下颌前牙与牙槽骨的位置关系对种植治疗设计的影响

目的 利用锥形束CT（CBCT）研究正中矢状面下颌前牙与牙槽骨的相对位置关系,为下颌前牙区的种植修复设计提供参考。方法 从CBCT影像库中选取下颌恒牙列完整的影像学资料150例,按照性别、牙位分为6组,以受测牙正中矢状面的牙槽骨长轴为基准,测量下颌前牙牙体长轴相对于牙槽骨长轴的倾斜角度（偏舌侧为正,偏唇侧为负）。使用SPSS 19.0软件对数据进行统计学分析。结果 男性下颌中切牙、下颌侧切牙、下颌尖牙牙体长轴相对于牙槽骨长轴倾斜角度的平均值分别为4.77°（-8.17°~16.10°）、6.12°（-2.87°~17.57°）、5.01°（-8.13°~17.67°）,女性倾斜角度的平均值依次为5.38°（-5.63°~12.93°）、5.81°（-7.70°~15.70°）、6.21°（-7.70°~17.87°）。其中,男性下颌中切牙、下颌侧切牙、下颌尖牙倾斜角度在-10°~10°区间的百分比依次为87.34%、80.67%、88.00%,女性依次为90.67%、82.66%、82.66%。无论男性还是女性,下颌前牙牙体长轴相对于牙槽骨长轴倾斜角度在（-10°~10°）的百分比均超过80%,且牙体长轴偏向唇侧均不超过10°,偏向舌侧均不超过20°。结论 绝大多数下颌前牙牙体长轴与牙槽骨长轴的方向基本一致,临床上可以参考二者的位置关系制定合理的种植治疗方案。

Influence of positional relationship between the long axis of the mandibular anterior teeth and the alveolar bone on the treatment design of dental implants

Objective This study aimed at investigating and measuring the positional relationship between the long axis of the mandibular anterior teeth and the alveolar bone using cone beam computed tomography (CBCT) to provide reference data for implant treatment.Methods From the CBCT image database, 150 cases of radiographic data were selected according to the inclusion criteria and then were divided into six groups: males' mandibular central incisors, males' mandibular lateral incisors, males' mandibular canines, females' mandibular central incisors, females' mandibular lateral incisors, and females' mandibular canines. The angle (β) formed by the long axis of the mandibular anterior teeth and the corresponding alveolar bone was measured and recorded. Based on the long axis of alveolar bone, if the teeth incline to the lingual side, the value of the angle (β) was positive; otherwise, the value was negative. The resultant data were analyzed by SPSS 19.0.Results Theβ of the mandibular central incisors presented a mean value of 4.77° (range: -8.17°-16.10°) for male subjects and 5.38° (range:-5.63°-12.93°) for female subjects. The β of the mandibular lateral incisors exhibited a mean value of 6.12° (range:-2.87°-17.57°) for male subjects and 5.81° (range: -7.70°-15.70°) for female subjects. Finally, the β of the mandibular canines presented a mean value of 5.01° (range: -8.13°-17.67°) for male subjects and 6.21° (range: -7.70°-17.87°) for female subjects. The percentages of the β between-10° and 10° of males'mandibular incisors, mandibular lateral incisors, and mandibular canines were 87.34%, 80.67%, and 88.00%, respectively and those of females were 90.67%, 82.66%, and 82.66%, respectively. Whether male or female, the percentages of the β between-10° and 10° of the mandibular anterior teeth were more than 80%. The β that inclined to the lingual was not more than 20° and to the labial did not exceed 10°. Conclusion The long axis of the mandibular anterior teeth was almost consistent with the long axis of the alveolar bone. Therefore, the positional relationship could be referred to make reasonable implants treatment plan.