Objective: To report a multidisciplinary treatment of gemination/fusion of the left maxillary first incisor. Case Report: An 11-year-old boy presented to our clinic with the chief complaint of an unpleasant appearance of his anterior teeth. Clinical and radiographic evaluation revealed gemination/fusion of the left maxillary first incisor combined with an Angle's Class II relationship (skeletal), retruded mandible, deep bite, short lower face height, and proclinaion of the maxillary incisors. The multidisciplinary approached treatment included orthodontic treatment engaged with root canal treatment of the left maxillary first incisor followed by periodontal surgical separation of the mesial root of the left maxillary first incisor and restoration of the crown using resin restoration. Conclusion: Tooth shape anomalies in general dental practice may be rare, but the dentist should be aware of the nature of the problems encountered and the specific treatment needs. The treatment may be complex and contain various treatment protocols that may include interdisciplinary endodontic, surgical, and periodontal interventions. Schlagwörter: fusion, gemination, orthodontic treatment, periodontal surgery, root canal treatment, root separation