Oral appliances reduce masticatory muscle activity-sleep bruxism metrics independently of changes in heart rate variability.

OBJECTIVES: Sleep bruxism (SB) is associated with physiological activities including sympathetic autonomic system dominance and sleep micro-arousal. While oral appliances (OA) are used to prevent SB harmful effects, the influence of OAs physiological mechanisms during sleep is unknown. The aim of this study is to assess whether heart rate variability (HRV) changes, as a marker of autonomic nervous system activity, would be associated with the OA mechanism of action on SB using occlusal splint (OS) and mandibular advancement splint (MAS). MATERIALS AND METHODS: A retrospective analysis, from data previously collected in 21 participants with SB (25.6 ± 4.5 years) with polysomnographic recordings, was done. HRV data were compared between a reference night (no-device) and ones during which OS or MAS was used in a crossover study design. Rhythmic masticatory muscle activity (RMMA) index was compared between nights. HRV was evaluated using autoregressive model analysis for three sections: baseline (distance from RMMA), immediately before, and after RMMA period. RESULTS: A significant reduction in RMMA index, when wearing OA during sleep, was observed (P < 0.01), but was not associated with HRV parameters change. HRV significantly changed after RMMA onset for nights with OA during non-REM sleep in comparison with baseline (P < 0.02). CONCLUSIONS: The usage of OAs for SB participants reduced RMMA, but most likely independently of changes in HRV linked to the mechanism associated with SB genesis. CLINICAL RELEVANCE: Wearing OA seems to reduce grinding noise and protect from dental injuries but does not seem to influence SB genesis.

Clinical Management of Interproximal and Occlusal Caries in Children and Adolescents by Canadian Dentists: A Survey.

PURPOSE: Early restorative interventions may have important implications in young patients, and the International Caries Classification and Management System strongly recommends non-surgical strategies in the management of dental caries. We aimed to assess management of interproximal and occlusal caries in children and adolescents (≤18 years of age) by Canadian dentists. METHODS: An electronic survey was created and sent to members of Canadian provincial regulatory dental bodies. The survey included 11 questions on demographic factors and 3 clinical situations on dental caries management. RESULTS: The response rate was 4.6% (n = 702). To treat interproximal carious lesions limited to enamel, 442 dentists (63.0%) reported using surgical caries removal on a permanent molar and 502 dentists (71.5%) did the same for a primary tooth. For occlusal carious lesions, the corresponding numbers were 300 dentists (42.7%) for a permanent molar and 269 (38.3%) for a primary molar. Age, year of graduation and province of practice appear to have a significant impact on the restorative threshold. CONCLUSIONS: According to the latest evidence-based recommendations for caries management, the presence of cavitated enamel should be the main indication to restore, and non-surgical interventions for non-cavitated lesions confined to enamel should be prioritized. Results show that a good proportion of respondents have a lower restorative threshold, particularly for interproximal lesions.

Prospective randomized clinical trial evaluating the effects of two different implant collar designs on peri-implant healing and functional osseointegration after 25 years.

OBJECTIVES: Evaluate the effects of two different machined-collar lengths and designs on peri-implant healing. MATERIAL AND METHODS: An implant with a microtextured surface and 3.6mm-long internal-connection machined collar was compared to two implants that had an identical 1.2mm-long external-connection machined collar, but one had the microtextured surface while the other's was machined. Participants received the three implants, with microgap at the crest, alternately at five sites between mental foramen, and a full-arch prosthesis. Peri-implant bone levels were measured after 23 to 26 years of function. Keratinized tissue height, plaque, probing depth, bleeding, and purulence were also evaluated. Descriptive and mixed models for repeated\measures analyses were used, with Bonferroni correction for pairwise comparisons. RESULTS: Twenty-two participants (110 implants) were evaluated at the 25-year examination. Microtextured implants with the longer machined collar had significantly greater mean marginal bone loss (-1.77mm ± 0.18, mean ± SE) than machined (-0.85mm ± 0.18, p < .001) and microtextured (-1.00 ± 0.18mm, p < .001) implants with the shorter machined collar. Keratinized tissue height was greater for internal-connection (0.74mm ± 0.10) versus external-connection (0.51 ± 0.08, p =  0.01) microtextured implants. No differences were observed for plaque (p = 0.78), probing depth (p = 0.42), bleeding (p  = 0.07), and purulence (p = 1.00). Implant survival rate was 99%. CONCLUSIONS: Implants with the 1.2mm machined collar limited bone loss to 1mm, while those with the longer machined collar showed > 1.5mm loss after 25 years of function with microgap at the crest. Internal-connection design and fixture surface microtexturing did not result in greater bone preservation. ClinicalTrials.gov Identifier: NCT03862482.

