Cephalometric Assessment of Upper Airway Effects on Craniofacial Morphology

X-Ray Cephalometric Analysis of the Effects of Angle Class II and III Malocclusion on the Upper Airway Width and Hyoid Position between Parents and Children of Uygur Nationality

Objective

The objective of this paper is to analyze the effect of angle class II and III malocclusion on the sagittal diameter of the upper airway between parents and children of Uygur nationality and to compare the degree of influence.

Methods

29 Uygur adolescents with malocclusion and their fathers (mothers) were selected as our subjects via X-ray cephalometric radiograph to analyze the difference between the upper airway sagittal dimension and normal occlusion and compare the influence of malocclusion on the upper airway between parents and children.

Results

Compared with normal group, the vertical distance from the hyoid point to orbital-ear plane (H-FH) and vertical distance from hyoid point to the mandibular plane (H-MP) in angle class II malocclusion elevated signally, while the vertical distance from hyoid point to anterior cervical plane (H-VL), PNS-UPW, H-FH, and H-MP decreased significantly; compared with normal group: the distance between the posterior nasal spine and the upper pharynx wall (PNS-UPW), H-FH, and H-MP in angle class III malocclusion visually reduced, while PAS, and horizontal distance from the hyoid point and center point of sella turcica to orbital-ear foot (H-S), increased markedly. The impact of class II malocclusion on parents' U-MPM was greater than their children.

Conclusion

The oropharyngeal space of upper airway becomes smaller and hyoid shifts downwards due to class II malocclusion. Class III malocclusion results in decreased nasopharyngeal gap with hyoid to shift upward. The influence of class II malocclusion on the upper pharyngeal tract of parents was greater than their children.

Upper Airway Characteristics in Young Individuals With Class II Division 1 Malocclusion: A Retrospective Inter-Ethnic Cephalometric Comparison

ABSTRACT

This study aimed to compare the upper-airway morphology between strictly matched Syrian (n = 43) and Hungarian (n = 43) adolescents with Class II/1 malocclusion and identify potential associations between upper airway depths and skeletofacial characteristics. Lateral cephalograms were analyzed, and independent-samples tests and correlation coefficients were used for the statistical analyses. The upper-pharyngeal airway was significantly narrower and the soft palate angle was significantly greater in the Syrian adolescents. Alternatively, the hyoid bone was more posteriorly positioned in the Hungarian adolescents when compared to their counterparts. Depths of the upper and middle pharynx were moderately correlated with sagittal and vertical skeletal dimensions only among Syrian subjects. The depth of the lower pharynx was moderately correlated with hyoid bone position, cervical length, and lip-chin-throat angle only among Hungarian subjects. These findings might have potential implications for optimizing the effects of orthognathic/orthodontic treatments on airway structures in these 2 groups.

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.

Soft palate cephalometric changes with a mandibular advancement device may be associated with polysomnographic improvement in obstructive sleep apnea

PURPOSE

It is unclear whether soft palate-associated changes in cephalometry associated with a mandibular advancement device (MAD) are independently associated with improvements in polysomnography (PSG) respiratory parameters in obstructive sleep apnea (OSA).

METHODS

This retrospective review aimed to identify the association between soft palate-associated changes in cephalometry and PSG changes after application of an MAD. Korean patients diagnosed with OSA who underwent cephalometry with or without an MAD were enrolled. All the patients were evaluated after undergoing full-night PSG twice: once with an MAD and once without. Cephalometric findings were measured using an image analyzer.

RESULTS

Mean apnea-hypopnea index significantly decreased with an MAD from 36.4/h to 14.7/h (p < 0.001). Retropalatal airway space significantly increased with an MAD from 6.6 to 7.3 mm (p = 0.013). Soft palate length also significantly decreased with an MAD from 43.6 to 42.3 mm (p = 0.02). Although these findings were shown by responders (patients with a reduction of apnea-hypopnea index by more than 50%), there were no significant changes in non-responders. However, retroglossal airway space did not significantly increase with an MAD even in responders.

CONCLUSIONS

Improvement of OSA with an MAD can be predicted with soft palate-associated upper airway changes shown in cephalometry.

A retrospective study: does upper airway morphology differ between non-positional and positional obstructive sleep apnea?

Objective

The objective of this study was to explore the differences in upper airway morphology between positional (POSA) and non-positional (NPOSA) obstructive sleep apnea.

Methods

This retrospective study enrolled 75 patients (45 NPOSA and 30 POSA) who underwent polysomnography (PSG) and computed tomography (CT). The differences in, and relationships of, the PSG values and CT data between POSA and NPOSA were analyzed.

Results

Significant (p < 0.05) differences between the two groups were found in the apnea/hypopnea index (AHI), lateral-AHI (L-AHI), soft palate length (SPL), cross-sectional palatopharyngeal area, and the coronal diameter (CD) of the palatopharyngeal area at the narrowest part of the glossopharynx, which were all higher in POSA, except for SPL, AHI, and L-AHI. L-AHI was correlated with the cross-sectional area (r =  − 0.306, p = 0.008) and CD (r =  − 0.398, p < 0.001) of the palatopharyngeal area, the cross-sectional area (r =  − 0.241, p = 0.038) and CD (r =  − 0.297, p = 0.010) of the narrowest level of the glossopharynx, the CD of the glossopharynx (r = 0.284, p = 0.013), body mass index (BMI, r = 0.273, p = 0.018), SPL (r = 0.284, p = 0.014), and vallecula-tip of tongue (r = 0.250, p = 0.030). The SPL and CD at the narrowest part of the glossopharynx were included in the simplified screening model.

Conclusions

In NPOSA, the CD of the upper airway was smaller, and the soft palate was longer, than in POSA. These differences may play significant roles in explaining the main differences between NPOSA and POSA.

Nasal patency and craniocervical posture in scholar children

ABSTRACT Changes in head posture have been observed as a compensatory mechanism for the nasal airflow impairment. This study aimed to compare the craniocervical posture between children with normal and decreased nasal patency and correlate nasal patency with craniocervical posture. Children aging from six to twelve years went through nasal patency and craniocervical assessments. The biophotogrammetric measures of craniocervical posture used were Cervical Distance (CD), Head Horizontal Alignment (HHA) and Flexion-Extension Head Position (FE), evaluated by SAPO software (v.0.68). Nasal patency was measured using Peak Nasal Inspiratory Flow meter (PNIF) and Nasal Obstruction Symptom Evaluation (NOSE) scale. One hundred thirty-three children were distributed into two groups: G1 (normal nasal patency - PNIF higher than 80% of predicted value) with 90 children; G2 (decreased nasal patency - PNIF lower than 80% of predicted value) with 43 children. Differences between groups were not found in CD and HHA measures. FE was significantly higher in G2 than G1 (p=0.023). Negative weak correlation between FE and %PNIF (r=-0.266; p=0.002) and positive weak correlation between CD and PNIF (r=0.209; p=0.016) were found. NOSE scores negatively correlated with PNIF (r=-0.179; p=0.039). Children with decreased nasal patency presented greater head extension. This postural deviation is prone to increase as nasal airflow decreases, thus indicating the relationship between craniocervical posture and nasal patency. Lower values of PNIF reflected on additional problems caused by nasal obstruction symptoms.