مرکز منطقه ای اطلاع رساني علوم و فناوري - Long term evaluation of class 2 activator therapy on lip posture and incisor position

Abstract :

OBJECTIVE: The aim of this study was to evaluate the long term effects of Class 2 activator therapy on the position of incisors and the lips. MATERIALS AND METHOD: Lateral cepholmetric radiographs of patients (8 males, 8 females; mean chronological age 11.36±0.77 years) who were skeletally Class 2 with mandibular retrognathia and received activator therapy were included in this retrospective study. Linear and angular measurements were made at the beginning of treatment (T1), at the end of active treatment (T2) and at the end of retention period. Mean treatment time (T2-T1) was 11.00±3.38 months, and mean retention period (T3-T2) was 1.98±0.93 years. Patients who used the same appliance in the retention period were included in the study. The difference between groups was analyzed with One Way ANOVA and Tukey tests; p 0.05 was assigned as statistically significant. RESULTS: There was no statistically significant difference between the mean values of measurements at T1-T2 and T2-T3 periods. When T1-T3 were analyzed, the ANB˚ decreased (p 0.05); the effective length of the mandible increased (Co-Gn; p 0.01), lower incisors protruded (NB-L1; p 0.05) and the thickness of the lower lip increased (LLB; p 0.05) at T3 compared to T1. CONCLUSION: With the activator therapy, sagittal maxillomandibular relationship enhanced, the effective mandibular length and lower lip thickness increased and lower incisors protruded and the effects were more pronounced in the retention period. Therefore, in order to analyze the real effects of functional therapies, evaluation of the retention period is crucial.