Upload
kent-e-moore
View
217
Download
2
Embed Size (px)
Citation preview
O
K
F
shloaair
DS
1d
Operative Techniques in Otolaryngology (2007) 18, 52-56
ral appliance treatment for obstructive sleep apnea
ent E. Moore, MD, DDS
rom the Office of Charlotte Oral and Maxillofacial Surgery, Charlotte, North Carolina.
Snoring and obstructive sleep apnea occur over a spectrum of upper airway narrowing and affect a largeportion of the general population. The consequences of this disorder can be substantial, leading tohypersomnolence, neurocognitive deficits, and significant cardiovascular morbidity and mortality.During the past 15 years, the use of oral appliances has developed into a viable and scientifically soundmethod to eliminate upper airway obstruction in a large percentage of patients. Although individualpatient selection criteria (predisposing to treatment success) are yet to be determined, it is incumbentthat the treating otolaryngologist maintains a working knowledge as relates to oral appliance therapy inthis set of patients.© 2007 Elsevier Inc. All rights reserved.
KEYWORDSObstructive sleepapnea;Snoring;Oral appliance;Mandibularrepositioning;Appliances
1
On the basis of a large body of high-level evidence-basedtudies,1 the American Academy of Sleep Medicine recentlyas published a newly revised Practice Parameter paper thatends substantial importance and credibility to the use ofral appliances (OAs) in the treatment of obstructive sleeppnea (OSA).2 (Within this article, the term “oral appli-nces” refers mainly to the subset of mandibular reposition-ng appliances, or MRAs.) A summary of the revised pa-ameters follows:
1. The presence or absence of OSA (along with the se-verity thereof) must be determined before initiatingtreatment with oral appliances.
2. OAs should be fitted by qualified dental personnel whohave received appropriate training and experience indental sleep medicine.
3. A cephalometric evaluation of patients in whom OAtherapy is being contemplated is recommended.
4. The goal of treatment in patients with primary snoringor upper airway resistance syndrome is to reduce snor-ing to a subjectively acceptable level; the goal of treat-ment in patients with OSA includes resolution of thesigns and symptoms of OSA and normalization of theapnea-hypopnea index (AHI) and oxygen saturation.
5. OAs are appropriate treatment for primary snoring.6. OAs (although not as efficacious as continuous positive
airway pressure [CPAP]) are indicated as a first-line
Address reprint requests and correspondence: Kent E. Moore, MD,DS, Office of Charlotte Oral and Maxillofacial Surgery, 1718 East Fourthtreet, Suite 804, Charlotte, NC 28204.
vE-mail address: [email protected].
043-1810/$ -see front matter © 2007 Elsevier Inc. All rights reserved.oi:10.1016/j.otot.2007.04.002
treatment option for patients with mild-to-moderateOSA (ie, for those who prefer OAs to CPAP, who donot respond to [or cannot tolerate] CPAP, or who failtreatment attempts with CPAP or other behavioral mea-sures.
7. OAs are not indicated as a first-line treatment for severeOSA because greater effectiveness has been shownwith this intervention that with the use of OAs. Someupper-airway surgical procedures (including uvulo-palato-pharyngoplasty, T&A, tracheostomy, and craniofacialsurgery) also may supersede use of OAs in those whomthese procedures are predicted to be highly effective.
8. Patients with OSA treated with OAs should undergo aposttitration polysomnography or participate in a car-diorespiratory sleep study (Type 3).
9. Follow-up dental visits are necessary (every 6 monthsduring the first year, and yearly thereafter) in thosepatients treated with OAs to assess the fit, efficacy,adherence, occlusion and to evaluate for signs of wors-ening OSA. OAs may worsen temporomandibular joint(TMJ) disease and may contribute to occlusal and orth-odontic malalignment. The appliance itself needs to becontinuously monitored for signs of deterioration, mal-adjustment, and ineffectiveness.
