A cephalometric comparison between Angle Class II, division 2 malocclusion and normal occlusion in adults

The lateral cephalometric radiographs of 56 adults with Angle Class II/2 malocclusion and of 81 persons with normal Class I occlusion are compared. The statistical analysis includes the calculation of the mean value, standard deviation and the determination of differences (Wilcoxon rank-test). Group characteristics are tested by stepwise discriminant analysis. The following statements regarding Angle Class II/2 as compared with normal Class I result from this study. The upper incisors are in a retruded position. The B-point is significantly retropositioned, whereas the pogonion is in a more normal position. The length of the mandibular corpus and the total length of the mandible are slightly diminished only. Normal values result for the size and position of the maxilla, the inclination of the mandibular corpus (angle between mandibular plane and NSe) and the gonion angle.     

A nonsurgical approach to treatment of high-angle Class II malocclusion

Malocclusions with a hyperdivergent vertical facial pattern are often difficult to treat without a combined surgical/orthodontic approach. The aim of this article is to describe a nonsurgical approach to the treatment of a high-angle Class II malocclusion in a growing patient. Some fundamental aspects, such as correct diagnosis, treatment timing, favorable mandibular growth pattern, and patient compliance, proved to be critical to correct the severe dentoskeletal disharmony.     

安氏II1与安氏II2错牙合下颌骨生长旋转的研究

目的：探讨安氏II类1分类及2分类不同CVM分期下颌骨旋转的差异。方法：安氏II类1分类422例（男197例,女225例）,2分类241例（男91例,女150例）,拍摄初诊头颅侧位片,按颈椎CVM分期及性别进行分组,测量下颌真性旋转角（SN－XiPm）、下颌平面角（SN－GoGn）、牙合平面角（SN－OP）,后前面高比（S－Go／N－Me（%））,通过SPSS16．0软件分析比较二者的生长发育差异。结果：安氏II类1分类与2分类男性下颌真性旋转的趋势相同;女性在各CVM分期呈相反的变化,男性安氏II类1分类下颌平面角较2分类者大1．58°~3．51°,在CS4期（P=0．021）,CS5期（P=0．04）差异均有统计学意义;女性在CS1－CS2期,安氏II类1分类下牙合平面角平均减小3．09°,之后有所增加,但变化较小;2分类下牙合平面角CS2－CS3期平均减小2．51°,在CS3－CS4期增加约2．68°,其余各期变化不明显。男性安氏II类1分类牙合平面角较2分类者小,在CS5期差异有统计学意义;女性安氏II类1分类的牙合平面角在CS1－CS6期逐渐减小,2分类牙合平面角在CS1－CS2期大幅增加,在CS2－CS3期又逐渐减小,之后变化幅度较小,CS5,CS6期安氏II类1分类与2分类的差异有统计学意义。结论：安氏II类1分类与2分类男性下颌真性旋转方向相同,女性则相反．与安氏II类2分类相比,安氏II类1分类OP－SN角较小,GoGn－SN角较大,性别间无差异。     

Three-dimensional dynamic evaluation of a posed smile in normal occlusion and Class II malocclusion

PurposeThe purpose of this study was to quantify the three-dimensional movements of the lips during a posed smile and to verify the differences in the dynamic characteristics among normal occlusion and Class II malocclusion.Materials and methodsThe subjects included 30 healthy female volunteers with normal occlusion, 23 healthy female volunteers with dentoalveolar Class II malocclusion, and 20 adult female patients with skeletal Class II malocclusion. The three-dimensional measurements of the lips during a posed smile were generated using video-based tracking with three high-speed cameras. Eight landmarks on the lips were used to track lip movement. The Scheffé method of multiple comparisons was used to identify significant differences among the normal occlusion and both Class II groups.ResultsThe lower lip point moved significantly faster and farther backward in the skeletal Class II group compared with the other groups. The upper quarter point in the skeletal Class II group in the posed smile was significantly more medial than in the other groups. The vertical movements of the cheilion point of the normal occlusion group were faster than those in the other groups.ConclusionThree-dimensional dynamic evaluation of posed smiles showed significant differences in the characteristics of lip movement between the normal occlusion and Class II subjects.     

A comparison of arch widths in adults with normal occlusion and adults with class II, Division 1 malocclusion

This study compares arch widths and other cast and cephalometric measurements of 36 normal-occlusion subjects (19 males, 17 females) with 39 Class II, Division 1 subjects (20 males, 19 females). None of the subjects had received orthodontic treatment. Analysis of variance demonstrated that subjects with normal occlusion had larger maxillary molar widths, maxillary canine widths, and maxillary alveolar widths than subjects with malocclusion; only male subjects with normal occlusion had larger mandibular molar widths and mandibular alveolar widths than the malocclusion subjects; the normal occlusion and malocclusion groups had similar mandibular canine widths; and when the lower molar and alveolar widths were subtracted from corresponding upper widths, the remainders of the Class II group were negative instead of positive, contrary to the normal group. This revealed a posterior crossbite tendency in the Class II group.     

