Relationships of sagittal skeletal discrepancy, natural head position, and craniocervical posture in young Chinese children

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.

Craniocervical posture in patients with skeletal malocclusion and its correlation with craniofacial morphology during different growth periods

The association between craniocervical posture and craniofacial structures in the various sagittal skeletal malocclusion during different growth stages has been the focus of intense interest in fields of orthodontics, but it has not been conclusively demonstrated. Thus, this study aimed to investigate the association between craniofacial morphology and craniocervical posture in patients with sagittal skeletal malocclusion during different growth periods. A total of 150 from a large pool of cephalograms qualified for the inclusion and exclusion were evaluated and classified into three groups according to the Cervical Vertebral Maturation (CVM) by examining the morphological modifications of the second through fourth cervical vertebrae, each group consisted of 50 cephalograms. In each growth period, for the comparison of head and cervical posture differences among various skeletal classes, the radiographs were further subdivided into skeletal Class I (0° < ANB < 5°, n = 16), skeletal Class II (ANB ≥ 5°, n = 18), and skeletal Class III (0° ≤ ANB, n = 16) on the basis of their ANB angle. There was no significant difference in gender (P > 0.05). Some variables were found to be significant during pubertal growth and later in patients with sagittal skeletal malocclusion (P < 0.05). Most indicators describing craniocervical posture were largest in skeletal Class II and smallest in skeletal Class III during the peak growth periods and later. Cervical inclination variables were greater in skeletal Class III than in skeletal Class II. Variables of craniofacial morphology and craniocervical posture are more correlated during the pubertal growth period and later in patients with sagittal skeletal malocclusion. A tendency is an indication of the close interrelationship that a more extended head was in skeletal Class II while a flexed head was in skeletal Class III. Nevertheless, with the considerations of some limitations involved in this study, further longitudinal studies with large samples are required to elucidate the relationship clearly.

Comparative Evaluation of the Relationship Between Airway Inadequacy, Head Posture, and Craniofacial Morphology in Mouth-Breathing and Nasal-Breathing Patients: A Cephalometric Observational Study

BACKGROUND

The process of respiration is the primary factor of the posture of the jaws and tongue. Thus, a changed respiratory form like mouth breathing can change the posture of the head, jaw, and tongue. This, in turn, could change the equilibrium of pressure on the jaws and teeth thus affecting jaw growth and teeth positions. The influence of nasorespiratory function on craniofacial growth has stimulated interest and debate for more than a century. Mouth breathing is the reason for numerous orthodontic glitches such as a mouth breather's face evolving aberrantly because of of functional disruptions triggered by chronic airway obstruction. The relationship between nasorespiratory function and dentofacial development remains controversial despite the long-standing clinical concern of orthodontists, so there was a need to evaluate and compare the relationship between head posture, airway inadequacy, and craniofacial morphology in mouth breathers and nasal breathers.

METHODOLOGY

Forty patients were selected and divided equally into two groups: mouth breathers and nasal breathers. Patients were diagnosed as mouth breathers based on physical examination and a history of chronic allergic rhinitis, adenoid, and tonsil enlargement. Lateral cephalograms were taken for all patients in the natural head position (NHP) with the Planmeca Proline XC Dimax3 x-ray machine (Planmeca, Helsinki-Uusimaa, Finland). All lateral cephalograms were traced and analysis was done to check airway, head posture, and craniofacial morphology. Descriptive statistics were performed to obtain the means and standard deviation of all the sample sizes. Unpaired t test was performed between nasal breathers and mouth breathers to check and evaluate the relationship.

RESULT

Mouth-breathing patients varied from nasal-breathing patients in airway adequacy and craniofacial morphology. A little, but not statistically significant, difference was seen in head posture between the two groups.

CONCLUSIONS

Early interception of mouth breathing in patients could be very helpful, as the postural changes in the mouth-breathing patients, if continued for a longer period of time, could be the reason for severe skeletal deformities as well as dental malocclusion.

Does head and cervical posture correlate to malocclusion? A systematic review and meta-analysis

BACKGROUND

The association of head and cervical posture with malocclusion has been studied for many years. Despite extensively encouraging researches, no conclusive evidence has been reached for clinical application.

OBJECTIVE

To identify the question "Does head and cervical posture correlate to malocclusion?", a systematic review and meta-analysis based on the available studies were carried out (PROSPERO registration number: CRD42022319742).

METHODS

A search of PubMed, Embase, Cochrane Library, and the grey literature was performed without language restrictions. The study screening, data extraction, risk-of-bias evaluation and methodological quality assessment were performed by two independent investigators. When a disagreement arose, a third author was consulted.

