Skeletal open bite with amelogenesis imperfecta treated with compression osteogenesis: a case report

A 37-year-old male presented with masticatory disturbance and aesthetic complaints. His facial profile was straight, and the frontal view was almost symmetrical, with long lower facial height. When the patient smiled, upper incisors could not be seen below the upper lip. He exhibited no phenotypes and medical and family histories about osteogenesis imperfecta and bone diseases.

Molar relationships were Angle Class I on both sides. All erupted teeth showed severe AI without loss of congenital teeth (Fig. 1). Anterior open bite of − 10.0 mm was observed between the edges of the upper and lower central incisors. The upper dental midline shifted 2.0 mm to the right relative to the facial midline, and the lower dental midline shifted 0.5 mm to the left relative to the facial midline.

Clinical and radiographic examinations revealed a stump lesion on the patient’s lower right second molar and caries lesions on his upper right first premolar, upper and lower left first, second and third molars.

Cephalometric analysis revealed a skeletal Class I jaw-base relationship (Table 1). The mandibular plane and gonial angles were larger than historical values for Japanese control subjects [7], indicating a high mandibular plane angle. The maxillary incisors showed an average degree of inclination, but the mandibular incisors were inclined lingually.

The patient was diagnosed as a skeletal open bite with severe AI of all teeth erupted, a skeletal Class I jaw-base relationship, and high mandibular plane angle. The treatment objectives were: (1) to correct the anterior open bite and establish ideal overjet and overbite; (2) to achieve acceptable occlusion with good functional Class I occlusion; and (3) to recover the shape of the collapsed teeth with AI by prosthodontic treatment in order to prevent further wear and sensitivity. The treatment was planned as follows:

After the upper and lower left third molars and the lower second molar were extracted, 0.018″-slot pre-adjusted edgewise appliances were placed on both arches. After leveling, corticotomy was performed under local anesthesia with intravenous sedation. Surgery was performed on an outpatient basis (in two stages to avoid bone necrosis) [6]. In the first stage, corticotomy was initiated at the palatal surface of the first and second upper premolars with a mucoperiosteum incision on the alveolar ridge, 3 mm above the tooth root apices (Fig. 2). A fissure half the width of the desired amount was made with a round bar of 4 mm in diameter through the cortical plate of bone surrounding the teeth. The anchor plate was placed onto the center of the hard palate. The second corticotomy at the buccal site was performed 3 weeks after the first corticotomy (Fig. 2). The mucoperiosteal flap was abraded beforehand to visualize the area of the corticotomy and to ensure that the procedure was carried out in accordance with previously corticotomized regions. The anchor plates were bilaterally fixed to the zygomatic buttress. Then, elastomeric chains were added to move the corticotomized bone/teeth segments 3.5 mm superiorly. After 1 month, posterior maxillary segments were moved superiorly, which ultimately resulted in correction of the skeletal open bite.

After 8 months of postoperative orthodontic treatment, overbite was improved by − 2.0 mm, and molar relationships were maintained as a Class I relationship (Fig. 2). Prosthodontic treatment was initiated to protect dentin and establish stable occlusion. After 5 months of prosthodontic preparation, all edgewise appliances were removed, and provisional crowns were set on all teeth with AI. The total active treatment period was 16 months.

On facial photographs obtained after treatment, anterior lower facial height was reduced, resulting in a balanced facial profile (Fig. 3). The anterior open bite was corrected, and the occlusion was much more stable and acceptable, with Class I canine and molar relationships. The overjet and overbite were + 2.0 mm and + 1.5 mm, respectively. When the patient smiled, approximately one-third of the maxillary central incisors were properly exposed. Panoramic radiograph showed that root parallelism was achieved (Fig. 3).

Post-treatment cephalometric evaluation showed a skeletal Class I jaw base relationship (ANB 3.6°) (Table 1, Fig. 4). The mandible was rotated 3.0° counter-clockwisely (MP-FH plane 37.3°). The upper first molars were intruded 3.5 mm toward the palatal plane. The maxillary and mandibular central incisors were extruded 3.0 mm and 0.5 mm, respectively. These factors contributed to the maintenance of an acceptable interincisal relationship.

After 8-year retention, the occlusion was stable, and a good facial profile was maintained (Fig. 5). Panoramic radiograph revealed no or less changes in alveolar bone level and root parallelism (Fig. 5). Cephalometric analysis showed only minor changes in maxillary and mandibular position, which did not result in relapse (Fig. 4).