Experimental And Clinical Research On Zygomatic Arch Hypoplasia Treatment With Coral Hydroxyapatite

Objective1. To set up the digital model of zygomatic arch of normal people and patient with zygomatic arch hypoplasia. To discuss the clinical morphological characteristics of hypoplastic zygomatic arch by the measurement and analysis of them. To raise up an easy evaluation plan and individual classification primarily.2. To follow-up the patients with zygomatic arch hypoplasia who were treated by zygomatic arch reconstruction with calvarial bone graft. To evaluate the surgical plan and the bone absorption rate by comparing the CT data preoperatively, postoperatively and follow-up.3. To discuss the quality and stability of new bone conducted by coralline hydroxyapatite in animal experiment, with autologeous calvarial bone graft as the control.Method1. CT data of70normal people and44patients with zygomatic arch hypoplasia were collected. Then summarized the hypoplastic zygomatic arch. characteristics through follow steps:3D reconstruction, discrepancy analysis, partition and calculation.2. Follow-up8case of zygomatic arch hypoplasia that were treated by zygomatic arch reconstruction with calvarial bone graft. Compare the volume of the "new" zygomatic arch postoperatively and follow-up, and conclude the bone absorption rate of the new bone.3. Set up the large animal model with critical zygomatic arch bone defect, and repair by coralline hydroxyapatite. Evaluate the new bone by histology, morphology, X-ray, CT scan and biomechanics. Comparing with the autologeous calvarial bone graft, the quality and stability of the new bone conducted by coralline hydroxyapatite were evaluated generally.Result1. The digital models of zygomatic arch of normal people and patient with hypoplastic zygomatic arch were achieved. The inherent laws of zygomatic arch hypoplasia were observed primarily. The easy JKL way for hypoplastic zygomatic arch evaluation, base on the volume, and the individual classification (3types and7subtypes) were raised up primarily.2. The regularity of the new bone absorption were observed, base on the CT data of8patients.3.10mm over the zygosquamosal suture is a critical bone defect of zygomatic arch. It is successful to use coralline hydroxyapatite to repair the defect. The new bone was conducted in and formed the bony structure. Although the maturity and strength of the new bone would not fit well with the new bone formed by autologeous calvarial bone graft, the structure and function could meet the needs physiologically.Conclusion1. In part one of this study, we proposed a new method for measuring the hypoplastic zygomatic arch precisely. The method is base on3D’ medical image reconstruction technology and computer graphics processing technology. According to the measurements, there are certain trends of the development of the deformity of zygomatic arch. Easy way for evaluation and individual classification were raised up primarily.2. In part two of this study, we follow-up8patients with zygomatic arch hypoplasia who were treated by autologeous bone graft. Compare the CT data, the new bone absorption of zygomatic arch were funded. The gourd A is higher than group B. 3. In part three of this study, we proposed the critical bone defect of zygomatic arch and showed the asymmetry result. Sum up the result of the exam of histology, morphology, X-ray, CT scan and biomechanics, it can be inferred that the coralline hydroxyapatite could repair the defect by conducting new bone ingrowth. The maturity and strength of the new bone were achieved. In all, coralline hydroxyapatite could be a candidate method for clinical treatment.