Sleep Disordered Breathing (SDB) has become a chronic disease affecting more than 50% of US adults, according to the Foundation for Airway Health (FAH). Today, only 15% of patients with SDB are diagnosed. Untreated, it can lead to an increased risk of cardiovascular disease, stroke, and numerous other co-morbidities. It has become a goal of the FAH to dramatically increase the awareness, education, and treatment of sleep breathing disorders. To facilitate this end, they have called on the medical and dental community to come together and increase the education process both at the undergraduate and graduate levels. This includes the collaboration of both dentists and physicians to work in consort, with their patients who present with symptoms of SDB. The author, as an assistant professor, recognized that there was a sparsity of education at the pre-doctoral student level in most dental schools around the country. Therefore, it was set as a goal to increase the education in SDB here at the University of Texas at Houston School of Dentistry. The following case represents a step in the right direction to reach that end.
The following patient was referred to the pre-doctoral student clinic at the University of Texas Health Science Center at Houston School of Dentistry. She is a 71 year old female, 5’5” tall, weighing 172 lb. Her BMI is 21. Her medical history was significant for hypertension that is uncontrolled by current medication. She also reported a history of gastric reflux and seasonal allergies. The patient is taking hydrochlorothiazide, valsartan, solifenacin succinate, rantidine, estradiol, and fluticasone. Her chief complaint included a history of loud snoring, witnessed apnea, and daytime hypersomnolence, and bruxism. The reason she sought a consultation with a sleep physician was due to an avoidable complication she had while undergoing IV sedation for out- patient surgery in mid-2014. She suspected for years that she might have a sleep disorder, due to her nighttime snoring and witnessed pauses in breathing. She neglected to report this to her surgeon and anesthesiologist prior to having IV sedation for an outpatient procedure. She stopped breathing during the procedure and had to be resuscitated. The patient considered this episode a wake-up call and pursued the consultation with a sleep physician.
Figure 1: Protrusive bite record with George Gauge
She had an overnight polysomnography at Medical Clinic of Houston, Sleep Disorders Centeron 02/11/2015, upon which she was diagnosed with severe obstructive sleep apnea: AHI was 72.0, RDI 84.0, and Oxygen nadir of 87%. She spent 0% of the sleep test in REM and 0% in slow wave sleep, with 70% of the sleep test in N1 sleep, suggesting very poor-quality sleep. She was subsequently put on CPAP but could not tolerate any kind of mask on her face. Since she was already a patient of record at UTSD, Dr. Levine was asked to evaluate her for oral appliance therapy(OAT) as an alternative treatment.
When evaluating a patient for OAT who has been diagnosed with severe OSA, it is incumbent on the novice dentist torecognize individual patient phenotypes that would have an effect on treatment success. This can only be accomplished with a thorough clinical exam. Predicting success with OAT should be a part of the evaluation process for each patient that is screened for sleep disordered breathing. Every patient should be made aware that the general efficacy of OAT over all diagnoses of mild to severe is 51- 80%. Therefore, the dentist and patient will not enter into treatment with false expectations.
As part of the initial process before proceeding with a thorough clinic exam, a copy of the PSG was requested along with a prescription from the sleep physician to proceed with OAT. It is important for the overall success of OAT to collaborate with the referring sleep physician. The Texas State Dental Board requires collaboration with a licensed physician. The treating dentist can obtain valuable information from the sleep study to help predict successful outcomes with OAT, including sleep architecture, time spent below 90% oxygen saturation, amount of time spent in REM and N-3, and sleep position. Studies have shown that a patient with positional OSA has a better chance of successful treatment with OAT than a patient without it. This information can only be obtained by looking at the sleep study. I would encourage all dentists to ask for a copy of the sleep study and learn how to interpret the findings.
Figure 3: AM aligner
She was screened in the student clinic on 11/09/16. At that time, she was found to be a good candidate for OAT. She had a healthy dentition except for moderate wear from a life long history of bruxism, a healthy periodontium, and good range of motion. Her arch width was narrow, in both mandible and maxilla, with a high palatal vault, retrognathic chin, and very large mandibular tori taking up much of her tongue space. A complete muscle, TMJ, and range of motion examination was documented prior to initiating treatment to record baseline data. She signed an informed consent specifically for OAT and was given the opportunity to ask questions. It was stressed that she will need to return to her sleep physician for a post titration sleep test after subjective symptoms are alleviated with the oral appliance.
Full arch impressions were taken with Identium (Kettenbach USA) and a protrusive bite record at 60% of maximum was recorded with a George Gauge. A Narval (ResMed) appliance was chosen to match patient details. It is structurally smaller than some of the others, as this patient has a very small mouth with narrow arches and large mandibular tori. The protrusive adjustments are on the side, and does not interfere with her limited tongue space. It is also a sturdy and robust appliance that will resist the forces of bruxism. It uses replaceable side straps that are calibrated to be .5mm difference in length. The appliance was delivered on 01/18/17. Upon insertion, it was noted that there was not enough retention on the lower arch. I used a flameless torch to heat the lingual flange to obtain more retention. The device came with a 27mm strap in place and I advanced her mandible using the 24.0 mm strap.
This seemed to be a comfortable amount of protrusion to begin. The patient noted that she is a mouth breather and has trouble keeping her mouth closed at night. She could very easily open wide enough to dislodge the appliance from her lower arch. I first placed a lower tension rubber band on both sides of the appliance and she still reported that it dislodged with ease. So, I replaced the rubber bands with one that had more tension, 8oz., and this seemed to work well. I constructed a morning aligner using a preformed horseshoe shape of Thermacryl (AM Aligner, Airway Lab). The patient was informed of the proper use and maintenance of both the appliance and aligner.
