Unilateral Uprighting and Distalization of the Severely Crowded Posterior Mandibular Segment Using a Buccal Shelf Mini Implant: A Case Report

AimSevere lingual tipping of mandibular posterior teeth may result in traumatic occlusal contacts, periodontal complications, impaired mastication, and compromised oral hygiene. Conventional orthodontic mechanics can correct these discrepancies; however, they are often associated with undesirable side effects.This case report describes the management of severe unilateral lingual tipping and crowding of the mandibular posterior segment using a buccal shelf miniscrew-supported segmental uprighting approach.Case PresentationA ۱۷-year-old male patient presented with severe lingual tipping of the mandibular left posterior segment associated with localized crowding, traumatic occlusal contacts, masticatory discomfort, and transverse discrepancy. Clinical and radiographic examination revealed lingual inclination of the mandibular left second premolar and first molar, severe mesial root angulation of the mandibular left canine, overeruption of the maxillary left second premolar, and asymmetry of both midlines. The patient exhibited a skeletal Class I relationship with acceptable facial balance.InterventionsTreatment was completed over ۱۸ months in three phases. In phase I, retained roots of the maxillary left first molar were extracted, and intrusion of the overerupted maxillary left second premolar was achieved using two miniscrews (۱.۶×۸ mm) and elastic power chains. In phase II, the mandibular left second molar was extracted to facilitate distalization and uprighting because of the favorable position of the developing third molar. A buccal shelf miniscrew (۲×۱۰ mm) was inserted to provide skeletal anchorage, and elastic chains were applied to bonded buttons for simultaneous uprighting and distalization of the mandibular posterior segment. In phase III, comprehensive fixed orthodontic treatment was performed for alignment, leveling, crossbite correction, and final occlusal detailing using cross-elastics and auxiliary mechanics.ConclusionFavorable uprighting and distalization of the mandibular left posterior segment were achieved. Improvement of the posterior crossbite, dental asymmetry, and localized crowding was observed, and functional occlusal relationships were established. Traumatic occlusal contacts and masticatory discomfort were reduced following treatment. In addition, the mandibular left third molar erupted in an acceptable position.

کلیدواژه ها:

Buccal shelf miniscrew ، Molar distalization ، Temporary Anchorage Device