Review Article
Volume 2 Issue 4 - 2015
Prosthodontic Management of Obstructive Sleep Apnea
Abdelfattah AH1* Al-Ghamdi FA2 and Tubaigy Kh M3
1Professor of Prosthodontics, Egypt, Professor of Dental Postgraduate research, Egypt-Japan, Consultant of Prosthodontics, KSA
2Prosthodontist & Oral Implantologist, Chairman of Dental center, King Fahd General Hospital, KSA, Director of Dental services MOH
3Assistant Professor of Restorative Dentistry, Al-Farabi Dental College, Consultant of Restorative Dentistry, KSA
*Corresponding Author: Abdelfattah AH, Professor of Prosthodontics, Egypt, Professor of Dental Postgraduate research, Egypt-Japan, Consultant of Prosthodontics, KFH, Jeddah, KSA.
Received: September 14, 2015; Published: September 21, 2015
Citation: Abdelfattah AH., et al. “Prosthodontic Management of Obstructive Sleep Apnea”. EC Dental Science 2.4 (2015): 328-336.
Abstract
Obstructive sleep apnea (OSA) is a term used to describe the cession of breathing during sleep for not less than 10 seconds and repeated more than five times per hour of sleep. OSA is a common disorder that can adversely impact longevity and quality of life for adults and has also been linked to sudden infant death syndrome (SIDS). The frequency of snoring and sleep disorders among the population of Saudi Arabia is increasing, as the prevalence of obesity and smoking within the last few years. Patients with OSA are most often overweight, with associated peri-pharyngeal infiltration of fat and/or other anatomical alteration that may decrease the cross sectional area of the upper airway space. Smoking is widely known to impact upper airway physiology detrimentally. This sleep pattern can eventually leads to sudden death because of the continuous oxygen deprivation. Unfortunately, the number of patients who suffer from snoring and sleep apnea in Saudi Arabia is not well established. The treatment of OSA includes both surgical and conservative methods. Both treatment options aim at reducing the upper airway collapsibility which is considered the main cause of apneic attacks during sleep. It is well established as a thumb rule that the first line of OSA treatment should be directed towards the conservative approach owing to the questionable success rate achieved by surgical intervention. The conservative methods include; weight loss, change in sleep posture, drug therapy, nasal continuous positive airway pressure (CPAP) and oral devices. The oral devices in specific are gaining popularity among the medical profession owing to their diverse advantages and versatility. In this article, a review of the various prosthetic appliances used for management of OSA has been carried out.
Keywords: Obstructive sleep apnea; Mandibular advancement prostheses; Mandibular repositioning appliances; Oral devices
Introduction
  By the late twentieth century, the medical community recognized that snoring and daytime sleepiness were signs of obstructive sleep apnea syndrome (OSAS). Parts of the sleep apnea syndrome complex were however, known many years earlier by an insightful few [1]. Nowadays, OSA is recognized to be a common potentially life threatening well defined medical entity. Its recognition has been ascribed essentially to the continuous growth in sleep research within the past three decades. Increased public awareness, more frequent detection by medical professions, and the use of a more sophisticated diagnostic tools, has led to an obvious increase in the number of diagnosed patients. The medical implications of this condition are significant. Specifically, frequent obstruction of the upper airway results in stoppage of breathing (apnea) in association with repeated arousals from sleep and blood de-oxygenation. The more frequent apneic attacks, the more severe hypoxemia results with more serious medical complications including; loss of energy, loss of concentration, loss of productivity, high blood pressure, heart attacks, strokes and even sudden death. The primary sequel that results in apnea has been shown to be the upper airway collapsibility [2,3]. There are three typical patterns of apnea. Obstructive apnea is the absence of airflow irrespective of the respiratory effort [4]. Central apnea is an absence of airflow with no respiratory effort. Mixed apnea includes both a central and an obstructive component. The most typical mixed apnea pattern is a central apnea followed by an obstructive one [5].
Epidemiology
Sleep-disorders were first detected in mid-1960s in advance with the polysomnographic studies of Gustout's on obese patients with increased carbon dioxide level [6]. These studies ensured that obesity is an important factor in initiating the OSA. However, further studies revealed that OSA can also occur in non-obese patients and that a direct link between both the cardio-vascular and cerebro-vascular complications and the consequences of OSA exists [7]. Although snoring is common in 25% of the adult population, the epidemiological data estimated that only 2-5% of the population meets the criteria for OSA when estimated with polysomnographic recordings [8,9]. The problem of OSA can affect all age groups and both sexes. Traditionally, OSA was recognized as a syndrome of the middle-aged adults and that the apneic event tends to decline in length with age [10]. Community based studies have shown that OSA is seen in 2% of women and 4% of men between the ages of 30 and 60 years [11,12]. The increased risk of OSA in males has been ascribed to gender differences in airway morphology and the protective effects of female hormones on upper airway patency [13].
Clinical implications
The fragmented and restless sleep cause common symptoms such as morning headaches, daytime sleepiness, fatigue, depression and mood alterations, libido as a result of hypoxemia, hearing loss, cognitive deficiencies, automatic behavior, reduced mental alertness and short-term memory loss. Children with sleep apnea may exhibit poor school performance and hyperactivity. Hypoxia resulting from apnea may lead to severe medical conditions that hypertension, cardiac arrhythmias, systemic and pulmonary hyperten¬sion, chronic hypercapnia and polycythemia, left ventricular dysfunction, myocardial infarction, stroke and even sudden death [14].
Predisposing factors
