Snoring
The dictionary of the Royal Academy of the Spanish Language defines snoring as a bronco noise made when sleeping. In fact, snoring is a harsh breathing sound that occurs in the inspiration and can even manifest in the expiratory phase of the respiratory cycle of the sleeping subject. During sleep, the calm and "silent" breath generated with inhalation, measured at 10 cm from the mouth, is about 25 decibels (dBA), and during exhalation reaches an average of 17 dBA, which is barely audible at a distance of 1 meter. The respiratory noise must meet or exceed a threshold of sound intensity of 40 dBA at one meter distance from the mouth, to be called snoring.
Snoring occurs when the relative or complete sluggish dilator muscles of the upper airways accompanying the dream involves a narrowing of the pharynx, increasing resistance to airflow, increasing the speed of airflow and reducing the gas pressure in region, a tension between two opposing forces, the resistance of the pharyngeal walls to collapse and the negative air pressure tending thereto is then set, the result of this voltage between the opposing forces is a noisy pharyngeal wall vibration , especially of the soft palate, vibrating within a turbulent flow, like a flag in the wind, loudly. The origin of snoring, however is variable, although the noisy vibration of the soft palate predominates, may be involved in its origin the pharyngeal walls, tongue and even the epiglottis. These concepts are important because they mean that snoring is a manifestation of increased resistance in the upper airways.
Snoring is not a homogeneous acoustic phenomenon as it is subject to many influences, such as the position of the subject during sleep or sleep phase considered; in addition, there may be significant differences in the snore of the subject a few days to other. The characteristics of snoring can range from normal sleep or psychoactive substance-induced, the alcohol, as well-known example, aggravates snoring. Another factor that changes the characteristics of snoring is the type of breathing during sleep, as the nasal breathing, oral or mixed varies the sound characteristics. Snoring is also influenced, in his sound characteristics, by its place of origin (soft palate, pharyngeal walls, base of tongue, supraglottic larynx region or combination thereof). The pharynxendoscopy study found that snoring of complex waveform is associated with the vibration generated by the soft palate while simple snoring is associated with noisy vibration region of the tongue base, although other studies have not been able to find consistent results in terms of the anatomical origin of snoring as the same variability along one night offers little consistency studies.
On the other hand, snoring is also subject to variability in relation to its association with apneas and hypopneas; thus, patients with apneas disrupt breath sounds, including snoring, during breathing pauses, and after restarting your breath, frequently present considerable variation in their interapneas snoring. Meanwhile snoring accompanying hypopneas, characterized by decreased respiratory airflow, have a sound that goes “increasing" in the course of a hypopnea, so that the most intense snoring often coincides with the end of the same. The almost constant association of snoring with apnea and hypopnea snoring has made snoring a great clinical marker of diagnostic in the apnea- hypopnea síndrome of sleep.
The snoring that is not associated with apneas or hypopneas was classically called "simple" snoring , but this description has been discussed by several studies since it has been shown that some "simple" snoring present daytime symptoms such as fatigue or hyper-sleepiness which means that snoring is not just a breathing sound because there is a narrowing of the upper respiratory airway which implies a maintained respiratory effort and that entails an extra metabolic expense explaining other alterations, hence, is risky to qualify as irrelevant the snore that is not associatedwith apneas or hypopneas, and just when snore presents without apneas neither hypopneas , nor excessive daytime sleepiness or fatigue on vigil, is acceptable the denomination of simple snoring. Based on these considerations, snoring could be classified into three groups:
- Simple snoring.- It´s a snoring that does not bother others and there is not objective evidence of increased resistance of the upper airway.
- Social snoring.- It´s a snoring that bothers others but there is not objective evidence of increased resistance of the upper airway.
- Snoring accompanied by alterations in the vigil or associated with OSA (Obstructive Sleep Apnea-hypopnea Syndrome).
Snoring is also associated with other local and / or regional consequences, as the vibration caused by it on the pharyngeal walls can cause a vibratory trauma to the affected tissues, causing inflammation of the mucosa and even adjacent vessels. Snoring may also have some responsibility in facilitating gastroesophageal reflux.
But, how is frequent snoring? does it affect both men and women? is independent of age? These questions are answered by epidemiological studies although there is considerable disparity between them, depending on the study population (age, sex, morphotype), the questionnaire used to collect the data, the existence of a witness of the evaluated subject, and the method used in the diagnosis of it, all that implies a dispersion in the methodology for collecting data, explaining the disparity of published epidemiological results: So that, snoring would have a prevalence of up to 86 % in men and up to 59% in women, although a careful selection of studies and their data methods suggests that the actual prevalence of snoring is 40% in adult men and 20 % in adult women, the latter data refer to the general population because it is a known fact that snoring can be dependent on obesity, age and individual pathological factors as the adenoids and tonsils, nasal obstruction, retrognatia, hypertrophy of the tongue base, and others.
