Abstract:

Objective: To measure the labial bone thickness of mandibular anterior teeth and depth of medial lingual foramina (MLF) by cone beam CT (CBCT) and to provide data for immediate implant in the mandible anterior region. Methods: Two hundred patients aged 18 to 40 years old were selected. CBCT was used to measure the labial bone thickness at 2.0 mm (P1), 5.0 mm (P2) and 8.0 mm (P3) below the enamel-cemental junction of mandibular central incisors, mandibular lateral incisors and mandibular canines, and the distance between the MLF and the alveolar crest. The means and standard deviations were calculated, and the data was statistically analyzed by SPSS 25.0. Results: At P1, the percentage of the thickness of mandibular central incisors, lateral incisors and canines less than 1.0 mm was 81.0%, 87.0% and 91.5%; at P2, the percentage of the thickness of mandibular central incisors, lateral incisors and canines less than 1.0 mm was 94.0%, 98.0% and 95.0%; at P3, the percentage of the thickness of mandibular central incisors, lateral incisors and canines less than 1.0 mm was 35.5%, 65.5% and 70.0% respectively. The labial bone thickness in male patients of mandibular central incisors at P2 and canines at P2 and P3 were thicker than that in female patients (P<0.05). The detection rate of MLF was 97.9% for male patients and 96.2% for female patients, with no significant difference (P>0.05). The closest distance between the MLF and alveolar crest was 11.4 mm. 7.2% of the distance were less than 14.0 mm, 78.4% of the distance were concentrated between14.0 mm and 24.0 mm, and 14.4% of the distance were more than 24.0 mm. The majority of MLF was 1, accounting for 72.2%, and the maximum number was 3. "Large lingual foramina" with excessive diameter was also found. Conclusion: Most of the labial bone thickness in mandible was less than 1.0 mm, and only got thickened at 8.0 mm below the enamel-cemental junction of mandibular central incisor. The MLF is generally safe for implant, but there are variations in location, number, and diameter.

Key words: mandibular anterior region, immediate implant, labial bone thickness, medial lingual foramina, cone beam CT

摘要：

目的：应用锥形束CT（cone beam CT，CBCT）测量下前牙唇侧骨壁厚度及正中舌孔（medial lingual foramina，MLF）深度，为下颌前牙区即刻种植提供数据支持。方法：利用CBCT测量200例18~40岁患者的双侧下颌中切牙、侧切牙和尖牙釉牙骨质界下2.0 mm（P1）、5.0 mm（P2）和8.0 mm（P3）的唇侧骨壁厚度及MLF与牙槽嵴的距离。结果以均值±标准差（$\bar{x}±s$）表示，采用SPSS 25.0软件对数据进行统计学分析。结果：P1位点上，下颌中切牙、侧切牙和尖牙厚度<1.0 mm的占比为81.0%、87.0%和91.5%；P2位点上，中切牙、侧切牙和尖牙厚度<1.0 mm的占比为94.0%、98.0%和95.0%；P3位点上，中切牙、侧切牙和尖牙厚度<1.0 mm的占比为35.5%、65.5%和70.0%；男性在中切牙的P2处和尖牙的P2、P3处的骨壁厚度大于女性（P<0.05）。MLF男女检出率分别为97.9%和96.2%，差异无统计学意义（P>0.05）；MLF与牙槽嵴的距离最短的为11.4 mm，二者的距离有7.2%小于14.0 mm，78.4%为14.0~24.0 mm，14.4%大于24.0 mm；MLF多数为1个，占比72.2%，最多者为3个；发现直径过大的“大舌孔”。结论：下颌前牙唇侧骨壁多数<1.0 mm，仅在下颌中切牙釉牙骨质界下8.0 mm处骨质稍有增厚。MLF对种植术而言一般较为安全，但其位置、数量和直径也存在变异。

关键词: 下颌前牙, 即刻种植, 唇侧骨壁厚度, 正中舌孔, 锥形束CT

CLC Number: 

• R782