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OBJECTIVE@#To evaluate the effectiveness of the Frog appliance in three dimensions by using cone-beam computed tomography (CBCT) images.@*METHODS@#Forty patients (21 boys and 19 girls), averaged 11.7 years old, with an Angle Class II division 1 malocclusion were included in our study. They had either late mixed dentition or early permanent dentition, and the maxillary second molars had not yet erupted. All patients underwent CBCT before and after the treatment for measuring changes in the maxillary first molars, second premolars, central incisors, and profile. Paired-samples t-test was used to compare the mean difference in each variable before treatment and after the first phase of treatment.@*RESULTS@#The maxillary first molars were effectively distalized by 4.25 mm (p < 0.001) and 3.53 mm (p < 0.05) in the dental crown and root apex, respectively. The tipping increased by 2.25°, but the difference was not significant. Moreover the teeth moved buccally by 0.84 mm (p < 0.05) and 2.87 mm (p < 0.01) in the mesiobuccal and distobuccal cusps, respectively, whereas no significant changes occurred in the root apex. Regarding the anchorage parts, the angle of the maxillary central incisor's long axis to the sella-nasion plane increased by 2.76° (p < 0.05) and the distance from the upper lip to the esthetic plane decreased by 0.52 mm (p = 0.01).@*CONCLUSIONS@#The Frog appliance effectively distalized the maxillary molars with an acceptable degree of tipping, distobuccal rotation, and buccal crown torque, with only slight anchorage loss. Furthermore, CBCT image demonstrated that it is a simple and reliable method for three-dimensional analysis.
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Objective:To evaluate the effects of Sander Ⅱ appliance in the orthodontic treatment of adolescent ClassⅡmalocclusion. Methods:15 cases (6 male and 9 female)of adolescent ClassⅡ malocclusion with mandibular retrution were treated with Sander Ⅱappliance.Pre-treatment and post-treatment Lateral cephalogram measurements were traced and analyzed in terms of 28 indicators. SPSS 19.0 software package was used for paired t test.Results:After treatment,15 patients achieved remarkable improvement in the maxillofacial profile and normal overjet of teeth.The cephalometric analysis showed that ANB,OJ,H°and U1-E decreased(P <0. 05),SNB,B-OLP,Pg-OLP(mm),Ii-OLP,Ms-OLP(mm),Mi-OLP(mm),N-Me,ANS-Me,S-Go,Go-Gn,N'-Pg'/FH,Cm-Sn-Ls and Pg-Pg'increased(P <0.05).There was no significant change in SN-MP,SN-OL and Y-axis before and after treatment. Conclusion:Sander Ⅱ appliance is effective in the treatment of adolescent early Class Ⅱmalocclusion.
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Objective To evaluate the characteristics of brachyfacial types in adolescents with class Ⅱ~1 division 1 malocclusions by comparing with normal patterns.Methods 32 parameters were evaluated in pretreatment lateral cephalograms of 60 brachyfacial type adolescents,including 30 boys and 30 girls,aged from 11 to 13 years,with class Ⅱ~1 division 1 malocclusions(distal moral relationship,ANB＞5°,Go-Gn-SN＞28°).Results There was a remarkable increase in SNA,ANB,upper incisor inclination (U1-NA),U1-L1/N-Me and Me-L1/N-Me,so was lip protrusion of soft tissue facial profile(NB-Pg'-Ls);the lower sulcus depth(Si-Pg'-Ls)and the lower lip thickness(Li-L1).Mandibular plane(Go-Gn-SN),OP-MP,OP-FH,U1-L1,anterior lower facial height(ANS-Me),anterior lower facial height/anterior facial height(ANS-Me/N-Me),anterior lower facial height/posterior lower facial height (ALFH/PLFH)and mandibular length(B'-J')were significantly decreased.Conslusions Brachyfacial type in adolescents with class Ⅱ'division 1 malocclusions is characterized by decreased anterior lower facial height,increased posterior lower facial height,clockwise rotation of the palatal plane,anticlockwise rotation of the occlusion plane and mandibular plane,deepen overbite,soft tissue protrusive profiles with upper lip protrusion,crimpled lower lip and retracted chin.
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0.05). The cutaneous part occupied 2/3 of the entire upper lip height and the vermilion 1/3.The cutaneous part occupied more than 1/3 of the entire lower lip height.The chin occupied more than 60 percent of the entire mandibular height. Conclusion: The results of the study are consistent with the date of Farkas.