Facial morphology and obstructive sleep apnea

A Pilot Study on the Relationship between Obstructive Sleep Apnoea-Hypopnea Syndrome, Neurodevelopment, and Ricketts' Cephalometry

Background: The aim of this research is to achieve the early detection of facial characteristics in patients diagnosed with neurodevelopmental deficits and obstructive sleep apnoea-hypopnea syndrome (OSAHS) through the analysis of the VERT index and Ricketts' cephalometry to minimise the neurocognitive morbidity associated with these disorders. Methods: This clinical study was conducted on 44 patients aged 4 to 15 years. Participants completed an initial questionnaire about sleep disturbances, followed by a polysomnography, a radiographic study, and an oral examination. Results: The maximum variability in the data was obtained in the mandibular plane angle, where we observed that the measurement was higher in patients diagnosed with OSAHS. The relative and normalised indices of facial depth and the mandibular plane showed variations between patients with a clinical picture compatible with OSAHS and the control group without pathology. Conclusions: Our findings indicate that Ricketts' VERT index by itself is unable to provide evidence of a diagnosis compatible with OSAHS in patients with early neurodevelopmental deficits, but, after analysing the results obtained, we observed that for the cephalometric measurements of the mandibular plane angle and facial depth relative to the patient's age, there are sufficiently strong variations for creating a solid method of differential diagnosis, thus preventing complications at the neurocognitive level.

The enigma of sleep: Implications of sleep neuroscience for the dental clinician and patient

BACKGROUND

Sleep disturbances have been shown to result in considerable morbidity and mortality. It is important for dental clinicians to understand the neuroscience behind sleep disorders.

TYPES OF STUDIES REVIEWED

The authors conducted a search of the literature published from January 1990 through March 2024 of sleep medicine-related articles, with a focus on neuroscience. The authors prioritized articles about the science of sleep as related to dental medicine.

RESULTS

The authors found a proliferation of articles related to sleep neuroscience along with its implications in dental medicine. The authors also found that the intricate neuroscientific principles of sleep medicine are being investigated robustly. The salient features of, and the differences between, central and obstructive sleep apneas have been elucidated. Sleep genes, such as CRY, PER1, PER2, and CLOCK, and their relationship to cancer and neurodegeneration are also additions to this rapidly developing science.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The dental clinician has the potential to be the first to screen patients for possible sleep disorders and make prompt referrals to the appropriate medical professionals. This can be lifesaving as well as minimize potential future morbidity for the patient.

The role of upper airway and facial skeleton anatomy in the evolution of obstructive sleep apnea: an 8-year follow-up

PURPOSE

To evaluate the role of anatomic alterations of the upper airway and facial skeleton in the evolution of obstructive sleep apnea (OSA) in a prospective population-based study with an 8-year follow-up.

METHODS

This was a population-based, longitudinal, prospective study, which took place from 2007 to 2015 at the Instituto do Sono, Sao Paulo, Brazil. In 2007, type I polysomnography (PSG), otorhinolaryngological examination, and collection of anthropometric measurements of all volunteers were performed. Volunteers were classified according to their anatomical features of the upper airway and facial skeleton. After 8 years, volunteers were invited for reevaluation. The relationship between anatomical characteristics and polysomnographic evolution was evaluated.

RESULTS

The study included 554 patients. After 8 years of follow-up, there was an increase in neck circumference and body mass index of the participants. There was a worsening in all polysomnographic parameters analyzed, with an increase in the apnea-hypopnea index, a decrease in minimum saturation values, and an increase in the percentage of sleep time with peripheral oxyhemoglobin saturation <90%. There was no statistical relationship between the anatomical findings considered unfavorable and the worsening of polysomnographic parameters.

CONCLUSIONS

In a sample of the general population, after 8 years, we did not find any relationship between upper airway and facial skeleton characteristics and the progression of OSA.

Gender differences in the upper airway, craniofacial morphological and polysomnographic parameters in patients with obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation.

OBJECTIVE

This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea.

METHODS

This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS_min), hyoid bone to the mandibular plane (H_MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center.

RESULTS

A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively).

CONCLUSION

The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H_MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA.

Anthropometric 3D evaluation of the face in patients with sleep related breathing disorders

PURPOSE

To evaluate craniofacial measurements on 3D-stereophotogrammetry and see if particular measurements are more typical in obstructive sleep apnea (OSA) and have a correlation with its severity.

METHODS

Subjects included were adults undergoing a diagnostic polysomnography. Age, BMI, neck, abdominal and hip circumference (cm) were recorded. 3D-stereophotogrammetry was performed and landmarks were placed on the 3D-image. Different linear, angular and volume measurements were performed to gauge facial and neck anatomy. The relationship between these measurements and the severity of OSA, based on the obstructive apnea/hypopnea index (OAHI, events/h), was assessed by multiple linear regression, and adjusted for BMI and sex.

