Finite element analysis of the comprehensive impact of scar and maxillary expansion combined with protraction on the development of maxilla with cleft lip and palate after repair operation / 华西口腔医学杂志

OBJECTIVE@#To study the comprehensive impact of scar and maxillary expansion combined with protraction on the development of maxilla with cleft lip and palate after repair operation.@*METHODS@#In the original finite element model of the maxilla with cleft palate, a finite element model of the maxilla with cleft lip and palate was established by using Boolean operation in ANSYS. Scar force after cleft lip and palate repair and maxillary expansion force combined with protraction were added simultaneously to process the stress analysis.@*RESULTS@#Maxillary deformation occurred in the three-dimensional direction. The comparison of displacements was as follows: X-axis>Z-axis>Y-axis.@*CONCLUSIONS@#Maxillary growth is significantly inhibited in the three-dimensional direction under the comprehensive impact of scar and maxillary expansion combined with protraction after repair operation, especially transverse and sagittal growth.

Septopremaxillary ligament traction system: a review

Over the years, several animal studies have been conducted concerning the role of cartilaginous nasal septum, septopremaxillary ligament in midfacial growth. Most of the studies utilized non primate animal models at first and then more recently in primates such as chimpanzee. Proper choice of animal model to extrapolate from is critical for successful experimental design. Although nonhuman primates are phylogenetically closer to humans than other mammalian groups for better extrapolation to human condition, not all the craniofacial experiments require primate models. Renewed interests in understanding the influence of septopremaxillary ligament resection on midfacial growth led to many in vitro experiments on animal models. Recently systematic review of relevant animal experiment is regarded as a prerequisite for the conduct of the new clinical trials. Despite this fact, the literature addressing this topic in humans and systematic review on the effect of the septopremaxillary ligament is scarce. The more recent studies show that the maxillary labial frenum encloses the septopremaxillary ligament and forms an important constituent of septopremaxillary traction system. The biomechanical force mediating through the septopremaxillary ligament, maxillary labial frenum and nasolabial muscles results in stimulating their effects on sagital growth of the maxilla. The main purpose of this review is to update and extend the knowledge of the role of septopremaxillary traction system on the midfacial growth by synthesizing the available literature involving the septopremaxillary ligament resection in experimental models. If this review could synthesize the results of relevant research, a change in the therapeutic notions can also be expected.

Maxillary distraction osteogenesis in the management of cleft lip and palate: report of 2 cases

This study is to evaluate the growth and development of the maxilla advanced by transoral distraction osteogenesis of cleft lip and palate children. Subjects are two patients diagnosed as maxillary hypoplasia with cleft lip and palate, and followed up over 5 years after distraction. At the age of 11.4 years (mean), the distraction had been rendered and periodically taken lateral cephalograms were analysed to trace the growth of the maxilla. This cephalometric study showed continuous growth and development of the distracted maxilla to be stable through long term follow-up.

A cephalometric evaluation of anterior J hook headgear traction to the maxilla / 대한치과교정학회지

This study was aimed to observe the effect of Anterior J hook headgear on the craniofacial structures in mixed dentition with Class II malocclusion. The laterial c-phalograms of 20' children treated by Anterior J hook headgear were traced, digitized and statistically analyzed. The results were as follows 1. Forward growth of maxilla was inhibited. 2. Rotational effect of maxilla was not observed. 3. There was distal movement of maxillary dentition. 4. Maxillary_.dentoalveolar growth changes were more effective in anterior portion than posterior portion. &.Mandible maintained a normal growth and mandibular plane angle- was maintained during treatment period. 6. The ratio of anterior facial height to posterior facial height was almostly not changed.

Maxillary growth following cultured epidermal tissue graft and the administration of TGF-beta3 on surgically created palatal defects in rat

This study was designed to evaluate the influence of cultured epidermal tissue graft and the administration of transforming growth factor(TGF)-beta3 on maxillary growth in surgically created palatal defects. A total of 155 rats were divided into 2 groups according to surgical timing : postnatal 2 weeks(n=95), 4 weeks(n=40) and control(unoperated) group(n=20). The postnatal 2-week surgical group was subdivided into 3 groups according to repair methods: conventional surgery(Von Langenbeck technique)group(n=23); cultured tissue graft group(n=25); and full thickness skin graft group(n=25). Additionally, recombinant human TGF-beta3 was administered(30ng or 150ng) on collagen matrix in surgically created palatal defects during surgery(9 conventional surgeries, 9 cultured tissue grafts) in 2-week-old rats. The results showed that all types of surgical treatment decreased maxillary growth compared with the control(unoperated) group(p<0.0001). On the other hand, the tissue graft group, whether cultured tissue or grafted skin, contributed to increased maxillary growth(p<0.0001).And exogenous TGF-beta3 might play a role in connective tissue proliferation and new bone generation during wound healing on palatal defects. Our results suggest that grafting cultured epidermis with collagen matrix decreases the scar tension on maxillary growth more than conventional palatal surgery does. Therefore, exogenous TGF-beta3 may contribute to accelerate wound healing on palatal defects.