Timely relocation of subapically impacted maxillary canines and replacement of an ankylosed mandibular molar are the keys to eruption disturbances in a prepubertal patient.

Eruption disturbances such as impaction and ankylosis complicate orthodontic treatment because soft-tissue and hard-tissue considerations must be taken into account. Treatment is further complicated when such eruption disturbances occur in a growing patient. Extraction of impacted or ankylosed teeth can be an option that carries the weight of additional prostheses and bony defects, whereas exposure or luxation followed by orthodontic traction can preserve the patient's teeth and bony structure with improved esthetics. Therefore, an accurate diagnosis is needed in establishing an efficient and effective force system to achieve the desired tooth movements with few unwanted sequelae. This case report describes the process of differential diagnosis with the aid of 3-dimensional imaging in constructing a force-driven system, using the centers of resistance as reference points, to successfully bring a pair of impacted maxillary canines into alignment and protract a mandibular molar to achieve an acceptable occlusion in an adolescent girl.