Obstructive sleep apnea—an overview of the disorder and its consequences

Correlation between Polysomnographic Parameters and Tridimensional Changes in the Upper Airway of Obstructive Sleep Apnea Patients Treated with Mandibular Advancement Devices

BACKGROUND

The effectiveness of mandibular advancement devices has been solidly demonstrated in the past. They are considered a valid alternative treatment to continuous positive airway pressure for patients with obstructive sleep apnea. Nevertheless, the relationship between polysomnographic parameters and the increase in the volume of the upper airway in patients with obstructive sleep apnea syndrome has not been clearly established so far. This study aimed to determine the impact of these oral appliances upon the volume of the airway after the device titration phase and correlate it with the degree of mandibular advancement and the improvement of polysomnographic parameters.

METHODS

All patients were diagnosed by polysomnography and were treated with a customized, titratable mandibular advancement device. Three-dimensional volumetric measurements were performed using cone beam computed tomography.

RESULTS

The present study included 45 patients diagnosed with obstructive sleep apnea hypopnea syndrome (mild in 23 patients, moderate in 11 and severe in 11). Forty-four percent of the patients presented with an apnea hypopnea index <5/h at the end of treatment. The volume of the upper airway increased an average of 4.3 ± 5.9 cm3, this represents a percentage increase of 20.9%, which was significantly correlated with an apnea hypopnea index and a minimum oxygen saturation improvement.

CONCLUSIONS

The mandibular advancement device used was found to be effective in improving polysomnographic parameters. Moreover, the oral appliance was able to significantly increase the tridimensional dimensions of the upper airway. Moreover, this finding was correlated with a reduction in the apnea hypopnea index (p = 0.007) and an increase on minimum oxygen saturation (p = 0.033).

Soft tissue airway dimensions and craniocervical posture in subjects with different growth patterns

OBJECTIVE

To compare the dimensions of the nasopharynx and oropharynx of subjects with different growth patterns and to determine whether any correlation exists with their craniocervical posture.

MATERIALS AND METHODS

Cephalometric radiograph of 60 subjects (16-25 years old), taken in natural head position, were divided into three groups according to the mandibular plane angle: hypodivergent (SN/MP <26°), normodivergent (SN/MP 26°-38°), and hyperdivergent (SN/MP <38°). Correlations were calculated between nasopharyngeal area, oropharyngeal area, and craniocervical posture. Continuous variables were compared by one-way analysis of variance, and the significance of mean difference between the groups was done by the Tukey post hoc test. A value of P < .05 was considered statistically significant.

RESULTS

Patients in the hyperdivergent group were found to have significantly smaller nasopharyngeal and oropharyngeal areas than the other groups (P < .001 and P < .05, respectively). Similarly, the oropharyngeal area in the normodivergent group was significantly smaller than that in the hypodivergent group (P < .05). However, no significant differences were found in the nasopharyngeal area between the hypodivergent and normodivergent groups and between the hyperdivergent and normodivergent groups (P > .05). Reduced pharyngeal airways were typically seen in patients with a large craniocervical angle and a large mandibular inclination.

CONCLUSIONS

Smaller nasopharyngeal and oropharyngeal airways were seen in connection with a large craniocervical and a large mandibular inclination. We therefore suggest that the vertical skeletal pattern may be one of the factors that contribute to nasopharyngeal and oropharyngeal obstruction.

Orthodontic and orthopaedic treatment for anterior open bite in children

BACKGROUND

Anterior open bite occurs when there is a lack of vertical overlap of the upper and lower incisors. The aetiology is multifactorial including: oral habits, unfavourable growth patterns, enlarged lymphatic tissue with mouth breathing. Several treatments have been proposed to correct this malocclusion, but interventions are not supported by strong scientific evidence.

OBJECTIVES

The aim of this systematic review was to evaluate orthodontic and orthopaedic treatments to correct anterior open bite in children.

