The Influence Of Different Kinds Of Palatal Lateral Excisions On Maxillary And Dental Arch Growth And Development

Surgery is the exclusively final method to cure the cleft of palate,but there are always the following malformation of the maxilla and dental arch after surgery. Every surgeon must think about the problem that how to prevent this kind of malformation after surgery.At present routine surgery will result denudated palatal bone in lateral excision area inevitably,which use mucoperiosteal flap medial movement to close soft tissue defect. It's generally accepted that the bone denudation on palate is one of the most important factor contributed to the following malformation of the growth and development.There are many kinds of methods to prevent this impairment.Nowadays,coincident issue is that prevention of sharpey's fibers formation will lead to a more favorable dento-alveolar development.However,there still remain controversy that choose which kinds of preventing methods is better. Although different is indicated among all kinds of preventing methods in histological change,palatal bone formation and the influence on maxillary and dental arch growth has not been reported.It's clinically instructive to find out all these differents and thequantitative relationship between different kinds of palatal lateral excisions and the growth of maxilla and dental arch.Objective: To acquire the influence of different kinds of palatal lateral excisions on maxillary and dental arch growth and development by measuring the maxilla and dental arch width of rats with different kinds of palatal lateral excisions,and investigating the different of histological micrograph and bone fluorescent labeling,and experimental proof for sugeons to choose a more effective preventing method and appropriate surgery is expected.Materials and methods: 112 three-week old SD male rats werestochasticly divided into a control group and 3 experimental groups.In the three experimental groups,bilateral mucoperiosteal,mucosal flap and periosteum was excised respectively in the lateral one half of the palate.Then 48 animals were injected with calcein by week.Biweekly,three animals in each group were sacrificed and the maxillae dissected out were used to measure the width of the maxilla and dental arch. One animal was used for histological examination by HE and masson's dyeing.Another 48 animals,which fluorescent labeling were used,the dissected maxillary were used to investigate the difference of bone labeling.Result:(l)After surgery,each groups present the constriction of maxilla anddental arch,and medial inclination of tooth was obvious.Compare the degress of influence:experimental group I>experimental group III ) experimental II(2)There were different histological changes among the groups. Whenmucoperiosteal flap was excised,scar tissue was found in the lateral operation areas,and was connected to the periodontal fibers.Many fibers penetrated into the palatal bone as sharpey's fibers,thus creating an attachment of the scar tissue to the bone.The type of bone deposition was the bundle type. When mucosal flap and periosteum was excised,sharpey's fibers was not found,and the palatal bone was of the lamellar type.(3)There were different rates of bone deposition and formation of new bone among the groups. When mucoperiosteal flap was excised,the rate of new bone deposition was the most lower,the type of new bone deposition was the medullary osteogenesis type.When mucosal flap and periosteum was excised,the rate of new bone deposition was decreased,but the type of deposition was still the periosteal osteogenesis type.Conclusions: There were different effect on maxillary and dental archgrowth in different kinds of palatal lateral excisions.lt is important to new bone formation and the type of deposition that periosteum is not defective.Prevention of sharpey's fibers formation can lead to prevent the following malformation effectively.