Jaw Dimensions, Skeletal Maturation, and Salivary Hormones in Adolescents With Normal and Increased Body Mass Index: A Cross-Sectional Study.

OBJECTIVE

To evaluate jaw dimensions, skeletal maturation, and salivary hormonal and adipokine levels in adolescents with normal and increased body mass index (BMI).

SETTING AND SAMPLE POPULATION: This cross-sectional study included 50 adolescents (mean age 13.54 ± 1.39 years), categorized into normal (n = 26) or increased BMI (n = 24) groups.

MATERIALS AND

METHODS

Pre-treatment lateral cephalograms were analysed for effective maxillary (Co-A) and mandibular (Co-Gn) lengths, and skeletal maturation was assessed via the cervical vertebral maturation (CVM) index. The skeletal maturity index (SMI) was evaluated on hand-wrist radiographs. Unstimulated whole saliva (UWS) samples were analysed using multiplex immunoassays for growth hormone, IGF-1, cortisol, estradiol, testosterone, adiponectin, and resistin. Group comparisons used parametric or non-parametric tests with false discovery rate (FDR) correction. Spearman correlations and multivariable regression models, adjusted for age, sex, and race, were computed.

RESULTS

Adolescents with increased BMI had significantly greater effective mandibular length (Co-Gn; mean difference: 8.13 mm; FDR-adjusted p = 0.045). Effective maxillary length showed a similar trend (Co-A; FDR-adjusted p = 0.067). No significant differences were observed in vertical, dental, or soft tissue variables, CVM, or SMI. Salivary cortisol was lower (FDR-adjusted p = 0.003) and resistin was higher (FDR-adjusted p = 0.024) in the increased BMI group. In regression models, UWS adiponectin remained an independent negative predictor of Co-A and Co-Gn (both p = 0.005) after adjusting for covariates.

CONCLUSIONS

Increased BMI was associated with greater mandibular length in pre-treatment orthodontic adolescents. Salivary adiponectin was negatively associated with jaw dimensions.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT07217756.