Mandibular width as a novel anthropometric measure for assessing obstructive sleep apnea risk

Novel clinical screening method to identify patients at risk of obstructive sleep apnea

OBJECTIVE

To investigate whether the distance between the two retromolar trigones (RMTs) with the distance between the two posterior plicas (PPs) affects obstructive sleep apnea syndrome (OSAS) and to determine a physical examination method that can be used in the selection of patients to be referred to polysomnography (PSG).

METHODS

The study included 86 OSAS patients and 29 healthy controls. RMTs and PPs were measured using a caliper-like device. The values obtained from these measurements were evaluated in both groups.

RESULTS

The PPs were narrower, and the RMTs-PPs, RMTs-PPs/RMTs, and RMTs/PPs values were greater in the OSAS group (p < .05) compared to the control group. The cut-off values were 0.612 for RMTs-PPs/RMTs and 2.589 for RMTs/PPs. The specificity of these values for OSAS was 97%, and sensitivity was 57% and 58%, respectively.

CONCLUSION

The presented method may play a role in preventing unnecessary PSG among patients with suspected OSAS.

Features and networks of the mandible on computed tomography

The mandible or lower jaw is the largest and hardest bone in the human facial skeleton. Fractures of the mandible are reported to be a common facial trauma in emergency medicine and gaining insights into mandibular morphology in different facial types can be helpful for trauma treatment. Furthermore, features of the mandible play an important role in forensics and anthropology for identifying gender and individuals. Thus, discovering hidden information of the mandible can benefit interdisciplinary research. Here, for the first time, a method of artificial intelligence-based nonlinear dynamics and network analysis are used for discovering dissimilar and similar radiographic features of mandibles between male and female subjects. Using a public dataset of 10 computed tomography scans of mandibles, the results suggest a difference in the distribution of spatial autocorrelation between genders, uniqueness in network topologies among individuals and shared values in recurrence quantification.

Correlation analysis of upper airway morphology in patients with obstructive sleep apnea and anatomically small retruded mandibles

OBJECTIVE

To investigate the relationship between upper airway morphology and the severity of obstructive sleep apnea (OSA) in patients with anatomically small retruded mandibles.

METHODS

Fifty-two patients with small retruded mandibles underwent polysomnography and airway computed tomography. The airway morphology parameters and sleep assessment were compared between the patients with or without OSA.

RESULTS

Twenty-eight patients diagnosed with OSA, according to polysomnography, had a higher distance between the hyoid bone and mandibular plane (HMP), lateral dimension (LAT)/anteroposterior dimension (AP), but lower minimum cross-sectional area (mCSA), AP, surface area, volume, avgCSA, and airway uniformity (U). The apnea-hypopnea index had negative correlations with mCSA, AP, surface area, volume, avgCSA, and U, and had a positive correlation with HMP and LAT/AP.

CONCLUSION

OSA is common among patients with small retruded mandibles and is associated with a more compressed upper airway shape and longer HMP.

Predicting the presence and severity of obstructive sleep apnea based on mandibular measurements using quantitative analysis of facial profiles via three-dimensional photogrammetry

BACKGROUND

In obstructive sleep apnea (OSA), the upper airway is obstructed during sleep due to obesity and/or posterior collapse of the tongue root. Maxillofacial morphological abnormalities increase the risk of OSA in the Asian population. This study sought to elucidate whether three-dimensional (3D) photogrammetry measurements correlate with the severity of OSA irrespective of sex and degree of obesity.

METHODS

A prospective pilot study was performed, in which 37 consecutive adult patients (M/F = 28/9) underwent polysomnography and 3D photogrammetry in the supine position for the diagnosis of OSA. Measurements obtained from 3D photogrammetry included mandibular width (Mw), mandibular length (Ml), mandibular depth (Md), mandibular width-length angle (Mwla), and mandibular area (Ma). The effects of sex and body mass index (BMI) on the measurements and their association with the apnea-hypopnea index (AHI) were statistically analyzed. The inter-rater reliability of the measurements was evaluated using intraclass correlation coefficients (ICC).

RESULTS

Mwla (R = 0.73, p < 0.01), Mw (R = 0.39, p < 0.05), and Md (R = -0.34, p < 0.05) were significantly correlated with the severity of OSA. On multivariate analysis, Mwla (p < 0.01) and Md (p < 0.05) remained independent factors for AHI after adjusting for sex, age, BMI, and neck circumference. In addition, diagnosability analysis revealed that Mwla was useful for identifying the presence of OSA (AHI ≥5) (cutoff: 78.6°, sensitivity: 0.938, specificity: 0.800, area under the curve: 0.931). The ICC was >0.9, showing high reliability.

CONCLUSIONS

This study suggests that Mwla measured using 3D photogrammetry can predict the presence of OSA and correlates with the severity of OSA, independent of obesity and sex.

Three-Dimensional Measurement of Oropharynx and Laryngopharynx in Children With Hemifacial Microsomia

OBJECTIVE

This study focused on evaluating different parts of the airway in patients with hemifacial microsomia classified by the Pruzansky-Kaban classification system.

METHODS

Volumetric and morphologic airway parameters of 66 children with hemifacial microsomia were measured on 3D models. Using the Pruzansky-Kaban system, the patient cohort was composed of seven I-type, 14 IIa type, 27 IIb type, and 18 III type patients.

RESULTS

The total airway volume was not statistically different among groups. In the 3D oropharynx models, volume and surface area of the oropharynx decreased from the type I group to the type IIb group. However, no statistically significant difference was found for length (P = 0.965) or minimum cross-sectional area (mini-CSA, P = 0.550) of the oropharynx in the type III group compared to the other groups. In the 3D laryngopharynx models, the mean-CSA (P = 0.413) and mini-CSA (P = 0.378) were not statistically different among groups. In contrast, volume (P = 0.014), length (P = 0.005), and surface area (P = 0.032) of the laryngopharynx were reduced from type I to type III. Kruskal-Wallis analysis indicated statistically significant differences of volume (P = 0.004), length (P = 0.017), and surface area (P = 0.010) of the laryngopharynx among groups I, IIa, and IIb. The mean-CSA (P = 0.247) and mini-CSA (P = 0.206) of the laryngopharynx were not correlated with the different clinical types.

CONCLUSION

The mean-CSA varied significantly from type I to IIb at the level of oropharynx. In addition, the volume of the laryngopharynx decreased from type I to type III. However, type III was unique in this study with nonseverely airway measurement results.