Early developmental traits in Class II malocclusion

The occlusal traits of Class II occlusion in the deciduous dentition include distal terminal plane of the second deciduous molars, distal canine relation, large overjet, and large overbite. Other findings are narrow upper dental arch and maxillary base and poor anterior spacing. Skeletally, Class II children differ less from normal children. The cranial base, including the base flexure, and the maxilla are normal. The mandibular corpus and lower facial height are short, the gonial angle is large, and the dentoalveolar position of the mandible is retruded. The height of the ramus is normal, as is the skeletal position of the mandible, with the exception of the chin, which becomes slightly retruded after 5 years of age. As most skeletal traits of Class II occlusion develop later than the occlusal characteristics, it is suggested that no evidence can be found for a skeletal Class II growth pattern in the deciduous dentition. The deficient transversal growth of the maxilla and the sagittal growth of the mandible seem to cause the typical Class II occlusion. Further skeletal changes are likely to develop as secondary adaptations.     

Early treatment mechanics of the dental alveolar class II division I malocclusion

The most common type of early Class II Division I malocclusion is dental alveolar in development. It is the type of maloccusion that is etiologically environmental in nature, but delay in treatment can influence negative changes in dental, facial and skeletal pattern. This malocclusion is readily available for interception at age 7 or 8 to achieve a state of dental and skeletal normalcy with a protocol of defined objectives and predictable outcomes. With efficient and effective arch development (NPE) and utility arch wire (UAW) mechanics, a state of normalcy can be achieved within nine to twelve months of treatment.     

Two-phase treatment of class II malocclusion in young growing patient

The use of functional jaw orthopedics, at the correct time during growth, can ultimately result in malocclusion patients achieving a broad beautiful smile, an excellent functional occlusion, a full face with a beautiful jaw line and lateral profile. Following is a case report of a young growing individual with mandibular retrognathia. Treatment was planned in two stages with the use of twin block during the first phase for correction of skeletal malocclusion and forward positioning of the mandible, followed by the second phase of fixed pre-adjusted edgewise orthodontic appliance for camouflaging the remaining skeletal discrepancy and achieving a stable harmonious occlusion.     

Extraction therapy in patients with class II/2 malocclusion

The aim of this study was to analyze the dynamic development of Class II, Division 2 malocclusion with reference to the untreated patients from the Belfast Growth Study. As a second step, the influences of premolar extraction in all 4 quadrants and of maxillary second molar extraction in the upper jaw in Class II/2 patients were examined, focusing on the cephalometric variables in comparison to those of the untreated patients from the Belfast study. The longitudinal cephalometric values of 20 patients in each group were compared. In addition, the possibility of third molar eruption was evaluated in the extraction patients from the panoramic radiographs. The overbite based on study models at the beginning and end of treatment was calculated. Furthermore, renewed spacing after premolar extraction was assessed. The results derived from cephalometric analysis demonstrated that profile flattening was also observed in untreated Class II/2 patients during the growth period. Comparison of these data with those obtained from the extraction groups revealed a significantly marked recession of the upper lip after premolar extraction. In contrast, only slightly increased flattening after maxillary second molar extraction was observed compared with the untreated patients of the control group. Whereas the interincisal angle was reduced to a value approximating that of untreated Class I patients after maxillary second molar extraction, only a small decrease was recorded after premolar extraction. From our point of view, the claim that premolar extraction facilitates third molar eruption should be seen in an extremely critical light and should not contribute to the decision in favor of extraction. In addition, there is a problem of renewed spacing in the extraction area after premolar extraction.     

Extraction therapy in patients with class II/2 malocclusion

The aim of this study was to analyze the dynamic development of Class II, Division 2 malocclusion with reference to the untreated patients from the Belfast Growth Study. As a second step, the influences of premolar extraction in all 4 quadrants and of maxillary second molar extraction in the upper jaw in Class II/2 patients were examined, focusing on the cephalometric variables in comparison to those of the untreated patients from the Belfast study. The longitudinal cephalometric values of 20 patients in each group were compared.In addition, the possibility of thirds molar eruption was evaluated in the extraction patients from the panoramic radiographs. The overbite based on study models at the beginning and end of treatment was calculated. Furthermore, renewed spacing after premolar extraction was assessed.     

