Craniofacial characteristics of Syrian adolescents with Class II division 1 malocclusion: a retrospective study

Alaa Al Ayoubi,Daniel Dalla Torre,Melinda Madléna

doi:10.7717/peerj.9545

Abstract

BackgroundMalocclusion characteristics vary across different ethnic groups and populations. Limited data are available regarding the characteristics of Syrian adolescents with Class II division 1 (Class II-1) malocclusion, and the recent inflow of Syrian refugees and immigrants into Europe and many areas worldwide demonstrate the need for updated studies to discover the craniofacial characteristics of these new immigrants.ObjectivesThe present compound cephalometric and tooth-size study sought to assess the dentofacial morphology, upper-airway dimensions, and tooth-size characteristics of Syrian adolescents with Class II-1 malocclusion and compare the results with established Syrian population norms.Materials and MethodsThe study sample consisted of 43 Syrian patients including 24 females and 19 males with Class II-1 malocclusion (age: 14.3 (±1.5) years, mean (±SD)). Cephalometric radiographs and orthodontic casts were analyzed using special orthodontic software (OnyxCeph3™) and a universal digital caliper, respectively. Statistics were calculated using the SPSS software.ResultsIn Syrian adolescents with Class II-1 malocclusion, the position of the mandible relative to the nasion perpendicular (mean (95% confidence interval)) was −11.01 (−12.45, −9.57) mm. Facial axis angle showed a negative value: −6.25 (−7.65, −4.85) degrees. An obtuse nasolabial angle was observed: 104.05 (101.77, 106.33) degrees. The average width of the upper pharynx was 11.50 (10.53, 12.47) mm; however, there was no prevalence of an upper-pharyngeal width of 5 mm or less. The average value of the anterior tooth-size ratio was 80.69 (79.85, 81.53) percent. In total, 39.5% of the investigated subjects had anterior ratios outside two standard deviations from Bolton’s norm, while 25.6% of the investigated subjects had anterior ratios outside two standard deviations from Syrian population norm.ConclusionsIn this study, the inter-maxillary discrepancy of Class II-1 Syrian adolescents was a consequence of their hyperdivergent facial pattern. The observed small pharyngeal widths were not clinically significant, while the anterior tooth-size discrepancy might be clinically relevant.

Highlights

In orthodontics, it is essential to understand the complex relationship between skeletal, dental and facial aberrations in each malocclusion to achieve an accurate diagnosis followed by an optimal treatment plan
Syrians belong to the Middle Eastern ethnic group, limited data are available pertaining to the craniofacial characteristics of adolescents of Syrian nationality
Since there was no difference in the upper-lip angulation (CIs of UL-NP in Table 1 vs. their corresponding values in Table S2), our findings suggest that the angulation of the lower border of the nose may be a reason for the more obtuse nasolabial angle in Class II-1 subjects

Summary

Introduction

It is essential to understand the complex relationship between skeletal, dental and facial aberrations in each malocclusion to achieve an accurate diagnosis followed by an optimal treatment plan. Numerous studies have investigated the cephalometric and tooth-size characteristics of patients with Class II-1 malocclusion using various measurements either on cephalometric radiographs or orthodontic casts. The significance of these studies is limited by multiple factors, including the conflicting results; some cephalometric studies have reported that a retrognathic mandible is the key factor contributing to Class II-1 malocclusion with a normally positioned maxilla (Riedel, 1952; Hitchcock, 1973; Freitas et al, 2005; Sayın & Türkkahraman, 2005; Isik et al, 2006). Objectives: The present compound cephalometric and tooth-size study sought to assess the dentofacial morphology, upper-airway dimensions, and tooth-size characteristics of Syrian adolescents with Class II-1 malocclusion and compare the results with established Syrian population norms. The observed small pharyngeal widths were not clinically significant, while the anterior tooth-size discrepancy might be clinically relevant

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