THE EFFECT OF FIXED ORTHODONTIC APPLIANCES ON BODY WEIGHT AND BODY MASS INDEX IN A SAMPLE OF ORTHODONTIC PATIENTS IN ERBIL CITY (A PILOT STUDY).

Background: Fixed orthodontic appliances are widely used to manage malocclusion, yet their potential impact on body mass index remains unclear. The accessibility and adaptability of orthodontic brackets and wires, however, have nutritional implications that raise questions about body mass index (BMI). Patients with fixed appliances frequently have trouble chewing hard foods, which affects how many calories they consume and, in turn, their body mass index. Objective: To evaluate changes in body mass index (BMI) during fixed orthodontic treatment in a cohort of orthodontic patients over 18 months. Methods: This cohort study included 22 patients (12 males, 10 females; aged 18–24 years) with Class II division 1 malocclusion. Patients with an overjet between 0 and 6 mm and an overbite between 0 and 4 mm were included. The orthodontic treatment was performed by a single clinician using standardized brackets and arch wires. Body mass index (BMI) was measured at four time points: baseline (T1), six months (T2), twelve months (T3), and eighteen months (T4). Pairwise (post hoc) tests and repeatedmeasures ANOVA were used to analyze the data; p < 0.05 was considered significant. Results: At baseline (T1), the mean BMI was 23.43 (± 5.17), which decreased to 23.24 (± 4.51) at T2; and then slightly increased to 23.64 (± 4.63) at T3; and ultimately reached 24.45 (± 4.61) at T4. BMI values showed significant changes over the course of the study, according to a repeated-measures ANOVA (F=4.318, p=0.022). Compared to T1 (p = 0.048), T2 (p = 0.002), and T3 (p < 0.001), the BMI at T4 was significantly higher. At T2 and T3, the BMI changes were not statistically significant (P>0.05). Additionally, the BMI patterns of male and female patients did not differ significantly. Conclusion: According to this pilot study, BMI values decreased slightly at 6 months, then peaked significantly at 18 months relative to baseline. These findings emphasize the potential for long-term weight gain, though the lack of a control group prevents establishing direct causality.