Correlation between facial growth patterns and cortical bone thickness assessed with cone-beam computed tomography in young adult untreated patients

Abstract

Background 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. Methods 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). Results 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. Conclusions 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.

Bio-high entropy alloys: Progress, challenges, and opportunities

“…The human skeleton can be divided into dense bone (cortical bone) and trabecular bone (cancellous bone). Dense bone is almost solid, while the porosity of trabecular bone varies between 50 and 90%, and the mechanical properties of the bone vary significantly with age, anatomical location, and bone mass ( Lei et al, 2013 ; Al-Hafidh et al, 2020 ; Gaffuri et al, 2021 ). Such complex mechanical property modulation is difficult to achieve with a single principal element alloy, which requires substantial elemental modulation by HEA to meet specific bone-implant needs.…”

Treatment of severe Class II skeletal malocclusion in a hyperdivergent adult patient via hybrid clear aligner approach: A case report

“…In this case, the sagittal correction was obtained through pure dentoalveolar compensation, favoured by the excellent compliance demonstrated by the patient and likely the fact that her hyperdivergent skeletal pattern facilitated dentoalveolar movement, due to the reduced cortical thickness typical of subjects with increased verticality (Gaffuri et al, 2021). In addition, this correction was facilitated by the pre-treatment mesial crown tipping of the upper posterior teeth.…”

“…For instance, Class II malocclusion conditions can vary in difficulty from edge-to-edge (4 mm) to full Class II (8 mm), and cannot be solved predictably using aligners despite the continuous use of Class II elastics and sequential planned movement of the upper molars (Patterson et al, 2021) In this case, the sagittal correction was obtained through pure dentoalveolar compensation, favoured by the excellent compliance demonstrated by the patient and likely the fact that her hyperdivergent skeletal pattern facilitated dentoalveolar movement, due to the reduced cortical thickness typical of subjects with increased verticality (Gaffuri et al, 2021). In addition, this correction was facilitated by the pre-treatment mesial crown tipping of the upper posterior teeth.…”

Diagnostic efficacy of novel cephalometric parameters for the assessment of vertical skeletal dysplasia

“…This may seem to contradict studies suggesting that the location of maxillary incisors can be used to estimate facial abnormalities. 9 , 10 In our study, the maxillary angle was measured relative to the true vertical plane. However, the maxillary incisors’ proclivity has traditionally been assessed using cephalometric analysis of the incisor’s long axis (the line that connects the incisal tip to the apex) and planes such as the palatal, sella-nasion, or Frankfort horizontal.…”