Do postoperative antibiotics influence one-year peri-implant crestal bone remodelling and morbidity? A double-blinded randomized clinical trial.

OBJECTIVES: The primary objective of this study was to assess whether giving postoperative antibiotics to healthy patients after straightforward platform-switched implant placement would influence peri-implant crestal bone levels and postoperative morbidity after 1 year. METHODS: Thirty-eight healthy individuals were recruited in this pilot, randomized, double-blinded, placebo-controlled clinical trial. The intervention group (n = 18) received two grams of amoxicillin one hour before implant placement followed by a 7 days postoperative regimen (500 mg tid). The control group (n = 20) took the same preoperative dose of amoxicillin and an identical placebo postoperatively. Mesial and distal peri-implant crestal bone levels were measured at baseline, four months and one year later with standardized periapical radiographs. Postoperative pain severity was assessed through self-administered questionnaires for 7 days. Surgery-associated morbidities were evaluated after one, three, 16 weeks and 1 year. Descriptive and bivariate analyses were used. RESULTS: Thirty-seven participants completed the trial. At the one-year follow-up, the mean combined peri-implant crestal bone changes for the intervention (n = 18) and control (n = 19) groups were - 0.44 ± 0.41 mm and - 0.27 ± 0.56 mm, respectively. The difference between the groups (intervention-control) for mean combined crestal bone level changes was not statistically significant. There were no significant differences in surgery-associated morbidities between the intervention and control groups. The one-year implant survival rate was 100% in both groups. CONCLUSIONS: Study results suggest that a routine postoperative antibiotic regimen for healthy patients undergoing straightforward platform-switched implant placement might not be necessary to prevent postoperative peri-implant bone loss and complications.

Dental caries are positively associated with periodontal disease severity.

OBJECTIVES: To examine associations between periodontal disease severity and clinical and microbiological measures of caries in adults. MATERIALS AND METHODS: A cross-sectional study of 94 healthy adults ((mean ± SD) 55.4 ± 13.0 years) was conducted. Data were collected by means of questionnaire and a clinical examination that included the Decayed, Missing, Filled teeth Surfaces (DMFS) index, probing depth (PD), clinical attachment level (CAL), and gingival bleeding and plaque scores. Supra- and subgingival plaque samples were collected to assess the presence of Streptococcus mutans and six periodontal pathogens. Participants were subsequently categorized using Center for Disease Control and Prevention/American Academy of Periodontology (CDC-AAP) definitions and tertiles of percentage of sites with CAL ≥ 3mm. RESULTS: Significant positive associations were found between the periodontal disease severity (CDC-AAP) and the DMFS (aOR = 1.03; 95% CI 1.01-1.05) and DS indices (aOR = 1.18; 95% CI 1.05-1.32) as well as between the tertiles of percentage of sites with CAL ≥ 3 mm and DMFS (aOR = 1.03; 95% CI 1.00-1.05) and DS indices (aOR = 1.12; 95% CI 1.00-1.25). A significant positive association was also found between oral levels of F. nucleatum and S. mutans (aOR = 6.03; 95% CI 1.55-23.45). CONCLUSIONS: A small but positive association was found between clinical measures of caries and periodontal disease severity. Further research is warranted to examine the association between these two common oral diseases. CLINICAL RELEVANCE: Periodontal diseases and caries are the two most common oral diseases. There was a positive association between clinical and microbiological markers of both diseases. Therefore, strategies in oral health education should involve both caries and periodontitis prevention.

Mapping the Quebec dental workforce: ranking rural oral health disparities.