Signs of temporomandibular disorders in girls receiving orthodontic treatment. A prospective and longitudinal comparison with untreated Class II malocclusions and normal occlusion subjects

The aim of this investigation was to prospectively and longitudinally study signs of temporomandibular disorders (TMD) and occlusal changes in girls with Class II malocclusion receiving orthodontic treatment and to compare them with subjects with untreated Class II malocclusions and with normal occlusion subjects. Three groups of age-matched adolescent girls were examined for clinical signs of TMD and re-examined 2 years later. Sixty-five Class II subjects received orthodontic fixed straight-wire appliance treatment (Orthodontic group), 58 subjects were orthodontically untreated (Class II group), and 60 subjects had a normal occlusion (Normal group). In the Orthodontic group, the prevalence of muscular signs of TMD was significantly less common post-treatment. The Class II and the Normal groups showed minor changes during the 2-year period. Temporomandibular joint clicking increased in all three groups over the 2 years, but was less common in the Normal group. The Normal group also had a lower overall prevalence of signs of TMD than the Orthodontic and the Class II groups at both registrations. Functional occlusal interferences decreased in the Orthodontic group, but remained the same in the other groups over the 2 years. In conclusion, orthodontic treatment did not increase the risk for or worsen pretreatment signs of TMD. On the contrary, subjects with Class II malocclusions and signs of TMD of muscular origin seemed to benefit functionally from orthodontic treatment in a 2-year perspective. The Normal group had a lower prevalence of signs of TMD than the Orthodontic and the untreated Class II groups.     

Adult versus adolescent Class II correction: A comparison

The interest of the adult patient in orthodontics has increased as the demographics of the specialty of orthodontics has changed. There are major intreatment and posttreatment differences in Class II malocclusion correction between the adolescent and the adult. This article outlines the differences—and the similarities—between adolescent and adult Class II malocclusion correction. The differences and similarities are illustrated with case reports of a representative adolescent from the adolescent group and a representative adult from the adult group. (AM J ORTHOD DENTOFAC ORTHOP 1995;107:651-61.)     

Mandibular changes in persons with untreated and treated Class II Division 1 malocclusion

The growth potential of individuals with Class II malocclusions is of interest to the practicing orthodontist because such malocclusions constitute a significant percentage of cases. The purpose of this study was to evaluate on cross-sectional and longitudinal bases the changes in mandibular length and relationship and maxillary-mandibular relationships in untreated Class II subjects from deciduous to permanent dentition and also to evaluate the effects of orthodontic treatment, with and without the extraction of first premolars, on these relationships. Class II samples were compared with matched normal, untreated individuals. The Class II Division 1 (Class II/1) untreated sample comprised 30 subjects, 15 males and 15 females. Each subject had a complete set of data at three stages of dental development—namely, Stage I, after the completion of eruption of the deciduous dentition; Stage II, at the time when the permanent first molars and most of the incisors have erupted (i.e., in mixed dentition); and Stage III, at the completion of eruption of the permanent dentition, excluding third molars. The Class II treated sample comprised 44 subjects (21 males, 23 females) treated with four first-premolar extractions and 47 subjects (20 males, 27 females) treated without extraction. Treatment was accomplished with the use of an edgewise appliance, appropriate extraoral traction, and Class II elastics. The extraction decision was based mainly on the presence of crowding and profile consideration. Records on 35 normal subjects (20 males, 15 females) were available from the Iowa Longitudinal Facial Growth Study. Cephalograms for the normal individuals were matched to the corresponding ages of the Class II cases. With regard to these findings, few consistent differences were noted between the untreated Class II/1 and normal subjects on cross-sectional comparisons. The differences in mandibular length and position were more evident in the early stages of development than at later stages. Longitudinal comparisons of growth profiles indicated that the growth trends were essentially similar between the untreated Class II/1 and normal subjects in the various parameters compared. The comparisons of growth magnitude indicated the presence of greater skeletal facial convexity in the untreated Class II/1 subjects, accompanied by a tendency for a more retruded mandible. Initial comparisons between the Class II/1 treated groups and normal subjects indicated that the Class II/1 malocclusions were associated with a larger overjet, deeper overbite, and greater ANB angle. After a 5-year treatment and observation period, an overall “normalization” in the mandibular and maxillary-mandibular skeletal relationships was noted in the treated Class II/1 subjects in both the extraction and the nonextraction groups compared with normal subjects. The changes were more pronounced in the extraction group.(Am J Orthod Dentofacial Orthop 1998;113:661-73)