Cephalic, Facial, and Nasal Indices in Young Turkish Adults: Sexual Dimorphism and Its Relevance to Facial Feminization Surgery

Sexual dimorphism of the craniofacial skeleton plays a central role in gender perception and forms the anatomic basis of contemporary facial feminization surgery (FFS). Despite extensive global research, population-specific normative data remain limited for Turkish adults, particularly for measurements relevant to FFS planning. This study aimed to provide sex-stratified linear anthropometric reference values for young Turkish adults and to examine the distribution of cephalic, facial, and nasal index categories in relation to sex. A total of 187 (102 women, 85 men) healthy adults aged 18 to 25 years (mean age: 21.18±1.52) were evaluated using standardized anthropometry. Cranial, facial, and nasal dimensions were measured between defined osteological and soft-tissue landmarks using a digital caliper, and cephalic, facial, and nasal indices were calculated. Males exhibited significantly greater head breadth, occipitofrontal distance, facial width, morphologic facial height, total nasal length, and nasal width than females (all P<0.001), whereas the facial index did not differ significantly. Cephalic index categories showed substantial sex-based variation, with higher frequencies of hyperbrachycephaly among males and dolichocephaly among females (P<0.001). Nasal index categories also differed, with mesorrhine noses more common in males and leptorrhine noses predominant in females (P=0.002). Facial index groups demonstrated a significant association with sex, with mesoprosopic types observed exclusively in females (P=0.005). The sex-specific differences identified in cephalic, facial, and nasal indices provide proportional benchmarks that can inform patient-specific planning in facial feminization surgery. These normative data define craniofacial ratios characteristic of Turkish women and men, enabling surgeons to determine which dimensions require modification to approximate female norms during gender-affirming procedures.