INTRODUCTION: Ensuring access to oral health services is crucial for improving the oral health of rural and remote populations. A logical step towards addressing oral health disparities and underutilization of services in rural areas is to ensure the availability of the dental workforce. Geographical information systems are valuable in examining workforce dispersion patterns and identifying priority areas requiring administrative and policy attention. The objective of this study was to examine and map the distribution patterns of the dental workforce in Quebec, Canada. METHODS: Utilizing the membership directory of Quebec Professional Orders (2009-2010), data on practice locations, practice types and license issue date for all active members of the Quebec dental workforce were obtained. This was followed by reverse geocoding of the geographic coordinates using a global positioning system visualizer to reveal textual locations. These locations were classified according to various degrees of rurality as defined by the 2006 Census Metropolitan Area and Census Agglomeration Influenced Zone typology, developed by Statistics Canada. Cartography layers were extracted from a geospatial database provided by Canada Natural Resources using ArcGIS 9.3. Descriptive and bivariate analyses were performed using SPSS v17 for Windows. RESULTS: Data analysis revealed statistically significant differences in the distribution of dental professionals in rural and urban areas (urban 59.4±19.4/100 000 vs rural 39.9±17.6/100 000; p<0.001). Approximately 90.3% of the dental workforce was located in urban zones, 1.3% in the zones strongly influenced by metropolitan area, 4.9% in the moderately influenced zones, while only 0.3% of the dental workforce was located in non-metropolitan-influenced zones. Urban zones such as Montreal, Quebec and Sherbrooke had the highest workforce availability (4-6 dentists for every 5000 inhabitants). Of a total of 447 specialist dentists in Quebec, only five were located in rural areas. CONCLUSIONS: This study concludes that there is a strong relationship between the degree of urbanization and the highest concentration of dental professionals. In addition, there is a lack of dental workforce availability, particularly specialists in rural Quebec. Further research is needed to examine and evaluate to what degree these distribution patterns might contribute to oral health outcomes of the rural population.

Clinimetric evaluation of the Simpson-Angus Scale in older adults with schizophrenia.

OBJECTIVE: Parkinsonism (or Parkinson's syndrome [PS]) remains common in patients exposed to antipsychotic drugs. One clinical tool used in its detection and follow-up, the Simpson-Angus Scale (SAS), has been under revision lately. We further examined the discriminative power of the SAS to detect PS and its efficacy as a measure of PS intensity in chronic schizophrenia. METHODS: Fifty-six outpatients between 50 and 75 years of age, under stable antipsychotic drug therapy, provided consent to undergo an evaluation along the SAS and Unified Parkinson's Disease Rating Scale III motor subsection, split according to the presence or absence of PS defined in the UK Parkinson's Disease Society Brain Bank (UKPDSBB) criteria or Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. RESULTS: The identification rate for PS was 39.3% based on UKPDSBB criteria applied to the Unified Parkinson's Disease Rating Scale III, compared with 62.5% and 87.5% according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and SAS cutoff value greater than 0.3, respectively. Median SAS scores for PS and PS-free participants were comparable. The SAS yielded high sensitivity (90.9%) but low specificity (17.7%). κ Values generally revealed only slight agreement between the group allocation provided by the SAS and the UKPDSBB criteria. Receiver operating characteristic curve for screening performance of the SAS provided poor prediction of subject status. CONCLUSIONS: The SAS lacks specificity and constitutes an imperfect detection and measurement tool for PS in older adults. Raising the cutoff score would avoid inflation in PS identification. The scale is probably best used as a measure of change relative to baseline score following an intervention, but results should be interpreted with caution.

Females with sleep bruxism show lower theta and alpha electroencephalographic activity irrespective of transient morning masticatory muscle pain.