SEARCH METHODS

The following databases were searched: the Cochrane Oral Health Group's Trials Register (to 14 February 2014); the Cochrane Central Register of Controlled Trials (CENTRAL)(The Cochrane Library 2014, Issue 1); MEDLINE via OVID (1946 to 14 February 2014); EMBASE via OVID (1980 to 14 February 2014); LILACS via BIREME Virtual Health Library (1982 to 14 February 2014); BBO via BIREME Virtual Health Library (1980 to 14 February 2014); and SciELO (1997 to 14 February 2014). We searched for ongoing trials via ClinicalTrials.gov (to 14 February 2014). Chinese journals were handsearched and the bibliographies of papers were retrieved.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of orthodontic or orthopaedic treatments or both to correct anterior open bite in children.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of all reports identified. Risk ratios (RRs) and corresponding 95% confidence intervals (CIs) were calculated for dichotomous data. The continuous data were expressed as described by the author.

MAIN RESULTS

Three randomised controlled trials were included comparing: effects of Frankel's function regulator-4 (FR-4) with lip-seal training versus no treatment; repelling-magnet splints versus bite-blocks; and palatal crib associated with high-pull chincup versus no treatment.The study comparing repelling-magnet splints versus bite-blocks could not be analysed because the authors interrupted the treatment earlier than planned due to side effects in four of ten patients.FR-4 associated with lip-seal training (RR = 0.02 (95% CI 0.00 to 0.38)) and removable palatal crib associated with high-pull chincup (RR = 0.23 (95% CI 0.11 to 0.48)) were able to correct anterior open bite.No study described: randomisation process, sample size calculation, there was not blinding in the cephalometric analysis and the two studies evaluated two interventions at the same time. These results should be therefore viewed with caution.

AUTHORS' CONCLUSIONS

There is weak evidence that the interventions FR-4 with lip-seal training and palatal crib associated with high-pull chincup are able to correct anterior open bite. Given that the trials included have potential bias, these results must be viewed with caution. Recommendations for clinical practice cannot be made based only on the results of these trials. More randomised controlled trials are needed to elucidate the interventions for treating anterior open bite.

Health behavior and adherence to treatment for sleep breathing disorder in the patient with heart failure

BACKGROUND

Heart failure can be complicated by a variety of comorbidities including sleep breathing disorder (SBD). Treatment for SBD in the heart failure patient can improve quality of life and decrease mortality. Few studies have sought to examine the reasons why patients with heart failure who screen positive for SBD do not follow through with diagnostic testing and recommendations for evidence based treatments.

PURPOSE

The purpose of this study was to describe and compare the characteristics of patients with heart failure who adhered to recommendations for evaluation and treatment of SBD with those who did not. Additionally, the study sought to examine reasons for nonadherence.

METHODS

A descriptive comparative design was used. Descriptive statistics were used to define and compare the study population in terms of demographic data, which included age, gender, ethnicity, New York Heart Association heart failure classification, and comorbidities. Additionally, patients were surveyed to determine reasons for nonadherence to recommended overnight sleep study evaluation and or treatment with positive airway pressure.

RESULTS

Demographics with higher percentages of adherence to evaluation and treatment included younger individuals and male gender. Prevalent reasons for nonadherence for evaluation and treatment included negative perceptions of an overnight sleep study evaluation and advanced age.

IMPLICATIONS FOR PRACTICE

The community nurse educator can use the descriptive comparative findings in this study to tailor educational programs toward individuals with heart failure who have screened positive for SBD who are most at risk for nonadherence.

Treatment of obstructive sleep apnea with oral appliances

BACKGROUND

The purpose of this study was to evaluate the effectiveness of mandibular advancement devices (MADs) for treatment of obstructive sleep apnea syndrome (OSAS) compared with the results obtained with a placebo device in accordance with the following indicators: apnea hypopnea index (AHI) per hour of sleep, apnea index (AI) per hour of sleep, mean oxyhemoglobin saturation, sleep efficiency, and percentage of rapid eye movement (REM) sleep.

