Purmal Kathiravan, Alam Mohammad Khursheed, Pohchi Abdullah, Abdul Razak Noor Hayati
Oral and Maxillofacial Surgery Department, School of Dental Science, Universiti Sains Malaysia, Kota Bharu, Kelantan, Malaysia.
Orthodontic Unit, School of Dental Science, Universiti Sains Malaysia, Kota Bharu, Kelantan, Malaysia.
PLoS One. 2013 Dec 19;8(12):e84202. doi: 10.1371/journal.pone.0084202. eCollection 2013.
Intermaxillary (IMF) screws feature several advantages over other devices used for intermaxillary fixation, but using cone beam computed tomography (CBCT) scans to determine the safe and danger zones to place these devices for all patients can be expensive. This study aimed to determine the optimal interradicular and buccopalatal/buccolingual spaces for IMF screw placement in the maxilla and mandible. The CBCT volumetric data of 193 patients was used to generate transaxial slices between the second molar on the right to the second molar on the left in both arches. The mean interradicular and buccopalatal/buccolingual distances and standard deviation values were obtained at heights of 2, 5, 8 and 11 mm from the alveolar bone crest. An IMF screw with a diameter of 1.0 mm and length of 7 mm can be placed distal to the canines (2 - 11 mm from the alveolar crest) and less than 8 mm between the molars in the maxilla. In the mandible, the safest position is distal to the first premolar (more than 5 mm) and distal to the second premolar (more than 2 mm). There was a significant difference (p<0.05) between the right and left quadrants. The colour coding 3D template showed the safe and danger zones based on the mesiodistal, buccopalatal and buccolingual distances in the maxilla and mandible.The safest sites for IMF screw insertion in the maxilla were between the canines and first premolars and between the first and second molars. In the mandible, the safest sites were between the first and second premolars and between the second premolar and first molar. However, the IMF screw should not exceed 1.0 mm in diameter and 7 mm in length.
颌间（IMF）螺钉相对于其他用于颌间固定的装置具有多个优点，但对于所有患者而言，使用锥形束计算机断层扫描（CBCT）来确定放置这些装置的安全和危险区域成本可能较高。本研究旨在确定在上颌骨和下颌骨中放置IMF螺钉的最佳牙根间和颊腭/颊舌间隙。利用193例患者的CBCT容积数据生成两个牙弓从右侧第二磨牙到左侧第二磨牙之间的横断面。在距牙槽嵴2、5、8和11毫米的高度处获得平均牙根间和颊腭/颊舌距离以及标准差数值。直径1.0毫米、长度7毫米的IMF螺钉可放置于上颌尖牙远中（距牙槽嵴2 - 11毫米）且磨牙之间距离小于8毫米处。在下颌骨中，最安全的位置是第一前磨牙远中（超过5毫米）和第二前磨牙远中（超过2毫米）。左右象限之间存在显著差异（p<0.05）。彩色编码三维模板显示了基于上颌骨和下颌骨近远中、颊腭和颊舌距离的安全和危险区域。上颌骨中插入IMF螺钉最安全的部位是尖牙与第一前磨牙之间以及第一和第二磨牙之间。在下颌骨中，最安全的部位是第一和第二前磨牙之间以及第二前磨牙与第一磨牙之间。然而，IMF螺钉直径不应超过1.0毫米，长度不应超过7毫米。