0. Patients treated with OAs should be followed periodi-cally by the referring physician; objective re-evaluationduring sleep is indicated if signs or symptoms of OSAworsen.2
Although very few otolaryngologists will become in-
olved in actual OA delivery and maintenance, those in-vct(im
T
AtatmccCfi
H
AtsegipMctmttvmo
(ieonp
dmdrmStdpa
am
ptel
cgipers
E
SsOrmcatfdassobweci
FaseBw
53Moore Oral Appliance Treatment for Obstructive Sleep Apnea
olved in the treatment of patients with OSA must beognizant of the standards of care as relates to OA therapy;he importance of proper patient education and the ability toworking with their dental colleague) properly integrate thismportant nonsurgical modality into their treatment arma-entarium.
ypes of OAs
lthough several classes of OAs have been developed overime, the classes of tongue-retaining appliances and MRAsre the two that have received significant legitimate scien-ific study. MRAs are the class of appliances most com-only prescribed at this time and can be divided into non-
ustom (off-the-shelf or “boil-and-bite”) appliances andustom made (“monoblock” or “adjustable” appliances).urrently, the custom-made adjustable MRA has seemed tond the most merit, validation, acceptance, and patient use.
ow OAs work
lthough the precise mechanism of action of OAs in thereatment of snoring and OSA is yet to be defined, multipletudies suggest complex changes occurring within the lat-ral pharyngeal walls, tongue, soft palate, epiglottis, andenioglossus muscle during mandibular protrusion affectmprovement in airflow dynamics. Upper airway closingressure has been documented to improve with the use ofRAs (ie, a greater negative pressure is required to affect
losure of the airway when oral appliances are used),hereby improving airway soft-tissue collapsibility and di-inishing soft-tissue compliance.3 MRAs have been shown
o increase both lateral and anteroposterior dimensions ofhe upper airway at the hypopharyngeal, oropharyngeal, andelopharyngeal airway segments, and genioglossus neuro-uscular activity has been shown to be activated during use
f these appliances.4
Airflow is dictated by the size of the airway openingmore specifically, by the site and size of airway narrow-ng), as described by Poiseuille’s Law. As the radius in thisquation is raised to the fourth power, small changes in thepening of the tube (at its narrowest point) affect an expo-ential reduction in the resistance of the tube, thereby ex-onentially increasing airflow.
Protrusive range of motion is not as important as theegree of airway expansion produced as a result of forwardandibular posturing. Problematic to straightforward pre-
iction, not everyone with a large mandibular-protrusiveange of motion obtains sufficient airway expansion withaximal (comfortable) forward posturing of the mandible.imilarly, some patients with minimal ability to protrude
he mandible have significant degrees of airway expansionespite the minimal forward translation of the jaw. Eachatient is unique in this regards, requiring individual patientirway evaluation to allow prediction to therapy.
In Figure 1, as opposed to the patient in (B), the patient’sirway in (A) is seen to expand dramatically with anterior
andibular repositioning. Assuming that both patients wresent with a mild-to-moderate severity of OSA, a poten-ially favorable response with an OA therapy would bexpected in patient A, whereas an unfavorable response (orack of response) would be expected from patient B.
Not all airways, however, present with expansivehanges so dramatic as that presented. The influence of age,ender, body mass index (BMI), and respiratory disorderndex (RDI) must be factored along with expansion toredict response to therapy. A patient with severe OSA, forxample, will typically require more expansion to affectesolution of obstructive pathology than a patient that pre-ents with milder forms of OSA.
fficacy of OAs
ince 1995, 10 level I, 5 level II, 1 level III, and 24 level Vtudies have been generated evaluating the efficacy ofAs.1 The number of subjects reported within these studies
ange from 8 to 257. Subject selection varies between trials;any studies used consecutive patients attending a sleep
linic with symptoms of OSA, whereas others were offeredplace in a study because they had refused or failed other
reatment (most often nasal CPAP, but some involved UPPPailures). Although typical selection criteria included theiagnosis of OSA (with and AHI or RDI of more than 10 tos high as 30), some studies included subjects with moreevere OSA (ie, AHI �40). Overall effects on oxygenaturation suggest small incremental increases with the usef oral appliances; a significant reduction in arousals haseen reported in some studies, but the mean arousal indexas not always decreased (CPAP was sometimes more
ffective at reducing arousals than OAs). Although signifi-ant reductions in Epworth Sleepiness Scale were reportedn several studies, Mean Sleep Latency Test improvement
igure 1 With anterior mandibular repositioning, the patient’sirway in (A) is open considerably more than that of the airwayhown in (B). All factors considered equal, patient A would bexpected to receive a greater benefit with OA therapy than patient, who would not be expected to receive any therapeutic benefitith an OA. (Color version of figure is available online.)
