Soft tissue airway dimensions and craniocervical posture in subjects with different growth patterns

Correlation between craniocervical posture and upper airway dimension in patients with bilateral anterior disc displacement

OBJECTIVE

To investigate the relationship between upper airway dimension and craniocervical posture in adult patients with bilateral anterior disc displacement and to provide some references for clinical diagnosis and plan formulation in orthodontics.

METHODS

Based on RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorder), 98 Patients were divided into three groups by two experienced TMJ (Temporomandibular Joint) specialists: bilateral disc normal position group (BN), bilateral anterior disc displacement with reduction group (ADDWR) and bilateral anterior disc displacement without reduction group (ADDWoR). Inter-group comparison and correlation analysis were performed after 11 craniocervical posture and 15 upper airway dimension measurements finished with Dolphin and Uceph software in Two or Three-dimensional.

RESULTS

Anterior disc displacement often accompanied with extension of craniocervical posture, as ADDWR and ADDWoR groups have significantly higher cervical curvature and inclination than BN group (P < 0.05). Simultaneously anterior disc displacement often associated with constrained upper airway dimension for the total and each segment upper airway volume were significantly smaller in ADDWR and ADDWoR than BN group (P < 0.05). Correlation analysis revealed that C0-C1 (the distance from the base of the occipital bone (C0) to the posterior arch of the atlas (C1)) is significantly related to the total and each segment upper airway volume reduction (P < 0.05).

CONCLUSION

There exists markedly close correlation between anterior disc displacement and craniocervical posture forward extension, which may be physiologically adaptive cervical extension to keep oropharyngeal airway unobstructed as upper airway dimension constrained by anterior disc displacement.

CLINICAL RELEVANCE

These findings allow us to infer the potential consequences if the treatment of anterior disc displacement would result in an improvement of intervertebral relationships and upper airway constraint.

Three-dimensional evaluation of upper pharyngeal airway, hyoid bone, and craniocervical changes following stabilization splint therapy in adult patients with temporomandibular joint disorders and mandibular deviation: A retrospective study

OBJECTIVE

This study aimed primarily to analyze the three-dimensional (3D) changes in the pharyngeal airway (PA), and secondarily, the hyoid bone (HB) and the craniocervical (CC) following stabilization splint (SS) therapy in adult patients with temporomandibular joint disorders (TMD) and mandibular deviation (MD).

METHODS

Thirty-five adult patients with TMD and MD, who were treated using SS with a mean age of 25.14 ± 6.11 years, were enrolled in this retrospective clinical study. Pre- and post-therapeutic cone-beam computed tomography (CBCT) scans were analyzed. PA dimension,nasopharyngeal, oropharyngeal, hypopharyngeal, sub-hypopharyngeal, and total pharyngeal airway spaces were measured in surface area, volume, minimum constricted area (MCA) and width, HB position, and CC posture were analyzed three-dimensionally using InVivo 6.0.3 and Dolphin 11.95 software. Wilcoxon rank-sum or Paired t-test was conducted, and P < 0.05 was considered significant.

RESULTS

SS therapy was administered for a period of 9.49 ± 4.02 months. The oropharyngeal airway space showed a significant decrease in sagittal width. The hypopharyngeal surface area, volume, MCA, and sagittal width decreased significantly. In terms of HB, hyoid-mandibular plane (H-MP), retrognathia-third vertebra's most inferior-anterior (RGN-C3ia), and retrognathia-Sella (RGN-S) distances significantly decreased. The Nasion-Sella line and the line that passes through C2ip to the odontoid process posterior tangent (NSL-OPT) angle in CC posture also decreased significantly.

CONCLUSION

SS therapy in TMD patients with MD mainly results in narrowing of the hypopharyngeal region, no change in HB position and improvement in head posture. These results undoubtedly assist in diagnosis and treatment of clinical conditions.

Oropharyngeal complex differences related to sex and occlusal factors in adolescents aged 12-17 years

OBJECTIVE

To investigate oropharyngeal complex differences related to sex and occlusal factors in adolescents.