Early treatment of class III malocclusion with Petit facemask therapy

Class III malocclusion with retrusive maxilla can be orthopedically corrected in the deciduous or mixed dentition, with reverse pull headgear in combination with or without rapid maxillary expansion. The advantage of expansion in these patients is to correct the posterior cross bite, and disarticulate the maxilla. This is a case report of successful treatment of developing skeletal class III malocclusion using Petit facemask without maxillary expansion. A 10-year-old girl presented with concave facial profile and decreased lower facial height. She had bilateral class III molar and canine relationships with reverse overjet of 3 mm and over bite of 6 mm. The treatment objective was to correct the skeletal class III to achieve a more harmonious facial profile. Patient was treated with Petit facemask, by applying a force directed at angle of 30 degrees to occlusal plane for a period of 4 months. The intra-oral appliance used was an acrylic cap splint without expansion. The post treatment results showed a significant improvement in facial profile with class I molar relationship and no change in treatment time when compared with patients treated by facemask therapy and maxillary expansion.     

Vertical changes in class II division 1 malocclusion after premolar extractions

The purpose of this study was to compare changes in the facial vertical dimension in patients with Class II division 1 malocclusion after the extraction of either mandibular first premolars or mandibular second premolars. The records of two groups of patients were used: one group was treated with extraction of mandibular first premolars (age: 13.2 +/- 1.5 years) and the other group with extraction of mandibular second premolars (age: 13.4 +/- 1.4 years). Each group consisted of 26 subjects (16 boys and 10 girls). Maxillary first premolars were extracted in both groups. The two groups were matched by sex, age (within six months), and facial divergence measured by maxillary-mandibular plane angle (MM angle) and ratio of posterior facial height to the total anterior facial height. Student's t-test was used to compare the two groups. Significance was predetermined at P < .05. Second premolar extraction was associated with more forward movement of the mandibular molars, but there was no significant difference in vertical facial growth between the two groups. In both groups, there was no significant change in the mandibular plane angle and the MM angle. The results of this study do not support the hypothesis that mandibular premolar extraction is associated with mandibular overclosure or reduction in the vertical dimension, or both, in subjects with Class II division 1 malocclusion.     

安氏Ⅲ类错(牙合)畸形治疗方法的早期预测初探

目的 试探讨可用于判别手术与非手术治疗安氏Ⅲ类错(牙合)畸形患者替牙期颅面牙(牙合)特征的方法. 方法 早期治疗组为28例替牙期解除前牙反(牙合)的安氏Ⅲ类错(牙合)畸形患者(男性16例,女性12例),替牙期拍摄头颅侧位片的平均年龄为(9.1±1.4)岁, 在恒牙期采用非拔牙矫治.手术治疗组为21例随生长发育成为严重骨性安氏Ⅲ类错(牙合)畸形患者(男性12例,女性9例),替牙期拍摄头颅侧位片的平均年龄为(10.0±2.0)岁,最终接受正颌手术治疗.结果 早期治疗组与手术治疗组上下齿槽座点连线与下颌平面的夹角(AB-MP)分别为65.1°和61.2°,差异有统计学意义(P＜0.05);上颌切牙长轴与上下齿槽座点连线的夹角(U1-AB)分别为23.1°和27.3°,差异有统计学意义(P＜0.05). 结论 个体指数(IS)＝0.164×(AB-MP)-0.15×(U1-AB)-6.675.当安氏Ⅲ类错(牙合)畸形患者的IS＞0时,其较适合在替牙期进行早期矫治;IS＜0,患者更适合进行手术矫治.     

Early treatment mechanics of the Class II division 2 malocclusion

A most common type of early malocclusion that the pediatric dentist comes in contact with daily is the developing Class II Division 2 malocclusion (Fig 1-a,b). It is the malocclusion that the parents of the children we serve bring to our attention. Parental concern is the early crowding that develops in the anterior of the lower arch with risk of periodontal involvement. This malocclusion is readily amenable to interception at age 7 or 8 and can proceed with a protocol of defined objectives and predictable outcomes (Fig 2). With efficient and effective utility arch wire (UAW) mechanics a state of normalcy can be achieved within six to eight months of treatment.     

Early treatment versus late treatment Class II closed bite malocclusion

General and pediatric dentists should understand the controversy surrounding the issue of early versus late orthodontic treatment. The clinician also must quantify the outcome benefits of starting profiles versus final profiles, the frequency of distalization mechanics required to correct Class II problems, and starting skeletal position versus final skeletal position. Distal molar movement can result in Class I dental relations with retrognathic maxillary and mandibular positions. This article compares a conventional late treatment approach with a non-conventional early treatment strategy.     

Early treatment of a severe Class II Division 1 malocclusion

This case report shows the effects of functional therapy at an early age in a severe Class II, division 1 malocclusion. Favorable changes in the profile and in the lip seal were achieved. The dental irregularity was treated by fixed appliances and extraction therapy. The patient and her parents were pleased with the final outcome.