Anthropometric Reference Values for the Male Thorax in Mexican Adults: Implications for Chest Surgery.

Introduction Anatomical information regarding the nipple-areola complex (NAC) in men is limited. Our objective was to perform thoracic anthropometry in Mexican men and determine whether age and body mass index (BMI) influence the position and size of the NAC. Materials and methods Sociodemographic data and direct thoracic measurements were collected from 100 male subjects between January and June 2024 by the same physician. Descriptive statistics, the Mann-Whitney U test, and the Kruskal-Wallis test were applied for independent samples. A p-value < 0.05 was considered statistically significant. Results The average age was 29.6 years (±4), and the mean BMI was 25 kg/m² (±2.8). The mean difference between the midpoint of the right arm and the height of the right nipple was 4 mm (±13 mm), and 18 mm (±11 mm) on the left. The ratio between the inter-nipple distance and thoracic width was 60% (±4%), and the ratio between inter-nipple distance and chest circumference was 25% (±1%). No significant differences were found regarding age using the Mann-Whitney U test. However, the Kruskal-Wallis test showed significant differences between BMI groups for NAC size, sternal notch-nipple distance (right and left), inter-nipple distance, thoracic width, thoracic circumference, and the difference between the nipple and arm midpoint bilaterally. Discussion Age showed no statistically significant effect on anthropometric parameters. However, the NAC position varied according to BMI; individuals with higher BMI had nipples placed more laterally. Chest width and arm length can be easily measured intraoperatively, allowing real-time adjustments. Ratios such as inter-nipple distance to chest width and nipple-to-arm midpoint distance remained consistent across BMI subgroups, supporting their clinical applicability. These findings suggest that surgeons may use 60% of the chest width as a reliable guide for inter-nipple distance, even in patients with elevated BMI. Conclusion By systematically documenting areolar diameter and nipple position in relation to anatomical landmarks, this study contributes valuable quantitative data for plastic surgeons making decisions about optimal NAC placement during gender-affirming surgery (female-to-male) and gynecomastia treatment. These results offer a reproducible, anatomy-based framework for individualized NAC positioning and represent an important step toward establishing region-specific standards in male chest surgery.