[Effect of surgically assisted rapid maxillary expansion on maxillary skeletal movement: a comparative study between tooth-borne and bone-borne palatal distracters]

The transverse deficiency of the maxilla is considered as one of the common clinical orthodontic problem, whereas the Surgically Assisted Rapid Maxillary Expansion is one of the essential treatments for the correction of that skeletal deficiency in the adult patients. The aim of this study was to assess the ratio of horizontal skeletal movement and tipping movement of the two parts of the maxilla after Surgically Assisted Rapid Maxillary Expansion with Lefort-I cortical osteotomy, midpalatal suture and pterygoid-maxillary suture osteotomies by using tooth-borne palatal expanders and bone-borne transpalatal distracters. Twenty adult patients [with ages between 18-30 years without inborn deformities or congenital syndromes] with skeletal maxillary narrowness being clinically and radiologically assessed. The studied sample is separated randomly into two groups: Group I, the expansion performed by tooth-borne palatal expanders. Group II, the expansion performed by bone-borne transpalatal distracters. A 7 day latency period passed before the activation of the expansion device [1 mm/day]. The ratio of horizontal skeletal movement in the tooth-borne palatal expanders group after 4 months of expansion was 46.98% of the entire expansion, whereas that was a little higher 48.83% in the bone-borne transpalatal distracters group but this difference was not statistically significant. We conclude that the efficiency of the tooth-borne palatal expanders is nearly similar to that of the bone-borne transpalatal distracters after Surgically Assisted Rapid Maxillary Expansion with Lefort-I cortical osteotomy, midpalatal suture and pterygoid-maxillary suture osteotomies

[Comparative study of zygomaticmaxillary buttresses osteotomies with or without midpalatal osteotomy in surgically assisted rapid maxillary expansion by using palatal distractor]

Assessment the efficiency of separating zygomaticmaxillary buttresses, with or without midpalatal suture osteotomy, on shape and size expansion of the maxilla using palatal distractor. Fourteen adult patients [ages between 18-25 years and no inborn deformities or congenital syndromes] with skeletal maxillary narrowness being clinically and radially assessed. The studied sample is separated to two groups; Group I: seven patients with bilateral zygomaticmaxillary buttress osteotomy, Group II: the previous procedure was repeated on another 7 patients but with midpalatal osteotomy. The expansion in group II has V shape vertically and horizontally, but that was not clear in group I [p=0.03]. Also the maxillary width immediately and 6 months after the expansion in group II increased statistically when compared with group I [p=0.00], and the percentage of skeletal maxillary expansion after 6 months in group I was 26.17%, but it was 61.88% in group II. We conclude that midpalatal osteotomy affects the shape of expansion and increases the percentage of skeletal maxillary expansion in adults