Evaluation of the effects of maxillary incisor intrusion on dentofacial structures and masticatory muscle in patients with deep bite

The aim of this study was to determine the effects of maxillary incisor intrusion achieved with fixed mechanics on dentofacial structures and masticatory muscles in young adults with morphological deepbite. 26 patients with skeletal Class 2 or 1, Angle Class II,1,2 or Class I, optimum or low mandibular plane angle, increased overbite were included in the study.TMA utility intrusion arches were applied to both groups. 1.group included 14 patients with the mean chronological ages of 18.78 years. 2 mini-implants applied on right and left maxillary posterior regions as anchorage in the 2.group which included 12 patients with the mean chronological ages of 18.65 years. Mean treatment time was 11.68±3.37 months for 1.group and 10.5±3 months for the 2.group.The results were analyzed with parametric and nonparametric tests.Significant intrusion of upper incisors and decrease in overbite obtained in both groups were similar. Protrusion and inclination increase of upper incisors was found in both groups. Significant increases in overjet and maxillary molar vertical position obtained in 1.group.Significant decrease in the electrical activity of right DA during rest position was found in the 1.group. Significant increase in the electrical activity of right MM during `?chewing gum on the right side?? was found in 2.group. Positive correlation was found between the change in electrical activity of right MM and the change in distance between upper first molar and CT plane.It was observed that deepbite correction with utility intrusion arch causes dentofacial changes but has mild effect on the masticatory muscles.