Two bacterial diseases are the leading causes of tooth loss. One is dental caries (tooth decay), and the other is periodontitis (gum disease). Periodontitis affects all of the tissues that hold the tooth in place—the gum, periodontal ligament and the jaw bone itself. Over time, these tissues are destroyed by toxins produced by the bacterial infection and by the immune system’s inflammatory response to fight that infection. Nearly half of American adults aged 30 years or older have some level of chronic periodontitis. About 9% have a severe form of the disease.
Periodontitis is linked to other diseases with an inflammatory basis, such as heart disease and type 2 diabetes. My colleagues and I recently conducted research showing that periodontitis is more common in people with sleep-disordered breathing. In a study published in 2015, we assessed over 12,000 participants in the Hispanic Community Health Study (HCHS)/Study of Latinos. We determined the presence of periodontitis using a standardized oral examination and measured sleep apnea using home sleep studies. We found that people who had as few as one or two breathing pauses (apnea or hypopnea events) per hour of sleep were about 50% more likely to have severe periodontitis than people with no apnea or hypopnea events. This association between apneas/hypopneas and periodontitis appeared to be especially pronounced in young adults.
One possible explanation for the association between sleep-disordered breathing and periodontitis is dry mouth. In normal conditions, saliva cleanses the mouth of debris, regulates the acidity of dental plaque, and has a direct antibacterial activity. If the mouth becomes dry, these protective functions are impaired, leading to increased risk for bacterial infections. Mouth-breathing during sleep can lead to dry mouth. Many people who snore or who have sleep-disordered breathing such as sleep apnea—even mild forms—are mouth breathers during sleep. These findings highlight the possible benefit to oral health of treating sleep apnea. Use of CPAP and oral devices that move the jaw forward usually rely on nose breathing. For CPAP users, use of a humidifier may help reduce mouth drying and help reduce the risk of periodontitis.
This study raises some important questions that we hope will be answered by future research. For example:
Does treatment of sleep apnea prevent periodontitis?
If so, which treatments for sleep apnea may be best for preventing periodontitis?
If CPAP helps to prevent periodontitis, does the use of a CPAP humidifier provide additional protection?
While mouth-breathing seems a logical explanation for the association between sleep apnea and periodontitis, can this link be confirmed by further research?
Are there other mechanisms that explain the apparent association between sleep apnea and periodontitis? (For example, does sleep apnea also affect the ability of the immune system to fight bacterial infection?)
Is the association between sleep apnea and periodontitis similarly strong among different ethnic groups?
Temporomandibular disorder (TMD) is a painful musculoskeletal condition affecting the muscles surrounding the jaw point and the jaw itself. Pain and discomfort can be felt in the face, jaw and ear regions as well as around the neck and shoulders. The disorder affects between 5 and 12% of the population. The causes of TMD are not well understood. In studies of a large national sample of volunteers participating in the Orofacial Pain Prospective Evaluation and Risk Assessment (OPPERA) study, we asked whether individuals with a history of sleep apnea or symptoms of suggestive of sleep apnea such as loud snoring were at increased risk of developing TMD.
We studied over 3,000 people. We found that people who entered the study with sleep apnea symptoms were more than 3 times as likely to develop TMD over the next three years than were those without TMD symptoms. This suggests that sleep apnea is a risk factor in causing TMD.
We are still investigating why sleep apnea increases risk of TMD. One idea is that sleep apnea, by contributing to abnormalities in the autonomic nervous system and inflammation, may sensitize pain centers, making any pain, including that from TMD, more prominent. Another possibility is that sleep apnea may contribute to bruxism, or teeth grinding, which can trigger TMD.
We need more research to understand the ways sleep apnea and pain relate to one another and whether sleep apnea treatment can help with general pain management, as well as reduce risk of severity of TMD, as well as other pain syndromes.
The research described by Dr. Sanders highlights the links between oral health and sleep apnea. These associations have not been recognized commonly by patients or clinicians. Dentists can play an important role in helping to recognize sleep apnea. Dentists may consider further asking patients with dry mouth, periodontitis or TMD about symptoms of sleep apnea. Patients with symptoms of dry mouth, periodontitis or TMD also should consider whether they have symptoms of sleep apnea -- including loud snoring and poor sleep quality- and discuss this with their health care providers.
David Keepnews, PhD, JD, RN, NEA-BC, FAAN, Patient Engagement Panel member, and Susan Redline, MD, MPH
Sanders AE, Essick GK, Beck JD, Cai J, Beaver S, Finlayson TL, Zee PC, Loredo JS, Singer RH, Jiminez MC, Barnhardt JM, Redline S. Periodontitis and Sleep Disordered Breathing in the Hispanic Community Health Study/Study of Latinos. Sleep. 2015 Aug 1;38(8):1195-203.
Sanders AE, Essick GK, Fillingim R, Knott C, Ohrbach R, Greenspan JD, Diatchenko L, Maixner W, Dubner R, Bair E, Miller VE, Slade GD.Sleep apnea symptoms and risk of temporomandibular disorder: OPPERA cohort.J Dent Res. 2013 Jul;92(7 Suppl):70S-7S. do
My colleague Dr. Essick and I discuss the results of this study at this link: https://www.youtube.com/watch?v=I6-fyqwTd5o
Head anatomy diagram is from "Head Anatomy TMJ NO Labels" by TILT University of Dundee and licensed under CC BY-NC-ND 4.0.
This article was written by Dr. Anne Sanders, PhD, Associate Professor at the University of North Carolina Chapel Hill School of Dentistry.
