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Case Report

Class II Correction in a Severe Hyperdivergent Growth Pattern, Bilateral Open Bite and Oral Compromise
Sergio A. Cardiel Rıosa ´
Abstract: Severe vertical growth pattern and open bites are frequent problems the orthodontist must resolve but require a proper diagnosis, treatment plan, timing, and mechanotherapy to be properly treated. A case report with these problems ispresented. (Angle Orthod 2005;75: 870–880.) Key Words: Hyperdivergent growth; Vertical control

INTRODUCTION A 12-year two-month-old Latin girl was brought in by her parents for evaluation of her dentofacial appearance. The medical history revealed mouth breathing since early childhood. As a possible sequela of the mouth breathing, the patient exhibited bilateral open bite in the premolar areas.
aPrivate practice, Morelia, Michoacan, Mexico. ´ Corresponding author: Sergio A. Cardiel Rıos, CDO, Calle ´ Sargento # 40, Colonia Chapultepec Sur. 58260, Morelia, Michoacan, Mexico ´ e-mail: scardiel@unimedia.net.mx

There was no history of dental trauma or oral habits, but she exhibited hypoplasia of the enamel on the maxillary and mandibular first molars. The dentition was crowded—the mandibularleft second premolar was blocked out and both maxillary canines were unerupted. There were no significant signs or symptoms of temporomandibular disorders. Range of motion and amount of opening were normal. CASE REPORT Diagnosis and etiology The patient appeared facially symmetrical with normal lip competence. When smiling, she showed a full display of incisors and disharmony in the posteriorAccepted: July 2004. Submitted: June 2004. 2005 by The EH Angle Education and Research Foundation, Inc.

FIGURE 1. Pretreatment facial photographs.

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FIGURE 2. Pretreatment intraoral photographs.

FIGURE 3. Pretreatment dental casts.

teeth. She had a straight profile with excessive verticalfacial dimension (Figure 1). The plaster models exhibited a Class II division 1 subdivision right malocclusion with the left side in

Class I occlusion. She had two mm of overjet and two mm of overbite. Her upper midline deviated four mm to the right from the facial midline and the lower dental midline. The maxillary canines were impacted, and the
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FIGURE 4. Pretreatment panoramic and periapical radiographs.

FIGURE 5. Pretreatment Cephalometric radiograph and tracing.

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FIGURE 6. Directional force.

FIGURE 7. Presurgery.

maxillary arch form was triangular with a deep and constricted palatal vault. In themandibular arch, there was moderate crowding in the second premolar area and in the anterior area. The patient also had a bilateral open bite (4.5 mm on the right and three mm on the left) (Figures 2 and 3). The panoramic radiograph showed the complete dentition present including the third molars. The max-

illary right impacted canine had a pericoronal cyst with bone loss in the area, and the maxillarycentral incisors had some root resorption (Figure 4). Skeletally, the patient was a Class I (ANB 3 ) but was bimaxillary retrognathic. The FMA angle and the facial index confirmed the severe hyperdivergent growth pattern (Figure 5). The maxillary and mandibular incisor inclination was good, but the steep occluAngle Orthodontist, Vol 75, No 5, 2005

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FIGURE 8. Surgery.sal plane and the four mm curve of Spee confirmed the complexity of the problem. The etiology of the malocclusion was genetic. It was presumed that the open bite and the maxillary arch deformation were sequelae of mouth breathing during childhood. A diagnosis was achieved with the Differential Diagnostic Analysis System1 and Merrifield’s ‘‘dimensions of the dentition’’ concept.2 The cranial...