IntroductionBimaxillary orthognathic surgery (BOMS) serves as a standard approach for correcting severe skeletal-dental discrepancies, such as Class III malocclusion, significantly enhancing masticatory function, facial aesthetics, and patients’ quality of life(1).However, arch space deficiency affects 30-40% of BOMS candidates, complicating preoperative planning, particularly when impacted wisdom teeth are positioned in the mandibular lesser segment, necessitating extraction to ensure postoperative fixation stability(2, 3). The prevalence of impacted third molar impaction in the general population is approximately 27%, but in orthognathic patients with arch space deficiency, this rate exceeds 50%, potentially leading to complications such as root displacement, bone volume loss, and occlusal instability(3, 4).Recent advancements in virtual surgical planning (VSP) and 3D-printed surgical guides have increased intraoperative accuracy by up to 25% and reduced operative time, which is crucial for managing complex cases like extraction from the lesser segment(5, 6).Recent studies demonstrate the superiority of VSP over traditional methods in transferring planning to the intraoperative phase, with mean errors below 1 mm in three-dimensional displacements(7).Despite these benefits, case reports on the application of 3D guides in combining severe arch space deficiency and third molar extraction during BOMS remain limited to fewer than 5 in the recent literature, highlighting a significant knowledge gap(8).This case report describes the innovative application of a 3D-printed surgical guide for safe and minimally invasive extraction of a third molar from the lesser segment during BOMS in a 19-year-old female patient. By emphasizing bone volume preservation and enhanced surgical precision, this case not only addresses rare structural challenges but also provides a practical and educational model for surgeons, justifying its publication for advancing clinical standards in oral and maxillofacial surgery.