Consensus on Establishing Calibration Endpoint for Oral Appliance Therapy
(Steve Carstensen, Steve Lamberg, Kent Smith, Les Priemer, Erin Elliott, Dennis Marangos, Daniel Klauer, Gina Pepitone-Mattiello, Tony Soileau, Christopher Kelly, David Rawson, John Viviano)
The newly formed LinkedIn Discussion Group, “SleepDisordersDentistry” has just completed an open discussion on establishing calibration endpoint for oral appliance therapy. Here is a consensus for all to ponder.
What was asked,
“Regardless of how you take your initial bite registration, you are still required to use your clinical judgment to establish a calibration endpoint. Both technology and knowledge has come a long way since the 90’s. Devices currently available to aide in appliance calibration were unimaginable to most of us 20 years ago. Let’s hear about what techniques and devices you use and how you use them. IN SHORT, HOW DO YOU ESTABLISH "WHEN" THE PATIENT IS READY TO HAVE THEIR IN-LAB EFFICACY SLEEP STUDY?”
What was said,
Our discussion on the event “Establishing Endpoint Calibration” confirms much agreement amongst our peers with a scattering of some unique approaches.
Patient Baseline Questionnaires and Subjective Resolution:
In general, there was universal agreement that comprehensive documentation of baseline symptoms and quality of sleep is imperative. A direct comparison to these baseline findings with the initiative of “normalizing” sleep patterns helps establish calibration endpoint, at least from a subjective standpoint. Questionnaires such as the Epworth Sleepiness Scale, Stanford Sleepiness Scale and the STOPBANG along with information about various sleep related parameters garnered during the initial consultation provide a baseline to which you can compare improvements related to each appliance position. The use of questionnaires to be filled out at each patient visit helps to standardize this process, facilitating comparison to baseline. The objective being to have the Chief Complaints eliminated and have the patient’s sleep patterns be as Normal as possible. Tips for establishing end point included feedback from bed partners or housemates, and the use of a phone App that can be downloaded to a smart phone. “SnoreLab” is an inexpensive and easy to use phone App that provides objective feedback on snoring and is useful for those patients that sleep alone. However, it’s not about advancing the jaw as much as the patient can tolerate, increasing levels of advancement can be associated with an increase in side effects. This can be explained to patients as follows, “we need to advance the jaw as much as necessary to eliminate the symptoms, but as little as possible to reduce the side effects”. Sometimes, residual symptoms persist even after maximum advancement; our previous consensus discussion on Vertical provided some tips that may help improve outcomes when advancement alone falls short. Finally, the use of a “Counselor” to help the patient deal with compliance, weight loss, positional therapy and other behavioral based help was also discussed.
However, even with our best efforts using subjective methods alone, a subset of patients will have residual apnea even when the patient claims their problem is resolved. This is where the use of objective evaluation aids in the process of establishing an endpoint. (Steve Carstensen, John Viviano, Steve Lamberg, Kent Smith, Les Priemer, Erin Elliott, Dennis Marangos, Daniel Klauer)
The use of Oximetry to finalize calibration of the appliance was discussed. Once subjective evaluation and comparison to baselines demonstrates resolution of symptoms and normalization of sleep patterns, the patient is provided a device that monitors their blood oxygen saturation throughout their sleep period. This would usually occur about one month after initiating oral appliance therapy. The results are then reviewed by the clinician and compared to the blood oxygen saturation indices found on the patient’s baseline sleep study; providing objective evaluation of appliance calibration endpoint in a cost effective manner. The low cost and ease of patient use of this approach facilitates multiple tests as may be required in those difficult cases. One protocol discussed involved having the patient test blood oxygen levels for 2 or 3 consecutive nights before making a final decision, reporting a good correlation to the final in-lab sleep study findings. Finally, less can go wrong with a simple Oximetry test, leading to fewer wasted test sessions. The Oximetry indices evaluated are “time spent with blood oxygen desaturation below 90%”, “oxygen saturation minimum”, and “oxygen desaturation index”. If the Oximetry report is less than favorable, calibration efforts would be re-visited and a further Oximetry test would be performed. If the improvement being sought is minimal, the appliance would be advanced and then referred back to the Sleep Physician. However, if the improvement being sought is more meaningful, the appliance would be advanced and a further Oximetry evaluation would be performed before referral back to the Sleep Physician. Keeping in mind of course that all this further advancement is limited by the patient’s ability to accommodate further advancement. (Gina Pepitone-Mattiello, Les Priemer, John Viviano)
