Transverse maxillary stability assisted by a transpalatal device: a retrospective pilot study of 9 cases.

This retrospective pilot study assessed the transverse stability of an original surgical approach in nine patients with moderate transverse maxillary deficiency associated with a sagittal and/or vertical skeletal anomaly. During the one-stage surgical procedure, bi- or three-dimensional anomalies were corrected. Maxillary expansion was guided by a transpalatal bone-anchored device (TPD). Expansion measurements were made 1-2 months before surgery, 6 and at least 12 months after surgery. The transverse occlusion was corrected in all cases. After 12 months the gingival landmarks revealed an expansion range from -0.83 to +2.92 mm for the cuspids, +1.66 to +6.23 mm for the bicuspids and from +2.68 to +4.80 mm for the molars. For the occlusal landmarks, expansion ranged from -2.01 to +3.15 mm (cuspids), from +1.11 to +7.13 mm (bicuspids) and from +2.70 to +6.26 mm (molars). Cuspid expansion was significantly smaller than that of bicuspids and molars. This more posterior expansion was achieved through the surgical procedure. The transverse stability obtained with the aid of the bone-anchored TPD was satisfying. This preliminary study supports the principle of an original surgical approach, called 'Le Fort I--TPD', which combines a Le Fort I osteotomy with a controlled maxillary expansion.