A computerized tomography study of the morphological interrelationship between the temporal bones and the craniofacial complex

Abstract

The hypothesis that the temporal bones are at the center of the dynamics of the craniofacial complex, directly influencing facial morphology, has been put forward long ago. This study examines the role of the spatial positioning of temporal bones (frontal and sagittal inclination) in terms of influencing overall facial morphology. Several 3D linear, angular and orthogonal measurements obtained through computerized analysis of virtual models of 163 modern human skulls reconstructed from cone-beam computed tomography images were analyzed and correlated. Additionally, the sample was divided into two subgroups based on the median value of temporal bone sagittal inclination [anterior rotation group (n = 82); posterior rotation group (n = 81)], and differences between groups evaluated. Correlation coefficients showed that sagittal inclination of the temporal bone was significantly (P < 0.01) related to midline flexion, transversal width and anterior-posterior length of the basicranium, to the anterior-posterior positioning of the mandible and maxilla, and posterior midfacial height. Frontal inclination of the temporal bone was significantly related (P < 0.01) to basicranium anteriorposterior and transversal dimensions, and to posterior midfacial height. In comparison with the posterior rotation group, the anterior rotation group presented a less flexed and anterior-posteriorly longer cranial base, a narrower skull, porion and the articular eminence located more superiorly and posteriorly, a shorter posterior midfacial height, the palatal plane rotated clockwise, a more retrognathic maxilla and mandible, and the upper posterior occlusal plane more inclined and posteriorly located. The results suggest that differences in craniofacial morphology are highly integrated with differences in the positional relationship of the temporal bones. The sagittal inclination of the temporal bone seems to have a greater impact on the 3D morphology of the craniofacial complex than frontal inclination.

A 3D computerized tomography study of changes in craniofacial morphology of Portuguese skulls from the eighteenth century to the present

“…The results of these studies suggest that the largest component of secular changes in Americans is an increase in cranial vault height, with most of that change occurring in the cranial base. Other studies documented changes in cranial morphology and interesting interrelations between structures were observed in Austrians [5,16,23,37], Mexicans [30], Japanese [20,27], Croatians [14] and Portuguese [45]. The study by Weisensee KE, Jantz RL, 2011 [45] demonstrated a significant change in craniofacial morphology of the Portuguese from 1806 to 1954, with a decrease in facial breadth and a more inferiorly placed cranial base.…”

“…By this method the influence and relationship could be evaluated not only in the linear measurement, but also in the projection of the A point and B point to the medial plane. Surprisingly, 70.1 % of the variation of the SNA angle in the eighteenth century could be explained by the orthogonal A variable, whereas in the nineteenth 42] and reproducibility [16,31] by applying a different computer-based software such as the one used in this study. Multiple regressions associated with the stepwise method regression analysis were used in the present study to identify the important craniofacial measurements that influenced the architecture of Portuguese skulls.…”

“…While some theories argue that the cranial base influences craniofacial morphology [2,8], others report no significant effect [18,34,43]. The craniofacial architecture is the result of a very complex connection between different structures, and is constantly modified by the function of different organs [16,36,38]. It is important to take into account variations in craniofacial morphology over the course of time.…”

Evaluación cefalométrica de la longitud y deflexión de la base craneal anterior en pacientes con diferente patrón esquelético

“…Además, Costa et al 19 y Cendekiawan et al 20 relacionan los cambios en el área de la sincondrosis esfeno-occipital con cambios en la angulación de la base del cráneo. Por lo tanto, las variaciones en el ángulo SNFH y la longitud de la línea SN en pacientes con diferente patrón esquelético podrían estar directamente relacionadas con las diferentes modificaciones de la sincondrosis esfeno-occipital sobre la base craneal anterior durante el crecimiento y con el desplazamiento del punto nasion hacia adelante o en dirección vertical debido a los cambios en el proceso de remodelación.…”

Comprehensive dental diagnosis and treatment planning for occlusal rehabilitation: a perspective

“…[12][13][14][15][16] Knowing that occlusal sensitivity is within the range of 0.02-0.03 mm, 48,[50][51][52][53][54][55] that TMJ has a 'deflection' tolerance of only 0.6-0.8 mm, [12][13][14][15]49 and that the angular difference between the steepness of the articular eminence and the contra-lateral canine guidance of any skeletal class is ≤10°, [53][54][55] it becomes clear that dentistry is dealing with a highly individual and highly complex organ system. 3,[56][57][58]…”