OSA is caused by repeated airway obstruction during sleep as a result of narrowing of the respiratory passages [15-17]. This narrowing is often attributed to obesity and anatomical alteration. Over two-thirds of the patients with OSA are most often overweight. Generally, obesity is also associated with larger neck size. If an individual’s neck circumference is greater than 42.5 cm, the chance of apnea increases significantly [16-18]. Craniofacial as well as maxillofacial anomalies can also play an important role in OSA cases. These anatomical alterations include deviated nasal septum, enlarged nasal turbinate, increased size of soft palate and uvula, and bi-maxillary or mandibular retrognathism [16,17]. Micrognathia, acromegaly, and Down's syndrome may also be predisposing conditions [17]. Smoking is a detrimental factor to the physiology of the upper airways. The repeated use of an irritant such as smoking can significantly reduce the patency of the upper airway due to the irritation-inflammation-edema cycle [18]. The role of the genioglossus muscle in the pathogenesis of OSA has also been recently emphasized [19,20]. Decreased tone of this muscle during sleep as well as the pull of gravity in the supine position, further decrease airway size, and significantly contribute to airway obstruction [21].
Management of OSA
OSA can be managed by both surgical and non surgical methods. The conservative approaches to treatment include behavioural modification (weight loss, altered sleeping position, reduction in smoking and alcohol consumption), the use nasal continuous positive airway pressure (CPAP), medication, and/or oral devices [22]. It has been postulated that a 50% improvement in the apneic hypopneic index (AHI) or an AHI less than 10 indicates a treatment success [23,24]. Surgical treatment of snoring alone is much easier although there are no guarantees that they work for all or last forever. Several surgical procedures are available to correct the upper airway collapsibility with questionable prognosis. These include, nasal surgeries, such as septoplasty and inferior turbinate resection, uvulopalatopharyngoplasty, Laser-assisted uvuloplasty, Mandibular distraction osteogenesis, and tracheostomy [25-30]. Since 1981, continuous positive airway pres­sure (CPAP) has been the most commonly prescribed nonsurgical method of treatment for obstructive sleep apnea. CPAP treatment is considered the most effective method to manage obstructive sleep apnea. The most significant effect is enlargement of the airway by dimensional changes of the lateral pharyngeal walls. In addition to structural changes, CPAP augments the tone of the upper airway dilator muscles thereby reducing susceptibility to collapse. Despite of its great efficacy it requires the use of a mask interface, sealed tubing, and a device connected to a power source. This complexity limits its acceptance by patients and leads to suboptimal treatment adherence [31-33].
Oral appliances
Oral appliances for treatment of OSA was first described by a French physician called Pierre Robin in 1902. With his monobloc appliance, Robin treated children who suffered from breathing difficulties and glossoptosis due to mandibular hypoplasia. The classical form of an oral appliance that repositioned the mandible in an adult patient with OSA was not reported until 1980 [34]. Treatment of obstructive sleep apnea in dentate patients with oral appliances (OAs) is well documented, the objective of oral appliances is to advance the mandible and tongue base, increasing the space between the base of the tongue and the posterior pharyngeal wall. The tongue may also be advanced with the use of a tongue-retaining device. These appliances improve upper airway collapsibility during sleep. Subsequently assist in reducing the obstruction [35,36]. Prosthodontists have recently become one of the general team in the field of sleep medicine. However, it is very important that the dentist should not provide the primary care of the patient; instead he has to work through a medical team work. Most of the treatment options are medical in nature, the problem often ranges far beyond that of a dental condition, and it often requires multiple medical studies. Consequently, the role of dentist in treating that case should be linked to a team which include a thoracic physician, oral and maxillofacial surgeon ear, nose, and throat surgeon, restorative dentist, and an orthodontist. Therefore, it is imperative that the patient be referred to a physician for examination, appropriate studies, diagnosis, and course of treatment [37,38].
Oral appliance therapy for treatment of OSA can be categorized into; (a) those that hold the tongue forward and (b) those that reposition the mandible and the attached tongue forward during sleep [38]. Although rarely used because of poor results and patient tolerance; palatal lifting devices (which contact the soft palate directly, they seldom employed, most likely because of gag, discomfort, and the success of laser and radio frequency soft palate procedures). Tongue posture trainers, and labial shields are also oral appliances that claim to improve snoring and OSA [39]. Each of the oral appliances has a primary effect on either the tongue or the tongue and mandible together. Several appliances move the mandible anteriorly, for example, mandibular repositioner, PM Positioner, Herbst, Klearway, Snore Guard, and TheraSnore. The tongue is affected by all the appliances either by direct forward movement of the muscle itself or by changes secondary to an altered mandibular rest position. The tongue retaining device (TRD) is the most commonly used oral appliance that has a direct affect on tongue posture [40].
Tongue Retaining Device (TRD)
