Variations in dental and alveolar arch dimensions among different malocclusion groups in a sample of untreated patients.

This study compares the different transverse relationships of the upper and lower arches in the 4 different malocclusion groups and describes the origin of these transverse discrepancies. Knowledge of dental and alveolar arch dimensions will help the clinician in diagnosis and treatment planning of patients with different malocclusions.

Association between interleukin-1ß C (3953/4)T polymorphism and chronic periodontitis: evidence from a meta-analysis.

The aim of this study was to perform a meta-analysis to evaluated the association between interleukin-1ß (IL-1ß) C(3953/4)T polymorphism and chronic periodontitis (CP). Systematic searches of electronic databases and hand searching of references were performed, including PubMed, Embase and Web of Science. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated. Publication bias was tested by Begg's funnel plot and Egger's regression test. Sensitivity analysis was conducted by limiting the meta-analysis studies conforming to Hardy-Weinberg equilibrium (HWE) or high quality (score ≥ 7). Data analyses were carried out by Stata 11.0. There were significant associations between IL-1ß C(3953/4)T polymorphism and CP (for T allele vs. C allele: OR = 1.30, 95%CI = 1.05-1.60, p = 0.02; for T/T vs. C/C: OR = 1.66, 95%CI = 1.12-2.45, p = 0.01; for C/T+T/T vs. C/C: OR = 1.28, 95%CI = 0.99-1.65; and for T/T vs. C/T+C/C: OR = 1.62, 95%CI = 1.15-2.29, p = 0.006). When stratified by ethnicity, statistically significantly elevated risk was found for Caucasians, but not for Asians. When stratified by study design, evidences of significant association was observed between IL-1ß C(3953/4)T polymorphism and CP in both population-based studies and hospital-based studies. This meta-analysis indicates that there is strong evidence for association between IL-1ß C(3953/4)T polymorphism and CP.

[A longitudinal study of mandible growth of Angle Class II division 2 malocclusion from mixed dentition to permanent dentition].

OBJECTIVE: To determine the longitudinal growth changes of mandible from mixed dentition to permanent dentition on Angle Class II division 2 malocclusion. METHODS: The sample consisted of 95 students with Angle Class II division 2 malocclusion and 75 students with normal occlusion. Cephalometric radiographs and hand-wrist radiographs were obtained for all the samples. And analysis of all the cephalograms was carried out. RESULTS: The study of growth changes of mandible from mixed dentition to permanent dentition showed that: 1) angle: The control group showed an increase in SNB and S-Ba-Go and a decrease in Ar-Go-Me, SN-MP and NSGn. In the experimental group, the changes in SNB, Ar-Go-Me, Cd-Go-Me, SN-MP, S-Ar-Go, S-Ba-Go were not of statistical significance, however, Y angle and NSGn were increased. In the control group, there was no statistically significant change in the Y angle. 2)chin: In the experimental group, chin concavity increased. The changes were not statistically significant for the other index. In the control group, chin curvature decreased. The chin height, chin depth, chin concavity, chin depth/chin height, SL and Pog to NB increased. 3)spacing: The growth of Cd-Go, Gn-Cd, Go-Me, Ar-Pog, Ar-Go in the control group was more than that of the experimental group. CONCLUSION: The present finding will help the clinicians to come to a diagnosis and reasonable treatment plan in Angle Class II division 2 patients.