Assessment of Malar Prominence in Adolescents: Evaluating the Diagnostic Accuracy of a New Angle for Vector Profile Classification

TL;DR

This study introduces a new angle, the DWK angle, to assess malar prominence in adolescents, showing it is reliable and accurate for facial profile classification.

Contribution

The study introduces the novel double W-key ridge (DWK) angle as a new diagnostic parameter for assessing malar prominence.

Findings

The DWK angle and SNO angle were significantly higher in positive vector profiles compared to negative ones.

Both angles showed strong correlation and high diagnostic accuracy (AUC of 0.947 for SNO and 0.961 for DWK).

No significant sex-based differences were observed in either angle measurements.

Abstract

Introduction: The prominence of the malar region plays a crucial role in facial aesthetics; however, standardized diagnostic parameters for assessing midfacial deficiencies remain limited. This study introduced and evaluated a novel cephalometric parameter, the double W-key ridge (DWK) angle (formed between the double W plane and the key ridge point), in comparison with the established sella-nasion-orbitale (SNO) angle for assessing malar prominence. This study aimed to present a novel perspective for evaluating malar prominence, referred to as the DWK angle. The objectives of this study were to compare the mean SNO and DWK angles between positive and negative vector profiles, assess their correlation, evaluate their diagnostic accuracy using receiver operating characteristic (ROC) analysis, and examine the influence of sex on these parameters.

Materials and methods: This retrospective study analyzed the lateral cephalograms and profile photographs of 60 young adolescents (aged 11-14 years) from the Department of Orthodontics, Yogita Dental College. Based on clinical photographs, records were classified into positive and negative vector profile groups (n=30 each). The same observer obtained cephalometric measurements of the SNO and DWK angles. Reliability testing was conducted using the intraclass correlation coefficient. Statistical analyses, including Mann-Whitney U tests, Spearman’s rank correlation, mixed-model analysis, and ROC curve analysis using the area under the curve (AUC), were performed to assess the relationship, diagnostic accuracy, and potential sex differences in these measurements.

Results: Mean SNO and DWK angles were significantly higher in the positive vector group (SNO, 53.97°; DWK, 104.2°) than in the negative vector group (SNO, 44.1°; DWK, 94.6°) (p<0.001). A strong positive correlation (r=0.74, p=0.001) was observed between these two angles. ROC analysis demonstrated high diagnostic accuracy for both angles (AUC: 0.947 for SNO and 0.961 for DWK), with a sensitivity and specificity of 90%. No significant sex-based differences were found in either of the vector groups.

Conclusion: DWK angle is a stable and reliable cephalometric parameter for differentiating between adolescents' positive and negative vector profiles. The strong correlation and high diagnostic accuracy suggest that both SNO and DWK angles can effectively be utilized in orthodontics and maxillofacial planning to assess malar prominence.

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