Abstract
The aim of this study is a) to investigate the dental, dentoskeletal and skeletal characteristics associated with Angle Class II, Division 1 malocclusion in Greek children aged 10-12 years, b) to identify, within a sample of Class II malocclusion, different types of Angle Class II, Division 1 malocclusion and c) to investigate any differences of Class II, Division 1 and its types between sexes. The material examined included 138 lateral head cephalograms from which 69 belonged to boys with mean age 11,37 and 69 belonged to girls with mean age 11,41. Software PORDIOS was used and 46 measurements, divided to nine groups of variables, were performed. These groups of variables concerned the dental relationships, the dentoskeletal relationships of upper incisors, the dentoskeletal relationships of lower incisors, the dentoskeletal relationships of upper permanent first molars, the deep cranial structures, the position and size of the maxilla and the position and size of the mandible. Descri ...
The aim of this study is a) to investigate the dental, dentoskeletal and skeletal characteristics associated with Angle Class II, Division 1 malocclusion in Greek children aged 10-12 years, b) to identify, within a sample of Class II malocclusion, different types of Angle Class II, Division 1 malocclusion and c) to investigate any differences of Class II, Division 1 and its types between sexes. The material examined included 138 lateral head cephalograms from which 69 belonged to boys with mean age 11,37 and 69 belonged to girls with mean age 11,41. Software PORDIOS was used and 46 measurements, divided to nine groups of variables, were performed. These groups of variables concerned the dental relationships, the dentoskeletal relationships of upper incisors, the dentoskeletal relationships of lower incisors, the dentoskeletal relationships of upper permanent first molars, the deep cranial structures, the position and size of the maxilla and the position and size of the mandible. Descriptive statistics was performed for the intire sample, for each sex and comparison of the mean values. Mean values, standard deviations, maximum and minimum values of all variables were calculated. t - test was used for the comparison of the mean values, of all variables between sexes that followed the normal distribution. For variables that did not follow the normal distribution, even for one of the sexes, the Mann - Whitney test was applied. In order to investigate the characteristics’ combinations that constitute the clinical identity of Class II, Division 1 malocclusion, four variables were used as the basis for classification into groups. These variables were the overjet, the cranial base, the convexity and the distance between the lower lip and the esthetic plane of Ricketts. Cluster analysis formed two groups. Group 1 was characterized by increased overjet, decreased convexity and decreased distance between the lower lip and the esthetic plane of Ricketts. Group 2 was characterized by decreased overjet, increased convexity and increased distance between the lower lip and the esthetic plane of Ricketts. The cranial base was not statistically significant between groups, a finding that indicates that it does not contribute to the formation of Angle Class II, Division 1 malocclusion. Comparison of the mean values of all variables between the two groups and the simultaneous control of group - sex interaction were performed by ANOVA test. Evaluation of the study findings lead to the following conclusions: 1. The size and inclination of the cranial base, that were observed, do not participate in the formation of Angle Class II, Division 1 malocclusion in this sample of Greek children aged 10-12 years. 2. The maxilla was not observed prognathic. 3. The mandible was observed retrognathic. 4. The sample of the study has a tendency for the dolichofacial type. 5. The ramus height was found larger in boys than in girls. 6. Two groups of two types of Class II, Division 1 malocclusion were formed. Group 1 was characterized by increased overjet, decreased convexity and decreased distance between the lower lip and the esthetic plane of Ricketts. Group 2 was characterized by decreased overjet, increased convexity and increased distance between the lower lip and the esthetic plane of Ricketts. 7. Group 1, formed by Cluster analysis, consisted of 32 boys and 32 girls, a total of 64 persons, comprising 47,1% of the sample. Group 2 consisted of 36 boys and 36 girls, a total of 72 persons, comprising 52,9% of the sample. 8. Both groups were independent of gender, that is both boys and girls were evenly distributed in the two groups. 9. The cranial base did not show any statistically significant differences between the two groups, a finding that shows that it does not participate in the formation of types of Angle Class II, Division 1 malocclusion. 10. Group 1 or dento-alveolar type of Class II, Division 1 malocclusion was mostly characterized by the proclination of upper incisors. 11. Group 2 or skeletal type of Class II, Division 1 malocclusion was mostly characterized by the posterior rotation of the mandible.
show more