as noted in the one study in which it was measured, and
tTstbOtmau
srtcsptIdt
O
OOacTbtstn
P
Abtncptao
Optweat
wct
tfomIempPffmpWtd
O
Oacgffdmaiasacptamabasmcamm
bmcltpmeatc
54 Operative Techniques in Otolaryngology, Vol 18, No 1, March 2007
here was no difference in the Maintenance of Wakefulnessest between CPAP and OA. Overall, those with mild-to-evere OSA have a 52% chance of being able to controlheir OSA using and OA. OAs are less effective than CPAPut may be better accepted by patients than nasal CPAP.1
As are not recommended as a first-line treatment in pa-ients with severe OSA (AHI �40); however, these patientsay consider an OA if they have failed CPAP or upper
irway surgery (the results of OAs in severe OSA arenpredictable).2
Male supine-dependent OSA patients typically have lessevere disease, more normal upper airway physiology, andespond better to OA therapy than patients who obstruct inhe lateral position.5 Also, as supine REM sleep is typicallyonsidered the most vulnerable body position and stage ofleep, obstruction is commonly seen to worsen during thisosition and stage of sleep. In these patients, cervical ex-ension can be used to augment hypopharyngeal airway size.n many supine patients, mild cervical extension (as pro-uced through pillows designed for this purpose) may fur-her augment the airway effects of OAs.
A therapy: primary versus rescue
As are most commonly used as a primary treatment forSA; however, the use of these appliances is commonly
dopted by both sleep physicians and otolaryngologists inases of failed CPAP, UPPP, tongue-base, or nasal surgery.he use of an OA to reposition the mandible forward haseen associated with lower CPAP airway pressures requiredo ventilate the patient. As UPPP typically resolves areas ofoft palate redundancy, OA therapy focuses primarily onongue-base obstruction (thereby often making this combi-ation an effective form of therapy).
atient selection
clinical history (preferentially including input from theed partner) typically reveals the presence of one or more ofhe following: habitual snoring, excessive daytime sleepi-ess, and witnessed apneic events. Appropriate presentinglinical signs require a definitive diagnosis via overnightolysomnography. Clinical experience with MRAs in thereatment of snoring and OSA is largely restricted to adults,lthough one RCT in children has reported effective controlf OSA and airway-related symptoms.6
Nonapneic snorers represent the largest group for whichAs should be considered. As noted previously, the newractice parameters support the first-line application of OAso patients with mild-to-moderately severe OSA, or thoseho fail other forms of therapy. There is also emerging
vidence of the benefit of MRAs in the treatment of upperirway resistance syndrome, although randomized con-rolled trials are lacking.7
Young, thin patients with lower BMIs and RDIs (andith mandibular protrusive ranges of 8 mm or more) are the
lassic responders to MRA therapy. From a dental perspec-
ive, TMJ dysfunction may be a relative contraindication to the use of OAs, although anecdotal evidence suggests thatew patients with this disorder have problems with this formf therapy. Some literature does exist that shows no detri-ental TMJ changes over the period of 1 to 1.5 years.8
nsufficient numbers of teeth in each arch, the presence ofxtensive crowns and bridges, and periodontal bone lossay preempt straightforward MRA usage (in many of these
atients, a tongue-retaining appliance may be a possibility).atients with a class II facial skeletal pattern may benefitrom long-term incisal angulation changes induced with thisorm of treatment. Patients with supine-dependent OSAay have a greater success rate with MRA therapy com-
ared with those who have OSA in the lateral position.omen are overall more successfully treated with MRAs
han men, when controlled for disease severity, supine-ependent OSA, BMI, and age younger than 50.9
A Design, fabrication, and titration
As are classified by method of action: MRAs can bedjustable or nonadjustable (ie, fixed one-position), andustom-made or stock (off the shelf). MRAs also are cate-orized by the Food and Drug Administration as approvedor primary snoring versus OSA (those patients approvedor OSA tend to be heavier, more retentive, and moreurable than those approved for primary snoring). Theethod of retention varies for the prefit (ie, “boil-and-bite”)
ppliances and the custom-made appliances (which oftenncorporate metal ball and post clasps to provide mechanicalnchorage for the appliance). The materials used in con-truction of these appliances vary from relatively simplecrylic moldings to appliances incorporating metal rods,onnectors, and more durable materials. Although severalapers have suggested that some patients prefer one-posi-ion appliances, there is general consensus that customizeddjustable appliances are better tolerated and tend to beore effective than the less commonly used prefabricated
ppliances (which tend to possess minimal retentive capa-ility). Although little is known about the influence ofppliance design on treatment outcome, most MRAs pos-ess good retention and adequate protrusive capability whileinimizing vertical changes. The actual appliance that is
hosen is often determined by the interaction of the patientnd dentist. Those MRAs that permit some degree of jawovement (both lateral and vertical) may potentially mini-ize TMJ problems and improve patient acceptance.Custom appliances require impressions and a protrusive
ite for their fabrication. After pouring of the casts, theodels are sent for appliance fabrication to the laboratory of
