Nonsurgical maxillary orthopedic protraction treatment for an adult patient with hyperdivergent facial morphology, Class III malocclusion, and bilateral crossbite

Optimal treatment for an adult patient with hyperdivergent facial morphology, Class III malocclusion, bilateral posterior crossbite, and skeletal disharmony usually requires comprehensive orthodontics combined with extractions, orthognathic surgery, or both. However, treatment becomes more challenging when the patient rejects surgery because of fear or cost. This case report presents the orthodontic treatment of a 24-year-old woman with a Class III malocclusion and bilateral posterior crossbite without surgery using orthopedic and comprehensive orthodontic approaches. The extraoral evaluation showed a hyperdivervent pattern, paranasal deficiency, a slightly protrusive lower lip, and an obtuse labiomental angle with a chin deviated to the left. Intraorally, she exhibited a severe Angle Class III malocclusion bilaterally with edge-to-edge to -1 mm overjet, canting of the occlusal plane up to the left with mandibular midline 5.3 mm to the left of the maxillary and facial midlines, and bilateral posterior crossbite with 5.7 mm of arch width discrepancy. Therefore, the patient was diagnosed with skeletal and dental Class III relationship, hyperdivergent pattern, a deviation of the mandible to the left, bilateral posterior crossbite, mild to moderate maxillary and mandibular crowding, slightly proclined maxillary incisors and upright mandibular incisors. After 15 months of treatment, all treatment objectives were achieved, and the appliances were removed. Teeth were well leveled and aligned, ideal overbite and overjet were established with premolars and canines in a Class I relationship, bilateral posterior crossbite was corrected, vertical dimension was controlled, and the smile was improved with a slight improvement in the profile; however, bilaterally, the molar occlusion was not completely settled and remained in a Class III relationship. This case report demonstrates the successful nonsurgical treatment of an adult with Class III malocclusion, hyperdivergent facial morphology, and bilateral posterior crossbite using a midfacial skeletal expander and facemask for orthopedic correction. With reduced costs and fewer risks than surgical treatment options, this treatment protocol offers an alternative to adult patients.