Is sleep bruxism in obstructive sleep apnea only an oral health related problem?

BACKGROUND

The etiology of sleep bruxism in obstructive sleep apnea (OSA) patients is not yet fully clarified. This prospective clinical study aimed to investigate the connection between probable sleep bruxism, electromyographic muscle tone, and respiratory sleep patterns recorded during polysomnography.

METHODS

106 patients with OSA (74 males, 31 females, mean age: 56.1 ± 11.4 years) were divided into two groups (sleep bruxism: SB; no sleep bruxism: NSB). Probable SB were based on the AASM criteria: self-report of clenching/grinding, orofacial symptoms upon awakening, abnormal tooth wear and hypertrophy of the masseter muscle. Both groups underwent clinical examination for painful muscle symptoms aligned with Temporomandibular Disorders Diagnostic Criteria (DC/TMD), such as myalgia, myofascial pain, and headache attributed to temporomandibular disorder. Additionally, non-complaint positive muscle palpation and orofacial-related limitations (Jaw Functional Limited Scale-20: JFLS-20) were assessed. A one-night polysomnography with electromyographic masseter muscle tone (EMG) measurement was performed. Descriptive data, inter-group comparisons and multivariate logistic regression were calculated.

RESULTS

OSA patients had a 37.1% prevalence of SB. EMG muscle tone (N1-N3, REM; P = 0.001) and the number of hypopneas (P = 0.042) were significantly higher in the sleep bruxism group. While measures like apnea-hypopnea-index (AHI), respiratory-disturbance-index (RDI), apnea index (AI), hypopnea-index (HI), number of arousals, and heart rate (1/min) were elevated in sleep bruxers, the differences were not statistically significant. There was no difference in sleep efficiency (SE; P = 0.403). Non-complaint masseter muscle palpation (61.5%; P = 0.015) and myalgia (41%; P = 0.010) were significant higher in SB patients. Multivariate logistic regression showed a significant contribution of EMG muscle tone and JFLS-20 to bruxism risk.

CONCLUSION

Increased EMG muscle tone and orofacial limitations can predict sleep bruxism in OSA patients. Besides, SB patients suffer more from sleep disorder breathing. Thus, sleep bruxism seems to be not only an oral health related problem in obstructive apnea. Consequently, interdisciplinary interventions are crucial for effectively treating these patients.

TRIAL REGISTRATION

The study was approved by the Ethics Committee of Philipps-University Marburg (reg. no. 13/22-2022) and registered at the "German Clinical Trial Register, DRKS" (DRKS0002959).

Aneuploidy in oocytes from women of advanced maternal age: analysis of the causal meiotic errors and impact on embryo development

STUDY QUESTION

In oocytes of advanced maternal age (AMA) women, what are the mechanisms leading to aneuploidy and what is the association of aneuploidy with embryo development?

SUMMARY ANSWER

Known chromosome segregation errors such as precocious separation of sister chromatids explained 90.4% of abnormal chromosome copy numbers in polar bodies (PBs), underlying impaired embryo development.

WHAT IS KNOWN ALREADY

Meiotic chromosomal aneuploidies in oocytes correlate with AMA (>35 years) and can affect over half of oocytes in this age group. This underlies the rationale for PB biopsy as a form of early preimplantation genetic testing for aneuploidy (PGT-A), as performed in the 'ESHRE STudy into the Evaluation of oocyte Euploidy by Microarray analysis' (ESTEEM) randomized controlled trial (RCT). So far, chromosome analysis of oocytes and PBs has shown that precocious separation of sister chromatids (PSSC), Meiosis II (MII) non-disjunction (ND), and reverse segregation (RS) are the main mechanisms leading to aneuploidy in oocytes.

