The potential use of a portable monitor to assess the outcome of treatment with an oral appliance would ideally be performed by the dentist who is managing the patient’s sleep-disordered breathing. Portable monitoring is one of the most cost-effective ways to assess the response to the oral appliance, to determine if further adjustment to the appliance is needed, and to retest to determine the current status following any adjustment. This article emphasizes the use of portable monitors primarily for follow-up care and assessment as opposed to diagnosis or, as it is sometimes referred to, screening.
The potential use of a portable monitor to assess the outcome of treatment with an oral appliance would ideally be performed by the dentist who is managing the patient’s sleep-disordered breathing. A sleep medicine physician or sleep center may also perform such a study. The dentist may be using portable monitoring as a means of assessing the response to the oral appliance after an initial titration period along with assessment of the patient’s symptom resolution before referral back to the patient’s physician, sleep medicine specialist, or for a follow-up polysomnogram. Portable monitoring may be one of the most cost-effective ways for the treating dentist to assess the outcome or effect of the oral appliance, to determine if further adjustment/modification to the appliance is needed, and to retest to determine the current status following any adjustment or modification.
This article emphasizes the use of portable monitors primarily for follow-up care and assessment as opposed to diagnosis or, as it is sometimes referred to, screening. Many have advocated the use of portable monitor type devices as a means by which the dentist can screen patients who might be at risk for sleep apnea. This is clearly a diagnostic procedure for a potential medical condition that is not within the scope of dental practice at this time. Portable monitors, specifically level 3 devices, have limited use as an alternative to the overnight polysomnogram (level 1) as an effective instrument for the diagnosis of sleep apnea.
History and current status: a case report
A 54-year old man presents to a dentist who has advanced training and is competent in dental sleep medicine and the use of oral appliances for managing sleep-disordered breathing. He was referred to the dentist by the sleep center where the polysomnogram was done and his primary care physician, mainly because he was unable to tolerate continuous positive airway pressure (CPAP) despite trying numerous masks. He had a consultation with an otolaryngologist about possible surgery and was also informed that an oral appliance would be more appropriate at this time. His Epworth Sleepiness Scale score was 13 (the normal value is >10) and the apnea/hypopnea index (AHI) was 21 per hour of sleep. His body mass index is 28 kg/m 2 and his neck size is 40 cm. He has been diagnosed with hypertension, which is controlled with Lisinopril and hydrochlorothiazide. With medication, his blood pressure is 121/82. He denies having any other health-related issues, specifically cardiovascular disease or diabetes. He reports that his sleep onset is within 15 minutes but his sleep is restless with multiple awakenings (2–3 per night) and he gets 6 hours of sleep a night on average. He reports that he has snored for more than 20 years; and in the last 5 years the snoring has become more problematic and observed apnea has occurred.
A formal orofacial and airway evaluation was performed as has been described and recommended for the dentist who performs this type of service. This also included an evaluation of the nasal airway. During the evaluation, he denied being a mouth breather at night and has no difficulty breathing through the nose. However, nasal dilation (commonly known as the Cottle test) improved the patient’s ability to nose breath. He did report trying nasal strips for nasal dilation but they were not effective for the snoring and did not seem to affect his sleep.
By virtue of testing, it was determined that with the mandible repositioned, which included opening the vertical approximately 5 mm and advancing the mandible 2–3 mm, he believed his airway was improved and he would not snore. At this point, an oral appliance was determined to be an appropriate treatment and the necessary records were obtained for the fabrication of the oral appliance.
At the first follow-up 2 weeks after receiving the oral appliance, he reports that the snoring is significantly improved, he feels his sleep and feeling of being tired and sleepy during the day are improved. He also feels he is more productive at work and not as tired at the end of the day. Some adjustment to the oral appliance is done mainly for comfort and he is reappointed in a month. He has had the oral appliance for 6 weeks and reports that his symptoms continue to improve and his snoring is present but much improved. Because of the snoring, his mandible is advanced approximately 2 mm and with this change he feels his breathing is also improved. He is reappointed for a follow-up visit in another month.
At the third follow-up visit he reports that the snoring is no longer present according to his wife and he continues to believe that he has improved energy levels and is sleeping through the night. He awakens rested and wakes up without an alarm most mornings. By report, his initial complaints and neurocognitive symptoms are improved ( Table 1 ). At this point no further adjustment is deemed necessary and he is reappointed for a follow-up visit in 2 months.
| Symptom | Before Oral Appliance Use | With Oral Appliance Use |
|---|---|---|
| Snoring | Present | Resolved |
| Epworth Sleepiness Scale score | 13 | 5 |
| Excessive daytime sleepiness | Present | Reduced/improved |
| Drowsy driving | Present | Eliminated |
| Concentration | Difficult | Improved |
| Energy levels | Low | Improved/resolved |
| Observed apnea | Present at times | None |
| Mood swings/irritable | Present | Resolved |
| Restless sleep | Present | Resolved |
| Awakenings each night | 2 to 3 | None now |
| Headaches | Occasional (2–3 a week) | None |
He has now had the oral appliance for more than 4 months and is satisfied with the results. At this time a portable monitoring sleep study to assess the effect of the oral appliance and to determine if any further adjustment is needed, is arranged. It is explained that this is not the same type of sleep study that he had initially. This study is not for diagnosis of sleep apnea (this has already been done) but to determine if the appliance is managing the apnea adequately. The appropriate consent forms are completed and he is scheduled to have the study done.