TRD was first described by Carwright and Samelson [41]. The TRD appliance is especially useful in patients who have macroglossia. Because the TRD does not depend in its retention on the presence of good healthy natural dentition, it is considered an effective alternate to mandibular advancement prostheses in edentulous patients or in patients with compromised dentition. Moreover, OSA patients who are not capable of advancing the mandible for whatever reason can use the TRD safely [42]. The TRD is a custom-made appliance with a flange which fits between lips and teeth and an anterior soft plastic bulb that by means of negative pressure holds the tongue forward during sleep [43]. For those patients with blocked nasal passages, a modified TRD with lateral airway tubes to permit mouth breathing is also available. However, the use of TRD poses many disadvantages as it forces the nasal breathing and it locks the jaw in a single position which is not usually tolerated by the patients [44]. The TRD appears useful either alone or in conjunction with other treatments to improve patients with a wide range of apnea severity provided that the apnea is more severe in the supine position and the patient’s weight is not greater than 50% above the ideal [38]. The effects of the TRD on baseline tongue muscle activity have been studied. Ono., et al. [45] found that the TRD has different effects on the awake genioglossus muscle activity in control subjects and OSA patients. In awake OSA patients, the TRD reduces genioglossus muscle activity and corrects the delayed timing of the muscle before an apneic period during sleep. The TRD may counteract fatigue in the tongue muscles and fluctuations in the activity of the genioglossus muscle. In addition, the TRD may provide a pneumatic splint to enlarge the upper airway similar to that seen with nasal CPAP [45].
Mandibular repositioning appliances (MRAs)
In the last decade there has been an explosion of interest in using oral appliances especially the MRAsto treat OSA. The development of this prosthetic treatment option represents an important step in the management of this disease. They are generally appealing because they are simple to use, reversible, portable, and appear to be quite safe [46-48]. Randomized controlled clinical trials [49-51] have shown oral appliances to be an effective and well-established treatment option for patients with mild or moderate OSA and for patients with severe OSA who are unable to tolerate nasal CPAP. MRA is a removable dental prosthesis that creates a different, yet temporary, dental occlusal position that guides the mandible to close into a predetermined and altered position [52]. A great deal of studies have paid attention to the horizontal relation between the mandible and maxilla produced by the appliance and consequently, the optimum amount of mandibular protrusion required to achieve better results which was estimated to be approximately 60% of maximum protrusion [53]. However, the optimum vertical dimension of an oral appliance required to achieve a successful treatment outcome in patients with OSA has been an issue of debate. Some authors [54] believe that the vertical dimension should be determined according to the individual patient tolerance and acceptance. Others [55] believe that acceptable treatment outcome cannot be obtained without increasing the vertical dimension by the appliance. In a randomized, controlled crossover study, Bloch., et al. [56] compared two groups of patients who received oral appliances with identical amount of mandibular protrusion and different amount of vertical opening. The authors reported better improvement with the group of patients who received an oral appliance with greater amount of vertical opening. However, possible contributors to this result are the difference in the appliance design itself between the two groups since one group received a Herbst appliance while the other received a Monobloc fixed device. Furthermore, the results of this study may be also questionable because of the between-subject variability due to the parallel group study design. In another trial, Pitsis., et al. [57] tried to systematically evaluate two predetermined specific levels of mouth opening among patients who received the same oral appliance and with identical protrusion level. However, the evaluation parameters were not sufficient to draw a conclusive result. A more recent study [58] suggests that the fabrication of oral appliances used to treat the OSA should be made with the minimal vertical opening required to accommodate those appliances since increasing the vertical dimension does not markedly affect the treatment outcome.
MRAs are of either a one-piece (Monobloc) or a two piece design (Bibloc). The one piece design fixes the mandible rigidly in an anterior position, whereas the two piece MRA usually allows for some freedom of mandibular movement (i.e., lateral, vertical and/or anterior). This latter feature has been suggested to decrease the chance of temporomandibular disorders, increase the retention and improve patient comfort (particularly for those patients who suffer from sleep bruxism) [59,60]. But in another study where the prevalence of side effects were identified for Monobloc and Bibloc appliances, the effects could not be relieved by switching from one appliance to the other, in contrast there are some patients experienced transient mild mucosal erosions exclusively during use of the Bibloc appliance, caused by its lateral attachments [61]. Conversely, fixation of mandible with a one-piece appliance is suggested to prevent suppression of tongue protruding muscles resulting in a less collapsible upper airway [60,61]. Most two-piece appliances are sagittally adjustable, thereby allowing for individual titration and possibly greater mandibular advancement [62]. While single jaw position or nonadjustable appliances often need to be remade if the initial jaw position proves to be inadequate [59]. In addition, MRAs are either custom-made (e.g. Herbst, Klearway appliances) or pre-fabricated (e.g. Snore Guard) [59,60]. A prefabricated MRA generally requires only an individual molding of a thermolabile material, while a custom-made appliance usually requires dental impressions, bite registration, and fabrication by a dental laboratory [59]. Retention of the MRA is usually provided by wrought wire clasps. Appliances made of thermoplastic material necessitates that the patient softens the material in hot water before insertion. These materials were found to have considerable more retention than traditionally designed cold cure acrylic appliances [60].
Several exclusion criteria should be taken into account when MRA therapy is considered. These include insufficient number of teeth, (extensive) periodontal disease or dental decay, active temporomandibular joint disorders, and restrictions in mandibular opening or protrusion [58]. However, although some consider a minimum of ten sound teeth in each of the maxillary and mandibular arches a requisite in MRA treatment, the location rather than the number of teeth may be more important (i.e., posterior teeth provide more adequate retention) [59].
