上颌侧切牙牙槽骨壁厚度与尖牙关系相关性的锥形束CT研究

Cone-beam CT analysis of the correlation between the alveolar bone widths of maxillary lateral incisors and canine relationship

目的 利用锥形束CT(cone beam computed tomography, CBCT)研究上颌侧切牙牙槽骨板厚度与尖牙关系之间的相关性,评估影响上颌侧切牙即刻种植位点骨量的相关因素。方法 选取49例患者(共92颗上颌侧切牙)的CBCT影像学资料,确定尖牙关系(Ⅰ类、Ⅱ类及Ⅲ类),测量上颌侧切牙牙槽骨的根中颊侧骨板厚度(mid-root buccal width, MBW)、根中腭侧骨板厚度(mid-root palatal width, MPW)、根尖颊侧骨板厚度(apical buccal width, ABW)、根尖腭侧骨板厚度(apical buccal palatal, APW),并对各尖牙关系对应的上颌侧切牙骨板厚度及其分布情况进行统计学分析。结果 尖牙Ⅰ类和Ⅲ类关系人群中,上颌侧切牙的MPW(Ⅰ:(2.94±1.20)mm vs.Ⅲ:(1.97±0.69)mm)、ABW(Ⅰ:(1.60±0.55)mm vs.Ⅲ:(2.30±1.03)mm)及APW(Ⅰ:(8.52±1.99)mm vs.Ⅲ:(5.78±1.56)mm)在厚度及厚度分布存在统计学差异(P<0.05);尖牙Ⅰ类和Ⅱ类人群中,上颌侧切牙的MPW(Ⅰ:(2.94±1.20)mm vs.(2.18±1.10)mm)及APW(Ⅰ:(8.52±1.99)mm vs.Ⅱ:(6.53±2.34)mm)在厚度及厚度分布存在统计学差异(P<0.05)。结论 相较于尖牙Ⅰ类关系人群,尖牙Ⅲ类人群的上颌侧切牙根整体位置及根尖方向更偏腭侧,使得腭侧骨板相对菲薄。即刻种植时,种植体腭侧穿孔风险增加,类似结论在Ⅱ类尖牙关系伴上颌切牙唇倾的患者中也可成立。因此,尖牙Ⅲ类关系及牙齿唇倾可能是上颌切牙区即刻种植修复技术的潜在风险因素。

Objective To investigate the correlation between the alveolar bone widths of maxillary lateral incisors and canine relationship, and evaluate related factors influencing the alveolar bone morphology of sites for immediate implantation based on cone-beam CT(CBCT). Methods CBCT images of forty-nine patients(a total of 92 maxillary lateral incisors) were selected and canine relationships were determined(Class Ⅰ, Class Ⅱ and Class Ⅲ). The buccal and palatal bone width at both mid-root and apical level(mid-root buccal width/MBW;palatal/MPW;apical buccal width/ABW;palatal/APW) was measured. Then statistical analyses were performed to compare differences of alveolar bone width and their width distribution in three different canine relationships. Results MBW(Ⅰ:(2.94±1.20 mm) vs. Ⅲ:(1.97±0.69)mm), ABW(Ⅰ:(1.60±0.55)mm vs. Ⅲ:(2.30±1.03)mm), APW(Ⅰ:(8.52±1.99)mm vs. Ⅲ:(5.78±1.56)mm) along with their distribution in Class Ⅲ canine relationship and MBW(Ⅰ:(2.94±1.20)mm vs.(2.18±1.10)mm), APW(Ⅰ:(8.52±1.99)mm vs. Ⅱ:(6.53±2.34)mm) and their distribution in Class Ⅱ canine relationship were statistically different from Class Ⅰ canine relationship(P<0.05). Conclusion Compared to Class Ⅰ canine relationship, the root and apex of maxillary lateral incisors with Class Ⅲ relationship are positioned and pointed more towards palatal, which makes the associated palatal alveolar bone relatively thinner and increases the risk of palatal perforation during immediate implantation. Similar conclusions can be drawn from patients with Class Ⅱ canine relationship and proclined upper incisors. Therefore, Class Ⅲ canine relationship and tooth proclination can be potential risk factors for immediate implantation at maxillary incisors.