AIMS: To investigate the hypothesis that the presence of transient morning masticatory muscle pain in young, healthy sleep bruxers (SBr) is associated with sex-related differences in sleep electroencephalographic (EEG) activity. METHODS: Data on morning masticatory muscle pain and sleep variables were obtained from visual analog scales and a second night of polysomnographic recordings. Nineteen normal control (CTRL) subjects were age- and sex-matched to 62 tooth-grinding SBr. Differences in sleep macrostructure (stage distribution and duration, number of sleep-stage shifts), number of rhythmic masticatory muscle activity (RMMA) events÷ hour, and EEG activity were analyzed blind to subject status. The influence of pain and gender in SBr and CTRL subjects was assessed with the Fisher's exact test, Mann-Whitney U test, two-sample t test, and analysis of variance (ANOVA). RESULTS: Low-intensity morning transient orofacial pain was reported by 71% of SBr, with no sex difference. RMMA event frequency was higher in SB than CTRL subjects (4.5÷hour vs 1.3÷hour; P < .001). SBr had fewer sleep-stage shifts, irrespective of sex or pain status. Female SBr had significantly lower theta and alpha EEG activity compared to female CTRL subjects (P = .03), irrespective of pain. CONCLUSION: Female SBr had lower theta and alpha EEG activity irrespective of transient morning pain.

Relevance of animal models to human tardive dyskinesia.

Tardive dyskinesia remains an elusive and significant clinical entity that can possibly be understood via experimentation with animal models. We conducted a literature review on tardive dyskinesia modeling. Subchronic antipsychotic drug exposure is a standard approach to model tardive dyskinesia in rodents. Vacuous chewing movements constitute the most common pattern of expression of purposeless oral movements and represent an impermanent response, with individual and strain susceptibility differences. Transgenic mice are also used to address the contribution of adaptive and maladaptive signals induced during antipsychotic drug exposure. An emphasis on non-human primate modeling is proposed, and past experimental observations reviewed in various monkey species. Rodent and primate models are complementary, but the non-human primate model appears more convincingly similar to the human condition and better suited to address therapeutic issues against tardive dyskinesia.

Prevalence and risk factors of sleep bruxism and wake-time tooth clenching in a 7- to 17-yr-old population.

Sleep-related bruxism (SB) and wake-time tooth clenching (TC) have been associated with temporomandibular disorders (TMDs), headache, and sleep and behavioral complaints. This study aimed to assess the prevalence and risk factors of these signs and symptoms in a 7- to 17-yr-old population (n = 604) seeking orthodontic treatment. Data were collected by questionnaire and by a clinical examination assessing craniofacial morphology and dental status. Sleep-related bruxism was reported by 15% of the population and TC was reported by 12.4%. The SB group (n = 58) was mainly composed of children (67.3% were ≤12 yr of age) and the TC group (n = 42) was mainly composed of adolescents (78.6% were ≥13 yr of age). The craniofacial morphology of over 60% of SB subjects was dental class II and 28.1% were a brachyfacial type. Compared with controls (n = 220), SB subjects were more at risk of experiencing jaw muscle fatigue [adjusted OR (AOR) = 10.5], headache (AOR = 4.3), and loud breathing during sleep (AOR = 3.1). Compared with controls, TC subjects reported more temporomandibular joint clicking (AOR = 5), jaw muscle fatigue (AOR = 13.5), and several sleep and behavioral complaints. Sleep- and wake-time parafunctions are frequently associated with signs and symptoms suggestive of TMDs, and with sleep and behavioral problems. Their clinical assessment during the planning of orthodontic treatment is recommended.

A mandibular advancement appliance reduces pain and rhythmic masticatory muscle activity in patients with morning headache.

AIMS: To evaluate the influence of an oral appliance on morning headache and orofacial pain in subjects without reported sleep-disordered breathing (SDB). METHODS: Twelve subjects aged 27.6 ± 2.1 (mean ± SE) years and suffering from frequent morning headache participated in this study. Each subject was individually fitted with a mandibular advancement appliance (MAA). The first two sleep laboratory polygraphic recording (SLPR) nights were for habituation (N1) and baseline (N2). Subjects then slept five nights without the MAA (period 1: P1), followed by eight nights with the MAA in neutral position (P2), ending with SLPR night 3 (N3). Subjects then slept five nights without the MAA (P3), followed by eight nights with the MAA in 50% advanced position (P4), ending with SLPR night 4 (N4). Finally, subjects slept 5 nights without the MAA (P5). Morning headache and orofacial pain intensity were assessed each morning with a 100-mm visual analog scale. Repeated measures ANOVAs and Friedman tests were used to evaluate treatment effects. RESULTS: Compared to the baseline period (P1), the use of an MAA in both neutral and advanced position was associated with a ⋝ 70% reduction in morning headache and ⋝ 42% reduction in orofacial pain intensity (P ⋜ .001). During the washout periods (P3 and P5), morning headache and orofacial pain intensity returned to close to baseline levels. Compared to N2, both MAA positions significantly reduced (P < .05) rhythmic masticatory muscle activity (RMMA). CONCLUSION: Short-term use of an MAA is associated with a significant reduction in morning headache and orofacial pain intensity. Part of this reduction may be linked to the concomitant reduction in RMMA.

