Changes in Body Mass Index and Food Intake in Patients Undergoing Orthognathic Surgery

Background: The aim of the present study was to evaluate the changes in body mass index (BMI) and food intake in patients undergoing orthognathic surgery during their hospitalization period and until the end of intermaxillary fixation (IMF).Methods and Materials: This study included a total of 36 patients, scheduled for bimaxillary or monomaxillary orthognathic surgery in Emam Reza Hospital, Tabriz, Iran. Participants were healthy adults within the age range of 18-50 years. Demographic information was recorded in a corresponding questionnaire. Patients’ height was measured at the day of hospital admission. The patient’s weight was measured and recorded at three time points: the day of admission (T1), upon discharge form the hospital (T2) and after IMF was removed (T3). BMI was calculated (kg/m2) for each patient at all three mentioned time points. Information on food intake was collected using a 24-hour recall questionnaire on T1, T2 and T3. Nutritionist IV software was used to analyze the dietary intake of carbohydrates, protein and fats as well as the energy intake. Changes in patients’ BMI values, amount of macronutrient and energy intake were evaluated using repeated measures ANOVA. P-value <0.05 was considered statistically significant.Results: Participants comprised of 18 (50%) male and 18 (50%) female patients with an average age of 26.7±8 years. Patients’ BMI values exhibited a decreasing trend from T1 to T3, which was proven to be statistically significant (P<0.001). The average amount of energy, protein, fat and carbohydrate intake significantly decreased during the T1-T3 interval, i.e. from the preoperative state until after IMF was removed (P<0.05).Conclusion: According to the obtained results, orthognathic surgery caused a significant reduction in the BMI of the patients, which was probably due to a decrease in energy, protein and fat intake during the IMF period.