Sleep Bruxism & Obstructive Sleep Apnea
Obstructive Sleep Apnea (OSA) is a condition that has received an unprecedented level of attention over the past decade. The health implications of OSA are life
altering and life threatening. A growing body of research is linking OSA to heart attacks and strokes and other associated health risks.
Recent research has demonstrated that sleep bruxism or clenching may occur asa mechanism to prevent airway collapse.1
Bruxism has been classified by the American Academy of Sleep Medicine as a “Sleep related movement disorder”. Sleep apnea induced bruxism can have significant implications for standard dental procedures. When major dental restorative procedures are contemplated, the identification of bruxing patients who suffer from OSA becomes andeven more compelling objective.
The following CT scans of a sleep apnea patient’s airway response to clenching are very revealing. Top Figure – the resting airway, Middle Figure -the airway in a simulated sleep apnea event (Mueller maneuver), Bottom Figure – the very same airway during clenching. As the airway is collapsing during sleep the brain initiates clenching and grinding as a subconscious mechanical technique to open the airway and improve breathing.
This “reflex action” may go a long way to explain the often puzzling bruxism we see in children. If a child has large and extended tonsils that block the airway it is quite natural to expect that the child will resort to clenching, grinding and tongue thrusting to relieve the blockage.
Dentistry’s typical protocol to address bruxism is the fabrication of a night guard. However, research conducted at
the University of Montreal indicates that night guards have the potential to increase existing sleep apnea by a factor of 50% for half of the OSA patients.2 For patients with moderate sleep apnea, increasing their sleep apnea by such a factor could lead them to a level of “severe” sleep apnea, thus potentially placing the life of the patient at risk.According to a survey conducted by the Public Health Agency of Canada over 1 in 4 (26%) adultsreported symptoms and risk factors that are associated with a high risk of having or developing obstructive sleep apnea.
With simple screening techniques we are able to uncover patients who may suffer from OSA. Loud snoring is the earliest sign of a blocked airway. You may be surprised at how often questions about snoring will lead to the next questions “do you stop breathing at night?”, and “are you sleepy during theday”. A yes answer to any of these questions is a good indication for further assessment.
Validated questionnaires may be used to assist in the identification of potential sleep apnea patients.An example of these is the STOP Questionnaire.3 This questionnaire uses the following four simple questions, with two or more positive answers returning a “high risk” result.
- Snoring: Do you snore loudly (loud enough to be heard through closed doors)?
- Do you often feel tired, fatigued or sleepy during the daytime?
- Has anyone observed you stop breathing during your sleep?
- Do you have or are you being treated for high blood pressure?
In February of 2006 the American Academy of Sleep Medicine issued a position paper on the efficacy of Oral Appliance Therapy that recommended “Oral appliances are indicated for use in patients with mild to moderate OSA who prefer them to continuous positive airway pressure (CPAP) therapy, or who do not respond to, are not appropriate candidates for, or who fail treatment attempts with CPAP”.
Recommendations also included the requirement of “serious training” for dentists undertaking oral appliance therapy for their patients. As with many other areas of dental practice, dentists routinely evaluate seeking additional training as required to directly provide a procedure to our patients, or we refer to practitioners specializing in that field. As a “Best Practices” approach towards overall patient health the profession of dentistry has an opportunity and responsibility to address obstructive sleep apnea and related sleep bruxism.
1 47. Simmons JH, Prehn R, Airway protection: the missing link between nocturnal bruxism and obstructive sleep apnea. Sleep 32(abstract suppl):A218, 2009.
48. Simmons JH, Prehn R, Nocturnal bruxism as a protective mechanism against obstructive breathing during sleep. Sleep 31(abstract suppl):A199, 2008.
49. Prehn R, Simmons JH, Prevalence of sleep-disordered breathing (SDB) in patients with temporal mandibular joint disease (TMD). Sleep 34(abstract suppl):A125, 2011.
2 Aggravation of Respiratory Disturbances by the use of an Occlusal Splint in Apneic Patients: A Pilot Study – Yves Gagnon DM/Pierre Mayer, MD/Florence Morisson, DMD, PhD/Pierre H. Rom-pre, MSc/Gilles J. Lavigne, DMD, MSc, PhD.
3 STOP Questionnaire – A Tool to Screen Patients for Obstructive Sleep Apnea, Anesthesiology 2008; 108:812–21 Frances Chung, F.R.C.P.C.,* Balaji Yegneswaran, M.B.B.S.,† Pu Liao, M.D.,‡ Sharon A. Chung, Ph.D.,§ Santhira Vairavanathan, M.B.B.S., Sazzadul Islam, M.Sc., Ali Khajehdehi, M.D.,† Colin M. Shapiro, F.R.C.P.C.
He is the Past-President of The Canadian Dental Association (CDA) and The Association of Dental Surgeons of British Columbia (BC Dental Association). He has served as a member of the Board of Governors and a Director of the CDA.
Currently an Adjunct Professor, Respiratory Therapy at Thompson Rivers University, Dr. Halstrom has also served with the University of British Columbia as a part-time clinical instructor in the Department of Prosthodontics at various times over the years. Prior to his position of Diplomate of the American Board of Dental Sleep Medicines, he was a member of the Joint Medical-Dental sleep research team from 1989 to 1993, and carried a rank of Clinical Assistant Professor.