Cervical Vertebral Column Morphology Associated with Head Posture and Craniofacial Morphology

Assessing cervical spine and craniofacial morphology in Class II and Class III malocclusions: A geometric morphometric approach

To compare craniofacial and cervical morphology between skeletal Classes II and III applying Geometric Morphometric Methods (GMM). Twenty-six cervical and craniofacial landmarks of 40 Class II and 39 Class III individuals were digitalized on lateral cephalograms. Procrustes ANOVA, generalized Procrustes, principal component analyses, and thin-plate spline function were applied to assess the pattern of shape variation of craniofacial structure and the cervical spine in relation to skeletal classes. Compared with Class III, Class II individuals presented a maxillary protrusion, mandibular retrusion, shorter mandibular corpus, posterior mandibular ramus rotation, anterior cranial base rotation, and a smaller centroid size. Furthermore, a forward and smaller cervical spine were observed. With GMM, the shape and size differences between skeletal classes can be analyzed visually and numerically.

Relationship between craniocervical posture and skeletal class: A statistical multivariate approach for studying Class II and Class III malocclusions

Objective: To investigate the relationships between craniocervical posture and skeletal Class in cephalometric radiographs of adult subjects.Methods: Sixty-five cephalometric radiographs were classified after Delaire, as skeletal Class II and III. The craniocervical posture was evaluated using the variables proposed by Solow (1976) and Rocabado (1983). In order to test the null hypothesis (absence of an association between craniocervical posture and skeletal Class), uni- and multivariate statistical protocols were carried out.Results: Skeletal Class II presented a more posterior rotation of the ramus in relation to the cranium and a more extended head than skeletal Class III. Additionally, significant correlations were observed in Class II individuals between the rotation of mandibular ramus and cervical lordosis, as well as between rotation of mandibular ramus and craniocervical posture.Discussion: The findings of this research may help to understand the contradictory results described in clinical literature about the effect of skeletal class on craniocervical posture.

Cephalometrics of Pharyngeal Airway Space in Lebanese Adults

Purpose. The upper airway space is significant in orthodontic diagnosis and treatment planning. The objectives of this study are to assess the dimensions of soft tissue elements of the upper pharyngeal space and evaluate potential correlations with modifying variables such as gender, skeletal class, and anthropometric parameters. Materials and Methods. Lateral cephalograms were obtained from 117 healthy young adult Lebanese subjects. Nineteen cephalometric linear/angular measurements of the nasopharynx, oropharynx, and hypopharynx were recorded. Anthropometric parameters including body mass index and neck circumference were measured. Results. Significant differences were demonstrated for 12 out of the 19 parameters considered between genders. Uvula and tongue dimensions and the distances between epiglottis-posterior pharyngeal wall and epiglottis-posterior nasal spine were significantly larger in males. The anteroposterior inclination of the uvula and the distances between the uvula and posterior pharyngeal wall were significantly greater in females. No significant differences were found between skeletal classes relative to most of the variables. Body mass index and neck circumference were positively correlated with the dimensions of tongue and uvula. Conclusions. Sexual dimorphism relative to some cephalometric variables and anthropometric parameters may account partly for larger oronasopharyngeal spaces in females. Anthropometric data need to be accounted for in population-related comparisons.

Tooth agenesis and craniofacial morphology in pre-orthodontic children with and without morphological deviations in the upper cervical spine

AIM: To analyze differences in prevalence and pattern of tooth agenesis and craniofacial morphology between non syndromic children with tooth agenesis with and without upper cervical spine morphological deviations and to analyze associations between craniofacial morphology and tooth agenesis in the two groups together.

METHODS: One hundred and twenty-six pre-orthodontic children with tooth agenesis were divided into two groups with (19 children, mean age 11.9) and without (107 children, mean age 11.4) upper spine morphological deviations. Visual assessment of upper spine morphology and measurements of craniofacial morphology were performed on lateral cephalograms. Tooth agenesis was evaluated from orthopantomograms.

RESULTS: No significant differences in tooth agenesis and craniofacial morphology were found between children with and without upper spine morphological deviations (2.2 ± 1.6 vs 1.94 ± 1.2, P > 0.05) but a tendency to a different tooth agenesis pattern were seen in children with morphological deviations in the upper spine. In the total group tooth agenesis was associated with the cranial base angle (n-s-ba, r = 0.23, P < 0.01), jaw angle (ML/RLar, r = 0.19, P < 0.05), mandibular inclination (NSL/ML, r = -0.21, P < 0.05), mandibular prognathia (s-n-pg, r = 0.25, P < 0.01), sagittal jaw relationship (ss-n-pg, r = -0.23, P < 0.5), overjet (r = -0.23, P < 0.05) and overbite (r = -0.25, P < 0.01).

CONCLUSION: Etiology of tooth agenesis in children with upper spine morphological deviations was discussed. The results may be valuable for the early diagnosis and treatment planning of non syndromic children with tooth agenesis.

Cervical vertebral column morphology and head posture in preorthodontic patients with anterior open bite

INTRODUCTION

Cervical vertebral column morphology and head posture were examined and related to craniofacial morphology in preorthodontic children and adolescents with anterior open bite.

METHODS

One hundred eleven patients (ages, 6-18 years) with an anterior open bite of more than 0 mm were divided into 2 groups of skeletal or dentoalveolar open bite. The skeletal open-bite group comprised 38 subjects (19 girls, 19 boys). The dentoalveolar open-bite group comprised 73 subjects (43 girls, 30 boys). Visual assessment of the cervical column and measurements of craniofacial morphology and head posture were made on profile radiographs.

RESULTS

Deviations in the cervical vertebral column morphology occurred in 23.7% of the subjects in the skeletal open-bite group and in 19.2% in the dentoalveolar open-bite group, but the difference was not significant. Head posture was significantly more extended in the skeletal open-bite group compared with the dentoalveolar open-bite group (craniovertical angle [Mx/VER], P <0.05; craniocervical angles [Mx/OPT, Mx/CVT], P <0.01. Only head posture was associated with craniofacial morphology: extended posture was associated with a large cranial base angle (P <0.01, P <0.001), large vertical craniofacial dimensions (P <0.05; P <0.01; P <0.001), and retrognathia of the jaws (P <0.001).

CONCLUSIONS

Cervical column morphology is described for the first time in children and adolescents with open bite. No significant differences in the cervical vertebral column's morphologic deviations were found between the skeletal and the dentoalveolar open-bite groups. Significant differences were found in head posture between the groups and with regard to associations with craniofacial dimensions. This might indicate a respiratory etiologic component in children with anterior open bite.