METHODS

This is a controlled, prospective longitudinal study with a follow-up time of 10.5 months. Nineteen patients (8 females and 11 males) with mean age 48.6 years (SD 9.6) were selected for the study. The sample was randomized in terms of device use, and the evaluation design was double blind. A total of 57 polysomnography tests were studied (at baseline, after the use of a MAD, and after the use of placebo). The following variables were assessed: AHI, AI, mean oxyhemoglobin saturation, percentage of REM sleep, and sleep efficiency. Wilcoxon and Mann-Whitney tests were used for evaluating data (p<0.05).

RESULTS

Reductions from 16.3 to 11.7 in AHI and from 5.7 to 3.8 in AI were observed after MAD use. During the use of placebo, AHI increased from 16.3 to 19.6, and AI from 5.7 to 7.5. The other indexes showed no statistically significant differences.

CONCLUSIONS

Treatment with oral appliances, i.e., MADs, can be an effective alternative for mild and medium-to-moderate OSAS, but requires strict monitoring due to differences in individual response to this therapy.

Aparelho de avanço mandibular aumenta o volume da via aérea superior de pacientes com apneia do sono

INTRODUÇÃO: o diagnóstico, o tratamento e o acompanhamento de pacientes portadores da síndrome da apneia obstrutiva do sono (SAOS) são essenciais, por se tratar de um distúrbio que pode causar alterações sistêmicas. A efetividade do tratamento da SAOS com aparelhos intrabucais foi demonstrada através de estudos cefalométricos. OBJETIVO: o objetivo deste estudo foi avaliar o efeito do aparelho de avanço mandibular (Twin Block, TB) no volume das vias aéreas superiores, por meio de tomografia computadorizada Cone-Beam (CBCT). Dezesseis pacientes (6 homens e 10 mulheres) portadores de SAOS leve a moderada, idade média de 47,06 anos, utilizaram um aparelho de avanço mandibular e foram acompanhados por 7 meses, em média. MÉTODOS: foram feitas duas CBCT, sendo uma sem e outra com o aparelho em posição. A segmentação e a obtenção dos volumes das vias aéreas superiores foram realizadas e utilizado o teste t de Student pareado para análise estatística, com 5% de significância. RESULTADOS: houve aumento do volume da via aérea superior com TB quando comparado com o volume sem TB (p<0,05). CONCLUSÃO: pode-se concluir que o aumento de volume da via aérea superior observado foi associado ao aparelho de avanço mandibular.

Investigation of sequential properties of snoring episodes for obstructive sleep apnoea identification

In this paper, 'snore regularity' is studied in terms of the variations of snoring sound episode durations, separations and average powers in simple snorers and in obstructive sleep apnoea (OSA) patients. The goal was to explore the possibility of distinguishing among simple snorers and OSA patients using only sleep sound recordings of individuals and to ultimately eliminate the need for spending a whole night in the clinic for polysomnographic recording. Sequences that contain snoring episode durations (SED), snoring episode separations (SES) and average snoring episode powers (SEP) were constructed from snoring sound recordings of 30 individuals (18 simple snorers and 12 OSA patients) who were also under polysomnographic recording in Gülhane Military Medical Academy Sleep Studies Laboratory (GMMA-SSL), Ankara, Turkey. Snore regularity is quantified in terms of mean, standard deviation and coefficient of variation values for the SED, SES and SEP sequences. In all three of these sequences, OSA patients' data displayed a higher variation than those of simple snorers. To exclude the effects of slow variations in the base-line of these sequences, new sequences that contain the coefficient of variation of the sample values in a 'short' signal frame, i.e., short time coefficient of variation (STCV) sequences, were defined. The mean, the standard deviation and the coefficient of variation values calculated from the STCV sequences displayed a stronger potential to distinguish among simple snorers and OSA patients than those obtained from the SED, SES and SEP sequences themselves. Spider charts were used to jointly visualize the three parameters, i.e., the mean, the standard deviation and the coefficient of variation values of the SED, SES and SEP sequences, and the corresponding STCV sequences as two-dimensional plots. Our observations showed that the statistical parameters obtained from the SED and SES sequences, and the corresponding STCV sequences, possessed a strong potential to distinguish among simple snorers and OSA patients, both marginally, i.e., when the parameters are examined individually, and jointly. The parameters obtained from the SEP sequences and the corresponding STCV sequences, on the other hand, did not have a strong discrimination capability. However, the joint behaviour of these parameters showed some potential to distinguish among simple snorers and OSA patients.