Associations between sleep-disordered breathing symptoms and facial and dental morphometry, assessed with screening examinations.

INTRODUCTION: Chronic snoring is considered abnormal in a pediatric population. This disorder is often attributed to enlarged tonsils and adenoids, but multiple anatomic obstructions should also be considered. Facial and dental morphometry associations with various sleep-disordered breathing symptoms were investigated at an orthodontic clinic. METHODS: Parents or guardians were asked to complete a 4-part questionnaire on behalf of their children (n = 604; <18 years of age), including medical and dental history, bruxism and temporomandibular disorder habits, sleep and daytime behavior, and sleep duration and quality. All subjects underwent a clinical screening assessment by the same orthodontist to identify standard dental, skeletal, functional, and esthetic factors. RESULTS: In contrast to sleep-disordered breathing or sleep apnea in adults, which is predominantly associated with obesity, sleep-disordered breathing symptoms in this pediatric cohort were primarily associated with adenotonsillar hypertrophy, morphologic features related to a long and narrow face (dolichofacial, high mandibular plane angle, narrow palate, and severe crowding in the maxilla and the mandible), allergies, frequent colds, and habitual mouth breathing. CONCLUSIONS: Because of the recognized impact of pediatric snoring on children's health, the determination of these good predictors can help in preventing and managing sleep-disordered breathing. If a health professional notices signs and symptoms of sleep-disordered breathing, the young patient should be referred to a sleep medicine specialist in conjunction with an orthodontist if there are dentoskeletal abnormalities.

Effects of nocturnal wearing of dentures on the quality of sleep and oral-health-related quality in edentate elders with untreated sleep apnea: a randomized cross-over trial.

STUDY OBJECTIVES: This study aims to assess whether the nocturnal wear of dentures has an effect on the quality of sleep and oral-health-related quality of life of the edentulous elderly with untreated sleep apnea. METHODS: A single-blind randomized cross-over design with two sequences and two periods was used. Participants (n = 77) were randomly assigned either to sequence 1 (nocturnal wear followed by nocturnal nonwear of the denture for 30-30 days) or sequence 2 (nocturnal nonwear followed by nocturnal wear of denture for 30-30 days). The primary sleep outcome was the quality of sleep, assessed through sleep fragmentation measured as Apnea-Hypopnea Index (AHI) and respiratory arousal from portable polysomnography. Secondary outcomes were daytime sleepiness, sleep quality (Pittsburgh Sleep Quality Index, PSQI) and oral-health-related quality of life measured by validated questionnaires. RESULTS: The mean paired difference in AHI scores for the period of wearing versus not wearing dentures at night was small 1.0 event per hour (p = 0.50; 95% confidence interval (CI) = -2.0 to 4.1). The mean respiratory arousal index was higher when wearing dentures at night than when not wearing dentures at night, with a mean paired difference of 2.3 events per hour (p = 0.05; 95% CI = 0.0 to 4.6). No difference in sleepiness and PSQI were noted. Wearing dentures at night resulted in a statistically significantly higher mean score of psychological discomfort when compared to not wearing dentures at night. CONCLUSIONS: The results provide some support to usual practice guidelines to remove dentures at night in edentulous elders suffering from sleep apnea. CLINICAL TRIAL REGISTRATION: NCT01868295.

Clonidine has a paradoxical effect on cyclic arousal and sleep bruxism during NREM sleep.