RESULTS

Of 91 subjects included (61 male), mean age was 46 ± 12 years, BMI 30.1 ± 6.5 kg/m2, OAHI 19.3 ± 18.8/h. BMI was higher (p = 0.0145) in females (32.9 ± 7.7) than in males (28.6 ± 5.3). This was also true for hip circumference (118 ± 15 vs 107 ± 10, p = 0.0006), while the neck circumference was higher (p < 0.0001) in males (41 ± 4 vs 37 ± 4). The following parameters could predict the logOAHI (r2-adjusted = 0.51): sex (p < 0.0001), BMI (p = 0.0116), neck-depth/mandibular-length (p = 0.0002), mandibular-width angle (p = 0.0118), neck-depth euclidean distance/surface distance (E/S) (p = 0.0001) and the interaction terms between sex and neck-depth/mandibular-length (p = 0.0034), sex and neck-depth E/S (p = 0.0276) and BMI and neck-depth E/S (p = 0.0118). The interaction between sex and neck-depth/mandibular-length showed a steeper linear course in females. This is also true for the interaction term BMI with neck-depth E/S in patients with a higher BMI. With a same neck-depth ratio, the OAHI is larger in men.

CONCLUSION

Measurements involving the width of the face and addressing the soft tissue in the upper neck were found to have a significant relation with OSA severity. We found remarkable differences between non-obese/obese subjects and between males and females.

A Review of Novel Oximetry Parameters for the Prediction of Cardiovascular Disease in Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a sleep disorder with repetitive collapse of the upper airway during sleep, which leads to intermittent hypoxic events overnight, adverse neurocognitive, metabolic complications, and ultimately an increased risk of cardiovascular disease (CVD). The standard diagnostic parameter for OSA, apnoea-hypopnoea index (AHI), is inadequate to predict CVD morbidity and mortality, because it focuses only on the frequency of apnoea and hypopnoea events, and fails to reveal other physiological information for the prediction of CVD events. Novel parameters have been introduced to compensate for the deficiencies of AHI. However, the calculation methods and criteria for these parameters are unclear, hindering their use in cross-study analysis and studies. This review aims to discuss novel parameters for predicting CVD events from oximetry signals and to summarise the corresponding computational methods.

A comparison of hypoxic burden algorithms using three different methods for calculating baseline oxygen saturation for predicting cardiovascular death in the Sleep Heart Health Study

Respiratory event related oxygen desaturation area measures have recently shown merit as novel predictors of cardiovascular disease (CVD) outcomes. In this study, we investigate one such measure (hypoxic burden (HB)) and investigate how three different ways of calculating the SpO2 baseline of the HB algorithm impact its ability to predict cardiovascular mortality. The three baseline estimation steps include a pre-event baseline, a record-based baseline, and a fixed baseline. Pulse oximetry signals from the Sleep Heart Health Study and the corresponding CVD outcomes were analyzed. The performance of each baseline method was compared using adjusted Cox proportional hazard regression analysis. Results show that HB with the record-based baseline method returned the best performing results with a hazard ratio (HR) of 1.83 (95% CI: 1.03-3.27, p<0.05) in the fully adjusted model, compared to HB with the pre-event baseline method (HR: 1.60, 95%CI: 0.86-3.00, p>0.05) and HB with the fixed baseline method (HR: 1.73, 95%CI: 0.93-3.22, p>0.05).

Candidate genes for obstructive sleep apnea in non-syndromic children with craniofacial dysmorphisms - a narrative review

Pediatric obstructive sleep apnea (POSA) is a complex disease with multifactorial etiopathogenesis. The presence of craniofacial dysmorphisms influencing the patency of the upper airway is considered a risk factor for POSA development. The craniofacial features associated with sleep-related breathing disorders (SRBD) - craniosynostosis, retrognathia and micrognathia, midface and maxillary hypoplasia - have high heritability and, in a less severe form, could be also found in non-syndromic children suffering from POSA. As genetic factors play a role in both POSA and craniofacial dysmorphisms, we hypothesize that some genes associated with specific craniofacial features that are involved in the development of the orofacial area may be also considered candidate genes for POSA. The genetic background of POSA in children is less explored than in adults; so far, only one genome-wide association study for POSA has been conducted; however, children with craniofacial disorders were excluded from that study. In this narrative review, we discuss syndromes that are commonly associated with severe craniofacial dysmorphisms and a high prevalence of sleep-related breathing disorders (SRBD), including POSA. We also summarized information about their genetic background and based on this, proposed 30 candidate genes for POSA affecting craniofacial development that may play a role in children with syndromes, and identified seven of these genes that were previously associated with craniofacial features risky for POSA development in non-syndromic children. The evidence-based approach supports the proposition that variants of these candidate genes could lead to POSA phenotype even in these children, and, thus, should be considered in future research in the general pediatric population.

