Principles and Practice of Sleep Medicine

http://www.fo.usp.br/wp-content/uploads/Restauracao_posteriores.pdf

Longevity of posterior composite restorations: not only a matter of materials

Near-infrared spectroscopy (NIRS) was initiated in 1977 by Jobsis as a simple, noninvasive method for measuring the presence of oxygen in muscle and other tissues in vivo. This review honoring Jobsis highlights the progress that has been made in developing and adapting NIRS and NIR imaging (NIRI) technologies for evaluating skeletal muscle O(2) dynamics and oxidative energy metabolism. Development of NIRS/NIRI technologies has included novel approaches to quantification of the signal, as well as the addition of multiple source detector pairs for imaging. Adaptation of NIRS technology has focused on the validity and reliability of NIRS measurements. NIRS measurements have been extended to resting, ischemic, localized exercise, and whole body exercise conditions. In addition, NIRS technology has been applied to the study of a number of chronic health conditions, including patients with chronic heart failure, peripheral vascular disease, chronic obstructive pulmonary disease, varying muscle diseases, spinal cord injury, and renal failure. As NIRS technology continues to evolve, the study of skeletal muscle function with NIRS first illuminated by Jobsis continues to be bright.

https://www.spiedigitallibrary.org/journals/Journal-of-Biomedical-Optics/volume-12/issue-06/062105/Near-infrared-spectroscopy-imaging-for-monitoring-muscle-oxygenation-and-oxidative/10.1117/1.2805437.pdf

Near-infrared spectroscopy/imaging for monitoring muscle oxygenation and oxidative metabolism in healthy and diseased humans

In 2013, consensus was obtained on a definition of bruxism as repetitive masticatory muscle activity characterised by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible and specified as either sleep bruxism or awake bruxism. In addition, a grading system was proposed to determine the likelihood that a certain assessment of bruxism actually yields a valid outcome. This study discusses the need for an updated consensus and has the following aims: (i) to further clarify the 2013 definition and to develop separate definitions for sleep and awake bruxism; (ii) to determine whether bruxism is a disorder rather than a behaviour that can be a risk factor for certain clinical conditions; (iii) to re-examine the 2013 grading system; and (iv) to develop a research agenda. It was concluded that: (i) sleep and awake bruxism are masticatory muscle activities that occur during sleep (characterised as rhythmic or non-rhythmic) and wakefulness (characterised by repetitive or sustained tooth contact and/or by bracing or thrusting of the mandible), respectively; (ii) in otherwise healthy individuals, bruxism should not be considered as a disorder, but rather as a behaviour that can be a risk (and/or protective) factor for certain clinical consequences; (iii) both non-instrumental approaches (notably self-report) and instrumental approaches (notably electromyography) can be employed to assess bruxism; and (iv) standard cut-off points for establishing the presence or absence of bruxism should not be used in otherwise healthy individuals; rather, bruxism-related masticatory muscle activities should be assessed in the behaviour's continuum.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/joor.12663

International consensus on the assessment of bruxism : Report of a work in progress

Aims: To perform a systematic review of the literature dealing with the prevalence of bruxism in adult populations. Methods: A systematic search of the medical literature was performed to identify all peer-reviewed English-language papers dealing with the prevalence assessment of either awake or sleep bruxism at the general population level by the adoption of questionnaires, clinical assessments, and polysomnographic (PSG) or electromyographic (EMG) recordings. Quality assessment of the reviewed papers was performed according to the Methodological evaluation of Observational REsearch (MORE) checklist, which enables the identification of flaws in the external and internal validity. Cut-off criteria for an acceptable external validity were established to select studies for the discussion of prevalence data. For each included study, the sample features, diagnostic strategy, and prevalence of bruxism in relation to age, sex, and circadian rhythm, if available, were recorded. Results: Thirtyfive publications were included in the review. Several methodological problems limited the external validity of findings in most studies, and prevalence data extraction was performed only on seven papers. Of those, only one paper had a flawless external validity, whilst internal validity was low in all the selected papers due to their selfreported bruxism diagnosis alone, mainly based on only one or two questionnaire items. No epidemiologic data were available from studies adopting other diagnostic strategies (eg, PSG, EMG). Generically identified “bruxism” was assessed in two studies reporting an 8% to 31.4% prevalence, awake bruxism was investigated in two studies describing a 22.1% to 31% prevalence, and prevalence of sleep bruxism was found to be more consistent across the three studies investigating the report of “frequent” bruxism (12.8% ± 3.1%). Bruxism activities were found to be unrelated to sex, and a decrease with age was described in elderly people. Conclusion: The present systematic review described variable prevalence data for bruxism activities. Findings must be interpreted with caution due to the poor methodological quality of the reviewed literature and to potential diagnostic bias related with having to rely on an individual’s self-report of bruxism. J Orofac Pain 2013;27:99–110. doi: 10.11607/jop.921

