Department of Oral and Maxillo-Facial Sciences, Sapienza, University of Rome, Italy.
Med Oral Patol Oral Cir Bucal. 2013 Jul 1;18(4):e597-602. doi: 10.4317/medoral.18746.
To analyze the skeletal features of patients with maxillary canine impaction.
The complete pre-treatment records of 1674 orthodontic patients were examined. From the subjects with maxillary impacted canine 12 patients were excluded , remaining 108. The subjects with maxillary impacted canine were divided into two study groups: a palatally displaced canine group (PDCG) (77 patients) and a buccally displaced canine group (BDCG) (31 patients). The values of the skeletal features measured on the lateral cephalometric radiograph were compared with a control group (CG) of 121 subjects randomly selected from the initial sample without maxillary canine impaction. The statistical analysis of the difference between the study groups and the CG was tested using χ(2) test and Fisher's exact test. The level of significance was set at P ≤ 0.05.
The CG was characterized by increased values of sella- nasion- A point angle (ANB) and by a retro-positioned or smaller lower jaw. PDCG patients showed normal skeletal features compared to the CG, presenting mainly I class and lower rank of II and III sagittal skeletal features. PDCG subjects presented also normal values of the Steiner vertical skeletal relationship angles with normal facial divergence compared to the CG. PDCG cases were also characterized by horizontal and prognathic growth. BDCG did not present significant differences in skeletal features compared to the CG, except for an increased ANB.
Palatally displaced canine (PDC) was frequently the only orthodontic problem of patients and was not associated whit altered skeletal features. The frequent absence of malocclusion in PDC patients explains the delayed identification of this problem. BDCG patients did not present significant differences in skeletal features with respect to the orthodontic population (CG). The presence of both buccally displaced canine (BDC) and malocclusion makes the patient with BDC both aware of the need for, and motivated to undergo, orthodontic treatment.
分析上颌尖牙阻生患者的骨骼特征。
检查了 1674 名正畸患者的完整治疗前记录。从患有上颌尖牙阻生的患者中排除了 12 名患者，剩余 108 名。将上颌尖牙阻生的患者分为两组：腭侧移位的尖牙组（PDCG）（77 名患者）和颊侧移位的尖牙组（BDCG）（31 名患者）。在侧位头颅侧位片上测量的骨骼特征值与从初始样本中随机选择的无上颌尖牙阻生的 121 名对照者（CG）进行比较。使用卡方检验和 Fisher 精确检验对研究组与 CG 之间的差异进行统计学分析。显著性水平设为 P≤0.05。
CG 的特征是蝶鞍-鼻根-前点角（ANB）值增加，下颌后缩或较小。与 CG 相比，PDCG 患者的骨骼特征正常，主要表现为 I 类和较低的 II 类和 III 类矢状骨骼特征等级。PDCG 患者与 CG 相比，Steiner 垂直骨骼关系角的正常值也正常，面型发散正常。PDCG 病例还表现为水平和前突生长。与 CG 相比，BDCG 患者的骨骼特征无明显差异，除了 ANB 增加。
腭侧移位的尖牙（PDC）通常是患者唯一的正畸问题，且与骨骼特征改变无关。PDC 患者经常没有错颌，这解释了该问题的延迟识别。与正畸人群（CG）相比，BDCG 患者的骨骼特征无明显差异。颊侧移位的尖牙（BDC）和错颌的存在使 BDC 患者既意识到需要进行正畸治疗，又有动力接受正畸治疗。
