Evaluation of Changes in Serum Insulin like Growth Factor-1 Levels with Growth Modulation via Twin Block TherapyA Prospective Clinical Study

Introduction: Serum insulin like growth factor is a pertinent growth regulator in bone and cartilage, therefore assessment of changes in serum Insulin like Growth Factor (IGF) levels in patients undergoing functional appliance therapy can act as valuable tool to understand the mode of action of functional appliances.

Aim: To evaluate the changes in serum Insulin like Growth Factor-1 (IGF-1) levels in the patients undergoing twin block therapy and to establish IGF-1 as a biochemical marker produced in response to mechanical disturbance in the condylar region by twin block appliance.

Materials and Methods: This prospective clinical study was conducted in the Department of Orthodontics and Dentofacial Orthopedics, Postgraduate Institute of Dental Sciences, Rohtak, Haryana, India from May 2014 to November 2015. Total 27 patients included in study, divided into two groups, the test group which comprised of 15 patients treated with standard twin block appliance therapy and the control group which comprised of 12 patients not treated with the same. Serum samples were collected from test group and control group patients at four time intervals {pretreatment (T0), 1 month (T1), 3 months (T3) and 6 months (T6)} and subjected to Enzyme-Linked Immunosorbent Assay (ELISA) to measure IGF-1 levels. The data thus obtained was subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) for windows version 20.0. Intragroup differences were evaluated using paired t-test, while intergroup differences were evaluated using Independent sample t-test. The p-value <0.05 was considered as statistically significant.

Results: The data was obtained from 11 patients (6 males and 5 females) in the test group and 10 patients (6 males and 4 females) in the control group after elimination of dropouts. Mean age of the test group subjects was 12.8±0.9 years and that of control group subjects was 13.1±0.9 years. The mean IGF-1 levels in the test group were 124.5 ng/mL (T0), 126.27 ng/mL (T1), 130.90 ng/mL (T3) and 135.54 ng/mL (T6). In the control group, 151.5 ng/mL (T0), 140.8 ng/mL (T1), 157.8 ng/mL (T3) and 120.2 ng/mL (T6). In the test group, mean levels of serum IGF-1 did not change significantly when baseline levels were compared with the serum IGF-1 levels at T1 (0.467), T3 (0.729) and T6 (0.62) of functional appliance therapy, although an increase in IGF-1 levels was noted at each interval. Comparison of serum IGF-1 levels of test and control group showed no statistically significant difference between the groups at T0, T1, T3 and T6.

Conclusion: Functional appliance therapy was not found to be associated with concomitant increase in serum IGF-1 levels