Efficacy of oral appliances
Despite the effectiveness of surgical intervention in the treatment of some cases of OSA, there may be contraindications for such techniques as in medically unfit patients for general anaesthesia, and patient's refusal. Therefore attempts have been made to employ oral appliances alternatively. The aim of such modality is to advance the mandible and subsequently enlarges the antero-posterior diameter of the retro-glossal space thus reduces the pharyngeal collapsibility. Of particular interest in this context are the mandibular advancement prostheses, which are capable of advancing the lower jaw [38]. There are other possible mechanisms of oral appliances in reducing OSA. The forward jaw position is said to induce stretching and increased stiffness of the lateral pharyngeal walls and pillars. Movement of the tongue forward can also prevent any likelihood of seal forming between the tongue/soft palate/pharyngeal wall. Moreover stabilization of the mandible and hyoid bone prevent posterior rotation of the jaw and retro-lapse of the tongue during sleep. Eventually, the altered anatomic relationship induces a stretch-induced neurosensory stimulation that influences the motor tone and collapsibility of the airway [63,64]. Three dimensional imaging and (supine) cephalometric studies demonstrated that mandibular repositioning increases oropharyngeal, hypopharyngeal and velopharyngeal dimensions [65]. Endoscopic studies have demonstrated that mandibular advancement results in, particularly, an increased cross-section of the lateral dimension of the velopharynx [66].
Based on its effectiveness and patient compliance, oral appliances seem appropriate for the treatment of upper airway resistance syndrome, as well as sleep apnea syndrome or snoring [67].Based on subjective reports of patients and their bed partners, MRA therapy generally results in improvements of snoring in a high proportion of patients. Other reported benefits of MRA treatment include substantial decreases of daytime sleepiness, improvements in work performance, and improved sleep quality of both patient and bed partner. Sleep registration generally confirms the patient-perceived benefits by demonstrating a decrease in snoring frequency and intensity, AHI or RDI, oxygen desaturation frequency and intensity, and number of arousals [68]. Moreover, MRA treatment has been associated with significant increases in slow-wave and REM sleep. Although the initial effect of the MRA has been reported to be stable over a five-year period [69], there are studies suggesting a gradual decline in treatment effect in both the short (i.e., six weeks) and long term (i.e., four years). Despite an unsatisfactory change in the number of breathing events, patients may report fewer symptoms. Moreover, an increased AHI after MRA therapy has been reported in approximately 13% of patients. Because of this risk of an increased or suboptimal AHI, a follow-up sleep study should always be conducted in MRA treatment [70].
Complications and compliance of MRA
Although side-effects are frequently reported with MRA therapy, these are usually mild and acceptable, with most symptoms subsiding when treatment is continued. Tenderness of the teeth and jaws, myofacial pain, gum irritation, excessive salivation, and xerostomia are commonly reported in the initial period of use. In exceptional cases, treatment may be complicated by involuntary removal of the device, an exaggerated gag reflex, periodontal damage, or fractured teeth and fillings [71]. It has been suggested that advancement of the mandible for considerable periods may have adverse effects on the stomatognathic system. Mild complaints of pain and strain of the masticatory muscles and the temporomandibular joint frequently occur at the initiation of treatment [72]. Some studies have observed an increase in bruxism in response to MRA therapy. In the long term, MRA treatment has been suggested to initiate or aggravate temporomandibular joint disease in individual patients [73]. A temporary bite change in the morning after removal of the appliance occurs in almost all patients. In individual cases, permanent occlusal alterations have been observed after long-term treatment periods [74].
Mandibular repositioning appliances for edentulous patients
The splint consists of maxillary and mandibular vacuum formed splints over which heat polymerized clear acrylic resin blocks were attached (vent holes in middle of acrylic resin blocks were placed). The blocks were attached together by auto-polymerizing acrylic resin [75]. This splint is fabricated to achieve protrusion of the mandible (75% of maximum protrusion) without increasing the vertical dimension of occlusion. Therefore, there is no difficulty in inserting and removing the splint from the mouth, and the patient does not find the splint formidable to wear. This assists in improving patient compliance. It is indicated in patients with well formed ridges. Adequate retention could be obtained by making a mandibular impression with a properly extended lingual flange [75].
Conclusions
Sleep apnea syndrome is a relatively common yet potentially fatal syndrome that is characterized by the transitory cessation of the breathing impulse. The most prevalent type is obstructive sleep apnea (OSA), which results from a collapse or obstruction in the oropharyngeal region of the upper airway. Mandibular advancement devices (MADs) are the class of appliances most commonly prescribed at this time to manage cases with OSA. The actual appliance that is chosen is often determined by the interaction of the patient and dentist. Those mandibular advancement devices that permit some degree of jaw movement (both lateral and vertical) may potentially minimize TMJ problems and improve patient acceptance. However, many functional and anatomic factors that influence the syndrome make diagnosis or selection of therapy very difficult, so there is limited agreement on the effectiveness of specific methods. Therefore, patients must be carefully examined to ensure selection of the most suitable treatment. Further longitudinal studies on a relatively large number of patients are still needed to identify the long term efficacy and side effects of mandibular advancement prostheses.