METHODS

A cross-sectional study was conducted with 108 patients aged 12-17 years. The oropharyngeal complex was evaluated by imaging exams. Occlusal variables included molar relationship, facial growth pattern, maxilla shape, tooth loss, anterior crossbite, and anterior open bite. Statistical analysis included independent t-test, Mann-Whitney, ANOVA, and Kruskal-Wallis tests. The significance level was 5%.

RESULTS

There were increases of the tongue measurement (p = 0.026) and the hyoid approach at the base of the mandible among boys (p = 0.016) and the distance from the hyoid at the base of the mandible among girls (p = 0.039). There was shortening of the soft palate measurements (p = 0.003 and p = 0.007) and tongue (p = 0.018) among adolescents with an anterior crossbite.

CONCLUSION

Findings suggest sex, age, and anterior crossbite can be related to oropharyngeal morphology.

Differences in the effects of orthodontic treatment on airway-craniocervical functional environment in adult and adolescent patients with skeletal class II high-angle: a retrospective pilot study

INTRODUCTION

This retrospective cohort study aimed to compare the change in upper airway and craniocervical posture after orthodontic treatment between adolescent and adult patients with Class II high-angle malocclusion.

METHODS

A total of 12 adolescent (mean ± standard deviation age = 13.0 ± 2.0 years) and 12 adult patients with Class II high-angle malocclusion (mean ± standard deviation age = 23.7 ± 6.4 years) were selected in this study. The lateral cephalograms and cone beam computed tomography images of adolescent and adult patients were taken before and after treatment, which can be employed to evaluate the variables of craniofacial morphology, upper airway, and craniocervical posture through paired t tests, respectively. An independent sample t test was performed to observe the differences between two groups after orthodontic intervention. For adults and adolescents, the correlation between craniofacial morphology, upper airway, and craniocervical posture was determined through Pearson correlation analysis.

RESULTS

In all subjects, the improvements in vertical and sagittal facial morphology after treatment were observed. Anterior and inferior movements of the hyoid bone, an increase of upper airway dimension, posterior tipping of the head and a reduction of cervical inclination in the lower and middle segments post-treatment were identified in adolescence (P < 0.05). Adults displayed anterior movements of the hyoid bone, whereas no significant difference was observed in upper airway dimension and craniocervical posture (P < 0.05). Notable differences were identified in the change of hyoid position and airway volume between two groups (P > 0.05). Mandibular plane inclination, growth pattern, occlusal plane inclination, and chin position were all significantly correlated with craniocervical posture in adolescent patients. Besides, the mandibular growth pattern and chin position in adult patients were significantly correlated with craniocervical posture (P < 0.05).

CONCLUSIONS

Orthodontic treatment is capable of enhancing the facial profile of patients with skeletal class II high-angle while improving their upper airway morphology and craniocervical posture, where adolescents and adults differ substantially in that the former exhibit a more favorable alteration in the airway-craniocervical functional environment.

Relationship between craniofacial and dental arch morphology with pharyngeal airway space in adolescents

PURPOSE

The aim of the study was to investigate a possible relationship between pharyngeal airway space, craniofacial variables, and dental arch form in adolescents grouped by sex.

METHODS

This cross-sectional study included 108 adolescents aged between 12 and 17 years. Lateral cephalometric radiographs were used to analyze sagittal craniofacial variables and the pharyngeal airway space. For evaluation of the dental arch form, we used plaster models. Statistical analysis included Student's t‑test and Pearson's correlation coefficient (r).

RESULTS

Maxillary length was directly proportional to upper nasopharyngeal airway dimensions in males (r = 0.312, p = 0.021) and females (r = 0.310, p = 0.022). In the female group, upper oropharyngeal measurements showed an inverse correlation with a labial inclination of the upper incisors (r = -0.415, p = 0.001), protrusion of the upper incisors (r = -0.364, p = 0.006), and soft palate thickness (r = -0.27, p = 0.043). In the male group, upper nasopharynx measurements showed an inverse correlation with soft palate thickness (r = -0.277, p = 0.042). The upper arch form appeared to be related to oropharyngeal measurements in females, while the lower arch form was related to oropharyngeal dimensions in males.

