下颌骨髁突骨密度的相关性研究

A correlation study on the mandibular condyle bone density

目的利用锥形束CT(cone beam computed tomography,CBCT)测量下颌骨髁突骨密度,研究下颌骨髁突骨密度与性别、年龄、垂直及矢状骨面型的相关性。方法收集700例患者正畸治疗前的CBCT数据,将患者按照性别、年龄、垂直骨面型和矢状骨面型进行分组,测量双侧水平面下颌骨髁突最大径处的髁突骨皮质密度、骨松质密度及总体骨密度,比较各组间测量值。结果女性的骨皮质密度及总体骨密度均值明显高于男性(P<0.05)。与年龄较小组相比,年龄较大组的骨皮质密度及总体骨密度均值明显增高,各年龄组间差异有统计学意义(P<0.05)。垂直骨面型中,低角组的髁突骨皮质密度均值明显大于均角组(P<0.05)。矢状骨面型中,Ⅱ类组的髁突骨松质密度均值明显高于Ⅰ类组,且Ⅱ类组髁突总体骨密度平均值最高,与Ⅰ类组和Ⅲ类组之间存在显著差异(P<0.05)。矢状向Ⅰ类组中,低角组的髁突骨松质密度明显高于均角组及高角组,低角组总体骨密度高于均角组,且差异有统计学意义(P<0.05)。结论性别、年龄、垂直骨面型和矢状骨面型都会对下颌骨髁突骨密度造成影响,因青少年髁突处在生长发育期,正畸医生在治疗时应充分考虑这些因素。

Objective To study the correlation between the mandibular condyle bone density and gender,age,vertical and sagittal skeletal patterns by cone beam computed tomography(CBCT).Methods CBCT data of 700 patients before orthodontic treatment were collected to measure the condylar cortical bone density,cancellous bone density and total bone density at the maximum diameter of the mandibular condyle on both sides of the horizontal plane.Patients were grouped according to gender,age,vertical and sagittal skeletal patterns.The average bone density between the groups was compared.Results The average cortical bone density and total bone density of females were higher than those of males,and there was a significant difference between the two groups(P<0.05).The mean values of cortical bone density and total bone density gradually increased with age,and the differences between groups were statistically significant(P<0.05).In the vertical skeletal patterns,the condyle cortical density of the hypodivergent group was statistically larger than the normovergent group(P<0.05).In the sagittal skeletal patterns,cancellous bone density of the condyles in the groupⅡwas hinger than groupⅠ,and the total bone density of the condyles in the groupⅡwas the highest,which was significantly different from groupⅠand groupⅢ(P<0.05).In groupⅠof the sagittal skeletal patterns,the cancellous bone density of the hypodivergent group was significantly higher than the normovergent group and the hyperdivergent group,and a statistically significant difference was observed in the total bone density between the hypodivergent group and the normovergent group(P<0.05).Conclusion Gender,age,vertical and sagittal skeletal patterns all have an effect on the bone density of mandibular condyle.Orthodontists should take these factors into full consideration when treating adolescent patients.