Bibliography
  1. Vorona RD and Ware JC. “History and epidemiology of sleep-related breathing disorders”. Oral and Maxillofacial Surgery Clinics of North America 14.3 (2002): 273-283.
  2. Fletcher EC. “The relationship between systemic hypertension and obstructive sleep apnea: facts and theory”. The American Journal of Medicine 98.2 (1995): 118-128.
  3. Lowe AA., et al. “Facial morphology and obstructive sleep apnea”. American Journal of Orthodontics and Dentofacial Orthopedics 90.6 (1986): 484-491.
  4. Moore KE. “Current medical management of sleep-related breathing disorders”. Oral and Maxillofacial Surgery Clinics of North America14.3 (2002): 297-304.
  5. Smith DM and Stradling JR. “Can mandibular advancement devices be a satisfactory substitute for short term use in patients or nasal continuous positive airway pressure? “ Thorax 57.4 (2002): 305-308.
  6. Gastaut H., et al. “Etude polygraphique des manifestations episodique (hyponique et respiratories), diurnes et nocturne, du syndrome de Pickwick”. Rev Neurol (paris) 112 (1965): 568-579.
  7. American Academy of Sleep Medicine. Sleep related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. Sleep 22.5 (1999): 667-689.
  8. Kripke DF., et al. “Prevalence of sleep-disordered breathing in ages 40-64 years: a population-based survey”. Sleep 20.1 (1997): 65-76.
  9. White DP. Central sleep apnea. In: Kryger MH, Roth T, Dement WC, editors. Principles and practices of sleep medicine. Third Edition. Philadelphia: W.B. Saunders (2000): 827-839.
  10. Kato I., et al. “Frequency of obstructive and mixed sleep apneas in 1,023 infants”. Sleep 23.4 (2000): 487-4 92.
  11. Young T., et al. “The occurrence of sleep-disordered breathing among middle-aged adults”. New England Journal of Medicine 328.17 (1993): 1230-1235.
  12. Olson LG., et al. “A community study of snoring and sleep-disordered breathing: prevalence”. American Journal of Respiratory and Critical Care Medicine 152.2 (1995): 711-716.
  13. Young TB., et al. “Epidemiology of obstructive sleep apnea”. American Journal of Respiratory and Critical Care Medicine 165.9 (2002): 1217-1239.
  14. Malhotra A., et al. “Obstructive sleep apnoea”. Lancet 360.9328 (2002): 237-245.
  15. Olsen KD., et al. “Nasal influences on snoring and obstructive sleep apnea”. Mayo Clinic Proceedings 65.8 (1990): 1095-1105.
  16.  Colt HG., et al. “Hypoxemia vs sleep fragmentation as cause of excessive daytime sleepiness in obstructive sleep apnea”. Chest 100.6 (1991): 1542-1548.
  17. Mezon BJ., et al. “Sleep apnea in acromegaly”. American Journal of Medicine 69.4 (1980): 615-618.
  18.  Moore KE. “Current medical management of sleep-related breathing disorders”. Oral & Maxillofacial Surgery Clinics of North America 14.3 (2002): 297-304.
  19.  Muto T., et al. “Relationship between the pharyngeal airway space and craniofacial morphology, taking into account head posture”. International Journal of Oral and Maxillofacial Surgery 35.2 (2006): 132-136.
  20. Hoekema A., et al. “Efficacy and co-morbidity of oral appliances in the treatment of obstructive sleep apnea-hypopnea: A systematic Review”. Critical Reviews in Oral Biology & Medicine 15.3 (2004): 137-155.
  21.  Lee NR. “Genioglossus muscle advancement techniques for obstructive sleep apnea”. Oral & Maxillofacial Surgery Clinics of North America 15.2 (2007): 179-192.
  22. Nayar S., et al. “Management of obstructive sleep apnea in an edentulous patient with a mandibular advancement splint: A clinical report”. Journal of Prosthetic Dentistry 94.2 (2005): 108-111.
  23. Wiggins RV., et al. “Treatment of the obstructive sleep apnea syndrome”. Western Journal of Medicine 147.5 (1987): 561-568.
  24. Schmidt-Nowara WW., et al. “Treatment of snoring and obstructive sleep apnea with a dental orthosis”. Chest 99.6 (1991): 1378-1385.
  25. Madani M. “Surgical treatment of snoring and mild obstructive sleep apnea”. Oral Maxillofacial Surgery Clinics of North America 14.3 (2002): 333-350.
  26. Fujita S., et al. “Surgical correction of anatomic abnormalities in obstructive sleep apnea syndrome: uvulopalatopharyngoplasty”. Otolaryngology Head Neck Surgery 89.6 (1981): 923-934.
  27. Strauss RA. “Laser in the management of snoring and mild sleep apnea”. Oral Maxillofacial Surgery Clinics North America 14.3 (2002): 319-331.
  28. Nordgard S., et al. “Soft palate implants for treatment of mild to moderate obstructive sleep apnea”. Otolaryngology-Head and Neck Surgery 134.4 (2006): 565-570.
  29. Wang X., et al. “Distraction osteogenesis in correction of micrognathia accompanying obstructive sleep apnea syndrome”. Plastic and Reconstructive Surgery 112.6 (2003): 1549-1557.
  30. Gentry T. “The long-term evaluation of tracheostomy in the management of severe obstructive sleep apnea”. Laryngoscope 113.2 (2003): 201-204.
  31. Lombard Jr RM and Zwillich CW. “Medical therapy of obstructive sleep apnea”. Medical Clinics of North America 69.6 (1985): 1317-1335.
  32. Issa FG and Sullivan CE. “Reversal of central sleep apnea using nasal CPAP”. Chest 90.2 (1986): 165-171.
  33. Ryan CF., et al. “Magnetic resonance imaging of the upper airway in obstructive sleep apnea before and after chronic nasal continuous positive airway pressure therapy”. American Review of Respiratory Disorder 144.4 (1991): 939-944.
  34. Bear SE and Priest JH. “Sleep apnea syndrome: correction with surgical advancement of the mandible”. Journal of Oral Surgery 38.7 (1980): 543-549.
  35. Ellis SG., “Dental appliances for snoring and obstructive sleep apnoea: construction aspects for general dental practitioners”. Dent Update 30.1 (2003): 16-26.
  36. Kent E Moore. “Oral appliance for snoring and obstructive sleep apnea: A Review”. Sleep 29.2 (2006): 244-262.
  37. Ivanhoe J R., et al. “Dental considerations in upper airway sleep disorders: A review of the literature”. Journal of Prosthetic Dentistry 82.6 (1999): 685-698.
  38. Nayar S and Knox J. “Management of obstructive sleep apnea in an edentulous patient with a mandibular advancement splint: A clinical report”. Journal of Prosthetic Dentistry 94.2 (2005): 108-111.
  39. Barthlen GM., et al. “Comparison of three oral appliances for treatment of severe obstructive sleep apnea syndrome. Sleep Medicine 1.4 (2000): 299-305.