STUDY OBJECTIVE: Clonidine disrupts the NREM/REM sleep cycle and reduces the incidence of rhythmic masticatory muscle activity (RMMA) characteristic of sleep bruxism (SB). RMMA/SB is associated with brief and transient sleep arousals. This study investigates the effect of clonidine on the cyclic alternating pattern (CAP) in order to explore the role of cyclic arousal fluctuation in RMMA/SB. DESIGN: Polysomnographic recordings from a pharmacological study. SETTING: University sleep research laboratory. PARTICIPANTS AND INTERVENTIONS: Sixteen SB subjects received a single dose of clonidine or placebo at bedtime in a crossover design. MEASUREMENTS AND RESULTS: Sleep variables and RMMA/SB index were evaluated. CAP was scored to assess arousal instability between sleep-maintaining processes (phase A1) and stronger arousal processes (phases A2 and A3). Paired t-tests, ANOVAs, and cross-correlations were performed. Under clonidine, CAP time, and particularly the number of A3 phases, increased (P≤0.01). RMMA/SB onset was time correlated with phases A2 and A3 for both placebo and clonidine nights (P≤0.004). However, under clonidine, this positive correlation began up to 40 min before the RMMA/SB episode. CONCLUSIONS: CAP phase A3 frequency increased under clonidine, but paradoxically, RMMA/SB decreased. RMMA/SB was associated with and facilitated in CAP phase A2 and A3 rhythms. However, SB generation could be influenced by other factors besides sleep arousal pressure. NREM/REM ultradian cyclic arousal fluctuations may be required for RMMA/SB onset.

The Evaluation of Autonomic Arousals in Scoring Sleep Respiratory Disturbances with Polysomnography and Portable Monitor Devices: A Proof of Concept Study.

BACKGROUND: Autonomic arousals can be considered as surrogates of electroencephalography (EEG) arousals when calculating respiratory disturbance index (RDI). The main objective of this proof of concept study was to evaluate the use of heart rate acceleration (HRa) arousals associated with sleep respiratory events in a population undergoing full polysomnography (type 1) and in another undergoing portable monitor study (type 3). Our hypothesis is that when compared to other commonly used indexes, RDI based on HRa will capture more events in both types of recording. MATERIALS AND METHODS: A retrospective analysis was performed in two different populations of patients with suspected OSA: a) 72 patients undergoing one night of type 1 recording and b) 79 patients undergoing one night of type 3 recording. Variables for type 1 were 4% oxygen desaturation index (ODI), apnea/hypopnea index (AHI), RDI based on EEG arousals (RDIe), and RDI based on HRa with threshold of 5bpm (RDIa5). For type 3, variables were 4% ODI, AHI, and RDIa5 (it is not possible to calculate RDIe due to the absence of EEG). Calculated data were 1) Mean values for each sleep disturbance index in type 1 and 3 recordings; 2) Frequency of migration from lower to higher OSA severity categories using RDIa5 in comparison to AHI (thresholds: ≥5/h mild, ≥15/h moderate, ≥30/h severe); and 3) Bland-Altman plots to assess agreement between AHI vs RDIe and RDIa5 in type 1 population, and AHI vs RDIa5 in type 3 populations. RESULTS: More respiratory disturbance events were captured with RDIa5 index in both type 1 and type 3 recordings when compared to the other indexes. In type 1 recording, when using RDIa5 37% of patients classified as not having OSA with AHI were now identified as having OSA, and a total of 59% migrated to higher severity categories. In type 3 recording, similar results were obtained, as 37% of patients classified as not having OSA with AHI were now identified as having OSA using RDIa5, and a total of 55% patients migrated to higher severity categories. Mean differences for RDIa5 and AHI in type 1 and 3 populations were similar. CONCLUSION: The use of autonomic arousals such as HRa can help to detect more respiratory disturbance events when compared to other indexes, being a variable that may help to capture borderline mild cases. This becomes especially relevant in type 3 recordings. Future research is needed to determine its validity, optimization, and its clinical significance.

Efficacy of two mandibular advancement appliances in the management of snoring and mild-moderate sleep apnea: a cross-over randomized study.