Radial basis function classifiers to help in the diagnosis of the obstructive sleep apnoea syndrome from nocturnal oximetry

The aim of this study is to assess the ability of radial basis function (RBF) classifiers as an assistant tool for the diagnosis of the obstructive sleep apnoea syndrome (OSAS). A total of 187 subjects suspected of suffering from OSAS were available for our research. The initial population was divided into training, validation and test sets for deriving and testing our neural classifiers. We used nonlinear features from nocturnal oxygen saturation (SaO(2)) to perform patients' classification. We evaluated three different RBF construction techniques based on the following algorithms: k-means (KM), fuzzy c-means (FCM) and orthogonal least squares (OLS). A diagnostic accuracy of 86.1, 84.7 and 85.5% was provided by the networks developed with KM, FCM and OLS, respectively. The three proposed networks achieved an area under the receiver operating characteristic (ROC) curve over 0.90. Our results showed that a useful non-invasive method could be applied to diagnose OSAS from nonlinear features of SaO(2) with RBF classifiers.

Orthodontic and orthopaedic treatment for anterior open bite in children

BACKGROUND

Anterior open bite occurs when there is a lack of vertical overlap of the upper and lower incisors. The aetiology is multifactorial including: oral habits, unfavourable growth patterns, enlarged lymphatic tissue with mouth breathing. Several treatments have been proposed to correct this malocclusion, but interventions are not supported by strong scientific evidence.

OBJECTIVES

The aim of this systematic review was to evaluate orthodontic and orthopaedic treatments to correct anterior open bite in children.

SEARCH STRATEGY

Search strategies were developed for MEDLINE and revised appropriately for the following databases: Cochrane Oral Health Group Trials Register; CENTRAL (The Cochrane Library 2005, Issue 4); PubMed (1966 to December 2005); EMBASE (1980 to February 2006); Lilacs (1982 to December 2005); Brazilian Bibliography of Odontology (BBO) (1986 to December 2005); and SciELO (1997 to December 2005). Chinese journals were handsearched and the bibliographies of papers were retrieved.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of orthodontic or orthopaedic treatments or both to correct anterior open bite in children.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of all reports identified. Risk ratios (RRs) and corresponding 95% confidence intervals (CIs) were calculated for dichotomous data. The continuous data were expressed as described by the author.

MAIN RESULTS

Twenty-eight trials were potentially eligible, but only three randomised controlled trials were included comparing: effects of Frankel's function regulator-4 (FR-4) with lip-seal training versus no treatment; repelling-magnet splints versus bite-blocks; and palatal crib associated with high-pull chincup versus no treatment. The study comparing repelling-magnet splints versus bite-blocks could not be analysed because the authors interrupted the treatment earlier than planned due to side effects in four of ten patients.FR-4 associated with lip-seal training (RR = 0.02 (95% CI 0.00 to 0.38)) and removable palatal crib associated with high-pull chincup (RR = 0.23 (95% CI 0.11 to 0.48)) were able to correct anterior open bite.No study described: randomisation process, sample size calculation, there was not blinding in the cephalometric analysis and the two studies evaluated two interventions at the same time. These results should be therefore viewed with caution.

AUTHORS' CONCLUSIONS

:There is weak evidence that the interventions FR-4 with lip-seal training and palatal crib associated with high-pull chincup are able to correct anterior open bite. Given that the trials included have potential bias, these results must be viewed with caution. Recommendations for clinical practice cannot be made based only on the results of these trials. More randomised controlled trials are needed to elucidate the interventions for treating anterior open bite.