Correlation between Apnea Severity and Sagittal Cephalometric Features in a Population of Patients with Polysomnographically Diagnosed Obstructive Sleep Apnea

Background and Objective: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder featuring a repeated closure of the upper airway during sleep. Craniofacial anatomy is a potential risk and worsening factor for OSA. This study aims to assess the relationship between cephalometric features of craniofacial morphology and OSA severity in a population of patients with OSA. Material and Methods: A sample of forty-two patients (n = 42, M = 76%, mean age = 57.8 ± 10.8) with a polysomnographically (PSG) confirmed diagnosis of OSA were recruited and underwent cephalometric evaluation of 16 cephalometric variables. In addition, the apnea−hypopnea index (AHI), oxygen desaturation (SatMin), Epworth sleepiness scale (ESS), and body mass index (BMI) were assessed. Then t-tests were performed to compare the values of all cephalometric variables between two AHI severity-based groups (mild-to-moderate = AHI ≤ 30; severe = AHI > 30). Single- and multiple-variable regression analyses were performed to assess the associations between AHI scores and cephalometric features. Results: Mean AHI, SatMin, and BMI were 31.4 ev/h, 78.7%, and 28.1, respectively. The cephalometric variables were not significantly different between the two OSA-severity groups (p > 0.05). Multiple-variable regression analyses showed that gonial angle and nasopharynx space were negatively associated with AHI, explaining 24.6% of the total variance. Conclusion: This investigation reported that severity of AHI scores in patients with OSA showed a negative correlation with gonial angle and nasopharynx space. As a general remark, although maxillofacial anatomy can be a predisposing factor for OSA, disease severity depends mainly upon other variables.

A consideration of factors affecting palliative oral appliance effectiveness for obstructive sleep apnea: a scoping review

STUDY OBJECTIVES

This scoping review allows physicians, researchers, and others interested in obstructive sleep apnea to consider effectiveness of oral appliances (OAs). The intent is to improve understanding of OA effectiveness by considering morphologic interaction in patients with obstructive sleep apnea.

METHODS

Morphologic and biomechanical criteria for positional alterations of the mandible assessed success rates of OA appliances. Searches of databases (Medline, PubMed, The Cochrane Library, EBSCO) using terms: OA treatment effectiveness and positive and/or negative outcome predictors. Craniofacial predictors of OAs and obstructive sleep apnea biomechanical factors of anatomical traits associated with OA effectiveness were included. Databases searched radiographic cephalometric imaging for morphology/phenotypes and apnea-hypopnea index responses. Articles were excluded if title or abstract was not relevant or a case report. If the analysis did not report mean or standard deviation for apnea-hypoxia index, it was excluded. No language, age, or sex restrictions were applied.

RESULTS

Analysis of 135 articles included in searched literature indicated alterations in musculature and pharyngeal airway structure through OA use. These alterations were individually unpredictable with wide variability 61.81% ± 12.29 (apnea-hypoxia index mean ± standard deviation). Morphologic variations as predictors were typically weak and idiosyncratic. Biomechanical factors and wide variations in the metrics of appliance application were unclear, identifying gaps in knowledge and practice of OAs.

CONCLUSIONS

An integrated basis to identify morphologic and biomechanical elements of phenotypic expressions of sleep-disordered breathing in the design and application of OAs is needed. Current knowledge is heterogeneous and shows high variability. Identification of subgroups of patients with obstructive sleep apnea responding to OAs is needed.

Screening of obstructive sleep apnea (OSA) risk in adolescent population and study of association with craniofacial and upper airway morphology

Background

Obstructive sleep apnea (OSA) is a common form of sleep-disordered breathing with high prevalence and associated co-morbidities. It still goes largely under-reported due to events occurring in sleep and difficulty in identifying predisposing factors.

Aims

To perform questionnaire-based screening of OSA-risk in adolescents and study association of OSA-risk with craniofacial and upper airway morphology.

Material and methods

Modified STOP-BANG questionnaire was used for screening OSA-risk in adolescent orthodontic patients (10-19 years) in a government dental hospital in India. Patients were categorised into two groups: OSA-risk and non-risk, based on the questionnaire scores, and were subsequently evaluated for craniofacial and upper airway morphology, both on examination and on lateral cephalometric radiographs.

Results

Documented a high prevalence of 14% for OSA-risk in adolescent orthodontic patients. The extra-oral and intra-oral parameters found significantly associated with OSA-risk were convex profile [Odd's ratio (OR) - 3.824], steep mandibular plane angle [MPA] (OR- 79.75), Type 3/4 faucial pillars (OR- 11.227), Class II molar relationship (OR - 4.518), ovoid upper arch form (OR - 13.750). In addition, the cephalometric parameters: ANB (p- 0.025), SN-MP (p- 0.007), BA-SN (p- 0.020), PNS-AD1 (p < 0.001), PNS-AD2 (p - 0.001) also showed highly significant association to OSA-risk. The ROC curves demonstrated high sensitivity and specificity for PNS-AD1 (60%,83.3%), PNS-AD2 (73.3%, 70%) and SN-MP (60%,70%), respectively for OSA-risk.

