Dreidimensionale Charakteristika der Mandibula bei skelettalen Malokklusionen

Abstract

Purpose We aimed to comprehensively analyse a possible correlation between skeletal malocclusions, gender and mandibular characteristics in all three dimensions in adults and to identify mandibular characteristics that are typical for extreme skeletal patterns. Methods A 3D model of the skull was calculated in 111 adult patients (mean age = 27.0 ± 10.2 years; 49 women, 62 men) from available computed tomography or cone beam computed tomography scans of their heads. Based on the 3D models, the skeletal patterns were examined in (a) the transversal dimension regarding asymmetry according to menton deviation, (b) the sagittal dimension according to the Wits appraisal and (c) the vertical dimension according to the maxillomandibular plane angle. The mandibular characteristics assessed were linear (ramus height and width, body length), angular (ramus, gonial and body angle) and volumetric (ramus/mandibular volume, body/mandibular volume) parameters. Results No correlation between transversal skeletal asymmetry and mandibular characteristics were found, while sagittal (F(16, 174) = 3.32, p < 0.001, η2 = 0.23) and vertical (F(16, 174) = 3.18, p < 0.001, η2 = 0.23) skeletal patterns were shown to have a significant effect on the mandible. Gender correlated with mandibular characteristics independently from the skeletal pattern. Discriminant analysis revealed that class II and III patients differed in ramus and body angle with class II patients showing higher angles (ramus angle: class II = 89.8 ± 3.9° vs. class III = 84.4 ± 4.8°; body angle: class II = 87.7 ± 4.8° vs. class III = 82.1 ± 5.2°). Hypo- and hyperdivergent patients were discriminated by gonial angle, body angle and body/mandibular volume with hyperdivergent patients having a greater gonial and body angle and body/mandibular volume (gonial angle: hypodivergent = 114 ± 9.3° vs. hyperdivergent = 126.4 ± 8.6°; body angle: hypodivergent = 82.9 ± 4.4° vs. hyperdivergent = 87.7 ± 6.5°; body/mandibular volume: hypodivergent = 72.4 ± 2.7% vs. hyperdivergent = 76.2 ± 2.6%). Conclusion When analysing 3D data for treatment planning of adult patients, the orthodontist should pay attention to angular and volumetric characteristics of the mandible to identify extreme skeletal sagittal or vertical malocclusions.

Tridimensional assessment of the mandibular angle in patients with different skeletal patterns by cone-beam computed tomography scans: a retrospective study

“…Regarding the investigated variables of thickness and volume of the mandibular angle, there was no influence of the different skeletal patterns of development (skeletal malocclusions and facial types), which corroborates previous studies found in the literature [ 25 , 26 ]. In contrast, the study conducted by Olbrisch et al (2022) [ 27 ] found significant association between the different skeletal patterns of development and mandibular volume. In addition to the different methodologies applied and smaller sample size (n = 111) in relation to the present study, the authors assessed the volume of the mandibular body; thus, it is not possible to directly compare the results.…”

“…Mandibular asymmetry is characterized by dimensional differences in size, shape, and volume of the left and right sides of the mandible, which can be the cause of aesthetic and functional problems. The imbalance in the process of craniofacial development and growth of the individual may also be associated with skeletal asymmetry [ 27 ]. Previous studies have observed that individuals with different skeletal development patterns, such as Class III malocclusion and dolichocephalic, presented higher values of skeletal asymmetry [ 7 , 12 ].…”

3D analysis of maxillomandibular morphology in hyperdivergent and hypodivergent individuals: A cross‐sectional study

“…To this extent, cone beam computed tomography (CBCT) can be used to conduct an effective evaluation of the structures of the craniofacial complex three‐dimensionally. Studies have shown the effectiveness of evaluations performed by 3D surface models constructed from CBCT, thus confirming it as an innovative tool with high accuracy, which enables measurements to be conducted in different spatial planes 14–22 …”

“…Studies have shown the effectiveness of evaluations performed by 3D surface models constructed from CBCT, thus confirming it as an innovative tool with high accuracy, which enables measurements to be conducted in different spatial planes. [14][15][16][17][18][19][20][21][22] The aim of this study was to investigate maxillomandibular morphology in hyperdivergent and hypodivergent individuals using 3D surface models. The MP angle was used as a reference 23 to define the skeletal morphology, and to separate the groups.…”

Impact of class II and class III skeletal malocclusion on pharyngeal airway dimensions: A systematic literature review and meta-analysis

“…Management of these deformations calls for the prediction of the skeletal growth pattern to aid in the diagnosis and correction of these conditions. This integrates accurate estimation of the craniofacial growth patterns [ 10 ]. It is worth noting that malocclusions are influenced by the genetic makeup of individuals [ 9 ].…”