Outcome of combined orthodontic-surgical treatment in a United Kingdom university dental institute

Introduction: This retrospective observational cohort study evaluated effectiveness of combined orthodontic-orthognathic surgical treatment in a UK University Dental Institute. Methods: Patients were identified from a database maintained prospectively throughout a 5-year period of observation. Demographic and clinical data included age, malocclusion, Index of Treatment Need, Index of Orthognathic Functional Treatment Need, orthodontist, surgeon, surgical procedure and treatment-time. Peer Assessment Rating (PAR) scores were generated from pre- and post-treatment dental study casts by a single calibrated examiner. Results: One hundred and sixty two subjects began treatment during the period of observation, 92 completed, 14 elected to discontinue before surgery and 56 remained in treatment. Outcome data were available for 73, 16 males and 57 females (mean age 23.28 [SD, 7.92] years). Within this sample, 33 (45.2%) presented with class II division 1, 6 (8.2%) with class II division 2 and 34 (46.6%) with class III malocclusion. Isolated maxillary and mandibular surgery was carried out in 3 (4.1%) and 24 cases (32.8%), respectively; bimaxillary surgery was performed in 46 (63.1%). Mean total treatment time in fixed appliances was 920.28 days (30.7 months). Mean pre-treatment PAR score was 39.09 [SD, 9.42] and post-treatment 5.86 [SD, 4.25] with a mean 83.7% PAR score reduction, representing a greatly improved occlusal result. Kruskal-Wallis testing found no evidence of any relationship between independent variables and percentage PAR reduction; however, surgeon identity did significantly influence treatment length (P = 0.007). Conclusions: This investigation demonstrates that in terms of static occlusion combined orthodontic-orthognathic surgery is effective in correcting severe malocclusion.