Mihovil Strujić

Tooth size discrepancy in orthodontic patients among different malocclusion groups

An appropriate relationship of the mesiodistal (MD) widths of the maxillary and mandibular teeth favours optimal post-treatment results. The aims of this study were to determine whether there is a difference in the incidence of tooth size discrepancies among different skeletal malocclusion groups and if gender dimorphism exists. The dental casts and lateral cephalometric radiographs of 301 Croatian subjects (127 males and 174 females, mean age 16.86 +/- 2.93 years) were selected from a larger sample of records of the archives of the Orthodontic Department, School of Dental Medicine, University of Zagreb, Croatia. The subjects were from malocclusion groups according to Angle classification, with the corresponding skeletal characteristics. The MD dimensions of all teeth from first molar to first molar were measured on the dental casts using digital callipers. Statistical analysis was undertaken using Kolmogorov-Smirnov, t, and Scheffés tests and one-way analysis of variance. A statistically significant gender difference was found in anterior ratio (P = 0.017). A significant difference in the overall and posterior ratio was observed between Class II and Class III subjects. There was a tendency for mandibular tooth size excess in subjects with an Angle Class III malocclusion and for maxillary tooth size excess in those with an Angle Class II malocclusion. The percentage of subjects more than 2 standard deviations from Boltons means for anterior and overall ratios was 16.28 and 4.32, respectively.

Orthodontic anomalies and malocclusions in Late Antique and Early Mediaeval period in Croatia

OBJECTIVE Malocclusions are relative infrequently analysed in bioarchaeological investigations and if investigated the samples are very small. This research provides analysis of orthodontic anomalies of even 1118 individuals from the Late Antique (LA) and Early Mediaeval (EM) period. Aims were to describe the prevalence of orthodontic anomalies in this historical period and to analyse which orthodontic anomalies are best suitable for bioarchaeological investigations. METHODS 1118 skulls were examined for anomalies of tooth number, tooth displacement (rotation, malposition, diastema and crowding) as well as for malocclusions. RESULTS The prevalence of hypodontia in the LA was 41.02% and 30.61% in the EM sample. Tooth displacement was noticed in 15.63% individuals from the LA and in 12.42% individuals from EM. About 26% of the LA sample and 7.19% of the EM sample were affected with tooth crowding and the difference was statistically significant. CONCLUSION Orthodontic anomalies affecting only one tooth or group of teeth are more suitable for examination in bioarchaeological investigations than orthodontic features requiring presence of both jaws and all or almost all teeth. Clinical investigation protocols and methodology should be adopted for bioarchaeological researches and international standards and recommendations should be established for this kind of investigation on skeletal remains.