CONCLUSION

The findings suggest that there are sex-dependent correlations of the nasopharyngeal and oropharyngeal airway space with the sagittal craniofacial morphology and the transversal dental arch form.

Morphometric characteristics of cervical vertebrae in subjects with short, normal, and long faces

PURPOSE

The prolonged change in the head posture alters the morphological characteristics of cervical vertebrae. The difference in the head posture among subjects with short, normal, and long anterior facial heights might have a significant influence on the morphological characteristics of cervical vertebrae. Thus, the present study was conducted to evaluate the morphometric characteristics of cervical vertebrae in subjects with short, normal, and long faces.

METHODS

Based on Frankfort mandibular plane angle (FMA) on lateral cephalograms, 135 subjects were equally divided into three groups, i.e. Group I [Short face], II [Normal face], and III [Long face]. The angular variables like Atlas-dens angle (ADA), Pars interarticularis-dens angle (PDA), Pars interarticularis-vertebrae angle of C3 vertebrae (PVA3), Pars interarticularis-vertebrae angle of C4 vertebrae (PVA4), Lamina-Pars interarticularis angle of C2 vertebrae (LP2), Lamina-Pars interarticularis angle of C3 vertebrae (LP3), and Lamina-Pars interarticularis angle of C4 vertebrae (LP4) in the first four cervical vertebrae were measured, analyzed, and compared. Descriptive statistics, analysis of variance, Bonferroni, and Pearson's correlation coefficient tests were used. The P value of 0.05 was considered as the level of significance.

RESULTS

All parameters except PDA and PVA3 were comparable among the groups. The PDA was 54.35⁰ ± 1.87⁰, 57.89⁰ ± 1.55⁰, and 60.29⁰ ± 2.83⁰ in Group I, II, and III, respectively; these differences were statistically significant [P < 0.001]. The PVA3 was 42.70⁰ ± 5.64⁰ in Group I, 45.85⁰ ± 3.82⁰ in Group II, and 45.59⁰ ± 5.53⁰ in Group III subjects that were also statistically significant [P < 0.01]. A fairly strong positive correlation was observed between FMA and PDA.

CONCLUSION

A significant difference was found in the PDA among subjects with short, normal, and long faces. The vertical height of the face had a strong correlation with the morphology of axis vertebra.

A study of cervical vertebra anomalies among individuals with different sagittal and vertical facial growth patterns

Objective:

The objective was to evaluate the prevalence of cervical vertebra anomalies (CVA) in individuals with different sagittal and vertical skeletal growth patterns of jaws and also to establish the associations of anomalies with the type of growth, if any.

Materials and Methods:

A total of 293 lateral cephalograms were evaluated for CVA. Based on the Frankfort mandibular plane angle, cephalograms were categorized into three groups: Group I, II, and III. Based on the ANB angle, cephalograms were classified into three classes, Class 1, 2, and 3. Six types of CVA such as partial cleft (PC), block fusion (BF), dehiscence (D), fusion between C2 and C3 (F23), occipitalization (OC), and spina bifida (SB) were identified on lateral cephalograms. Descriptive statistics were applied along with multinomial logistic regression analysis. P = 0.05 was considered as the level of statistical significance.

Results:

PC was most common in the overall samples (36%). BF was the least common (3.2%) CVA. The frequency of various CVA was comparable between males and females in all the three classes of individuals. The association of vertical growth patterns with CVA was found to be statistically nonsignificant (P > 0.05). Class 2 malocclusion was found to be statistically significantly associated with the D (P = 0.043).

Conclusions:

PC, fusion, and D were the most frequently found CVA, and SB was found only among the hypodivergent growth pattern individuals. The association of CVA with vertical facial growth patterns was not significant, somewhat influenced by age, sex, and sagittal skeletal malocclusions.

Associations Among Temporomandibular Joint Osteoarthritis, Airway Dimensions, and Head and Neck Posture

PURPOSE

This study sought to investigate associations among progressive temporomandibular joint osteoarthritis (TMJ OA), airway dimensions, and head and neck posture.

