Weight Loss Following Orthognathic Surgery: a Descriptive Prospective Cohort Study

Objectives: The purpose of this prospective cohort study was to assess weight loss in kg following orthognathic surgery focusing on gender, type of surgery, employment, and living arrangements, as effect modifiers.

Material and Methods: Patient weights were measured at four points during their trajectory; two weeks preoperatively, week one, week three, and week eight postoperatively. Additionally, the registered nurse collected the following information: (1) patient age; (2) gender; (3) status of employment; (4) type of surgery; and (5) living arrangement.

Results: Mean weight loss of 3.35 kg (95% CI [confidence interval] = 3.07 to 3.62, P < 0.001), 3.56 kg (95% CI = 3.23 to 3.89, P < 0.001), and 2.79 kg (95% CI = 2.36 to 3.21, P < 0.001) for week 1, 3 and 8. Higher weight loss was observed in males 3.81 kg (95% CI = 3.31 to 4.31) compared with females 3 kg (95% CI = 2.71 to 3.29) at week 1 (P = 0.01). Highest weight loss following bimaxillary surgery was observed at week 1 (P = 0.00) and week 8 (P = 0.04).

Conclusions: Postoperative proportional weight loss is observed in all patients undergoing orthognathic surgery. Being male and having bimaxillary surgery predicts for a higher weight loss. Patients who had bimaxillary procedures showed greater weight loss compared to those who had a single jaw procedure, possibly due to longer surgery times, increased facial swelling and restricted mouth opening. Interestingly, living arrangements seemed to have an effect on weight loss at week 3, suggesting that social support may influence nutritional status.

J Oral Maxillofac Res 2025;16(1):e3

doi: 10.5037/jomr.2025.16103

Accepted for publication: 31 March 2025

Keywords: cohort studies; orthognathic surgery; postoperative period; weight loss.