Evaluation of parameters affecting thoracic morphology by computed tomography in individuals with anterior chest wall deformity

Objective: Anterior chest wall deformities are mostly congenital in origin and represent structural abnormalities that can cause both physiological and aesthetic/psychosocial effects in individuals. Among these, the most common types—pectus excavatum (PE) and pectus carinatum (PC)—are typically studied separately in the literature. In this study, however, the deformities were evaluated from a general "anterior chest wall deformity" perspective. Since only PE and PC types were observed in the sample, analyses were conducted on these two groups. The aim was to evaluate morphometric parameters of the sternum and thoracic structures in these individuals and contribute to the literature through comparative analyses with healthy individuals. Materials and Methods: In this retrospective study, thoracic computed tomography (CT) images of 200 individuals diagnosed with PE or PC and 200 healthy controls were analyzed. Length and width measurements of the manubrium, corpus sterni, and xiphoid process; sternal torsion angle and direction; Haller Index (HI), Asymmetry Index (AI), Vertebral Index (VI), and Fronto-Sagittal Index (FSI) were evaluated. Vertebral levels at which the deformities were observed were systematically analyzed. Results: In individuals with deformities, manubrium length, xiphoid process length, and sternal torsion angle were found to be significantly higher compared to the control group. The corpus sterni width was greater in the PE group compared to the PC group. VI and FSI values were significantly higher in the PE group. A significant relationship was found between sternal torsion direction and AI; AI values were higher in individuals with right-sided torsion. PE deformities were most frequently localized at the T9 level, whereas PC deformities were most commonly observed at the T8 and T9 levels. Additionally, anatomical variations specific to the deformity types, such as sternal foramen and sternal cleft, were detected in 4.2% of all individuals. Conclusion: This study presents a detailed morphometric analysis of anterior chest wall deformities via computed tomography and offers a comparative evaluation of PE and PC deformities. The findings highlight the importance of considering sternal torsion, index values, and vertebral localization in deformity classification. These data may guide clinicians in diagnosis, follow-up, and surgical planning.