What social significance is the loudness of snoring? It has been found that there is a poor correlation between the objective measure of emitted sound by the snorer and the assessment made by different observers of the same, which has led to claims that, socially speaking, the noise and nuisance of snoring is in the listener's ear. The mean snoring intensity varies over 46.2 db, exceeding 55 db more than 12% of snorers, according to a study of 1139 snorers, if we consider that acceptable sound to sleep should be less than 30 db, with maximun peaks of 45 db according to the World Health Organisation, it is clear that the noise caused by snoring exceeds those standards of comfort.
On the other hand, there are contrasting reports indicating poor sleep quality in couples of snorers. One of the limitations of the social consequences of snoring, as already mentioned, is that the simply sound intensity generated is not adequate to determine their degree of discomfort.
Finally, in addition to physical and psychoacoustic measures of sound, there is a third level of acoustic assessment, the "nuisance" that sound causes in the listener, this parameter has not only to do with the loudness, frequency and perceived fones but also, and especially, to the psychological state of the person who hears it, influenced by the kind of relationship between the snorer and the listener, although physical aspects of sound influence, for example, related to the temporal structure of snoring. An important clinical question respect to snoring is whether its sound characteristics allow to distinguish between simple snoring and snoring associated with sleep apnea-hypopnea syndrome. The interest of response is given because the polysomnographic study of snorers is relatively expensive and it would be of great help and saving to know whether a study of the sound characteristics of snoring, much cheaper, could identify polysomnography subjects and those with simple snoring without apneas, daytime symptoms free, and in which polysomnography is dispensable.
Snoring´s Treatment is currently based on two pillars: surgical resection of part of the soft palate (or other pharyngeal regions as the base of the tongue), and mandibular advancement prosthesis (MAP). However, there is ample history of other treatments applied in snoring, now mostly abandoned, thus the first information about the treatment of snoring dates from 1772, when Morand made a uvulectomy to solve a snoring (147). Between 1900 and 1947, various anti snoring gadgets consisting of bracelets around his shoulders and head, sometimes associated with chin rests and other external mechanical elements, were developed. In the 50s , although reported in 1964, Ikematsu published a procedure called palatoplasty to treat chronic snoring (148), which is the basis of the currently most practiced treatment, palatopharyngoplasty, which was reported by Fujita in 1981 to treat snoring associated with sleep apnea (149), however , to be fair, it should be noted that some Spanish authors reported similar surgical procedures in congresses and national publications and international communications, years before Fujita did (150,151).
In 1981, Sullivan et al. (24) introduced a novel therapy to treat sleep apnea síndrome, that they called "continuous prositive airway pressure" (CPAP), which we have already referred, and whose functional basis is to maintain a positive pressure in upper airway to prevent its collapse or vibration during sleep. Its application in snoring is only correct if associated with OSA, but is not indicated in simple snoring.
Treatment of snoring with devices inside the mouth, began in 1951 when Leppitch he developed a very primitive intraoral anti snoring device (152). In 1982, Cartwright (153), made another attempt to relieve snoring with an intraoral device trying to retain the tongue. Hoffstein (2007) (154) conducted a review of 89 articles that assemble more than 3000 patients, the pooled studies have evaluated the ability of these intraoral devices to reduce the apnea/hypopnea, its ability to eliminate snoring, its efficacy compared with CPAP and surgical treatment, side effects and complacency or comfort. The results of these studies conclude by stating the relative efficacy of intraoral devices, misses the effectiveness of CPAP but exceeds surgical treatment, although there could be complications, lower in general. On the other hand, they have greater long-term acceptability than CPAP.
Many patients do not support snoring treatments, and though snoring is often a scarce social problem, because the subject sleeps alone or the spouse has any solution to avoid the inconvenience of it, it is also true that snoring may be cause for serious confrontation couples, or even social rejection. Snoring disrupts snorer´s partner sleep, determinig whether a physical or emotional conflicto. About the social problem of snoring, some famous architects propose that comfortable homes should have two master bedrooms to maintain marital stability when there is a snorer in the couple. Some American architects have gone further and have proposed the existence of a special room for the snorer, which is conveniently soundproofing.
The intensity that makes unbearable the snoring is that whose loudness in decibels is above 45 to 50. The Guinness Word Record cites a case of snoring sound intensity of 93 dB which is well above the level that can be in a central and busy street in a big city during rush hour (about 70 dB) noise and slightly less than produced by an airplane. This noise is incompatible with a social life.
From: Doctoral Thesis, Department of Physiology Title: STUDY OF THE EFFICACY AND SAFETY OF A DEVICE INTRAORAL JAW FORWARD IN PATIENTS WITH SYNDROME habitual snorers apnea-hypopnea - MODERATE SLIGHT OF CHARACTER Author: RAFAEL MARTINEZ CROVETTO, 2010. ISBN: 978-84-694-1040-0.