PURPOSE: The aim of the study was to identify patient-specific and/or surgery-specific factors that may predict complications following orthognathic surgery, using data from the Swedish National Register of Orthognathic Surgery (NROK).

METHODS: In this retrospective register-based cohort study, data from NROK (2017-2020) was analyzed to identify risk factors for complications following single-jaw maxilla surgery, mandibular surgery, and bimaxillary surgery. Outcome data on postoperative infection (POI), removal of osteosynthesis material, re-operation, and persistent neurosensory disturbance (NSD) were collected 12-months postoperatively.

RESULTS: Among the 428 patients included in the study, 100 had single-jaw maxilla surgery, 130 had mandible surgery, and 198 had bimaxillary surgery. The site of surgery showed to be the main factor linked to postoperative complications after orthognathic surgery. Mandibular interventions and bimaxillary surgery increased the risk of POI, removal of osteosynthesis material and NSD more than three (3) times compared to maxillary surgery. For re-operation, there was no significant difference between the groups. Other factors associated with increased risk were overweight, age over forty, smoking, and no postoperative antibiotics.

CONCLUSION: Mandibular and bimaxillary procedures are associated with increased postoperative complication rates. Age, BMI, smoking, and antibiotic use should be considered in preoperative planning and postoperative care.