STUDY DESIGN, SIZE, DURATION

Data were sourced from the ESTEEM study, a multicentre RCT from seven European centres to assess the clinical utility of PGT-A on PBs using array comparative genomic hybridization (aCGH) in patients of AMA (36-40 years). This included data on the chromosome complement in PB pairs (PGT-A group), and on embryo morphology in a subset of embryos, up to Day 6 post-insemination, from both the intervention (PB biopsy and PGT-A) and control groups.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ESTEEM recruited 396 AMA patients: 205 in the intervention group and 191 in the control group. Complete genetic data from 693 PB pairs were analysed. Additionally, the morphology from 1034 embryos generated from fertilized oocytes (two pronuclei) in the PB biopsy group and 1082 in the control group were used for statistical analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, 461/693 PB pairs showed abnormal segregation in 1162/10 810 chromosomes. The main observed abnormal segregations were compatible with PSSC in Meiosis I (MI) (n = 568/1162; 48.9%), ND of chromatids in MII or RS (n = 417/1162; 35.9%), and less frequently ND in MI (n = 65/1162; 5.6%). For 112 chromosomes (112/1162; 9.6%), we observed a chromosome copy number in the first PB (PB1) and second PB (PB2) that is not explained by any of the known mechanisms causing aneuploidy in oocytes. We observed that embryos in the PGT-A arm of the RCT did not have a significantly different morphology between 2 and 6 days post-insemination compared to the control group, indicating that PB biopsy did not affect embryo quality. Following age-adjusted multilevel mixed-effect ordinal logistic regression models performed for each embryo evaluation day, aneuploidy was associated with a decrease in embryo quality on Day 3 (adjusted odds ratio (aOR) 0.62, 95% CI 0.43-0.90), Day 4 (aOR 0.15, 95% CI 0.06-0.39), and Day 5 (aOR 0.28, 95% CI 0.14-0.58).

LIMITATIONS, REASON FOR CAUTION

RS cannot be distinguished from normal segregation or MII ND using aCGH. The observed segregations were based on the detected copy number of PB1 and PB2 only and were not confirmed by the analysis of embryos. The embryo morphology assessment was static and single observer.

WIDER IMPLICATIONS OF THE FINDINGS

Our finding of frequent unexplained chromosome copy numbers in PBs indicates that our knowledge of the mechanisms causing aneuploidy in oocytes is incomplete. It challenges the dogma that aneuploidy in oocytes is exclusively caused by mis-segregation of chromosomes during MI and MII.

STUDY FUNDING/COMPETING INTEREST(S)

Data were mined from a study funded by ESHRE. Illumina provided microarrays and other consumables necessary for aCGH testing of PBs. None of the authors have competing interests.

TRIAL REGISTRATION NUMBER

Data were mined from the ESTEEM study (ClinicalTrials.gov Identifier NCT01532284).

[Jean-Nicolas Corvisart (1755-1821) - Personal Physician of Napoleon, Preserver of Auenbrugger's Chest Percussion and Founder of Modern Cardiology]

Jean-Nicolas Corvisart des Marets (1755-1821) was the personal physician of the Emperor Napoleon I. He was one of the leading french physicians to promote and teach clinical and anatomical medicine. Corvisart was a pioneer of modern cardiology. He became famous by his contribution to the development and popularization of the chest percussion technique of Leopold Auenbrugger (1722-1809).

[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound]

INTRODUCTION

 Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring.

METHODS AND INTENTION

 In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57 ± 11 years. Average weight was 100 ± 19 kg by a mean body  mass  index (BMI) of 33 ± 7 kg/m². 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound.

RESULTS

 3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0 %), polysomnography in 2229 (58,8 %) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound.

DISCUSSION

 In nearly 60 % of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60 % of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.

