# Association Between Facial Biotype and Condylar Spaces in Orthodontic Patients: A Cross-Sectional Cone-Beam Computed Tomography (CBCT) Study

## TL;DR

This study explores how facial shape relates to jaw joint spaces in orthodontic patients using 3D imaging, finding that certain facial types are linked to specific jaw joint patterns.

## Contribution

The study identifies distinct condylar space patterns and their association with facial biotype, emphasizing the importance of individualized diagnosis in orthodontics.

## Key findings

- Dolichofacial patients have significantly smaller right anterior condylar spaces compared to others.
- Three condylar space patterns were identified, with dolichofacial biotype strongly predicting membership in the ideal pattern.
- Bilateral symmetry in condylar spaces was observed in only a minority of patients.

## Abstract

Background: Condylar position is a key element in diagnosis and treatment planning in orthodontics and rehabilitation. Facial biotype influences features such as muscular strength and vertical dimension. Evidence associated with a possible relationship between them is still limited, which keeps the topic clinically and scientifically relevant.

Objective: This was an observational, analytical, cross-sectional study conducted using CBCT records of adult patients treated at the Orthodontics and Maxillofacial Orthopedics Graduate Clinic of Universidad Cuauhtémoc, San Luis Potosí, Mexico. It aimed to evaluate the association between facial biotype and condylar position in orthodontic patients using cone-beam computed tomography (CBCT) and to identify condylar space distribution patterns, bilateral symmetry, and factors associated with ideal condylar position and specific pattern membership.

Materials and methods: CBCT scans of 100 adult orthodontic patients were analyzed in this study. The anterior (AS), superior (SS), and posterior (PS) condylar spaces were measured on both sides. Facial biotypes were determined using Ricketts cephalometric analysis. Descriptive statistics, analysis of variance (ANOVA), cluster analysis, bilateral symmetry assessment, and multivariate regression models were used in the study.

Results: Dolichofacial patients exhibited a significantly smaller right AS than those with the brachyfacial and mesofacial types (p = 0.011). Cluster analysis revealed three condylar space patterns: Group 1 (close to ideal), Group 2 (moderately enlarged), and Group 3 (enlarged) patterns. Bilateral concordance was observed in 37 (37%) patients in G1, 20 (20%) in G2, and five (5%) in G3. Dolichofacial biotype significantly increased the likelihood of bilateral G1 membership (odds ratio (OR) = 4.08, p = 0.041). None of these factors consistently predicted strict compliance with Ikeda's ideal values.

Conclusions: Facial biotypes selectively influence condylar position, with dolichofacial patients showing reduced AS. The condylar position exhibits distinct subgroup patterns, and bilateral symmetry is not always present. The dolichofacial biotype was the main predictor of condylar configuration. These findings emphasize the need for individualized joint evaluation, interpretation of the biotype as a modulator of the condylar-fossa relationship, and reliance on distribution patterns rather than rigid values for orthodontic diagnosis and treatment planning.