BACKGROUND: Mandibular advancement appliances (MAA) are a recognized alternative treatment to continuous positive airway pressure (CPAP) for mild-moderate obstructive sleep apnea syndrome (OSAS). The aim of this study is to assess the efficacy of and subject satisfaction with two MAA in the management of OSAS. METHODS: Five women and 11 men (47.9+/-1.6 years), previously untreated with CPAP, were recruited from a sleep disorders clinic following a polysomnographic diagnosis of mild-moderate OSAS with Respiratory Disturbance Index (RDI) of 9.4+/-1.1. A randomized single blind cross-over study was completed with both Klearway and Silencer (three months for each study arm). Subjects completed standardized questionnaires on sleep quality, sleepiness and functional outcomes (Functional Outcome Sleep Questionnaire: FOSQ). MAA satisfaction (e.g., comfort) and efficacy (e.g., reduction of respiratory noises, headache) were assessed by subjects and sleep partner. RESULTS: The two MAA (Silencer 4.7+/-0.9 and Klearway 6.5+/-1.3) significantly reduced the RDI compared to the baseline night (10.0+/-1.2, respectively p<0.001 and p<0.01). The RDI was slightly lower with the Silencer (p0.05) but subjects' preference for comfort was in favor of the Klearway (Klearway 7.0+/-0.4 vs Silencer 5.8+/-0.4, p=0.04). The Epworth score, FOSQ, respiratory noise and morning headache were also improved following use of both appliances (p0.05 to 0.001). CONCLUSION: Although both MAA decreased RDI and subjective daytime sleepiness in a similar manner, the choice between various types of MAA needs to be taken into account when considering the benefit of RDI reduction over the benefit of subject compliance. The long term benefit of increased RDI reduction vs. a better subject compliance needs to be assessed in prospective studies.

Impact of implant support for mandibular dentures on satisfaction, oral and general health-related quality of life: a meta-analysis of randomized-controlled trials.

OBJECTIVES: The aim of this study was to examine systematically the data published on the efficacy of mandibular implant-retained overdentures from the patient's perspective. MATERIAL AND METHODS: Medline, Embase, The Cochrane Central Register of Controlled Trials and The Cochrane Systematic Reviews Database were searched and complemented by hand searching. All randomized-controlled trials published in English or French up to April 2007 were included, in which conventional dentures and mandibular implant overdentures in adult edentulous individuals were compared. The outcomes of interest were patient satisfaction, oral and general health-related quality of life. Random effects models were used to pool the effect sizes (ES) of all included studies. RESULTS: Ten publications of seven randomized-controlled trials were identified and eight were included in the meta-analysis. When compared with mandibular conventional dentures, implant overdentures were rated to be more satisfactory at a clinically relevant level [pooled ES 0.80, z=3.56, 95% confidence intervals (CI) 0.36-1.24, P=0.0004], but a statistical heterogeneity was found (chi(2)=31.63, df=5, P<0.00001, I(2)=84%). The pooled ES for oral health quality of life was -0.41 (z=1.31, 95% CI, -1.02 to 0.20; P=0.19, chi(2)=11.53, df=2, P<0.003, I(2)=83%). There was a lack of evidence to show the impact of mandibular implant overdenture on perceived general health. CONCLUSIONS: Our findings suggest that, although mandibular implant-retained overdentures may be more satisfying for edentulous patients than new conventional dentures, the magnitude of the effect is still uncertain. There is a need for additional evidence including cost-effectiveness analyses on the impact of mandibular implant overdentures and conventional dentures.

Bond strength of a sealant to permanent enamel: evaluation of 3 application protocols.

PURPOSE: The purpose of this study was to compare sealant-enamel bond strengths of 3 application protocols. METHODS: Sixty extracted third molars were randomly distributed into 3 groups according to the sealant's application protocol. The enamel was conditioned with: phosphoric acid in group 1; phosphoric acid and a single-bottle dentin bonding agent in group 2; and a self-etching adhesive in group 3. The specimens were thermocycled and tested in a shear mode at a cross-head speed of 1 mm/minute until fracture. Groups were compared using Kruskall-Wallis one-way analysis of variance and Mann-Whitney U tests. RESULTS: No statistically significant difference was observed between groups 2 and 3 (P=.96), but both groups showed significantly higher bond strength than group 1. Group 3 appeared to be the most reproducible application protocol as shown by its coefficient of variation (27). CONCLUSIONS: Self-etch adhesives are potentially attractive because of the easier clinical protocol required, provided that they have similar bond strengths compared to other products. The bond strength tests used in this study suggest that self-etch adhesives are equivalent to those using a separate bonding agent. Long-term clinical trials should be performed to assess performance of self-etch adhesives before definitive conclusions can be drawn.

