Surgery Versus Nonsurgery Option for Scissors Bite Treatment

This article compared the use of temporary skeletal anchorage devices (TSADs) and orthognathic surgery for scissors bite correction.

To correct the scissors bite without orthognathic surgery, a cross-type titanium miniplate was placed with 3 miniscrews (1.5 mm in diameter and 5 mm in length) in the midpalatal area, without a surgical incision and under local anesthesia. In addition, a 1 miniscrew was placed on the buccal alveolar bone to avoid molar extrusion during uprighting. In the surgical case, a 3-piece Le Fort osteotomy was performed to decrease maxillary arch width for transverse correction, and to close the extraction space by anterior retraction. The maxilla was stabilized with 4 L-shaped plates at the zygomatic buttresses and the pyriform aperture, as well as 2 straight plates between the 3 segments.

After 15 months of treatment in the nonsurgery case, the scissors bite was successfully resolved by decreasing maxillary arch width and uprighting the molars. In the mandibular arch, correction of the crowding was aided by extraction of # 41. In the surgery case, after 24 months of treatment in the orthognathic surgery case, the bilateral scissors bite was successfully resolved and the facial asymmetry was corrected. The molar occlusion finished in Class II and the facial profile was improved.

In scissors bite cases, a good diagnosis will help the clinician to decide whether treatment should involve orthognathic surgery. The authors have shown a case that was corrected with surgery and a case that was corrected using TSAD anchors. Treatment planning must include evaluation of the basal arch width of maxilla and mandible in class I occlusion, any skeletal asymmetry concomitant with a mandibular shift, the inclinations or atypical eruption degree of the posterior teeth, and the number of teeth involved in the scissors bite.