Osteogenic uni- or bilateral form of the guided rapid maxillary expansion.

Surgically assisted rapid palatal expansion is an important treatment procedure in patients with constricted maxillae. Several surgical methods have been proposed to expand the maxilla bilaterally. A new technique was developed for performing a symmetric or asymmetric maxillary expansion guided by the stability of the mid-palatal area employing two osteotomy cuts on either side of mid-palatal suture. A Hyrax-type expansion device was used post-operatively. Seventeen patients were included in the study (9 males, 8 females) with a mean age of 30.7 years. Inter-canine and inter-molar widths were evaluated at three assessment intervals: before treatment (T1), immediately after appliance removal (T2) and at six months follow-up (T3). Between T1 and T2, a mean expansion of 7.1 and 9.9mm was achieved at the canine and molar areas, respectively. The amount of relapse measured between T2 and T3 was minimal (a mean value of 0.35 and 0.8mm at the canine and molar areas, respectively). Asymmetric expansion was performed in 6 patients who exhibited unilateral skeletal constriction at the initial assessment and these cases appeared stable at T3. The surgical approach described in the current study enabled rapid maxillary expansion of unilateral and bilateral skeletal constriction cases effectively and with good stability.