MATERIALS AND METHODS

In total, 114 temporomandibular disorders (TMDs) patients were enrolled. Among 114 patients, 28 had no pathologic bony changes in the TMJ condyles (TMDnoOA), 45 had progressive TMJ OA (TMJOApro), and 41 demonstrated TMJ OA which had not progressed for 12 months (TMJOAnopro). TMJ OA was diagnosed based on the Diagnostic Criteria for TMD axis I. Computed tomography (CT) images and lateral cephalograms were obtained at baseline (T0) and 12 months after treatment (T1). The head and neck posture and airway area in upright position were analyzed using lateral cephalograms whereas airway volume in supine position was determined by 3D reconstructed CT images.

RESULTS

The volume change of the oropharynx in supine position was more prominent in the TMJOApro than in the TMDnoOA but no significant differences in changes in the pharyngeal airway while in upright position were detected. The retrognathic facial profile became more remarkable at T1 in the TMJOApro and TMJOAnopro compared to those at T0. The forward head posture seemed to be progressed in the TMJOApro than in either the TMJOAnopro or TMDnoOA.

CONCLUSION

Progressive TMJ OA may have associations with retrognathia and decreased oropharyngeal airway volume in the supine position but not in the upright position. Progressive TMJ OA may be related with altered head posture in the upright position to compensate for reduced airway dimensions.

Assessment of airway dimensions in skeletal Class I malocclusion patients with various vertical facial patterns: A cephalometric study in a sample of the Saudi population

OBJECTIVE

To compare airway widths among skeletal Class I malocclusion patients with different vertical facial patterns.

MATERIAL AND METHODS

A total of 103 lateral cephalograms of skeletal Class I patients (mean age of 20 ± 2.3 years) with no history of orthodontic treatment, trauma, facial syndromes, or nasopharyngeal dysfunction were included. Based on the Frankfort-mandibular plane angle measurements, the sample was divided into three groups: low-angle, high-angle, and normal-angle groups. Upper and lower pharyngeal airway widths were measured as described by McNamara. The analysis of variance test was performed to compare the means of groups. Pairwise comparisons were performed using Tukey's post-hoc test. Differences were considered statistically significant at P < 0.05.

RESULTS

ANOVA showed a significant mean difference between the groups for both the upper and lower airway widths with P values of 0.011 and 0.003, respectively. Tukey Pairwise comparisons showed the upper airway width to be significantly narrower in the high-angle group compared to the normal-angle (P = 0.021) and low-angle groups (P = 0.013). Furthermore, the lower airway width in the high angle group was significantly narrower than the normal angle (P = 0.020) and low-angle groups (P = 0.017). There were no statistically significant differences between normal and low angle groups.

CONCLUSIONS

The upper and lower pharyngeal widths in the Class I high-angle group were significantly narrower than those in the normal-angle and low-angle groups.

Upper airway asymmetry in skeletal Class III malocclusions with mandibular deviation

The purpose of this study was to investigate the relationship between bilateral differences of upper airway and mandibular morphologic patterns in subjects with skeletal Class III mandibular deviation. 47 skeletal Class III (ANB < 0°) adult patients with and without mandibular deviation were divided into 2 groups. Bilateral differences of minimum cross-sectional area, mean cross-sectional area, volume of subdivisions (nasopharynx, palatopharynx, glossopharynx, hypopharynx) were assessed paired t test. Stepwise linear regression analysis and Pearson correlation coefficients were computed between a significant pair of upper airway variables and a pair of mandibular deviation variables to examine the quantitative relationship between the upper airway asymmetry and mandibular deviation. The mean cross-sectional area and the volume of palatopharynx on the deviated side in mandibular deviated group was significantly smaller than non-deviated side. The asymmetry index of the palatopharyngeal volume showed significant correlations with CRA asymmetry (r = 0.49) and Ramus asymmetry (r = 0.54). However, in the glossopharyngeal and hypopharyngeal segment, the mandibular deviated group showed significant asymmetry, characterized by larger mean cross-sectional area and volume in deviated side. The asymmetry index of the glossopharyngeal volume and hypopharyngeal volume showed significant correlations with CRA asymmetry (r = 0.42), Me-s (r = 0.72) and Me-s (r = 0.67) respectively.