Some concerns were expressed regarding the use of Oximetry to evaluate endpoint. There are those patients that have Moderate to Severe levels of OSA but do not exhibit meaningful blood oxygen desaturation; obviously, using Oximetry to evaluate calibration endpoint for these patients would be fruitless. The judicious use of a Home Sleep Test (HST) for these patients was discussed, resorting to Oximetry only for those patients that exhibit meaningful blood oxygen desaturation at baseline, helping to contain overall costs. The additional meaningful information captured with a HST was also discussed. What a HST brings to the table is specific information such as level of apnea and hypopnea, positional info, length of time slept in each position, and for some HST's, bruxism (to name just a few) along with the blood oxygen saturation information you get with simply Oximetry. Having this additional information enables the clinician to make more informed clinical decisions regarding further advancement, positional therapy etc. (Kent Smith, Gina Pepitone-Mattiello, John Viviano, Steve Lamberg)
In-Lab Sleep Study Calibration:
Having the calibration finalized or “tweaked” during the in-lab efficacy sleep study was also discussed. The importance of reviewing titration protocol in detail with the patient and also providing a letter for the sleep technicians outlining what was expected of them along with a chart for them to document results for various appliance positions was discussed. It was reported that this type of collaboration and “Teamwork” has resulted in very good results. (Les Priemer)
Home Sleep Tests:
Many clinicians discussed the use of a HST to help establish calibration end point. Of course, this is done once subjective criteria has been assessed, as discussed above. The “autoscore” option was discussed as these tests are only meant to help ensure the appliance is optimally calibrated, not to officially establish efficacy, satisfy any insurance, guideline or Physician criteria; a subtle but meaningful point. Timing of the HST varied from about a month out, 8 to 12 weeks out and 3 to 6 months out, but always after subjective resolution of symptoms was documented. Rational for the longer time frame was that this extra time would allow tissue healing, which could improve outcomes. Some clinicians send their HST results to an RSPGT for scoring and if the Apnea Hypopnea Index (AHI) is less than 5 (10 for more severe cases), the patient and the results are referred back to the referring Physician for review. Sometimes, this HST is used as a validation study by the Physician (varies depending on region). For patients that are in the process of losing weight or having Nasal surgery, sometimes a HST is done to compare not only to baseline, but to a second HST after the weight loss levels off or the Nasal surgery heals. The practice of doing a HST even when the patient is not feeling better was discussed; in some cases the apnea is actually resolved but there is another reason for the symptoms, which would require further investigation on the Physicians part. Some clinicians routinely do a baseline HST and then repeat HST over a few different jaw positions after a month of appliance wear to fine tune the final end point calibration.
A number of HST devices were discussed; NOX T3, WatchPat, and Braebon. The clinicians describing their particular device were all very happy with them and reported that final in-lab efficacy sleep studies seemed to co-relate well with outcomes reported by their devices. The most recent AASM “HST” guidelines were published in 2007. Essentially, these guidelines mandate the following requirements for HST, two belts, use of the same biosensors as used for in-lab studies and use of a thermistor (temperature sensor) in addition to pressure cannula airflow. To the best of my knowledge there are only four HST units that meet those guideline standards available in North America, “Braebon”, “NOX T3”, “Embleta” and “Alice PDx”. The MediByte and NOX T3 seemed to have a lower disposable (usage) cost. However, in a clinic with enough volume, the WatchPat can be leased, with virtually unlimited disposable probes, bringing the usage cost down substantially (depending on usage). The benefit of obtaining information about positional apnea was discussed. Knowing if the residual apnea is positional in nature allows the clinician to try placing elastics to prevent mouth opening (if appropriate) or simply counsel the patient on positional therapy if further advancement is not helpful or possible. Of course, the calibration HST is always forwarded to the Sleep Physician for their review. The study of bruxism as it relates to “Flow Limitations” was also mentioned, an area we need to learn more about. It was discussed that “Bruxism” could be documented by both the NOX T3 and Braebon units, and that “Position” could be documented by all three. Regarding Bruxism, end point calibration results in a reduction in the events being caused by the Sleep Disorder, but not the Idiopathic events.
Criteria for use of HST vs. Oximetry aside from cost, was discussed. Sometimes (older populations), blood oxygen desaturates but OSA is mild. An HST is less accurate with milder apnea, so using Oximetry may be a more accurate indicator of calibration endpoint. On the other hand, younger individuals may have more significant apnea but no desaturation, so HST may be more appropriate for these patients.