RESULTS

6 original cross-sectional studies involving 505 participants were included, which were of moderate methodological quality. NL/VER in Class Ⅱ group and NL/CVT in Class Ⅲ group showed significant differences compared to Class Ⅰ group, but no significant differences were observed in most of the variables like NSL/VER, OPT/CVT, OPT/HOR, CVT/HOR, NSL/OPT, NSL/CVT, NL/OPT in Class Ⅱ and Ⅲ groups.

CONCLUSIONS

The results suggested that the current research evidence is not sound enough to prove the association of head and cervical posture with sagittal malocclusion. Better controlled design and a larger sample size are required for clarifying this question in future study.

Temporomandibular Joint Disk Displacements in Class II Malocclusion and Cervical Spine Alterations: Systematic Review and Report of a Hypodivergent Case with MRI Bone and Soft Tissue Changes

(1) Background: This study aimed to perform a literature review related to disk displacement (DD) in class II malocclusion or cervical vertebrae position alterations and to report a hypodivergent case with cervical pain and right anterolateral DD with reduction, left anterolateral DD with reduction, and left joint effusion. (2) Methods: A structured electronic search was conducted between March 2022 and April 2022, without time limits, following PRISMA guidelines, in the following databases: PubMed, Scopus, Embase and Cochrane; the terms “disc displacement”, “disk displacement”, “temporomandibular joint”, “class II malocclusion” and “cervical vertebrae” are searched. (3) Results: the following thirteen publications are included in this review: two prospective studies and eleven cross-sectional studies; for evaluating disk position, eight included publications used magnetic resonance imaging (MRI), whilst six studies used lateral cephalogram to determine craniofacial morphology and relationships between the cranial base, vertical skeletal pattern, maxilla and mandible. (4) Conclusions: although the literature still shows contradictory opinions, a relationship between temporomandibular disorders and cervical posture has been shown in the presented case as well as in the literature review.

Relationship between Craniocervical Posture and Sagittal Position of the Mandible: A Systematic Review

Changes in craniocervical posture are a critical issue in modern society. Alterations of the mandible position in the anterior-posterior direction in association with head and neck posture are reported. The objective of the present review was to evaluate the relationship between craniocervical posture and sagittal position of the mandible and to evaluate the risk of bias inthe included studies. Electronic databases used to perform the search were PubMed, Wiley Online Library, and Cochrane. Only clinical trials that assessed sagittal craniocervical posture and mandible position in lateral cephalograms were included. Selected inclusion criteria were used to assess the finally selected studies. The upper and lower cervical spine was evaluated by seven and six studies, respectively. The risk of bias in the included studies varied from low to moderate. Literature research identified 438 records from 3 databases. Eventually, seven eligible clinical trials were included in this review. Evaluating the relationship between craniocervical posture and mandible position in the sagittal plane, it can be concluded that increased cervical inclination and head upright position are associated with the posterior position of the mandible. Attention to patients’ craniocervical posture should be paid as a part of clinical evaluation since it might be the reason for the changed mandible position.

Breathing pattern, orthognathic surgery and head posture in dentofacial deformity

Abstract Introduction: Dentofacial deformity (DFD) and the breathing mode can change the head posture. However, head posture changes after orthognathic surgery are controversial, and no studies were found on the relationship between the head posture and breathing mode in adults with DFD. Objective: To identify the main head posture changes in young adults affected by DFD, to verify if orthognathic surgery modifies the breathing mode and head posture, and if the breathing mode is associated with the head posture. Methods: Twenty-five young adults were assessed and divided in dentofacial deformity group (DFD; n = 15; x̅ = 28 years) and control group with dentofacial harmony (CG; n = 10; balanced by gender and age with the study group). Breathing mode was evaluated according to the orofacial myofunctional evaluation protocol, and biophotogrammetry was used in the head posture analyses. For the DFD group, the evaluations were performed pre and post the orthognathic surgery (pre- and post-DFD). Results: For the DFD group, the breathing mode modified after orthognathic surgery (p = 0.003), but with difference from GC (p = 0.027). No changes were found in head posture after orthognathic surgery, but significant difference was seen between post-DFD and GC for head inclination (p = 0.017). No relationship was observed between breathing mode and head posture (p > 0.05). Conclusion: After orthognathic surgery, a spontaneous improvement of breathing was seen in the sample. It was not possible to verify changes in head posture and association with breathing mode and head posture.

Body postural realignment in the first 2 months after orthognathic surgery

INTRODUCTION

This study aimed to assess the static posture in patients with Angle Class II and III malocclusions in the first 2 months after orthognathic surgery.

