Role of posterior transverse interarch discrepancy in Class II, Division 1 malocclusion during the mixed dentition phase

Posterior transverse interarch discrepancy (PTID), measured as the difference between the maxillary and mandibular intermolar widths, was investigated in a sample of 60 Class II, Division 1 subjects during the mixed dentition phase. Two main groups were detected: Class II group 1 (30 subjects) with PTID and Class II group 2 (30 subjects) without PTID. A sample of 30 Class I subjects in the mixed dentition phase was used as a control group. In Class II group 1, PTID was found to be due to a significantly narrower maxillary arch. The craniofacial skeletal features of both Class II groups and of the Class I group were assessed. The Class II group with PTID showed mandibular retrusion associated with a posteriorly displaced mandible of normal size (functional mandibular retrusion). The Class II group without PTID had mandibular retrusion due to a micrognathic mandible (anatomic mandibular retrusion). The relevance of these findings for treatment planning in Class II, Division 1 malocclusion in the mixed dentition was stressed.

Orthodontic treatment need and the dental aesthetic index

The Dental Aesthetic (DAI) was devised as a measure of dental appearance and based on lay opinions as opposed to professional assessments of need. The DAI is calculated from the weighted scores of ten occlusal variables. These same variables have been used in other malocclusion indices intended to measure morphological deviations from normality. It is, therefore, important to ask if the DAI might be used to screen both deviations of dental appearance and deviations of occlusion from accepted norms. The original DAI design was based on analysis data from permanent dentitions. However, a large percentage of orthodontic assessments are carried out in the mixed dentition. Therefore, the present study includes a sample of mixed dentitions to test the effectiveness of the DAI in this group. The DAI was tested against the subjective assessments of severity made by orthodontists. Sensitivity and negative predictive power were high. Performance in the mixed dentition group was slightly lower than the permanent dentition group. It is concluded that while the DAI is not sufficiently reliable for assessment of treatment need in the individual, its sensitivity and negative predictive power might provide a useful screening mechanism which reflects both the concerns of patients regarding appearance and the general treatment recommendations of orthodontists. Testing on much larger samples is now required.

A modification to the incisor classification of malocclusion

During the study of two-hundred orthodontic cases under treatment in the General Dental Service, four clinicians showed only moderate agreement using the British Standard Classification of Incisor Malocclusion. Cohen's Kappa statistic was used to measure the inter-examiner agreement. The 35 cases in which there was high disagreement between the examiners were scrutinized to determine the source of this disagreement. Following discussion, revised definitions were produced which included the introduction of a Class II-intermediate group. After an interval of 2 months these 35 cases were reclassified using the new definitions. Increased inter-examiner agreement was found. Four examiners (three of whom were common to the original study) then used the modified classification to describe the incisal relationship of 100 cases referred for treatment at Bristol Dental Hospital. The inter-examiner and the intra-examiner agreement were both found to be good. It is recommended that the Incisor Classification of Malocclusion be extended to include a Class II-intermediate group.

[Clinical picture and orthodontic-surgical therapeutic problems in treatment of Class II division 1 dento-skeletal malformations]

In the present study different types of Class II, Division 1 malocclusions have been taken under consideration. First of all, have been analysed the main etiopathogenetic factors which are the causes of an anomalous development of the Maxillo-Facial complex. It has been pointed out the clinical characteristics of these malformations, necessaries for a careful therapeutical program. The Authors, therefore, in the first face describe the principal orthodontic problematics to tackle, in the second face they describe the surgical techniques mostly used to correct the Class II malocclusions; finally it has been pointed out the role of the orthodontic post-operative treatment, to improve the occlusion and the rehabilitation of the neuromuscular system after correcting maxillo facial skeleton alterations. Three cases are presented for this kind of malformation, treated with the various surgical techniques on the ground of the different kinds of clinical variants.

Occlusal considerations for partially or completely edentulous skeletal class II patients. Part I: Background information

Although approximately 15% of the population may be classified as having the skeletal class II relationship, this group of patients is far from homogeneous. Two prototypes were used to delineate various problems in the prosthodontic occlusion that dentists may encounter with these patients. A satisfactory occlusion is difficult to achieve because of skeletal discrepancies, limited space for occlusal contact, steep guidance factors, and the necessity for multiple eccentric occlusal contacts because of the significant range of mandibular motion.

Differential diagnosis of class II malocclusions. Part 1. Facial types associated with class II malocclusions

By means of computer-based statistical methods, several types of Class II malocclusion have been discovered with defining horizontal and vertical characteristics. Of the six horizontal types, four are severe syndromes, one is a loose, ill-defined grouping of cases with mild skeletal features, and one has only the dental features of Class II. Five vertical types associates with Class II were also revealed, although each vertical is not associated with all horizontal types. A simplified simulation of the computerized procedures has been developed for routine use in clinical practice.