The political correctness of using HST was also discussed. Some clinicians are using HST less and less, not because they feel it is not useful and not because they and their patients are not curious about effectiveness, but because the Sleep Physicians in their area are all being pushed to use HST by insurance payers. The major coverage in their area requiring HST prior to in-lab studies for most patients; so all the Sleep Physicians have their own HST devices and get paid for using them. So, the potential conflict with the referring Physicians for those Dentists is obvious. In those circumstances, the model of a Dentist providing an HST as part of their over all program (at no additional cost to the patient) does not work when the Sleep Physician will be expecting to repeat what the Dentist has already done at a cost. It’s easy to imagine the patient saying “Why do I have to do that again?” and “Why do I have to pay for it?”, both followed by “It was just done for free by my Dentist!”; not a position any Dentist wanting to build a Sleep Practice wants to be in. It was suggested that clinicians in this political environment best limit their HST use for detailed engineer-types (Analyzers) who really need to see numbers and for those occasional patients who just can't get back to the sleep lab or were referred by a PCP or other Physician where no Sleep Specialist is involved. In some area’s, for instance, Ontario Canada, patients have often already utilized their in-lab sleep study allotment (socialized medicine), often leaving them with no objective evaluation of their appliance for over a year. So, in these cases, a HST provides both the Dentist and the Sleep Physician an objective reporting on outcome with the appliance in place, often relied on until the patient qualifies for an efficacy in-lab sleep study. Finally, if the Sleep Physician is co-operative, they can fee for reading a HST you dispense to establish your end point calibration. This is obviously a highly sensitive subject with regional differences that you must be aware of. It is really unfortunate that efforts on our part to do the best job we can for the patient using the very latest technology has to be dictated by the Physician's needs rather than the Patient's needs. However, it is what it is! (Steve Carstensen, Kent Smith, Erin Elliott, John Viviano, Steve Lamberg, Tony Soileau, Daniel Klauer, Dennis Marangos, Christopher Kelly, David Rawson)
Proponents of the Phonetic bite shared with us that there are minimal adjustments required from insertion to efficacy study, commonly referring back to the physician after just one or no advancement at all. Patients with supine apnea may take longer and may require elastics depending on the appliance style. There was also some heated discussion regarding the use of CBCT to evaluate the airway and the condyles, baseline vs. end point calibration; the overwhelming consensus being concern for excessive radiation exposure. (Dennis Marangos, Daniel Klauer, David Rawson, Steve Lamberg, John Viviano)
It was suggested,
“Sometimes the end point is determined by the health of the TMJ complex, the patient’s willingness to accept and comply with daytime TMJ therapy as well as OAT treatment. These are cases when we must instruct the patient (as we should always be doing) in lifestyle changes such as weight loss, smoking, alcohol use, medications, positional therapy and finally collaboration with MDs.”
Unlike CPAP titration, where the pressure can go much higher than they will ever need to go, we do not have an open-ended ability to calibrate an Oral Appliance, and a healthy TMJ with a good range of motion is helpful in our efforts to establish an acceptable end point. (David Rawson, John Viviano)
Use of the MATRx to establish end point calibration was discussed briefly. There appeared to be little or no first hand experience with it amongst this group. Sustainability of the position established during the sleep study was discussed as a potential issue with this approach. After all, knowing an appliance will work in a certain position is of little use if the patient cannot manage to wear the appliance in that position throughout the sleep period. Also, in the event the MATRx evaluation establishes the patient to be a non-responder, they would be steered away from an Oral Appliance. However, for some CPAP non-compliant patients, the best you are going to get is a partial response with an Oral Appliance, often accompanied by meaningful improvement in symptoms. Using the MATRx model, these patients may never have the opportunity to try an Oral Appliance, and that is unfortunate as an Appliance may be the beginning of a spiral upward toward health due to the increased energy they are likely to experience. The fear of even more CPAP non-compliant patients falling through the cracks and remaining untreated is a real concern. After all, who would be interested in trying an oral appliance if a test told you it wasn’t going to work? Finally, a partial Oral Appliance responder may be a candidate for Combo CPAP / Oral Appliance therapy; the literature showing very effective outcomes with patients that have been intolerant to CPAP and have had incomplete resolution of OSA with an Appliance alone. Patients may be lost to this possibility if they are steered away from trying an Oral Appliance. (Steve Lamberg, John Viviano, David Rawson)
To sum up, it is obvious that we are all trying our best to work to the highest of standards, seeking a balance between risk and benefit, cost and benefit, all the while maintaining a high level of respect regarding what the referring Physician expects of us. Of course, this last point seems to vary greatly from region to region which is directly related to variance in factors such as insurance coverage. David Rawson pointed out that, “sometimes the end point is determined by the health of the TMJ complex”, and that our actual end point may in fact include the use of CPAP along with an Oral Appliance; Combo Therapy. Steve Lamberg summed end point up with the following three requirements:
1) Must be a sustainable appliance/and position
2) Must successfully address Chief Complaints subjectively
3) Must successfully treat some metrics objectively
Once again, I would like to express a heartfelt thanks to all that participated in this discussion. As always, these consensus articles should be considered working documents, meant to guide those clinicians beginning in this field and also present some valuable insights to those of us that have been at it a while. I look forward to future discussions on our SleepDisordersDentistry LinkedIn group!
John Viviano DDS D ABDSM