Longitudinal syudy on analyzing three-dimensional changes of the maxillary dental arch and palatal form. When is optimal for the secondary bone grafting?

唇腭裂患儿上颌骨扩弓后牙槽骨形态变化的三维评价[对象与材料]76例唇腭裂患儿上颌牙弓扩弓。[方法]采用非接触式激光三维数字化测定仪(Vivid 700，Minolta公司)，对上颌扩弓前后的两组模型进行三维重建，得到上颌骨扩弓前后的牙列模型。[结果]骨架式上颌骨扩张器与其他扩张器相比，上颌骨体积增加幅度最大。在另一只手。节流扇形膨胀机的表面积增加幅度最大。四螺旋扩张器显示颊外侧段倾斜和Po…唇腭裂儿童二期植骨术后腭槽骨形态变化的三维评价[材料]九州大学63例唇腭裂儿童二期植骨手术前后的牙型。[方法]应用非接触式激光三维数字化测量仪(Vivid 700)获得牙弓形态的三维图像。[结果]所有病例二次植骨后腭槽组织的表面积、横截面积、体积均有不同程度的缩小。这一下降与手术年龄和术后时间无关。由于大多数病例年龄在10岁左右，正畸植骨后裂段的后牙前移。上牙槽组织横截面积增加，而表面积减少。[结论]正畸牙移动二次植骨的最佳时机为尖牙萌出前，即尖牙萌出前。但对于牙槽裂有侧切牙的病例，早期行二期植骨效果较好。较少

Three-dimensional evaluation of the palato-alveolar form changes following maxillary expansion in the cleft lip and palate children[Subjects ＆ Materials] Subjects were 76 cleft lip and palate children whose maxillary dental arches were expanded. The materials were dental casts taken before and after maxillary expansion.[Methods] Using non-contact laser 3-D digitizer (Vivid 700, Minolta Co.), the three dimensional palato-alveolar forms were obtained from two casts, which were taken before and after maxillary expansion. The surface area, volume of the palato-alveolar tissue, directions of both lateral segments, and inclinations of some tooth axes were calculated by 3D analyzing software (3D rugle).[Results] Skeleton type maxillary expander showed the maximum increment of the palatal volumes comparing with other expanders. On the other hands. Jointed fan-type expander gained the largest increment of superficial area. Quad helix expander showed buccal inclination of lateral segments and po … More sterior teeth, and it didn't gain fan-type expansion.Three-dimensional evaluation of the palato-alveolar form changes following with secondary bone grafting on cleft lip and/or palate children[Materials] Pre- and post-operative dental casts of 63 cleft and/or palate children who have received secondary bone grafting in Kyushu Univ. Dental Hospital.[Methods] Three-dimensional palato-alveolar forms were obtained using non-contact laser 3-D digitizer (Vivid 700). The changes of superficial area, cross-sectional areas, and volume of the palato-alveolar tissue were measured on the anterior field to the maxillary 1st molars.[Results] Superficial area of the palato-alveolar tissue showed decrements following with secondary bone grafting in every case. This decrement has relationship with neither the age of operation nor the postoperative period. As most of the cases were around 10 years of age, the posterior teeth on the cleft segments were driven forward after bone grafting orthodontically. The cross-sectional area of the palato-alveolar tissue showed increment even though superficial area showed decrement. The high alveolar region showed increment of the volume, but infra-alveolar region showed decrement.[Conclusion] The best time of secondary bone grafting for orthodontic tooth movement is considered to be just before the eruption of the canine on cleft site as practiced in Kyushu University. But it is better to practice secondary bone grafting earlier in the case with lateral incisor on alveolar cleft. Less