Gaffuri Francesca, Cossellu Gianguido, Maspero Cinzia, Lanteri Valentina, Ugolini Alessandro, Rasperini Giulio, Castro Iury O, Farronato Marco
Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Department of Biomedical, Surgical and Dental Sciences, School of Dentistry, University of Milan, Milan, Italy.
Orthodontic Section, Department of Sciences Integrated Surgical and Diagnostic, University of Genova, Genova, Italy.
Saudi Dent J. 2021 Mar;33(3):161-167. doi: 10.1016/j.sdentj.2020.01.009. Epub 2020 Feb 6.
The vertical facial growth pattern is one of the most important issue in the orthodontic diagnosis and treatment. Previous studies investigated the association between interdental bone thickness and facial divergence using mainly bidimensional analysis. When two-dimensional dental radiographic views are not sufficient for diagnosis and measurements, cone-beam computed tomography (CBCT) images should be used to assess the alveolar bone structure three-dimensionally and with high accuracy and reliability.The aim of the present study was to evaluate the correlation between alveolar bone thickness and facial divergence in young adults untreated patients using a three-dimensional method analysis with CBCT images.
Records of 30 untreated patients (mean age 16 ± 2 years) with Angle Class I and mild to moderate crowding were analyzed. Subjects were classified as hypodivergent (<39˚), normodivergent (41 ± 2˚), and hyperdivergent (>43°). according to the inter-maxillary angle between the sagittal maxillary plane (ANS-PNS) and the mandibular plane (GN-ME). The alveolar bone thickness measurements were taken for the buccal and palatal/lingual surfaces of maxillary and mandibular anterior teeth. Axial-guided navigation (AGN) was used to locate all landmarks using a specific software (Horos 3.0).
The statistical analysis showed a significant difference between the hypodivergent and hyperdivergent group regarding buccal bone height (P = 0.005), buccal apical bone thickness (P = 0.003) and palatal mid-root bone thickness (P = 0.006). Moreover, buccal bone height (P = 0.006) was found to be statistically significant different in normodivergent compared with hypodivergent individuals.
Facial types were found to be correlated with alveolar bone thickness. The hyperdivergent subjects presented thinner alveolus bone in the anterior maxilla and at almost all sites in the mandible. Clinicians should be aware of the possibility of thin cortical bone plates in hyperdivergent patients, reducing antero-posterior movements to avoid fenestration and dehiscence.
垂直向面部生长模式是正畸诊断和治疗中最重要的问题之一。以往的研究主要使用二维分析来研究牙间骨厚度与面部发散度之间的关系。当二维牙科X线片不足以进行诊断和测量时，应使用锥形束计算机断层扫描（CBCT）图像来三维地、高精度且可靠地评估牙槽骨结构。本研究的目的是使用CBCT图像的三维方法分析来评估年轻未治疗患者的牙槽骨厚度与面部发散度之间的相关性。
分析了30例安氏I类、轻度至中度拥挤的未治疗患者（平均年龄16±2岁）的记录。根据矢状上颌平面（ANS-PNS）与下颌平面（GN-ME）之间的上颌间角度，将受试者分为低发散型（<39˚）、正常发散型（41±2˚）和高发散型（>43°）。对上颌和下颌前牙的颊侧和腭侧/舌侧表面进行牙槽骨厚度测量。使用轴向引导导航（AGN）通过特定软件（Horos 3.0）定位所有标志点。
统计分析显示，低发散型和高发散型组在颊侧骨高度（P = 0.005）、颊侧根尖骨厚度（P = 0.003）和腭侧牙根中部骨厚度（P = 0.006）方面存在显著差异。此外，发现正常发散型个体与低发散型个体相比，颊侧骨高度（P = 0.006）在统计学上有显著差异。
发现面部类型与牙槽骨厚度相关。高发散型受试者上颌前部和下颌几乎所有部位的牙槽骨较薄。临床医生应意识到高发散型患者存在皮质骨板变薄的可能性，减少前后向移动以避免开窗和骨裂。
