Orthodontic treatment of skeletal maxillary protrusion with dual bite: a case report and literature review

To evaluate the clinical efficacy and stability of a centric relation (CR)-guided approach combined with micro-implant anchorage and long traction hooks for root-controlled retraction of the maxillary anterior teeth in a patient with skeletal maxillary protrusion and dual bite, and to provide a reference for clinical practice.

A case of a 29-year-old female patient with skeletal maxillary protrusion and an asymptomatic discrepancy between the maximum intercuspation position (MIP) and CR (dual bite) was reported. First, the CR was identified and obtained by cone beam computed tomography examination and clinical techniques, then was stabilized by glass ionomer bite registration and myofunctional training. Maintaining the CR, the maxillary micro-implants combined with long traction hooks were used to correct skeletal maxillary protrusion by facilitating maxillary anterior teeth retraction, and finally a new intercuspal occlusion was established to maintain long-term stability. A literature review was conducted to contextualize the treatment rationale and key steps.

Post-treatment, a coordinated and stable functional occlusion was established in CR without temporomandibular joint symptoms, and the condylar location was coordinated with the glenoid fossa. Controlled root retraction of the maxillary anterior segment and facial profile improvement were achieved. At 3-year follow-up, both occlusion in the CR and condylar positions remained stable. The literature review indicated that, in patients with CR-MIP discrepancy, prioritizing the identification and stabilization of CR is critical, and micro-implant anchorage with long traction hooks effectively facilitates maxillary anterior teeth retraction and profile improvement.

For skeletal maxillary protrusion with dual bite, a CR-first strategy combined with micro-implant anchorage and long-hook mechanics for root-controlled anterior retraction can concurrently improve stomatognathic function and facial aesthetics, demonstrating favorable mid- to long-term stability.