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

唇腭裂儿童上颌牙弓扩张后腭牙槽形态变化的三维评价[对象与材料]研究对象为76例上颌牙弓扩张的唇腭裂儿童。材料为上颌扩张前后的牙模。[方法]采用非接触式激光三维数字化仪（Vivid 700，美能达公司），对上颌扩张前后的2个模型进行腭-牙槽三维成像。通过三维分析软件（3D rule）计算腭牙槽组织的表面积、体积、两侧牙段的方向和部分牙轴的倾角。[结果]骨架型上颌扩张器与其他扩张器相比，上颌扩张器的腭体积增量最大。另一方面。连接式风机膨胀机表面积增量最大。四螺旋扩张器表现为侧段颊向倾斜，后牙多，未实现扇形扩张。九州大学口腔医院唇腭裂/腭裂儿童二次植骨术后腭牙槽形态变化的三维评价[材料]63例接受二次植骨的唇腭裂/腭裂儿童手术前后牙模。[方法]采用非接触式激光三维数字化仪（Vivid 700）获得腭牙槽三维形态。测量上颌第一磨牙前野腭牙槽组织表面积、横截面积和体积的变化。[结果]二次植骨术后腭牙槽区组织表面积均有明显减少。这种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，因此在正畸植骨后将裂段上的后牙前移。腭-肺泡组织的横截面积增加，表面面积减少。肺泡高区体积增大，肺泡下区体积减小。[结论]九州大学的临床实践表明，正畸牙活动的二次植骨时机为牙裂部位出牙前。牙槽骨裂伴侧切牙者，宜及早行二次植骨。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