Anterior tooth loss in children and adolescents presents a clinical challenge because treatment must restore esthetics and function while accommodating ongoing craniofacial growth and changes in the developing dentition. Conventional removable partial dentures may provide an interim replacement; however, their bulk, retention requirements, and patient acceptance may affect compliance. Essix appliances offer a lightweight, esthetic, and minimally invasive alternative that can be adapted to the existing dentition and modified to replace a missing anterior tooth. This case report describes the management of a 13-year-old male patient with a missing mandibular left central incisor following extraction of a previously fractured tooth. A conventional removable partial denture had initially been provided; however, the patient demonstrated poor compliance with its use. Considering the patient's age, esthetic concerns, ongoing dental development, and need for a conservative interim prosthesis, a modified Essix-based transitional prosthesis was fabricated. The appliance utilized the remaining dentition for retention and incorporated a replacement tooth corresponding to the missing mandibular left central incisor. Following delivery, satisfactory adaptation, retention, esthetics, and comfort were observed. The patient reported greater acceptance of the appliance compared with the previously provided removable partial denture. This case highlights the potential use of a modified Essix-based transitional prosthesis as a conservative and reversible option for anterior tooth replacement in growing adolescents, particularly when conventional removable prostheses are poorly accepted.