Skeletal Anchorage-Assisted Space Closure in a Patient with Bilateral Peg-Shaped Maxillary Lateral Incisors and Severe Crowding

Background: Peg-shaped maxillary lateral incisors are among the most common developmental anomalies affecting the anterior dentition and are frequently associated with Bolton tooth-size discrepancies and severe crowding. Treatment planning in these patients requires careful management of esthetics, occlusion, periodontal health, and anchorage control during space closure. Case Presentation: A 17-year-old female patient presented with bilateral peg-shaped maxillary lateral incisors, severe maxillary and mandibular crowding, deep bite, mild skeletal Class II relationship, and proclined mandibular incisors. Three treatment options were considered, including restorative enlargement of the lateral incisors, extraction of both peg-shaped lateral incisors with space closure, and extraction of the maxillary right lateral incisor followed by unilateral space closure and restorative enlargement of the contralateral lateral incisor. The selected treatment involved extraction of the peg-shaped maxillary lateral incisors followed by orthodontic space closure and canine substitution. Skeletal anchorage with temporary anchorage devices (TADs) was used to optimize biomechanical control during anterior space closure and midline correction. A maxillary TAD placed between the central incisors provided anchorage during mesial movement of the posterior segments, while bilateral mandibular TADs were used to control lower incisor proclination during leveling and alignment. Results: Treatment resulted in satisfactory alignment, correction of crowding, improvement of sagittal occlusal relationships, and achievement of stable intercuspation. Cephalometric analysis demonstrated improvement of the skeletal relationship (ANB from 5° to 3.5°) with maintenance of a balanced facial profile and favorable nasolabial angle. Despite the extraction-based mechanics, maxillary incisor torque was preserved and slightly increased. Conclusions: Extraction of peg-shaped maxillary lateral incisors combined with skeletal anchorage-assisted space closure may represent an effective and clinically efficient treatment option in patients with severe crowding and tooth-size discrepancy.