片側臼歯抜歯とミニスクリュー支援後方遠心移動を併用した重度両顎歯列不正の管理：症例報告

Unilateral extraction of the compromised maxillary first molar combined with miniscrew-assisted posterior distalization provides a focused, non-surgical approach to correct asymmetrical Class III subdivision and severe bimaxillary crowding while preserving soft-tissue balance.

A 26-year-old female with severe bimaxillary crowding, unilateral Class III subdivision, mandibular midline deviation, and a pulp-necrosis maxillary left first molar, seeking a minimally invasive solution without surgery or prosthetic rehabilitation.

A unilateral dental Class III subdivision malocclusion, severe mandibular and moderate maxillary crowding, right mandibular midline deviation, a poor-prognosis necrotic maxillary left first molar, mild lip protrusion with a slightly convex profile, and impaction of all third molars.

The treatment plan involved the extraction of the maxillary left first molar, followed by space closure using conventional anchorage. This was combined with miniscrew-assisted distalization of the maxillary right and mandibular left posterior segments to retract the maxillary dentition, correct the dental midline discrepancy, and create space for alleviating bimaxillary crowding. Temporary anchorage devices were employed to facilitate controlled tooth movement and to minimize undesirable side effects such as incisor tipping and anchorage loss.

After 17 months of active treatment, the patient achieved a Class I canine relationship, coincident dental midlines, ideal overjet and overbite, and a notably improved facial profile. The mandibular midline deviation was corrected via unilateral distalization using buccal-shelf miniscrews, while the left posterior maxillary segment was protracted to substitute the extracted molar. From a soft tissue perspective, lip protrusion was reduced, and overall facial balance was enhanced.

This case underscores the clinical effectiveness of combining asymmetric molar extraction with skeletal anchorage mechanics as a non-surgical and non-prosthetic treatment alternative for adult patients with asymmetrical Class III malocclusion and compromised molars.