hoice. The appliance is delivered after return from theaboratory, and the patient typically is allowed to adapt tohe appliance for the first several weeks of treatment. As therotrusive bite dictates the starting position of the mandible,any patients may obtain a satisfactory degree of airway
xpansion when the appliance is first placed and require nodditional titration. Others, however, may require additionalitration before adequate airway expansion is achieved. In-remental titration (spread over several weeks or months) is
he most commonly used technique to affect progressivemdcpaafsacm(acowdtei(bn
C
Ta(Mbpwswl5es4aoahtdccoOl
S
Tcsm
pmruiwwvabntdtiwbmscp5ph9tflmlsssRot
C
OatfentitatsDtcsaD
55Moore Oral Appliance Treatment for Obstructive Sleep Apnea
andibular protrusion (and is felt to possibly induce lessetrimental TMJ changes), although rapid titration is advo-ated by some. Determination of the amount of mandibularrotrusion required to eliminate upper airway obstruction inny given patient is, however, a matter of trial and error, asdvancing the mandible too far may result in significantacial muscle spasm and pain. Furthermore, reliance onymptomatic improvement alone by the patient can be in-ccurate because of the placebo effect. The commonly ac-epted technique at this time is to continue advancing theandible until the patient’s symptoms of OSA and snoring
ie, EDS, lethargy, hypersomnolence) have improved (orbated entirely); at this point, the patient is studied (mostommonly with a portable monitoring device performedver two nights—once as a baseline, and the second nightith the appliance in place). Once adequate titration isocumented by the treating dentist, and referral back to thereating sleep physician is indicated. The correlate alsoxists: in some patients, an inadequate therapeutic responses not achieved when the mandible has been fully titratedor, the patient is unable to comfortable tolerate the mandi-le in a fully protruded position); in these patients an alter-ative treatment option must be sought.
ompliance with therapy
he weak link with any device is the ability of the patient todhere and comply with therapy. A surgical solution to OSAif successful) eliminates any question with compliance.
ost reports dealing with compliance of OAs are generatedy self-reports (one study exists which does employ a com-liance monitor, however, this technology has not beenidely applied to the field at this time).10 In the majority of
tudies, adherence was calculated based on those patientsho completed the study and who were available for fol-
ow-up. Self-reported adherence rates range (on the 2- to-year interval) from a median of 48% to 75%, and adher-nce rates tend to decrease with duration of use (with onetudy of 53 patients reporting 60% adherence at 1 year, and8% at 2 years). Common reasons for discontinuation of usere side effects, complications, and lack of efficacy.1 Thene objective (compliance monitor) study showed patientsveraged 6.8 hours per night (with a range of 5.6 to 7.5ours). The objective data (for hours of nightly use) are inhe same range as the self-reported patient data.10 Theseata must be interpreted in light of similar and early CPAPompliance data, in where on 46% of patients met theriteria for regular use (which was defined as at least 4 hoursf CPAP administered at least 70% of the days monitored).nly 6% of patients were found to use nasal CPAP for at
east 7 hours on more than 70% of days monitored.11
ide effects/medicolegal implications
he literature suggests two types of complications that areommonly associated with OAs: those that are minor (ie,elf-limited, such as tooth pain, excess salivation, dry
outh, TMJ discomfort, and muscle pain) and tend to not lrevent regular use of the appliance and those that areoderate to severe (these may be continuous and tend not to
esolve over time and lead to discontinuation of appliancese [these include TMJ dysfunction, gagging, tooth pain,ntractable muscle pain]). These side effects occur over aide range of patients attempting therapy with OAs. Note-orthy within the literature is that the frequency of thesearious types of side effects is not different between level Vnd level I and II studies- indicating good concordanceetween studies.1 Tooth movement is noted in a significantumber of studies (the most common of which is lingualipping of the maxillary incisors, proclination of the man-ibular incisors, and anterior shifting of the lower first molareeth). Although these changes tended to occur with increas-ng length of treatment, the most significant dental changesere observed at 30 months. No relationship has been foundetween the presence of these side effects and the degree ofandibular protrusion or existing malocclusion, and it
hould be noted that in some cases, these changes may beonsidered as orthodontically favorable (particularly in theresenting Class II patient). In one study (performed at theyears after the OA placement time period), 14% of 106
atients had evidence of occlusal changes. Eight of these,owever, were not aware of these changes, and conversely,of 16 reported bite changes but had no clinical evidence of
he changes.12 Besides appropriate informed consent, care-ul monitoring of the occlusal changes over time (via cepha-ometrics, dental models, and serial records) is a criticaledicolegal maneuver that must be performed to avoid
egal challenges. Likewise, careful documentation of re-ponse to therapy and titration must also be performed, anderial monitoring for each of these variables is the acceptedtandard for the entire lifespan of use of the appliance.esponse to therapy may decline over an extended periodf time with these appliances, as wear on the applianceakes a toll.