The portable monitoring study is completed after the patient is instructed on the use and application of the equipment. He will do a 1-night study and return the equipment to the office the next day. At that time, the data will be downloaded for review. The results of the portable monitoring study reveal that the AHI is now 7 and his blood oxygen levels are in the 90% or greater range, nearly 100% of the time. His Epworth Sleepiness Scale score is now 5. At this time he seems to be deriving a reasonable outcome with the oral appliance. A report is generated and will be sent to the referring physician, to the sleep center where the initial sleep study was performed, and to any other physicians who are directly involved with the patient’s care. A decision will be made regarding the need for an attended level 1 sleep study to further substantiate the effect of the oral appliance and his current level of apnea.
Portable Monitoring for Diagnosis Before Oral Appliance Therapy
The dental sleep medicine practitioner is the one who will most likely be providing an oral appliance. However, the use of portable monitoring to screen for sleep-disordered breathing in those patients who may be at risk for sleep apnea is not within the scope of practice by the dentist. Despite the advanced training the dentist may have in sleep medicine, they, like most primary care physicians, are not well-versed in the recognition of coexisting sleep disorders that may present as the same type of symptoms as sleep-disordered breathing. Even with advanced training, the level 3 portable monitor will not provide adequate information to allow for the diagnosis of comorbid sleep disorders such as central sleep apnea, periodic limb movements (PLMs), parasomnias, various circadian rhythm sleep disorders, or narcolepsy. In addition, the portable monitor is not indicated for use as a general screening device in an asymptomatic population. The more appropriate action is to identify those patients who are at risk for sleep-disordered breathing. Once it is established that the patient is at risk, the patient should be referred to their primary care physician or to a sleep center for a polysomnogram.
In general, the use of the level 3 portable monitor is not accepted as the optimal method for diagnosing sleep-disordered breathing at the present time. The gold standard continues to be the overnight polysomnogram. However, there are numerous articles that support the use of these portable monitors for patients with high pretest probability of being at risk for sleep-disordered breathing.
The main issue is that the sensitivity and specificity of these devices at an AHI less than 15 is not as good compared with an AHI greater than 15. One study did find that portable monitoring was most reliable at an AHI of 10 or more. In addition, portable monitors may actually underestimate the severity of sleep apnea. This is related to the computation of the AHI and more specifically, the respiratory disturbance index (RDI) per hour of recording time because of the difference in total sleep time versus total recording time.
Another issue related to diagnosis using a portable monitor, even if it is being used to assess just snoring, is if the outcome is negative (RDI >5), then the patient may not seek or obtain treatment. Who then assumes the liability for the medical consequences of the sleep apnea? Given that the portable monitor may underestimate the degree of sleep apnea, this is of particular concern in patients who are asymptomatic and may only perceive the issue as snoring, not sleep apnea.
The role of the dentist, regardless of the level of training, is to perform risk assessment for a sleep-disordered breathing condition. Risk assessment is initially done by having an awareness of the following :
- 1.
Assessment of findings through questions in the health history (screening)
- 2.
Assessment of the most common symptoms of sleep-disordered breathing
- 3.
Awareness of existing medical conditions that indicate the possible risk for sleep-disordered breathing
- 4.
Use of standard questionnaires such as the Epworth Sleepiness Scale or the Berlin questionnaire
- 5.
Findings from the head/oral/airway clinical evaluation.
Based on the assessment of risk and comorbid conditions, the patient is referred to a sleep medicine specialist or for a sleep study. That study would most likely be a polysomnogram.
Portable Monitoring for Progressive/Follow-Up Testing with Oral Appliance Therapy
The use of level 3 portable monitoring based on published clinical guidelines has been recommended (consensus) for the purpose of determining the effectiveness of oral appliance therapy for sleep-disordered breathing. This is stated as follows:
Sect 1.4 PM: “Portable Monitoring (PM) may be indicted to monitor the response to non-CPAP treatments for obstructive sleep apnea, including oral appliances, upper airway surgery, and weight loss.”
Furthermore, the use of level 3 portable monitors for assessment of the effectiveness of an oral appliance after the final adjustment is a practice parameter guideline. A more practical point of view would potentially use the portable monitor at various points in the titration process of the treatment to determine if added adjustment or modification is needed before a more definitive sleep study. Assuming that the level 3 portable monitor is reliable, its use would contribute to improvement in consistent and successful use of the oral appliance for the management of sleep apnea. In some cases, the level 3 portable monitoring study may actually be satisfactory in determining that the oral appliance is adequately addressing the sleep-disordered breathing. This is a decision that ultimately should be made by the sleep medicine specialist, not the treating dentist.
The American Academy of Dental Sleep Medicine (AADSM) in 2005 also established a position as it relates to the use of portable monitoring. The position that has been taken is that the use of portable monitoring should be restricted to use for titration of the oral appliance (the need for adjustment and modification) for an enhanced effect and to document the effectiveness of the treatment. Furthermore, the use of portable monitors “as a screening tool” designed to identify those patients who may require an overnight polysomnogram is not endorsed at this time. In 2009, the AADSM published a treatment protocol for oral appliances that indicated that portable monitoring was applicable for gathering objective data for the purpose of oral appliance titration.
Based on studies that have looked at the use of level 3 portable monitors compared with polysomnograms for diagnosis, it seems that the portable monitor should provide information to determine that the oral appliance is adequately resolving the sleep-disordered breathing and has also improved the patient’s symptoms. Concern for the recognition of other coexisting sleep disorders is not an issue with the use of this technology because these conditions have most likely been recognized (diagnosed) from the original polysomnogram and their management is being considered aside from the use of the oral appliance for the sleep-disordered breathing. Consequently, not all of the parameters of the sleep study are needed to ascertain that the oral appliance is effectively managing the sleep-disordered breathing. The parameters of greatest value in evaluating the effectiveness of the oral appliance are listed in Table 2 .
