Cranial base characteristics in anteroposterior malocclusions: A meta-analysis

Abstract

ABSTRACT Objective:  To investigate cranial base characteristics in malocclusions with sagittal discrepancies. Materials and Methods:  An electronic search was performed in PubMed, Embase, Web of Science, and the Cochrane Library. A fixed- or random-effect model was applied to calculate weighted mean difference with 95% confidence intervals (CIs) according to statistical heterogeneity. Outcome measures were anterior, posterior, and total cranial base length and cranial base angle. Sensitivity analysis and publication bias were conducted. Results:  Twenty studies that together included 1121 Class I, 1051 Class II, and 730 Class III cases qualified for the final analysis. Class III malocclusion demonstrated significantly reduced anterior (95% CI: −1.74, −0.53; P < .001 vs Class I; 95% CI: −3.30, −2.09; P < .001 vs Class II) and total cranial base length (95% CI: −3.33, −1.36; P < .001 vs Class I; 95% CI: −7.38, −4.05; P < .001 vs Class II). Further, Class II patients showed significantly greater anterior and total cranial base length than did Class I patients (95% CI: 0.51, 1.87; P < .001 for SN; 95% CI: 2.20, 3.30; P < .001 for NBa). Cranial base angle was significantly smaller in Class III than in Class I (95% CI: −3.14, −0.93; P < .001 for NSBa; 95% CI: −2.73, −0.68; P  =  .001 for NSAr) and Class II malocclusions (95% CI: −5.73, −1.06; P  =  .004 for NSBa; 95% CI: −6.11, −1.92; P < .001 for NSAr) and greater in Class II than in Class I malocclusions (95% CI: 1.38, 2.38; P < .001 for NSBa). Conclusions:  This meta-analysis showed that anterior and total cranial base length and cranial base angle were significantly smaller in Class III malocclusion than in Class I and Class II malocclusions, and that they were greater in Class II subjects compared to controls.