Photographic Soft Tissue Profile Measurements as Predictors of Sagittal Skeletal Patterns: A Low-Cost Diagnostic Alternative for Resource-Limited Settings.

Abstract

Objective: To evaluate the diagnostic value of two soft tissue measurements (facial angle and angle of convexity) in predicting sagittal skeletal patterns using standardized lateral facial photographs.

Materials and methods: This cross-sectional study included 73 subjects aged 18 to 30 years who met inclusion criteria. Standardized lateral cephalograms and profile photographs were captured in natural head position (NHP). Anatomical landmarks were identified and utilized to derive angular measurements. All imaging and assessments followed a consistent protocol to evaluate sagittal skeletal relationship (specifically the angle of convexity and facial angle) using CorelDraw software for Windows.

Statistical analysis: Repeatability and reproducibility were assessed using intraclass correlation coefficients (ICCs) from NHP measurements on lateral photographs and cephalograms. Bivariate analyses examined associations between soft tissue predictors and their skeletal counterparts, with age and sex considered as confounders. Variables with p ≤0.25 were included in multivariable linear regression to predict skeletal angle of convexity and facial angle. Stepwise exclusion was applied for nonsignificant predictors (p > 0.05), and final relationships were represented using regression equations.

Results: Reliability was excellent (Cronbach's α = 0.977; ICC = 0.933-0.977). Photographic angles significantly correlated with their cephalometric counterparts (p < 0.001). Regression analysis confirmed sex and photographic measurements as significant predictors for angle of convexity (R ² = 0.371) and facial angle (R ² = 0.545), with all model assumptions met.

Conclusions: Photographic measurements of the angle of convexity and facial angle, alongside sex, were reliable predictors of skeletal morphology. Standardized profile photographs offer a valuable nonradiographic adjunct in sagittal assessment, especially in resource-limited settings where specialized imaging is unavailable. While not intended to replace cephalograms, these measurements serve as a viable screening tool. Further studies with larger, more diverse populations are warranted to expand applicability and refine predictive accuracy.