https://www.lucaguarda.it/articoli/159-Epidemiology.pdf

Epidemiology of Bruxism in Adults: A Systematic Review of the Literature

Awake bruxism is defined as the awareness of jaw clenching. Its prevalence is reported to be 20% among the adult population. Awake bruxism is mainly associated with nervous tic and reactions to stress. The physiology and pathology of awake bruxism is unknown, although stress and anxiety are considered to be risk factors. During sleep, awareness of tooth grinding (as noted by sleep partner or family members) is reported by 8% of the population. Sleep bruxism is a behaviour that was recently classified as a 'sleep-related movement disorder'. There is limited evidence to support the role of occlusal factors in the aetiology of sleep bruxism. Recent publications suggest that sleep bruxism is secondary to sleep-related micro-arousals (defined by a rise in autonomic cardiac and respiratory activity that tends to be repeated 8-14 times per hour of sleep). The putative roles of hereditary (genetic) factors and of upper airway resistance in the genesis of rhythmic masticatory muscle activity and of sleep bruxism are under investigation. Moreover, rhythmic masticatory muscle activity in sleep bruxism peaks in the minutes before rapid eye movement sleep, which suggests that some mechanism related to sleep stage transitions exerts an influence on the motor neurons that facilitate the onset of sleep bruxism. Finally, it remains to be clarified when bruxism, as a behaviour found in an otherwise healthy population, becomes a disorder, i.e. associated with consequences (e.g. tooth damage, pain and social/marital conflict) requires intervention by a clinician.

Bruxism physiology and pathology: an overview for clinicians*

Purpose: This study investigated whether the presence of tooth wear in young adults can help to discriminate patients with sleep bruxism (SB) from control subjects. Materials and Methods: The tooth wear clinical scores and frequency of sleep masseter electromyographic activity of 130 subjects (26.6 ± 0.5 years) were compared in this case-control study. Tooth wear scores (collected during clinical examination) for the incisors, canines, and molars were pooled or analyzed separately for statistics. Sleep bruxers (SBrs) were divided into two subgroups according to moderate to high (M-H-SBr; n = 59) and low (L-SBr; n = 48) frequency of masseter muscle contractions. Control subjects (n = 23) had no history of tooth grinding. The sensitivity and specificity of tooth wear versus SB diagnosis, as well as positive and negative predictive values (PPV and NPV), were calculated. One-way analysis of variance and the Mann-Whitey U test were used to compare groups. Results: Both SBr subgroups showed significantly higher tooth wear scores than the control group for both pooled and separated scores (P < .001). No difference was observed between M-H-SBr and L-SBr frequency groups (P = .14). The pooled sum of tooth wear scores discriminates SBrs from controls (sensitivity = 94%, specificity = 87%). The tooth wear PPV for SB detection was modest (26% to 71%) but the NPV to exclude controls was high (94% to 99%). Conclusions: Although the presence of tooth wear discriminates SBrs with a current history of tooth grinding from nonbruxers in young adults, its diagnostic value is modest. Moreover, tooth wear does not help to discriminate the severity of SB. Caution is therefore mandatory for clinicians using tooth wear as an outcome for SB diagnosis. Int J Prosthodont 2009;22:342‐350.

Tooth Wear in Young Subjects: A Discriminator Between Sleep Bruxers and Controls?

Sleep less and bite more: Sleep disorders associated with occlusal loads during sleep

Sclerostin, a secreted protein encoded by the Sost gene, is produced by osteocytes and is inhibited by osteoblast differentiation and bone formation. Recently, a functional association between bone and fat tissue has been suggested, and a correlation between circulating sclerostin levels and lipid metabolism has been reported in humans. However, the effects of sclerostin on adipogenesis remain unexplored. In the present study, we examined the role of sclerostin in regulating adipocyte differentiation using 3T3-L1 preadipocytes. In these cells, sclerostin enhanced adipocyte-specific gene expression and the accumulation of lipid deposits. Sclerostin also upregulated CCAAT/enhancer binding protein β expression but not cell proliferation and caspase-3/7 activities. Sclerostin also attenuated canonical Wnt3a-inhibited adipocyte differentiation. Recently, the transcriptional modulator TAZ has been involved in the canonical Wnt signaling pathway. Sclerostin reduced TAZ-responsive transcriptional activity and TAZ-responsive gene expression. Transfection of 3T3-L1 cells with TAZ siRNA increased the lipid deposits and adipogenic gene expression. These results show that sclerostin upregulates adipocyte differentiation in 3T3-L1 cells, suggesting a possible role for the osteocyte-derived sclerostin as a regulator of fat metabolism and as a reciprocal regulator of bone and adipose tissues metabolism.

/pdf/sclerostin-enhances-adipocyte-differentiation-in-3t3-l1-znps06sdue.pdf

Sclerostin Enhances Adipocyte Differentiation in 3T3-L1 Cells.

Planetary habitat simulation : interactions between bedrest, hypoxia and confinement on sleep and breathing

https://onlinelibrary.wiley.com/doi/pdf/10.1111/jsr.12099

Taihiko Yamaguchi

Papers

Bruxism physiology and pathology: an overview for clinicians*

Tooth Wear in Young Subjects: A Discriminator Between Sleep Bruxers and Controls?

Sleep less and bite more: Sleep disorders associated with occlusal loads during sleep

Sclerostin Enhances Adipocyte Differentiation in 3T3-L1 Cells.

Temporal association between sleep apnea-hypopnea and sleep bruxism events