Department of Biomedical Sciences for Health, Università degli Studi di Milano, Via Mangiagalli 31, 20133, Milan, Italy.
Private Practice in Orthodontics, Brescia, Italy.
Prog Orthod. 2018 Jul 16;19(1):20. doi: 10.1186/s40510-018-0220-6.
The aetiology of the canine displacement still remains controversial. Some authors implicated a deficiency in maxillary width as a local mechanical cause for impacted canines. The aim of the study was to examine whether there is a relationship between impacted maxillary canines, early diagnosed by using panoramic radiographs, and the morphology of the maxilla on 3D model casts.
The displaced maxillary canines (DMC) group consisted of 24 patients (mean age, 9.1 ± 1.1 years), while the control group consisted of 25 subjects (mean age, 8.7 ± 0.9 years). Seven measurements were calculated on the digital casts of each subject: intermolar width (IMW), arch length (AL), depth of the palatal vault (PVD), available arch space (AAS), the sum of the anterior segments (SAS), the right/affected (R-Af) and left/unaffected (L-Un) available spaces.
Both IMW and AL in the DMC group were significantly decreased relative to the control group (P < 0.01), indicating that patients with displaced canines presented a shorter and narrower palate than subjects without eruption problems. Moreover, the values of the SAS and AAS were significantly decreased (P < 0.01) in the DMC group relative to the controls.
The shape of the maxillary arch was narrower and shorter in the displaced maxillary canines group compared with the control group.
犬齿阻生的病因仍然存在争议。一些作者认为上颌宽度不足是导致犬齿阻生的局部力学原因。本研究旨在通过全景片早期诊断上颌埋伏阻生犬齿,探讨上颌埋伏阻生犬齿与上颌 3D 模型 casts 形态之间的关系。
将 24 例(平均年龄 9.1±1.1 岁)上颌埋伏阻生犬齿(DMC)患者纳入 DMC 组,将 25 例(平均年龄 8.7±0.9 岁)无埋伏阻生犬齿患者纳入对照组。对每位患者的数字化模型进行 7 项测量:磨牙间宽度(IMW)、牙弓长度(AL)、腭穹窿深度(PVD)、可用弓间隙(AAS)、前牙段总和(SAS)、右侧/受累(R-Af)和左侧/未受累(L-Un)可用间隙。
DMC 组的 IMW 和 AL 均明显小于对照组(P<0.01),表明埋伏阻生犬齿患者的腭部比无萌出问题的患者更短、更窄。此外,DMC 组的 SAS 和 AAS 值明显小于对照组(P<0.01)。
与对照组相比,DMC 组上颌弓的形状更窄、更短。