Role of salivary Insulin-like Growth Factor-1 (IGF-1) in the regulation of biomechanical process following mandibular advancement with a twin block appliance-a prospective observational study.

BACKGROUND

An increased expression of Insulin-like growth factor-1 (IGF-1) in the condyle following mandibular advancement has been observed in animal studies. However, the exact role of IGF-1 in the regulation of biomechanical process of Twin block in humans is still unclear. Hence, the aim of the present study was to investigate the role of salivary IGF-1 following mandibular advancement with Twin block appliance in subjects having skeletal Class II malocclusion.

MATERIALS AND METHODS

This prospective observational study enrolled 49 subjects with skeletal Class II malocclusion who were administered Twin block. Salivary samples were collected at: pre-treatment (T0), one week (T1), 6-10 weeks (T2), 8-10 months (T3) and post-treatment (T4). Subjects who were non-compliant were taken as the non-compliant group (NCG; n = 10), (Twin block group, TBG; n = 39). Lateral cephalograms were obtained at T0, T3 and T4 for TBG and at T0, T4 for NCG to evaluate the various skeletal and dentoalveolar effects. Friedman test, Wilcoxon signed test and Mann-Whitney test were performed for statistical comparison of salivary IGF-1 levels and cephalometric parameters within and between the two groups.

RESULTS

In TBG, salivary IGF-1 levels significantly increased at one week (p = 0.000), followed by a plateau, while NCG showed no significant changes. Cephalometric analysis revealed significant improvements in mandibular length and other parameters in TBG compared to NCG.

CONCLUSIONS

The study demonstrates a significant increase in salivary IGF-1 levels following mandibular advancement, suggesting its regulatory role in biomechanical process of the Twin block appliance.

CLINICAL RELEVANCE

The findings of this study hold significant future potential in the field of dentofacial orthopaedics. The development of a panel of salivary biomarkers could offer a more comprehensive understanding of the biological processes involved in mandibular advancement and growth, leading to more precise and customized treatment plans.