Abstract
Purpose
This study describes the quantitative relations between the intrusion of posterior teeth and changes in overbite and lower anterior facial height after treatment of open bite patients with miniscrew implants and posterior bite plates. The study also assessed changes in masticatory muscular activity that may result from the use of bite plate.
Materials and methods
Fifteen patients (mean age ± SD = 20.6 ± 4) with anterior open bite were treated with two miniscrew implants in each side of posterior maxillary dentoalveolar bone and fixed posterior bite plate. Changes in upper posterior dental height (UPDH), overbite (OB) and lower anterior facial height (LAFH) were measured using cephalographs. Activities of masseter and anterior temporalis muscles during clenching and swallowing were assessed before treatment, after placement of bite plate and after removal of the plate. Linear regressions were used to investigate the relationships between morphologic parameters, and paired t-test was used to test changes in muscular activity.
Results
Linear relationships were found between posterior teeth intrusion and the increase of overbite and reduction in LAFH. Each 1 mm intrusion improves the open bite by 1 mm and the LAFH by 0.7 mm. The muscular activity decreased after placement of the plate but recovered immediately after its removal.
Conclusion
Outcomes after treatment with miniscrew implants and bite plate can be predicted by the amount of intrusion in posterior teeth. The bite plate seems not to affect the muscular activity after removal of the plate.