METHODS

This was a longitudinal observational study. Eligible participants were adult patients who had an indication of orthognathic surgery (bilateral sagittal split osteotomy of the maxilla and/or mandible, can be associated or not with genioplasty). Thirty-five patients were evaluated from the orthognathic surgery group (OSG) and control group (CG). Measurements in OSG were performed at 3 time points: preoperative orthognathic surgery (P0), first postoperative month (P1), and second postoperative month (P2). Static posture was evaluated using the PostureScreen Mobile (PostureCo Inc, Trinity, Fla) application in 4 views.

RESULTS

Patients with Angle Class II malocclusion in the OSG evidenced a tendency to a left hip translation at P1 with a significant difference at P2 in the anterior view (P = 0.052). In the right lateral view, patients with Angle Class II malocclusion in the OSG at P1 presented an accentuated anterior shoulder translation when compared with CG (P <0.001). At P1, patients with Angle Class II malocclusion in the OSG showed a significant anterior knee translation compared with the CG and OSG at P0 and P2 (P <0.001 for all). Patients in the OSG with Angle Class III malocclusion presented an average posterior head translation in the right lateral view at P1 when compared with those in the CG and OSG at P0, who presented an anterior translation (P = 0.0008).

CONCLUSIONS

These findings suggest a realignment of static posture in the first 2 months after orthognathic surgery.

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.

Is PostureScreen® Mobile app an accurate tool for dentists to evaluate the correlation between malocclusion and posture?

OBJECTIVE

To determine whether PostureScreen® Mobile app is a useful, simple tool that is accessible for dentists to evaluate the correlation between malocclusion and posture.

METHODS

Twenty-nine subjects underwent static and dynamic dental occlusion examinations and a postural exam with PostureScreen® Mobile app, a photographic method. The subjects were divided into groups depending on their static and dynamic occlusion features. The postural parameters were then compared between these groups.

RESULTS

Statistically significant differences (p < 0.05) for some postural parameters were obtained for Angle Class 1 vs. 2 and 3 and for the passive interference group and active premature contacts group during left lateral movement. There were no statistically significant differences regarding protrusion and right lateral movement.

DISCUSSION

Dental occlusion anomalies and posture pathological modifications can be inter-related. PostureScreen® Mobile app might represent a useful tool in the early diagnosis of dental occlusion pathology.

Relationships of vertical facial pattern, natural head position and craniocervical posture in young Chinese children

OBJECTIVE

To investigate relationships of vertical facial patterns, natural head position (NHP), and craniocervical posture in young Chinese children with skeletal Class I relationship.

METHODS

Ninety-four patients with skeletal Class I relationship were classified into low, average, and high angle groups according to their mandibular plane angle (NSL/ML). Cephalometric radiographs in NHP were taken. Variables representing vertical and sagittal craniofacial morphology, head posture, and craniocervical posture were measured and compared.

RESULTS

Inclinations of the mandible to the true vertical and cervical column were smallest in the high angle group and largest in the low angle group. Other variables representing head posture and craniocervical posture were largest in the high angle group, smallest in the low angle group. Inclinations of ramus to cervical column were largest in the high angle group and smallest in the low angle group.

DISCUSSION

Subjects with large NSL/ML angles showed extended head and craniocervical posture, while subjects with small NSL/ML angles exhibited flexed head and craniocervical posture.

[Inclination of crown and tooth longitudinal axis in cephalometric analysis of normal occlusions]

OBJECTIVE

We measured and analyzed the angle between the longitudinal axis of incisor crown and tooth to provide a reference for orthodontists for selecting orthodontic methods and evaluating treatment results.

METHODS

A total of 120 participants were included according to the criteria of Andrews' six keys, and cephalometric radiograph under the instructions of modified natural head position acquirement method was performed. The angles of maxillary incisor crown longitudinal axis, tooth longitudinal axis, occlusion plane (OP), and true vertical (TV) plane were measured, as well as mandibular incisors.

RESULTS

As for maxillary incisors, the angle between crown longitudinal axis and TV plane, OP, and tooth longitudinal axis were 11.72°±4.71°, 73.29°±5.69°, and 20.04°±3.71°, respectively. For mandibular incisors, the angle between crown longitudinal axis and TV plane, OP, and tooth longitudinal axis were 16.03°±5.40°, 81.76°±4.81°, and 14.82°±4.01°, respectively. For the maxillary incisor, the angles between crown longitudinal axis and tooth longitudinal axis were mainly within 15° to 25°, whereas those for mandibular incisors were within 10° to 20°.

CONCLUSIONS

The longitudinal axis inclinations of the maxillary and mandibular incisor crown and of the incisor tooth need to be considered when cephalometric radiographs are used for treatment planning or for evaluating the treatment result.