Conclusions

The study supported applicability of modified STOP-BANG questionnaire for OSA-risk in Indian adolescents. The parameters [extra-oral, intra-oral, cephalometric and upper airway (PNS-AD1, PNS-AD2, SN-MP)] significantly associated with OSA-risk, were identified.

Postural control abnormalities related to sleep deprivation in patients with Marfan Syndrome

BACKGROUND

Marfan syndrome (MFS) is a rare autosomal dominant connective tissue disorder affecting virtually every organ. Sleep disturbances, associated to high collapsibility in upper airways, are common in MFS; daytime sleepiness could lead to reduction in attention and motor coordination, with detrimental effects on balance.

OBJECTIVE

To evaluate otoneurological function in MFS patients, compared to healthy subjects, and to investigate possible correlations with sleep deprivation extent.

METHODS

Forty-one MFS patients underwent a thorough otoneurological examination, video Head Impulse Test (vHIT), and static posturography. Sleep parameters were recorded by home monitoring. Daytime sleepiness and dizziness-related handicap were screened by means of Dizziness Handicap Inventory (DHI) and Epworth Sleepiness Scale (ESS). Results were compared with 49 healthy controls (HC).

RESULTS

DHI and ESS scores were increased in MFS patients (p < 0,01). vHIT scores showed no between-group effect. Classical (surface and length) and frequency-domain posturographic parameters were significantly increased in MFS with respect to HC (p < 0,01). A positive correlation was found between ESS scores and posturographic parameters in MFS patients.

CONCLUSIONS

An impaired postural control, related to the extent of sleep deprivation, was found in MFS patients. Such results could advocate for screening and treating sleep deprivation and balance dysfunctions in MFS patients.

Validation of the Vertical Facial Growth Screening Test

Background. Vertical facial growth has a high prevalence. Nonspecialized professionals have shown low sensitivity to identify patients at risk. In the face of this difficulty, we designed and validated a screening checklist for vertical facial growth. Methods. A multidisciplinary team of 5 members developed the Vertical Facial Growth Screening Test. A sample of 160 evaluations was obtained. We consider as the gold standard the evaluation of 2 specialists in dentofacial orthopedics. Results. Consistency measured with Cronbach α was .675 for 10 items. Test-retest reliability was .956. The interobserver concordance was .886. The receiver operating characteristic curve has .987 area under the curve. Conclusion. This is the first study to design and validate a screening checklist for vertical facial growth for nonexpert evaluators. We think that given its good performance, ease of use, inexpensiveness, and availability, the test could be useful for nontrained professionals dealing with children.

Orthodontic view in the diagnoses of obstructive sleep apnea

Obstructive sleep apnea is an exciting area for orthodontists to be involved. The level of awareness of sleep apnea and related health issues is growing rapidly. The demand of integrating sleep into the orthodontic practice shortly will be driven by the need of the societies as some of our patients will be shortly coming into our offices aware of sleep apnea. However, with our busy clinical orthodontic practice, the need of condense short review become more demanding. Therefore, this review will try to summarize the clinical and orthodontic observation in the diagnoses of adult obstructive sleep apnea with clinical application in orthodontic practice.

Facial phenotype in obstructive sleep apnea-hypopnea syndrome: a systematic review and meta-analysis

This systematic review and meta-analysis explores the association between facial phenotype and obstructive sleep apnea-hypopnea syndrome in adults. A comprehensive electronic (Medline via Ovid, Scopus, and Embase) database and reference search were undertaken in relation to imaging modalities for surface craniofacial assessments in subjects with sleep apnea. The outcome measures were surface facial dimensions, morphology and profile. The quality of studies was assessed and a meta-analysis conducted. The studies were weighted using the inverse variance method, and the random effects model was used to analyse data. This systematic review identified eight case-control studies. In five studies (906 participants), adults with sleep apnea showed increased weighted mean differences in neck circumference by 1.26 mm (P = 0.0001) with extensive heterogeneity between studies (I² = 93%). Only two studies (467 participants) shared the following outcomes: mandible length, lower facial height, mandible width and anterior mandible height parameters. The pooled results demonstrated obstructive sleep apnea syndrome was associated with larger parameters than controls. In conclusion, the surface facial assessment was able to demonstrate some characteristic morphological features, facilitating a meta-analysis, in adults with obstructive sleep apnea-hypopnea syndrome. The strength of these findings, however, was limited by the heterogeneity of the studies precluding the identification of a clear phenotype.