Motamedi Mohammad Hosein Kalantar, Tabatabaie Fataneh Alavi, Navi Fina, Shafeie Hasan Ali, Fard Behnam Khosravani, Hayati Zahra
Trauma Research Center, Baqiyatallah Medical Sciences University and Azad University of Medical Sciences, Dental College, Tehran, Iran.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Jun;107(6):772-5. doi: 10.1016/j.tripleo.2008.12.022. Epub 2009 Feb 8.
Impacted canines require a combination of both surgical and orthodontic management. In this study, patients treated for bone-impacted canines of the hard palatal were evaluated to assess which radiographic factors influenced the feasibility to move impacted maxillary permanent canines from the hard palate into the alveolar arch.
Eighty patients aged 12 to 24 (average 16 years) were treated surgically and orthodontically to align 146 bone-impacted canines of the hard palate (from 1994 to 2008). Factors such as age, sex, angulation of the canine to the midline (CAM), anomaly of the canine root (RA), overlap of the adjacent lateral incisor root (OALIR), and ratio of root formation (RRF) upon treatment were documented. Radiographic records and demographic data were assessed. The following radiographic measurements of canine position were made from the orthopantomogram (OPG): (1) angulation to the midline, (2) anteroposterior position of the root, (3) overlap of the adjacent incisor. RA or dilaceration was assessed from the OPG, maxillary occlusal (MO), and periapical (PA) radiographs. Whether the impacted canine had responded to surgical exposure and was orthodontically aligned, or surgically removed and discarded was also recorded. The data were analyzed to assess and correlate significance.
Eighty patients aged 12 to 24 (19 males and 61 females) with 146 bone-impacted permanent canines of the hard palatal were treated. One hundred and three teeth (70.54%) had responded to surgical exposure and orthodontic alignment within 9 to 12 months. Forty-three impacted canine teeth (29.46%) had to be surgically removed because of ankylosis and no movement after 8 to 9 months using 50 to 60 g of traction force via elastic chains. Data analysis via chi-square and Pearson correlation tests showed that as the CAM increased (> 45 degrees), the canine was more likely to be unresponsive to treatment (P < .001). Increased overlap (> half the root) of the adjacent lateral incisor root (OALIR) via the canine crown influenced the treatment results negatively (P < .001). Additionally, presence of RA was also negatively influential (P < .001). However, the anteroposterior position of the canine did not influence the treatment results significantly, neither did age, sex, nor amount of root formation.
Bone-impacted canines of the hard palatal are more likely to respond to surgical exposure and orthodontic management if AM is less than 45 degrees on the OPG; there is no RA found on OPG, periapical (PA), and maxillary occlusal (MO) radiographs; and OALIR by the canine crown is nonexistent or less than grade 2 (half the root) on the OPG.
埋伏阻生犬齿需要手术和正畸联合治疗。本研究对硬腭骨埋伏阻生犬齿的治疗患者进行评估，以确定哪些影像学因素会影响上颌恒埋伏阻生犬齿从硬腭移动到牙槽弓的可行性。
对80例年龄在12至24岁（平均16岁）的患者进行了手术和正畸治疗，以排齐146颗硬腭骨埋伏阻生犬齿（1994年至2008年）。记录了治疗时的年龄、性别、犬齿与中线的夹角（CAM）、犬齿牙根异常（RA）、相邻侧切牙根的重叠情况（OALIR）以及牙根形成比例（RRF）等因素。对影像学记录和人口统计学数据进行了评估。从曲面断层片（OPG）上对犬齿位置进行了以下影像学测量：（1）与中线的夹角；（2）牙根的前后位置；（3）相邻切牙的重叠情况。从OPG、上颌咬合片（MO）和根尖片（PA）评估RA或牙根弯曲情况。还记录了埋伏阻生犬齿对手术暴露和正畸排齐的反应情况，或者是否通过手术拔除并弃用。对数据进行分析以评估并关联其显著性。
对80例年龄在12至24岁（19例男性和61例女性）的患者的146颗硬腭骨埋伏阻生恒牙进行了治疗。103颗牙齿（70.54%）在9至12个月内对手术暴露和正畸排齐有反应。43颗埋伏阻生犬齿（29.46%）因牙根粘连，在使用弹力链施加50至60克牵引力8至9个月后仍未移动，不得不通过手术拔除。通过卡方检验和Pearson相关性检验进行数据分析显示，随着CAM增大（>45度），犬齿对治疗无反应的可能性更大（P<0.001）。通过犬齿冠部的相邻侧切牙根重叠增加（>牙根一半）对治疗结果有负面影响（P<0.001）。此外，RA的存在也有负面影响（P<0.001）。然而，犬齿的前后位置对治疗结果没有显著影响，年龄、性别和牙根形成量也没有显著影响。
如果在OPG上AM小于45度；在OPG、根尖片（PA）和上颌咬合片（MO）上未发现RA；且在OPG上犬齿冠部的OALIR不存在或小于2级（牙根一半），硬腭骨埋伏阻生犬齿更有可能对手术暴露和正畸治疗有反应。