Autonomic Arousals as Surrogates for Cortical Arousals Caused by Respiratory Events: A Methodological Optimization Study in the Diagnosis of Sleep Breathing Disorders.

INTRODUCTION: Portable monitoring (PM) is an alternative to laboratory polysomnography (PSG) for diagnosing obstructive sleep apnea (OSA). However, PM tends to underestimate the apnea-hypopnea index (AHI), as it does not identify non-desaturating events associated with electroencephalographic (EEG) arousal. The objectives were to explore heart rate acceleration (HRa) and decrease in pulse transit time (PTT) as surrogates to EEG arousal for non-desaturating hypopnea and respiratory effort-related arousal (RERA), and to estimate cut-off values for their use with both total sleep time (TST), the standard method for PSG, and total recording time (TRT), the usual method for PM. METHODS: Twenty-four consecutive individuals with suspected OSA were studied with PSG. Calculated outcomes were: AHI, respiratory disturbance index with EEG arousal (RDIe) and autonomic arousal by HRa (RDI-HRa) and PTT decreases (RDI-PTT) at different time cut-offs. Using RDIe as reference, Bland Altman and intraclass coefficient of correlation (ICC) were used to calculate agreement between indexes, and receiver operating curves (ROC) for sensitivity/specificity of the different cut-offs. RESULTS: Autonomic arousals, limited to respiratory events, were present in 36% of non-desaturating hypopneas and 29% of RERAs. Using TST, RDI-HRa of 10 bpm (ICC= 0.89) and RDI-PTT with a decrease of -15 msec (ICC=0.90) agreed better with RDIe. With TRT, the RDI-HRa of 5 bpm agreed better with the RDIe (ICC=0.89). Bland-Altman plots showed mean differences of 1.53 between RDI-HRa10-TST and RDIe and 0.89 between RDI-HRa5-TRT and RDIe. CONCLUSION: Autonomic arousals (HRa and PTT) may be a suitable proxy of EEG arousals associated with respiratory events, using both TST and TRT. Therefore, they could potentially help to capture borderline symptomatic patients and to monitor treatment outcomes.

Association of Circulating YKL-40 Levels and CHI3L1 Variants with the Risk of Spinal Deformity Progression in Adolescent Idiopathic Scoliosis.

The cellular and molecular mechanisms underlying spinal deformity progression in adolescent idiopathic scoliosis (AIS) remain poorly understood. In this study, 804 French-Canadian patients and 278 age- and sex-matched controls were enrolled and genotyped for 12 single nucleotide polymorphisms (SNPs) in the chitinase 3-like 1 (CHI3L1) gene or its promoter. The plasma YKL-40 levels were determined by ELISA. We showed that elevation of circulating YKL-40 levels was correlated with a reduction of spinal deformity progression risk. We further identified significant associations of multiple CHI3L1 SNPs and their haplotypes with plasma YKL-40 levels and scoliosis severity as a function of their classification in a specific endophenotype. In the endophenotype FG3 group, we found that patients harboring the haplotype G-G-A-G-G-A (rs880633|rs1538372|rs4950881|rs10399805|rs6691378|rs946261), which presented in 48% of the cases, showed a positive correlation with the plasma YKL-40 levels (P = 7.6 × 10-6 and coefficient = 36). Conversely, the haplotype A-A-G-G-G-G, which presented in 15% of the analyzed subjects, showed a strong negative association with the plasma YKL-40 levels (P = 2 × 10-9 and coefficient = -9.56). We found that this haplotype showed the strongest association with AIS patients in endophenotype FG2 (P = 9.9 × 10-6 and coefficient = -13.53), who more often develop severe scoliosis compared to those classified in the other two endophenotypes. Of note, it showed stronger association in females (P = 1.6 × 10-7 and coefficient = -10.08) than males (P = 0.0021 and coefficient = -9.01). At the functional level, we showed that YKL-40 treatments rescued Gi-coupled receptor signalling dysfunction occurring in primary AIS osteoblasts. Collectively, our findings reveal a novel role for YKL-40 in AIS pathogenesis and a new molecular mechanism interfering with spinal deformity progression.