Sleep apnea and caries
There is no direct link between sleep apnea and caries, but mouth breathing caused by sleep apnea affects the occurrence of caries. When breathing is difficult, the intake of breathing air is ensured by opening the mouth. Oral respiration has been found to affect the microbial composition of the mouth, causing caries.
As a result of mouth breathing, the oral mucous membranes dry out. Induced dry mouth is the most commonly reported oral symptom in sleep apnea patients. In one control study, there were 668 subjects, of whom 541 were sleep apnea patients and 127 were snorers.
They underwent a sleep polysomnography study and a questionnaire survey to determine sleep patterns and symptoms as well as general health. Dry mouth occurred in sleep apnea patients from 22.4% to 40.7% depending on the degree of disease, when the corresponding percentage in the control group was only 3.2%.
Sleep apnea and gingivitis
A 2012 study in Turkey examined the association between dental symptoms, oral health behaviors, type 2 diabetes, obesity, and sleep apnea patients with type 2 diabetes. The study involved 165 people aged 30–65 years, whose data were clarified using a patient information system and a survey. Sleep apnea patients were found to be at increased risk for gingivitis and tooth defects. One risk factor is mouth breathing, which often affects sleep apnea patients and affects the microbial composition of the mouth, causing gingivitis.
One study looked at the link between obstructive sleep apnea and periodontitis, a disease of the connective tissue in the teeth. The result states that obstructive sleep apnea and periodontitis have many similarities. Both diseases are closely related to systemic inflammation and thus to the incidence of cardiovascular disease. Thus, it can be assumed that periodontitis is more common in people with obstructive sleep apnea than in healthy people. There is no research evidence for this, but there are three possible grounds for the connection. First, obstructive sleep apnea contributes to the systemic inflammatory state and increases the incidence of periodontitis. Second, periodontitis may be a major mediator of inflammation. As a third argument, it can be argued that periodontitis may be an unknown factor between obstructive sleep apnea and cardiovascular disease.
Sleep apnea and bite problems
Mouth breathing also has its own effects on the bite. This is a significant factor, especially in children with sleep apnea, who are still in the process of developing a bite. In a child breathing through the mouth, the tongue is low and the width of the mouth is abnormal. This causes the tongue to push forward as the child swallows as it should push towards the palate. The abnormally functioning tongue moves the lower jaw backwards, thus causing incorrect positions of the teeth and interfering with the normal growth of the face. Mouth breathing also affects the position of the head and neck, causing the position of the head tilted forward. This can be a cause of headaches and jaw joint problems.
A thesis published in 2011 examined the connection of nocturnal breathing problems and facial and jaw growth, bite development, and upper airway structure in children. The study included 70 children who had been hospitalized for more than six months due to snoring or nocturnal breathing problems. Children were diagnosed with nocturnal breathing problems in 2000–2002. Healthy children of the same sex and age who did not have any nocturnal breathing problems were used as controls. All children were examined by both an orthodontist and an ear, nose, and throat specialist, as well as by lateral skull imaging and plaster model replicas of the teeth.
The study found that patients with obstructive sleep apnea had significantly more bite defects than healthy children. The horizontal overbite was increased, the vertical overbite was reduced, the upper jaw was narrower, and the lower tooth arch was shorter. Anterior open bite occurred more frequently, as did Angle II or asymmetric molar ratio. Sleep apnea was also found to have an effect on the development of head structures. In children with sleep apnea, the lower jaw was more often posterior and the face height lower. The soft palate was longer and thicker, the lingual bone was lower, and the position of the head was elevated.
How does sleep apnea treatment affect oral health?
Sleep apnea mouthpiece
The sleep apnea mouthpiece improves the quality of life of many patients, but its use has several side effects, both short-term and long-term. Short-term side effects reported in many studies include increased salivation with the instrument in the mouth and tenderness in the teeth and jaw joints. Headaches and gnashing of teeth may also occur. The mucous membranes are affected by sleep apnea mouthpiece, causing dry mouth and irritation. In a toothless mouth, the mouthpiece causes depressions on the alveolar ridge. However, as treatment continues, these symptoms become insignificant for the most part.
A 2009 study examined subjective and objective assessments of short-term adverse events by sleep apnea mouthpiece users. The study included 12 individuals whose bite sensation, bite force, chewing surface contact area, and muscle fatigue were measured for four hours every 15 minutes both with and without mouthpiece after a night of sleep. The most significant side effects according to the study were abnormal biting, which afflicted an average of 90 minutes after removal of the mouthpiece, as well as decreased biting force lasting for 15 minutes after use of the mouthpiece.
The use of a sleep apnea mouthpiece can cause the patient various bite changes. According to one study, 14% of sleep apnea mouthpiece users showed changes in overbite from one to three millimeters after five years of use. According to one article, about one-fifth of those using a sleep apnea mouthpiece had a bite more than a millimeter after two years of treatment. Studies have also reported changes in bite ratios and lower jaw position. Sleep apnea mouthpiece users have been found to have increased face height, increased maximal mouth opening, and anterior teeth tilt. Bite-related side effects can be prevented with soft plastic devices with protrusions over the alveolar ridges, less forward jaw forward, and less use of the instrument. Side effects are minor, if the patient has a deep bite and they often decrease after stopping treatment.
The effect of CPAP treatment on oral health
A Japanese study investigated the incidence of oral symptoms and interest in sleep apnea mouthpiece treatment in CPAP patients. 744 people participated in the survey. According to the results, oral symptoms occurred in 39.4% of the respondents. 10.7% felt that they had started suffering from halitosis, a bad breath after starting CPAP treatment. There were an equal number of people suffering from bleeding gums.
However, dry mouth was the most common symptom; it occurred in 44.6% of patients. One dissertation study published in 2013 found that more than half of CPAP patients suffered from dry mouth.
The effect of surgical treatment on oral health
Oral and maxillofacial surgery for sleep apnea patients is often extensive and could be expected to have a significant impact on the patient’s oral health and quality of life. However, there are only few studies that have addressed this issue. The only mention found in the side effects of surgical treatment was related to extensive UPPP surgery. It was found to cause dry throat, difficulty swallowing and speaking, and changes in sound.
Effect of orthodontics on breathing problems
The study, published by Manuela Mandu in 2011, aimed to describe the prevalence and risk factors for nocturnal breathing problems in children and adolescents who have received orthodontic treatment. In addition, the effects of different orthodontic treatment methods on the symptoms of nocturnal breathing problems were investigated.
The study population consisted of 168 children and young people, who were in orthodontics at the University of Montreal Orthodontics Clinic. who received orthodontic treatment at the University of Montreal Orthodontic Clinic. Questionnaire and clinical study were used as research methods. 17.5% of the subjects had jaw joint sounds, 6% with jaw locks and 9.7% with masseter pain. 35.9% of respondents reported biting their teeth against each other while awake. Bruxism occurred in 14.5%. Horizontal and vertical overbite had increased, as did upper and lower jaw stenosis.
The effect of sleep apnea medication on oral health
One of the side effects of modafinil used to treat sleep apnea is dry mouth. Likewise, thyroxine, antihypertensives, topical steroids, and antidepressants commonly used by sleep apnea patients may dry out the mouth. In addition, it is known that the continuous use of three drugs already reduces salivation.