Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 13 3 2026 10 24 411 417 Raghavi Viswanathan Department of Orthodontics, Post Graduate Institute of Dental Sciences, Pandit Bhagwat Dayal Sharma University of Health Sciences, Rohtak–124001, Haryana, India. Amrita Gupta Department of Orthodontics, Post Graduate Institute of Dental Sciences, Pandit Bhagwat Dayal Sharma University of Health Sciences, Rohtak–124001, Haryana, India. Rekha Sharma Department of Orthodontics, Post Graduate Institute of Dental Sciences, Pandit Bhagwat Dayal Sharma University of Health Sciences, Rohtak–124001, Haryana, India. Devender Kumar Department of Orthodontics, Post Graduate Institute of Dental Sciences, Pandit Bhagwat Dayal Sharma University of Health Sciences, Rohtak–124001, Haryana, India. 2026 05 01 2026 08 24 Abstract: The surgery-first approach (SFA) to orthognathic treatment has emerged as a compelling alternative to conventional protocols, offering immediate skeletal correction without prolonged presurgical orthodontics. A key biological advantage is the regional acceleratory phenomenon (RAP), a post-surgical response that accelerates orthodontic tooth movement and reduces overall treatment duration significantly. The present case involved a patient presenting with a concave facial profile, retrusive upper lip, reverse overjet and overbite of 3 mm, proclined maxillary incisors, retroclined mandibular incisors as dental compensation, Class I molar relationship, maxillary arch spacing, mild mandibular anterior crowding, and congenitally absent maxillary lateral incisors. This constellation of findings, combined with the patient's desire for early aesthetic improvement and the anticipated benefit of RAP-driven accelerated tooth movement, guided the decision toward SFA as the most appropriate patient-centred strategy. Le Fort I maxillary advancement was performed, followed by expedited postoperative orthodontics. Canine substitution addressed the congenitally missing lateral incisors and restored smile harmony. Treatment was completed in seven months, substantially shorter than conventional protocols. At the 24-month follow-up, Class I occlusion with ideal overjet and overbite was maintained, facial profile improvement remained stable, and functional outcomes were consistent. Keywords: Canine substitution; Class III malocclusion; Maxillary retrognathism; Orthognathic surgery; Surgery-first approach   https://jcr.tums.ac.ir/index.php/jcr/article/view/645 https://jcr.tums.ac.ir/index.php/jcr/article/download/645/525