  40.  Ferguson KA., et al. “Effect of mandibular and tongue protrusion on upper airway size during wakefulness”. American Journal of Respiratory and Critical Care Medicine 155.5 (1997): 1748-1754.
  41. Cartwright RD and Samelson CF. “The effects of a nonsurgical treatment for obstructive sleep apnea.The tongue-retaining device”. JAMA  248.6 (1982): 121-126.
  42. Samelson C. “The role of tongue retaining device in treatment of snoring and obstructive sleep apnea”. CDS Rev 81 (1988): 44-47.
  43. Lowe AA. “Titratable oral appliances for the treatment of snoring and obstructive sleep apnea”. Journal (Canadian Dental Association) 65.10 (1999): 571-574.
  44. Ono T., et al. “The effect of the tongue retaining device on awake genioglossus muscle activity in patients with obstructive sleep apnea”. American Journal of Orthodontics and Dentofacial Orthopedics 110.1 (1996): 28- 35.
  45. Ono T., “A tongue retaining device and sleep-state genioglossus muscle activity in patients with OSA”. The Angle Orthodontist 66.4 (1996): 273-280.
  46. Hou HM., “Long-term dentofacial changes in Chinese obstructive sleep apnea patients after treatment with a mandibular advancement device”. The Angle Orthodontist 76.3 (2006):  432-440.
  47. Ferguson K. “Oral appliance therapy for obstructive sleep apnea”. American Journal of Respiratory and Critical Care Medicine 163.6 (2001): 1294-1295.
  48. Ferguson K. “The role of oral appliance therapy in the treatment of obstructive sleep apnea”. Clinics in Chest Medicine 24.2 (2003): 355-364.
  49. Bloch KE., et al. “A randomized controlled crossover trial of two oral appliances for sleep apnea treatment”. American Journal of Respiratory and Critical Care Medicine 162.1 (2000): 246-251.
  50. Pitsis AJ., et al. “Effect of vertical dimension on efficacy of oral appliance therapy in obstructive sleep apnea”. American Journal of Respiratory and Critical Care Medicine 166.6 (2002): 860-864.
  51. Gagnon Y., et al. “Aggravation of respiratory disturbances by the use of an occlusal splint in apneic patients: A pilot study”. International Journal of Prosthodontics 17.4 (2004): 447-453.
  52. “The Glossary of prosthodontic terms". The journal of prosthetic dentistry 94.1 (2005): 10-92.
  53. Clark GT., et al. “A crossover study comparing the efficacy of continuous positive airway pressure with anterior mandibular positioning devices on patients with obstructive sleep apnea”. Chest 109.6 (1996):1477-1483.
  54. L'Estrange PR., et al. “A method of studying adaptive changes of the oropharynx to variation in mandibular position in patients with obstructive sleep apnea”. Journal of Oral Rehabilitation 23.10 (1996) 699-711.
  55. George PT. “Selecting sleep-disordered-breathing appliances. Biomechanical considerations”. Journal ofAmerican Dental Association 132.3 (2001): 339-347.
  56. Bloch KE., et al. “A randomized controlled crossover trial of two oral appliances for sleep apnea treatment”.  American Journal of Respiratory and Critical Care Medicine 162.1 (2000): 246-251.
  57. Pitsis AJ., et al. “Effect of vertical dimension on efficacy of oral appliance therapy in obstructive sleep apnea”. American Journal of Respiratory and Critical Care Medicine 166.6 (2002): 860-864.
  58. Khamis M., et al. “The Effect of Raising the Vertical Dimension of Mandibular Advancement Prostheses in Treatment of Obstructive Sleep Apnea”. Egyptian Dental Journal 52 (2006): 42-46.
  59. Lindman R and Bondemark L. “A review of oral devices in the treatment of habitual snoring and obstructive sleep apnoea”. Swedish Dental Journal 25.1 (2001): 39-51.
  60. Ferguson KA., et al. “Effect of mandibular and tongue protrusion on upper airway size during wakefulness”. American Journal of Respiratory and Critical Care Medicine 155.5 (1997): 1748-1754.
  61. Eckhart JE. “Comparisons of oral devices for snoring”. JCA Dental Association 26.8 (1998): 611-623.
  62. Pancer J., et al. “Evaluation of variable mandibular advancement appliance for treatment of snoring and sleep apnea”. Chest 116.6 (1999): 1511-1518.
  63. Masumi Wiliams AJ and Clark GT. “Effect of jaw position and posture on forced inspiratory airflow in normal subjects and patients with obstructive sleep apnea”. Chest 109.6 (1996): 1484-1489.
  64. Loube DI. “Oral appliance treatment for obstructive sleep apnea”. Clinical Pulmonary Medicine 5 (1998): 124-128.
  65. Liu Y., et al. “Effects of a mandibular repositioner on obstructive sleep apnea”. American Journal of Orthodontics and Dentofacial Orthopedics 118.3 (2000): 248-256.
  66. Ryan CF., et al. “Mandibular advancement oral appliance therapy for obstructive sleep apnoea: effect on awakecaliber of the velopharynx”. Thorax 54.11 (1999): 972-977.
  67. Mehta A., et al. “A randomized, controlled study of a mandibular advancement splint for obstructive sleep apnea”. American Journal of Respiratory and Critical Care Medicine 163.6 (2001): 1457-1461.
  68. Marklund M., et al. “Mandibular advancement device in patients with obstructive sleep apnea: long-term effects on apnea and sleep”. Chest120.1 (2001): 162-169.
  69. Randerath WJ., et al. “An individually adjustable oral appliance vs continuous positive airway pressure in mild-to-moderate obstructive sleep apnea syndrome”. Chest122.2 (2002):569-575.
  70. Schmidt-Nowara W., et al. “Oral appliances for the treatment of snoring and obstructive sleep apnea: a review”. Sleep18.5 (1995): 501-510.
  71. Rose E., et al. “Treatment of obstructive sleep apnea with the Karwetzky oral appliance”. European Journal of Oral Sciences 110.2 (2002): 99-105.
  72. Pantin CC., et al. “Dental side effects of an oral device to treat snoring and obstructive sleep apnea”. Sleep 22.2 (1999): 237-240.
  73. Walker-Engström ML., et al. “4-year follow-up of treatment with dental appliance or uvulopalatopharyngoplasty in patients with obstructive sleep apnea: a randomized study”. Chest 121.3 (2002): 739-746.
  74. Rose EC., et al. “Occlusal side effects caused by a mandibular advancement appliance in patients with obstructive sleep apnea”. The Angle Orthodontist 71.6 (2001): 452-460.
  75. Nayar S and Knox J. “Management of obstructive sleep apnea in an edentulous patient with a mandibular advancement splint: A clinical report”. Journal of Prosthetic Dentistry 94 (2005): 108-111.
Copyright: © 2015 Abdelfattah AH., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

