Abstract: This case report described a 28-year-old female who presented with a retained maxillary deciduous tooth and palatally displaced permanent tooth 25. Cone-beam CT revealed extensive pneumatization of both maxillary sinuses, with the residual bone height at the left sinus floor measuring only 1.45 mm. To augment the deficient alveolar bone, autogenous tooth bone graft (ATBG) was prepared chairside and used to perform a lateral sinus floor elevation at the site of tooth 25. At 2.5 months postoperatively, CBCT demonstrated a significant increase in vertical bone height to approximately 15.99 mm. Subsequently, staged invisible orthodontic treatment was adopted: in the first stage, tooth 25 was tractioned to rotate and be upright into the dental arch; in the second stage, fine adjustment was conducted. CBCT examination at 2 years postoperatively demonstrated that the bone height in the bone-grafted area was maintained at approximately 14.39 mm, the bone width exceeded 9 mm, the newly formed bone showed good integration, and it could support normal masticatory function.

Key words: Autogenous tooth bone graft, Alveolar bone deficiency, Orthodontics, Maxillary sinus pneumatization