Evaluation of the effects of modified bonded rapid maxillary expansion on occlusal force distribution: A pilot study.

OBJECTIVE: To evaluate the effects of modified bonded rapid maxillary expansion (RME) on occlusal force distribution. MATERIALS AND METHODS: The sample included 12 patients (7 girls and 5 boys; mean age: 13.1 years) at the permanent dentition stage with bilateral posterior cross-bite. The patients were treated with a modified bonded RME appliance, activated twice a day. The study was terminated when the palatal cusps of the maxillary posterior teeth were occluding with the buccal cusps of the mandibular posterior teeth. The postretention period was 3 months. The T-Scan III device was used to analyze the percentages of occlusal force distribution, and records were taken at the pretreatment (T1), the postreatment (T2), and the postretention (T3) periods. Wilcoxon signed rank test was used for statistical analyses. RESULTS: Incisors were most frequently without contact, followed by canines. The highest forces were seen in the second and first molar regions. A significant decrease was seen in total occlusal force during treatment (T1-T2); however, during retention, the force returned to its initial value, and no significant differences were found (T1-T3). No differences were found between right and left sides and in occlusal forces of the teeth in all time periods. CONCLUSION: The use of modified bonded RME decreases the total occlusal forces during the treatment period, but it does returns to its initial value after the postretention period.

Secular trend in the maturation of permanent teeth in a sample of Turkish children over the past 30 years.

This study was performed to evaluate the influence of secular trends on dental maturation among Turkish children over the past 30 years. Orthopantomograms of 757 (385 boys, 372 girls) Turkish children born in the 1980s, 1990s, and 2000s were evaluated. Three groups were formed based on decade with five subgroups by age from 9 to 13 years old for each gender. The number of samples in each age group and gender were matched. The mandibular left seven permanent teeth were evaluated based on formation stage to determine the overall dental maturity score. The groups were compared based on decade and gender. The Bonferroni-corrected Mann-Whitney U test and Kruskal-Wallis tests were used for statistical evaluation. Among 11-, 12-, and 13-year-olds born in the 2000s, girls exhibited significantly more mature dentition than did boys (p<0.01, p<0.05, and p<0.05, respectively). Twelve-year-old girls born in the 1990s and 2000s exhibited significantly more mature dentition than did girls born in the 1980s (p<0.01). Girls generally exhibited more mature dentition than boys. No significant positive secular trends in dental maturity were observed from the 1980s through the 2000s. Dental maturation among Turkish children was not affected by a secular trend.

Combined fixed-functional treatment of skeletal class II malocclusions with the EVAA appliance: a preliminary study.

OBJECTIVES: The aim of this study was to compare the skeletal and dental effects of the EVAA appliance with those of an activator appliance in growing children with skeletal Class II anomalies. MATERIALS AND METHODS: A total of 34 subjects with Class II anomalies were recruited for this study. They were divided into three groups: the EVAA group (n=13; mean chronological age: 11 years 9 months), activator group (n=13; mean chronological age: 11 years 8 months) and control group (n=8; mean chronological age: 10 years 8 months). Lateral cephalometric radiographs were taken at the beginning and end of functional therapy. Fixed orthodontic treatment was completed in the EVAA group. A statistical software program (SPSS 18) was used for one-way analysis of variance and multiple comparisons with the Duncan test. RESULTS: We observed a significant decrease in the ANB, convexity, and 1┴NA (°), while a significant increase appeared in upper anterior facial height, posterior facial height, 1┴NB (mm), SN-lower occlusal plane values in the EVAA and activator groups after treatment (p<0.05). No significant difference in study parameters in the control group during the treatment period except for the increase in SNA and 1┴NA (mm) values (p<0.05) were observed. There were no significant differences between EVAA and activator treatment groups in terms of study parameters except for the articular angle, which was significantly higher in the EVAA group after therapy (p<0.05). CONCLUSION: The effects of EVAA appliances were similar to those of activator treatment.

Dentoalveolar surgery techniques combined with orthodontic treatment: A literature review.

Surgery on the dentoalveolar process combined with orthodontic treatment was emphasized as an alternative method for reducing the treatment time and improving the orthodontic treatment on post-adolescent and adult patients. This combined treatment facilitates and accelerates orthodontic tooth movement. This article reviews the clinical practice in surgery-assisted orthodontic treatment in relation to historical perspective, indications and biological principles, as well as limitations and risks of dento-osseous surgical techniques, including dento-osseous osteotomy and/or ostectomy, dento-osseous microfracture, dento-osseous corticotomy, and/or corticoectomy, and dental distraction.

Effects of Class II activator and Class II activator high-pull headgear combination on the mandible: a 3-dimensional finite element stress analysis study.

INTRODUCTION: The aim of this study was to evaluate the effects of the Class II activator and the Class II activator high-pull headgear (HG) combination on the mandible with 3-dimensional (3D) finite element stress analysis. METHODS: A 3D finite element model of the mandible was constructed from a dry human mandible. To investigate the effects of the Class II activator, a 3D model of the lower part of this appliance was constructed and fixed on the mandibular model. The Class II activator high-pull headgear model was established as described, and an extraoral traction force of 350 g was directed from the middle of the Class II activator to the top of the mandibular condyle. The stress regions were studied with the finite element method. RESULTS: The regions near the muscle attachment areas were affected the most. The inner part of the coronoid process and the gonial area had the maximum stress values. CONCLUSIONS: Both functional appliances can cause morphologic changes on the mandible by activating the masticatory muscles to change the growth direction.

Changes in the soft tissue profile after extraction orthodontic therapy.

PURPOSE: The purpose of this study was to evaluate the effects of extraction therapy and use or nonuse of headgear on the soft tissue profile in subjects with different growth patterns. METHODS: A total of 41 subjects were included in the study. The patients were treated with standard edgewise mechanics and had 4 first premolars extracted. The type of growth pattern was assessed as mesiodivergent or hyperdivergent. The results were analyzed by 2-way analysis of variance. RESULTS: When comparing the mean changes between growth pattern types, the vertical changes in Sn and A' were found to be statistically significant (P<.05). The vertical change in A' was also found to be significant between the headgear use and nonuse groups (P<.05). Interaction was found to be significant for Steiner upper and lower lip values and the vertical change in A. The upper and lower lips were retracted significantly more by headgear use in patients with hyperdivergent growth pattern (P<.05). CONCLUSIONS: The results of this study indicate that the use of headgear should be avoided in hyperdivergent patients. The avoidance of premolar extraction, based on the possibility of a significant detrimental effect on the facial profile, is not justified.