patients were included into the control group. The patients' age was 10-14 years (mean age 11.78±0.91), the duration of treatment was 1.5-2 years (mean duration 1.82±0.43). To avaluate the changes in stomatognathic system, cephalometric analysis was performed before and after treatment, and in the control group cephalometric analysis was performed with a 2-year interval.

Results. During treatment with modified twin block appliance, SNB angle reached norm (80°). This is an important positive result in the treatment of distoclusion. ANB angle reflecting sagittal relationship between the upper and lower jaws and WITS decreased and reached normal size. Overjet normalized due to upper incisors retrusion and repositioning of the mandible forward in patients of the study group. In this group due to changes in soft tissues, in-profile esthetic and harmonious appearance of lips and chin was restored. In case of relative physiological rest the opened lips became closer and provided esthetic optimum of the face.

Conclusion. Use of modified twin block appliance for the treatment of patients with distoclusion due to repositioning of the mandible forward allows improving sagittal relationship between the upper and lower jaws as well as overjet correction without increasing face height; use of modified twin block appliance allows normalizing sagittal occlusion and protrusion of upper incisors and upper lip.