[The Nocturnal Respiratory Rate in COPD Patients of Varying GOLD Severity with/without Nicotine Consumption: Calculation by Means of Breath Sound Analysis]

Respiratory rate is an important risk marker and enables early detection of critically ill and vulnerable patients in clinical routine. The aim of this pilot study with 31 patients (COPD severity levels II - IV) was to determine the mean nocturnal respiratory rate based on breath sound recordings and to investigate the dependence of respiratory rate on COPD severity level and smoker status. The mean respiratory rate of the total collective was 19/min. For the COPD-GOLD severity levels, no significant differences in mean respiratory rate could be observed. When nicotine consumption is taken into account, active smokers showed a significantly higher mean respiratory rate of 20.84 ± 4.45/min compared to non-smokers with 17.41 ± 3.14/min (p < 0.05). In addition, active smokers in the study were significantly more frequent among patients with night-time wheezing (60 % vs. 23.8 %). This might suggest that smokers need to perform increased breathing work with increased breathing rate to compensate for oxygen deficiency in bronchial obstruction. The results of the present study show that with the acoustic recording of breath sounds, a reliable representation and calculation of the breath frequency is possible.

[The Pathogenesis of Pulmonary Emphysema - Laennec was right!]

Pulmonary emphysema is characterised by irreversible destruction and enlargement of alveolar structure distal to terminal bronchioles. Small conducting airways < 2 mm in diameter are the major site of chronic airway inflammation and obstruction in COPD patients. 80 - 90 % of the last generation of small conducting airways, the terminal bronchioles, are destroyed in patients with very severe COPD. Recent data showing, that small airways disease is also a pathological feature in patients with COPD GOLD stage 1 and 2. Although 40 % of terminal and 60 % of transitional bronchioles were destroyed, there was no sign for emphysema. Only a significant loss of terminal and respiratory bronchioles seems to be able to induce pulmonary emphysema and respiratory symptoms.

Sind die „kleinen Atemwege“ der Schlüssel zum Verständnis von Pathophysiologie und Therapieeffizienz chronisch obstruktiver Atemwegserkrankungen?

Die vorliegende Übersichtsarbeit vermittelt Informationen über die Bedeutung der „kleinen Atemwege“ hinsichtlich der Pathogenese chronisch obstruktiver Atemwegserkrankungen, insbesondere der COPD. Die Verzweigungen der Bronchien werden in Generationen eingeteilt. Bis zu den Bronchioli terminales hat das Bronchialsystem eine vorwiegende Luftleitungsfunktion (Generationen 0 – 16), mit den Bronchioli respiratorii beginnt die eigentliche Respirationszone (Generationen 17 – 23). Nach heutigem Wissen sind insbesondere die kleinen Atemwege mit einem Durchmesser < 2 mm von pathogenetischer Bedeutung, zumal die chronisch protrahiert verlaufende Inflammation hier zu morphologischen und strukturellen Veränderungen sowie zu einer Erhöhung des Atemwegswiderstandes führt. Bei schwergradiger COPD ist eine hochgradige Reduktion und Destruktion der bronchioli terminales festzustellen. Ob es bereits in einem frühen COPD-Stadium zu einem Atemwegsremodeling kommt, ist noch unklar. Hinsichtlich der In-vivo-Diagnostik morphologischer und funktioneller Veränderungen der kleinen Atemwege existiert bislang noch kein Goldstandard. Die Mikro-CT eröffnet jedoch neue Optionen der Darstellung von Mikrostrukturen im Bereich der terminalen Bronchiolen. Von therapeutischer Seite stellt sich die Frage, ob und wie eine Optimierung der inhalativen Medikamentendeposition im Bereich der „small airways“ zu erreichen ist.

[Asthma Control in Adults and Children Must be Improved!]

Medication management of asthma is based on level of asthma control. GINA defined criteria for asthma control include asking about daytime symptoms, limitation of activity, nocturnal symptoms/awakenings and need for reliever treatment. Effective asthma control is necessary for preventing exacerbations and worsening of lung function. Standardized and validated questionnaires such as asthma control test (ACT) help to assess the level of asthma control. Asthma control is classified as controlled, partially controlled or uncontrolled. Multicenter studies like REALISE and AIRE give health care professionals information about effectiveness and adherence to medication over nearly 15 years. Asthma is still poorly controlled in more than 50 % of patients despite the availability of very effective drugs. Low adherence to the treatment, fear of systemic side effects related to long term treatment with inhaled corticosteroids, inadequate knowledge of the disease may be responsible factors for bad asthma control. Optimized tools for disease management and intensified education are necessary for therapeutic success.