She was told that the aligner will help prevent permanent protrusion of her mandible, but she will likely have long term craniofacial changes that include changes in overbite and overjet and minor teeth movement. It was recommended she use Retainer Brite (Dentsply) to clean her appliance. The patient was told to return for a follow up in 2-3 weeks for a follow up appointment. She left very satisfied and excited to start treatment. This delivery re-emphasized to me the importance of examining the teeth to determine the proper appliance.
The Narval requires more retention on the posterior teeth than other appliances do. The contours of this patient’s posterior teeth only had moderate retentive contours, so I had to increase the retention by heating the flanges and reshaping them. This is not as easily accomplished with this appliance as it is with others. In addition, the patient had much trouble keeping her mouth closed at night while sleeping. She required rubber bands with an increased amount of tension to help keep her mouth closed. Fortunately, being at the dental school, I had access to a variety of rubber bands.
Figure 5. Note: lack of tongue space
The patient returned for her first follow up on 02/22/2017. She reported that she was extremely happy with alleviation of her subjective symptoms. She only reported mild snoring on 2-3 occasions and no longer was suffering from daytime fatigue. She found the rubber bands to be very useful and wanted to continue using them. She is compliant with her morning aligner and her bite was stable. She had no masticatory muscle soreness nor any TMD issues. Due to residual light snoring, I protruded her mandible 1.5 mm using the 22.5 strap. The patient left happy and shared with me that her husband was most satisfied at her greatly reduced amount of snoring. I told her we will follow up in another 2-3 weeks, and if she is doing well, I will recommend she go back to her sleep physician for a post titration sleep test to confirm efficacy of her oral appliance. The patient was not able to make an appointment for another follow up, but we spoke on the phone and she said that she was continuing to do very well with her appliance. So, I decided to leave her appliance at the current amount of protrusion and send her back to her sleep physician for a sleep test. She subsequently got very busy and was not able to schedule a sleep test until 06/27/2017. I received the results of the PSG on 07/11/2017. This post titration PSG showed an AHI of 3.2, an RDI of 4.6, and O2 Nadir of 86% and T90 was less than 1%. The hypnogram revealed two brief dips to 86% oxygen saturation, remaining above 90% the rest of the night.
Mild snoring was reported during this sleep study and it was suggested by her sleep physician to try and sleep in a non-supine position. She spent 76.3 % of her PSG in a supine position. Part of dental sleep medicine is to council our patients on other aspects of sleep disordered breathing such as sleep position. Positional therapy is an important component in the overall success of treating a patient with OSA.
The patient will be scheduled for another follow up in approximately 6 months, to monitor structural integrity of her appliance and morning aligner, any return of subjective symptoms, side effects, and changes in occlusion. After that, yearly follow ups will be recommended. This was a patient who was diagnosed with severe OSA and subsequently failed CPAP therapy. She was screened in the pre-doctoral student clinic at the University of Texas at Houston School of Dentistry. She was subsequently deemed to be a candidate for oral appliance therapy and impressions and a bite record were taken. The appliance was delivered and follow ups with appropriate titrations were performed. After titration was complete, the patient returned for a post titration PSG. The results showed successful treatment with an oral appliance according to AASM and AADSM parameters of care. This included alleviation of subjective symptoms and a reduction of AHI below 5. The patient was very happy and felt a vast improvement in her quality of life. Oral appliance therapy is a recommended treatment for patients who fail CPAP after being diagnosed with severe OSA. Studies have shown that CPAP is superior to OAT for lowering AHI and raising blood oxygen levels. However, compliance with CPAP has always been an issue that must be addressed. This case demonstrated the effectiveness of OAT for severe OSA. This does not insinuate that all cases of severe OSA can be successfully treated with OAT, but it should be considered as a viable alternative in cases of non-compliance of CPAP. It is important for clinicians to recognize the clinical factors that will lead to a successful outcome with OAT. This can only come with proper education and an understanding of the principles of airway management.
This represents the first case of OAT performed in the pre-doctoral student clinic at the University of Texas at Houston School of Dentistry. It involved a senior dental student after successfully completing 16 hours of additional education in sleep disordered breathing as an elective course at this school. This author recognizes that the education of all dentists in the field of sleep disordered breathing must start at the pre-doctoral student level. It should be incumbent on all dental schools throughout the country to teach courses in dental sleep medicine. This institution is at the forefront of this education process both at the pre-doctoral andpost graduate level. I hope to expand our program here to heighten the awareness of the importance of recognizing sleep disordered breathing in every patient. To date, it is said that only 15% of patients with SDB will be referred to a sleep physician for consultation. Untreated OSA represents a significant risk for cardiovascular events, along with a host of additional co-morbidities. We are doing our part at this institution to help rectify this. It is estimated that over 40 million Americans may suffer from sleep disordered breathing. The future of our profession should see a significant increase in the awareness, education, and treatment of SDB. This is a challenge that I embrace and look forward to.
The patient left happy and shared with me that her husband was most
satisfied at her greatly reduced amount of snoring
Appreciation is given to the University of Texas at Houston School of Dentistry, Department of General Dentisty and Dental Public Health, chaired by Gary Frey DDS. Recognition is given to Tom Guu, senior dental student and Debra Stewart DDS, group practice director, UTSD.