Pommer Bernhard, Tepper Gabor, Gahleitner André, Zechner Werner, Watzek Georg
Department of Oral Surgery, Bernhard Gottlieb School of Dentistry, Medical University of Vienna, Vienna, Austria.
Clin Oral Implants Res. 2008 Dec;19(12):1312-6. doi: 10.1111/j.1600-0501.2008.01590.x.
Altered pulp sensitivity of anterior lower teeth is a frequent finding following chin bone harvesting. Persistent loss of tooth sensitivity has been reported in up to 20% of the patients. The aim of this study was to evaluate current recommendations for the location of the harvest zone with respect to the course of the mandibular incisive canal (MIC), the intrabony continuation of the mandibular canal mesial to the mental foramen.
On computed tomographic (CT) scans of 50 dentate mandibles, the MIC was located and its distance to the root apices, to the labial bony surface, and to the inferior margin of the mandible was assessed. The risk of nerve injury and the percentage of patients suitable for chin bone grafting were calculated.
Respecting current recommendations for chin bone grafting, the content of the MIC was endangered in 57% of the CTs. Therefore, new safety margins are suggested: the chin bone should be harvested at least 8 mm below the tooth apices with a maximum harvest depth of 4 mm.
Applying the new safety recommendations and proper patient selection in chin bone harvesting could reduce the risk of altered postoperative tooth sensitivity due to injury of the mandibular incisive nerve.
下颌前牙牙髓敏感性改变是取颏骨后常见的表现。据报道，高达20%的患者存在持续性牙齿敏感丧失。本研究的目的是评估关于颏骨采集区域位置的现行建议，该区域相对于下颌切牙管（MIC）的走行，即颏孔内侧下颌管的骨内延续部分。
在50例有牙下颌骨的计算机断层扫描（CT）图像上，定位MIC，并评估其与牙根尖、唇侧骨面以及下颌下缘的距离。计算神经损伤风险和适合颏骨移植的患者百分比。
按照现行颏骨移植建议，57%的CT图像显示MIC内容物有风险。因此，建议新的安全边界：颏骨应在牙根尖下方至少8mm处采集，最大采集深度为4mm。
在颏骨采集过程中应用新的安全建议并进行适当的患者选择，可降低因下颌切牙神经损伤导致术后牙齿敏感性改变的风险。
