Multiregional Fractal Analysis of Mandibular Trabecular Architecture for Sex Estimation: A Panoramic Radiographic Study.

BACKGROUND/

OBJECTIVE

Fractal Analysis (FA) is a mathematical method used to quantify complex self-similar structures and provides a numerical representation of trabecular bone microarchitecture on radiographic images. This study aimed to evaluate region-specific sex differences in Fractal Dimension (FD) and assess the forensic applicability of FA for sex estimation.

MATERIALS AND

METHODS

This prospective study analyzed 130 digital panoramic radiographs from a systemically healthy cohort (65 males, 65 females; aged 20-40 years). Six bilateral regions of interest (50 × 50 pixels), representing the condylar, angular, and interdental trabecular regions, were selected, yielding 780 ROIs. FD values were calculated using ImageJ with a standardized box-counting method. Sex-related differences were analyzed using appropriate statistical tests and binary logistic regression.

RESULTS

Intra-observer reliability was good to excellent (ICC: 0.767-0.879). Bilateral analysis showed significant sex-related differences in the left condylar (p < 0.001) and left interdental regions (p = 0.048). After bilateral averaging, only the condylar region remained significant. Females showed lower mean condylar FD values than males (1.381 ± 0.094 vs. 1.423 ± 0.091; p = 0.012). Logistic regression identified condylar FD as a significant predictor of sex (OR = 0.61, 95% CI: 0.41-0.91; p = 0.014), although discrimination was limited (AUC = 0.628; accuracy = 58.5%).

DISCUSSION: Sex-related differences in mandibular trabecular architecture appeared to vary across anatomical regions, with the condylar region showing the most consistent discriminatory ability. This finding may be related to the condyle's greater susceptibility to biomechanical adaptation and hormonal influences, both of which can affect trabecular organization.

CONCLUSION

FA of panoramic radiographs may serve as a useful adjunct in forensic sex estimation. However, its moderate discriminative performance suggests that it should be used in combination with complementary analytical methods rather than as an independent diagnostic tool.