Nonsurgical Treatment of Anterior Crossbite in a Cleft Lip and Palate Patient Using a Fan-Type Rapid Palatal Expander and Fixed Appliances

The panoramic radiograph revealed short upper central- and lateral-incisor roots and absence of the left third-molar germs. Cephalometric analysis (Table 1) indicated a skeletal Class III malocclusion (ANB = –5°), a retropositioned maxilla (SNA = 78°), and a forwardly displaced mandible (SNB = 83°). The patient also had a dolichofacial growth pattern (SN-GoGn = 37°), with well-positioned upper incisors (U1-NA = 25°, 4mm) and retroclined lower incisors (L1-NB = 18°, IMPA = 80°).

Treatment objectives were to correct the anterior transverse maxillary deficiency, resolve the anterior crossbite, improve facial balance, and establish an ideal occlusion.

The first option was to delay orthodontic treatment until the patient had finished growing, but this would have had a negative effect on his quality of life during adolescence.⁶ In addition, the malocclusion would likely have worsened, making surgical maxillary advancement imperative. A second option was to perform immediate orthodontic nonextraction treatment to improve the patient’s facial esthetics and to balance maxillomandibular growth, notably the lip relationship. The parents and the patient opted for this second alternative.

Treatment Progress

A banded fan-type RPE with an acrylic cover was prescribed to promote expansion of the anterior maxilla, where the transverse deficiency was more pronounced (Fig. 2A). The appliance was activated .5mm per day for 21 days until over­correction of the posterior teeth was achieved (Fig. 2B). At that point, the expansion screw was fixed in place for six months of passive retention.

Once the active expansion was completed, .022" × .028" standard edgewise brackets were bonded in the maxillary arch, and an .014" nickel titanium archwire was placed from the upper left first molar to right central incisor (Fig. 3).

The archwire sequence continued with .016", .018", and .020" stainless steel archwires. When the .020" archwire was in place, the maxillary midline shift was addressed with elastomeric chains (Fig. 4). The lower canines and premolars were bonded, and the lower first and second molars were banded for leveling and alignment of the posterior teeth with sectional mechanics to avoid proclination of the lower incisors. The lower archwire sequence involved .016", .018", and .020" stainless steel wires.

After the maxillary midline correction, an .012" nickel titanium upper archwire was placed from first molar to first molar. The archwire sequence then progressed to .016", .018", and .020" nickel titanium and .019" × .025" stainless steel, with 1st-, 2nd-, and 3rd-order bends placed in the finishing wire. Maxillary incisor torque was increased to compensate for the anterior crossbite. In the mandibular arch, brackets were bonded to the incisors, but a full archwire was not placed until the upper archwire reached .019" × .025" stainless steel (Fig. 5). Temporary miniscrews were inserted between the upper and lower right first molars and second premolars, and a sliding jig was used to distalize the lower right posterior teeth and correct the mandibular midline shift.

The sliding jig was removed after the midline correction, and the patient then wore settling elastics for intercuspation. Total treatment time was four years (Fig. 6A and 6B). 

A mandibular 3-3 lingual retainer wire was bonded. A wraparound retainer was used in the upper arch full-time for the first year, at night only for the next six months, and on alternating days for the subsequent six months, for a total of two years.

Treatment Results

After four years of treatment, Class I molar and canine relationships were obtained, and the anterior crossbite, midline shifts, overjet, and overbite were corrected. The anterior transverse expansion resulted in a more pleasant smile. Facial esthetics were improved, and the concave profile was balanced.

The panoramic radiograph evidenced root parallelism and confirmed the absence of the left third molars and root resorption of the upper central incisors. Cephalometric analysis (Table 1) demonstrated the effects of treatment: the skeletal Class III relationship (ANB = −6°) and the vertical pattern (SN-GoGn = 36°) were maintained, while the upper incisors were proclined and protruded (U1-NA = 43°, 11mm).

Five years after treatment, the facial and occlusal results were maintained (Fig. 7).

Discussion

In a patient with unilateral cleft lip and palate, the skeletal anterior crossbite and maxillary anterior transverse deficiency can be attributed more to the surgically repaired lip than to the surgically repaired palate, because the pressure exerted by the scar tissue of the lip causes atresia of the premaxilla.⁷ The maxillary bone fails to grow normally and tends to narrow, which affects its relationship with the mandibular basal bone over time.⁸ A conventional Hyrax^* expander is unsuitable for such a case, in which a posterior crossbite is not present and only the premaxilla is affected.^1,7 A fan-type palatal expander produces a more V-shaped opening in the anterior region,^5,9 with the further advantages of moving the maxilla downward and forward and increasing labial tipping of the incisors.⁴

This report shows how such effects, typically associated with a fixed appliance, can be used in compensatory treatment of a young patient in the permanent dentition. Significant expansion was achieved, palatal root torque of the upper incisors was accentuated, and the lower incisors were retracted to normalize the overjet while the patient was still growing. Additionally, there was no clockwise rotation of the mandible, and the patient’s vertical growth pattern was not accentuated.