onclusion
As are now a recognized first-line treatment for snoringnd mild-to-moderate OSA and can be a legitimate alterna-ive (or rescue therapy) for some severe OSA patients whoail first-line therapies (CPAP or UPPP). Short-term sideffects to MRAs are common but typically are transient inature, and long-term side effects seem to be common butypically mild. Although airway response varies betweenndividuals, overall, 52% of all comers respond to OAherapy. An appropriate working knowledge of this fieldnd relationship with knowledgeable and experienced den-al sleep medicine providers is needed for otolaryngologistseeking this therapy for their patients. The Academy ofental Sleep Medicine (www.dentalsleepmed.org) is an in-
ernational professional organization of dentists and physi-ians advocating use and research of oral appliances, anderves as a valuable resource for identification of individu-ls knowledgeable about the field. The American Board ofental Sleep Medicine has been established as a credible
icensing body for certification within this field.
R
1
1
1
56 Operative Techniques in Otolaryngology, Vol 18, No 1, March 2007
eferences
1. Ferguson K, Cartwright R, Rogers R, et al: Oral appliances for snoringand obstructive sleep apnea: A review. Sleep 29:2:244-262, 2006
2. Kushida C, Morgenthaler T, Littner M, et al: Practice parameters forthe treatment of snoring and obstructive sleep apnea with oral appli-ances: An update for 2005. Sleep 28:499-521, 2005
3. Ng AT, Gotsopoulos H, Qian J, et al: Effect of mandibular advance-ment splint therapy on upper airway collapsibility in obstructive sleepapnea. Am J Respir Crit Care Med 168:238-241, 2003
4. Tsuiki S, Ono T, Kuroda T: Mandibular advancement modulatesrespiratory-related genioglossus electromyographic activity. SleepBreath 4:53-58, 2000
5. Marklund M, Persson M, Franklin KA: Treatment success with amandibular advancement device id related to supine-dependent sleepapnea. Chest: 114:1630-1635, 1998
6. Villa MP, Bernkopf E, Pagani J, et al: Randomized controlled study of
an oral jaw-positioning appliance for the treatment of obstructive sleepapnea in children with malocclusion. Am J Respir Crit Care Med165:123-127, 2002
7. Yoshida K: Oral device therapy for the upper airway resistance syn-drome patient. J Prosthet Dent 87:427-430, 2002
8. de Almeida F, Bittencourt L, de Almeida C, et al: Effects of mandib-ular posture on obstructive sleep apnea severity and the temporoman-dibular joint in patients fited with an oral appliance. Sleep 25:507-513,2002
9. Marklund M, Stenlund H, Franklin KA: Mandibular advancementdevices in 630 men and women with obstructive sleep apnea andsnoring—tolerability and predictors of treatment success. Chest 125:1270-1278, 2004
0. Lowe A, Sjoholm T, Ryan C, et al: Treatment, airway and complianceeffects of a titratable oral appliance. Sleep 23:S172-178, 2000
1. Kribbs N, Redline S, Smith P, et al: Objective monitoring of nasalCPAP usage in OSAS patients. Sleep Res 20:270-1, 1991
2. Pantin C, Hillman D, Tennant M: Dental side effects of an oral device
to treat snoring and obstructive sleep apnea. Sleep 22:237-240, 1999