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

唇腭裂儿童上颌扩弓后腭-牙槽形态变化的三维评价[研究对象与材料]研究对象为76名唇腭裂儿童，均行上颌牙弓扩大术。材料为上颌扩弓前后牙模。[方法]采用非接触式激光三维数字化仪（Vivid 700，Minolta Co.），上颌扩弓前后的腭牙槽骨三维模型。应用三维分析软件3D rugle计算腭-牙槽组织的表面积、体积、牙体两侧向和牙轴倾角。[结果]与其他扩弓器相比，骨骼式扩弓器对腭部体积的增加最大。另一方面。联合扇形扩张器的表面积增量最大。四螺旋扩张器可使侧段颊侧倾斜， 关于我们 [材料]对63例在九州大学齿科医院行唇腭裂二次植骨术的唇腭裂患儿术前、术后的牙模进行三维评估。[方法]采用Vivid 700型非接触式激光三维数字化仪获得腭-牙槽骨的三维形态。测量上颌第一磨牙前牙区腭-牙槽骨组织表面积、横截面积和体积的变化。[结果]二期植骨术后腭牙槽骨组织表面积均减少。这种降低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，在进行骨移植后，将裂节上的后牙向前推进。腭-牙槽组织的横截面积增加，而表面积减少。高肺泡区体积增大，低肺泡区体积减小。[结论]九州大学正畸牙移动二期植骨的最佳时机为裂位尖牙萌出前。但对于侧切牙位于牙槽嵴裂的病例，应尽早进行二期植骨。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