OBJECTIVE: To evaluate and compare the treatment effect of Reverse Twin-Block (RTB) and Reverse Pull Face Mask (RPFM) on Pharyngeal Airway Space (PAS) in early and late mixed dentition Class III samples.
METHODS: Ninety-five mixed dentition Malay children with Class III malocclusion were included in this study. Data consists of 190 pre- and post-treatment lateral cephalograms of early (8-9 years) and late (10-11 years) mixed dentition Class III samples. forty-nine samples were under RTB and forty-six samples were under RPFM. Treatment changes were evaluated by McNamara airway analysis and changes in tongue and hyoid bone position.
RESULTS: Both upper and lower pharyngeal airway width were increased after treatment with RTB and RPFM ruling out the chance of airway constriction. There was also posterior positioning of the tongue and hyoid bone indicating mandibular retrusion. No significant treatment changes were found on the Pharyngeal Airway Space by the factor age, gender or type of appliance.
CONCLUSIONS: Both RTB and RPFM increased the Pharyngeal Airway Space and produced similar treatment effect. As age does not affect the treatment outcome significantly, treatment can be delayed until late mixed dentition stage.
METHODS: Data consisted of pre- and post-treatment lateral cephalograms of 95 children, 49 patients with RTB and 46 patients with RPFM, divided into an early (8-9 year) and late (10-11 year) group. Treatment changes were assessed by the Ricketts analysis using CASSOS software, where 71 anatomic landmarks were identified in each cephalogram. Paired and independent t tests were performed for statistical comparison.
RESULTS: Paired t test revealed significant changes in facial axis, facial angle, MD plane to FH, lower facial height, mandibular arc, maxillary convexity, U1 to APog, L1 to APog, L1 to APog angle and upper lip to E-plane measurements in RPFM, whereas significant changes were found in facial taper, U1 to APog and lower lip to E-plane values with RTB in the early treatment group. Independent t test revealed significant changes in U1 to APog, L1 to APog and U6 to PtV values in the RTB group. Post-treatment comparison of RTB and RPFM showed significant differences in L1 to APog and L1 to APog angle values.
CONCLUSIONS: RPFM revealed more favourable craniofacial changes than RTB, particularly in the late mixed dentition stage.
STUDY DESIGN: Observational, cross-sectional study.
PLACE AND DURATION OF STUDY: Orthodontic Department of Baqai Medical University, Karachi, Pakistan, from August to October 2013.
METHODOLOGY: Atotal of 209 pre-treatment lateral cephalometric radiographs of orthodontic patients were selected from departmental records, comprised of 92 males and 117 females. Radiographs were traced for measurements of ANB, Wits appraisal, Beta-angle, W-angle and Yen-angle. Patients were categorized into skeletal classes I, II, and III on the basis of performed measurements, incisor classification, and profile recorded from their records. Descriptive analysis was used to obtain median interquartile range in both the genders and Mann-Whitney U-test was used to observe gender dimorphism.
RESULTS: Skeletal class II was the most prevalent type of malocclusion. There were no difference in the obtained measurements between males and females except the Wits appraisal and Beta-angle in class II patients, which showed significant difference in values (p < 0.05).
CONCLUSION: Pakistani population has no significant different difference in the craniofacial morphology of males and females, with the exception of Wits-appraisal and Beta-angle in class II cases.
METHODS: An electronic search was conducted using PubMed, Embase and Google Scholar search engines, to retrieve data on malocclusion prevalence for both mixed and permanent dentitions, up to December 2016.
RESULTS: Out of 2,977 retrieved studies, 53 were included. In permanent dentition, the global distributions of Class I, Class II, and Class III malocclusion were 74.7% [31 - 97%], 19.56% [2 - 63%] and 5.93% [1 - 20%], respectively. In mixed dentition, the distributions of these malocclusions were 73% [40 - 96%], 23% [2 - 58%] and 4% [0.7 - 13%]. Regarding vertical malocclusions, the observed deep overbite and open bite were 21.98% and 4.93%, respectively. Posterior crossbite affected 9.39% of the sample. Africans showed the highest prevalence of Class I and open bite in permanent dentition (89% and 8%, respectively), and in mixed dentition (93% and 10%, respectively), while Caucasians showed the highest prevalence of Class II in permanent dentition (23%) and mixed dentition (26%). Class III malocclusion in mixed dentition was highly prevalent among Mongoloids.
CONCLUSION: Worldwide, in mixed and permanent dentitions, Angle Class I malocclusion is more prevalent than Class II, specifically among Africans; the least prevalent was Class III, although higher among Mongoloids in mixed dentition. In vertical dimension, open bite was highest among Mongoloids in mixed dentition. Posterior crossbite was more prevalent in permanent dentition in Europe.