[Apnea Detection by Means of Respiratory Sound Recordings and Polysomnography - A Comparative Study]

Introduction In this study, recognition of apnoeas by means of polysomnography (PSG) and nocturnal respiratory sound recordings in patients with obstructive sleep apnoea (OSA) was analyzed and compared. Methods In 45 patients with OSA requiring treatment (AHI > 15/h), concomitant polysomnographic recordings and long term respiratory sound recordings by means of LEOSound were performed. Patients' average age was 58 ± 12 years (mean ± standard deviation), average BMI was 33 ± 7 kg/m². Audio-visual apnoea detection by LEOSound was compared to polysomnographic apnoea detection. Increased artifact rate due to dislocation of microphones led to rejection of 11 out of 45 recordings for detailed analysis. Results Comparison of apnea detection by audio-visual analysis and polysomnography yielded a median of 164 apneas for LEOSound recordings and 158 apneas for PSG. Median apnoea index (AI) was calculated to be 20/h for respiratory sounds recording and 21/h for PSG. The correlation of apnea indices from acoustic long term registration and PSG was 0.939 (p < 0.001). Discussion Acoustic long term registration of primary and secondary respiratory sounds is also capable to recognize apnoeas. Exact differentiation between apnoeas and hypopnoeas is only possible in a limited fashion.

[Chronic hypoxia and cardiovascular risk : Clinical significance of different forms of hypoxia]

It is of fundamental importance to differentiate whether chronic hypoxia occurs intermittently or persistently. While chronic intermittent hypoxia (CIH) is found typically in patients with obstructive sleep apnea (OAS), chronic persistent hypoxia (CPH) is typically diagnosed in patients with chronic lung disease. Cardiovascular risk is markedly increased in patients with CIH compared to patients with CPH. The frequent change between oxygen desaturation and reoxygenation in patients with CIH is associated with increased hypoxic stress, increased systemic inflammation, and enhanced adrenergic activation followed by endothelial dysfunction and increased arteriosclerosis. The pathophysiologic consequences of CPH are less well understood. The relationship between CPH and the development of pulmonary hypertension, pulmonary heart disease as well as polycythemia has been established.

[Normal and Adventitious Breath Sounds]

Auscultation of the lung is an inexpensive, noninvasive and easy-to-perform tool. It is an important part of the physical examination and is help ful to distinguish physiological respiratory sounds from pathophysiological events. Computerized lung sound analysis is a powerful tool for optimizing and quantifying electronic auscultation based on the specific lung sound spectral characteristics. The automatic analysis of respiratory sounds assumes that physiological and pathological sounds are reliably analyzed based on special algorithms. The development of automated long-term lungsound monitors enables objective assessment of different respiratory symptoms.

[Pilot Project: Improved Lung Deposition via a New Nasal Inhalation Procedure]

INTRODUCTION

Inhaled drugs can only be effective if they reach the middle and small airways. This study introduces a system that combines a trans-nasal application of aerosols with noninvasive pressure support ventilation.

METHODS

In a pilot study, 7 COPD patients with GOLD stages II and III inhaled a radiolabeled marker dissolved in water via a trans-nasal route. The mean aerosol particle size was 5.5 µm. Each patient took part in two inhalation sessions that included two application methods and were at least 70 hours apart. During the first session ("passive method"), the patient inhaled the aerosol through an open tube system. The second session ("active method") included pressure support ventilation during the inhalation process. A gamma camera and planar scintigraphy was used to determine the distribution of aerosol particles in the patient's body and lung.

RESULTS

The pressure supported inhalation ("active method") results in an increased aerosol lung deposition compared to the passive method. Above all, we could demonstrate deposition in the lung periphery with relatively large aerosol particles (5.5 µm).

DISCUSSION

The results prove that the combination of trans-nasal inhalation with noninvasive pressure support ventilation leads to significantly increased particle deposition in the lung.