PubMed Indexed Article


EC Pharmacology and Toxicology
LC-UV-MS and MS/MS Characterize Glutathione Reactivity with Different Isomers (2,2' and 2,4' vs. 4,4') of Methylene Diphenyl-Diisocyanate.

PMID: 31143884 [PubMed]

PMCID: PMC6536005


EC Pharmacology and Toxicology
Alzheimer's Pathogenesis, Metal-Mediated Redox Stress, and Potential Nanotheranostics.

PMID: 31565701 [PubMed]

PMCID: PMC6764777


EC Neurology
Differences in Rate of Cognitive Decline and Caregiver Burden between Alzheimer's Disease and Vascular Dementia: a Retrospective Study.

PMID: 27747317 [PubMed]

PMCID: PMC5065347


EC Pharmacology and Toxicology
Will Blockchain Technology Transform Healthcare and Biomedical Sciences?

PMID: 31460519 [PubMed]

PMCID: PMC6711478


EC Pharmacology and Toxicology
Is it a Prime Time for AI-powered Virtual Drug Screening?

PMID: 30215059 [PubMed]

PMCID: PMC6133253


EC Psychology and Psychiatry
Analysis of Evidence for the Combination of Pro-dopamine Regulator (KB220PAM) and Naltrexone to Prevent Opioid Use Disorder Relapse.

PMID: 30417173 [PubMed]

PMCID: PMC6226033


EC Anaesthesia
Arrest Under Anesthesia - What was the Culprit? A Case Report.

PMID: 30264037 [PubMed]

PMCID: PMC6155992


EC Orthopaedics
Distraction Implantation. A New Technique in Total Joint Arthroplasty and Direct Skeletal Attachment.

PMID: 30198026 [PubMed]

PMCID: PMC6124505


EC Pulmonology and Respiratory Medicine
Prevalence and factors associated with self-reported chronic obstructive pulmonary disease among adults aged 40-79: the National Health and Nutrition Examination Survey (NHANES) 2007-2012.

PMID: 30294723 [PubMed]

PMCID: PMC6169793


EC Dental Science
Important Dental Fiber-Reinforced Composite Molding Compound Breakthroughs

PMID: 29285526 [PubMed]

PMCID: PMC5743211


EC Microbiology
Prevalence of Intestinal Parasites Among HIV Infected and HIV Uninfected Patients Treated at the 1o De Maio Health Centre in Maputo, Mozambique

PMID: 29911204 [PubMed]

PMCID: PMC5999047


EC Microbiology
Macrophages and the Viral Dissemination Super Highway

PMID: 26949751 [PubMed]

PMCID: PMC4774560


EC Microbiology
The Microbiome, Antibiotics, and Health of the Pediatric Population.

PMID: 27390782 [PubMed]

PMCID: PMC4933318


EC Microbiology
Reactive Oxygen Species in HIV Infection

PMID: 28580453 [PubMed]

PMCID: PMC5450819


EC Microbiology
A Review of the CD4 T Cell Contribution to Lung Infection, Inflammation and Repair with a Focus on Wheeze and Asthma in the Pediatric Population

PMID: 26280024 [PubMed]

PMCID: PMC4533840


EC Neurology
Identifying Key Symptoms Differentiating Myalgic Encephalomyelitis and Chronic Fatigue Syndrome from Multiple Sclerosis

PMID: 28066845 [PubMed]

PMCID: PMC5214344


EC Pharmacology and Toxicology
Paradigm Shift is the Normal State of Pharmacology

PMID: 28936490 [PubMed]

PMCID: PMC5604476


EC Neurology
Examining those Meeting IOM Criteria Versus IOM Plus Fibromyalgia

PMID: 28713879 [PubMed]

PMCID: PMC5510658


EC Neurology
Unilateral Frontosphenoid Craniosynostosis: Case Report and a Review of the Literature

PMID: 28133641 [PubMed]

PMCID: PMC5267489


EC Ophthalmology
OCT-Angiography for Non-Invasive Monitoring of Neuronal and Vascular Structure in Mouse Retina: Implication for Characterization of Retinal Neurovascular Coupling

PMID: 29333536 [PubMed]

PMCID: PMC5766278


EC Neurology
Longer Duration of Downslope Treadmill Walking Induces Depression of H-Reflexes Measured during Standing and Walking.

PMID: 31032493 [PubMed]

PMCID: PMC6483108


EC Microbiology
Onchocerciasis in Mozambique: An Unknown Condition for Health Professionals.

PMID: 30957099 [PubMed]

PMCID: PMC6448571


EC Nutrition
Food Insecurity among Households with and without Podoconiosis in East and West Gojjam, Ethiopia.

PMID: 30101228 [PubMed]

PMCID: PMC6086333


EC Ophthalmology
REVIEW. +2 to +3 D. Reading Glasses to Prevent Myopia.

PMID: 31080964 [PubMed]

PMCID: PMC6508883


EC Gynaecology
Biomechanical Mapping of the Female Pelvic Floor: Uterine Prolapse Versus Normal Conditions.

PMID: 31093608 [PubMed]

PMCID: PMC6513001


EC Dental Science
Fiber-Reinforced Composites: A Breakthrough in Practical Clinical Applications with Advanced Wear Resistance for Dental Materials.

PMID: 31552397 [PubMed]

PMCID: PMC6758937


EC Microbiology
Neurocysticercosis in Child Bearing Women: An Overlooked Condition in Mozambique and a Potentially Missed Diagnosis in Women Presenting with Eclampsia.

PMID: 31681909 [PubMed]

PMCID: PMC6824723


EC Microbiology
Molecular Detection of Leptospira spp. in Rodents Trapped in the Mozambique Island City, Nampula Province, Mozambique.

PMID: 31681910 [PubMed]

PMCID: PMC6824726


EC Neurology
Endoplasmic Reticulum-Mitochondrial Cross-Talk in Neurodegenerative and Eye Diseases.

PMID: 31528859 [PubMed]

PMCID: PMC6746603


EC Psychology and Psychiatry
Can Chronic Consumption of Caffeine by Increasing D2/D3 Receptors Offer Benefit to Carriers of the DRD2 A1 Allele in Cocaine Abuse?

PMID: 31276119 [PubMed]

PMCID: PMC6604646


EC Anaesthesia
Real Time Locating Systems and sustainability of Perioperative Efficiency of Anesthesiologists.

PMID: 31406965 [PubMed]

PMCID: PMC6690616


EC Pharmacology and Toxicology
A Pilot STEM Curriculum Designed to Teach High School Students Concepts in Biochemical Engineering and Pharmacology.

PMID: 31517314 [PubMed]

PMCID: PMC6741290


EC Pharmacology and Toxicology
Toxic Mechanisms Underlying Motor Activity Changes Induced by a Mixture of Lead, Arsenic and Manganese.

PMID: 31633124 [PubMed]

PMCID: PMC6800226


EC Neurology
Research Volunteers' Attitudes Toward Chronic Fatigue Syndrome and Myalgic Encephalomyelitis.

PMID: 29662969 [PubMed]

PMCID: PMC5898812


EC Pharmacology and Toxicology
Hyperbaric Oxygen Therapy for Alzheimer's Disease.

PMID: 30215058 [PubMed]

PMCID: PMC6133268


News and Events


August Issue Release

We always feel pleasure to share our updates with you all. Here, notifying you that we have successfully released the August issue of respective journals and can be viewed in the current issue pages.

Submission Deadline for September Issue

Ecronicon delightfully welcomes all the authors around the globe for effective collaboration with an article submission for the September issue of respective journals. Submissions are accepted on/before August 21, 2020.

Certificate of Publication

Ecronicon honors with a "Publication Certificate" to the corresponding author by including the names of co-authors as a token of appreciation for publishing the work with our respective journals.

Best Article of the Issue

Editors of respective journals will always be very much interested in electing one Best Article after each issue release. The authors of the selected article will be honored with a "Best Article of the Issue" certificate.

Certifying for Review

Ecronicon certifies the Editors for their first review done towards the assigned article of the respective journals.

Latest Articles

The latest articles will be updated immediately on the articles in press page of the respective journals.

Immediate Assistance

The prime motto of this team is to clarify all the queries without any delay or hesitation to avoid the inconvenience. For immediate assistance on your queries please don't hesitate to drop an email to editor@ecronicon.uk