
4 minute read
The trouble with sleep...
We take an in depth look at how sleep disordered breathing can affect oral health and what can be done about it
Story by Sahil Bareja
Dental professionals, including Dental hygienists, Dental therapists, Oral health therapists, play a crucial role in identifying the link between a patient’s oral and systemic health. Chronic conditions like Diabetes, Arthritis and Cardiovascular disease have been studied extensively in respect to their connection with oral health.
Obstructive Sleep Apnea and the oral health connection has been studied for a number of years, yet very little training is available in dental schools or CPDs to make dental professionals aware of risks associated with sleep apnea and oral health.
An average person living for 75 years and sleeping for eight hours-a-day, would have spent 25 years of their life sleeping. This is equivalent to 9,125 days of 219,000 hours, and yet we continue to give very little importance to sleep.
Sleep disordered breathing (SDB) refers to a range of breathing disorders while asleep, however for the purpose of this article, we will be referring to three main categories: Obstructive Sleep Apnea (OSA), Central Sleep Apnea (CSA) and Complex (mixed) Sleep Apnea.
Research has shown that individuals are 24.1 % more likely to visit their dentist for an annual check-up, as compared to a general physician. Thus, dental professionals are crucial in assessment, identification and in some cases, management of sleep disordered breathing. Dental hygienists/therapists and oral health therapists need to be aware about the effects of SDB on oral health and other potential side effects.
The sleep disorder that is closely related to oral health is Obstructive Sleep Apnea (OSA). By definition, OSA is partial or complete cessation of breathing during sleep due to an obstruction in airways. This obstruction can be both soft tissue obstruction (large tongue, reduced muscle tone, deviated septum, enlarged turbinates and tonsils) or craniofacial/skeletal obstruction (narrow maxilla, constricted maxilla, retrognathic mandible and deviated septum).
A normal human sleep cycle comprises of two states – Rapid Eye Movement (REM) and Non-Rapid Eye Movement (Non-REM) sleep. A humans’ sleep cycle is comprised of different cycles that alternate between Non-REM and REM stages throughout the night, depending on various factors, including age. During middle age, the sleep cycle is a complex mixture of 3-5 cycles of Non-Rem and REM cycles distributed across the night, lasting on an average 90-100 minutes. A typical middle aged sleep cycle comprises of a stage of wakefulness, stage Non-REM (70-80% approximately consisting of stage N1, N2, N3) and stage R (REM sleep) comprising 18-20% of average sleep.
How are sleep apnea and oral health linked?
Systemic inflammation which causes vascular morbidities from OSA is one of the mechanisms linked to periodontal disease. Research suggests that patients with sleep apnea have increased systemic markers of inflammation and increased levels of circulating cytokines. This inflammatory response (which is then readily available) might potentiate disease in individuals who already have inflammatory disease (periodontal disease).
Additionally, symptoms of OSA include chronic and loud snoring and partial obstruction. During sleep, mouth breathing causes decreased saliva production. OSA patients often complain of dry mouth and this further acts as a risk factor for periodontal disease.
Furthermore, treatments to treat OSA; the CPAP (Continuous Positive Airway Pressure) and MAS (Mandibular Advancement Splint) are both associated with xerostomia. CPAP forces high pressure air (through a facial mask) into the oral cavity, while MAS leads to disruption in lip seal, hereby promoting air through the mouth.
OSA can be managed both surgically and non-surgically and the clinician should focus on contributing risk factors, such as history, upper airway imaging and physical examination when formulating a treatment modality for a patient.
Patients suspected of SDB should be assessed through the following process:
Clinical tools
The increase in current obesity trends would cause the workload of sleep clinics to increase; therefore, predictors of SDB are required to allow both recognition and prioritisation of SDB within populations. Tools available to evaluate SDB include both Subjective Tools (which can be used in dental clinics) and Objective Tools. Subjective tools include the Epsworth Sleepiness Scale (ESS), the Karolinska Sleepiness Scale and the STOP-Bang Questionnaire. Objective tools are those such as the Multiple Sleep Latency Test and Multiple Wakefulness Test.
Following presentation of sleep history, clinicians should utilise these clinical tools, such as the STOP-Bang Questionnaire and ESS to determine the need for further evaluation, such as polysomnography(PSG)
Physical Examination
Clinical tools should be used in conjunction with physical examination when determining the need for PSG. Physical examination for OSA should be targeted to Body Mass Index (BMI), presence of anatomical factors such as retrognathia, or palatal abnormalities, nasal passages, neck circumference, placement of hyoid bone and oropharyngeal area (macroglossia).
The classic four risk factors associated with SDB post adenotonsillectomy in children are;
• enlarged nasal inferior turbinates
• retro placement of mandible
• nasal septum deviation
• Mellampati score three or four.
Mellampati score has been considered the most important exam predictor of both presence and persistence of SDB post surgery with 98.2% children having incomplete symptoms controlled. Incidence of OSA peaks between the ages 2-8 years when adenotonsillar hypertrophy is prominent, therefore physical examination for children should include adenotonsillar assessment. Enlarged tonsils, adenoids and obesity are among the largest risk factors associated with SDB in children, with 37-66% prevalence of SDB reported in Obese children. Therefore, physical examination highlighting thick neck circumference, retrognathic jaw, high BMI, macroglossia should be investigated further through the use of PSG or at home sleep study.
Treatments
Treatment for SDB varies according to age, for example, Tonsilloadenoidectomy often has been first line of treatment to treat SDB in children, while adult treatments include behavioral modifications, oral appliance therapy, surgical therapy, CPAP/ BPAP and topical/oral agents.
Obesity is a major factor of OSA, so a weight loss program should be considered when modulating a treatment plan for OSA.
Oral appliance therapy customised for a patients’ mouth can help in treatment of mild to moderate OSA, while CPAP and Bilevel Positive Airway Pressure (BPAP) help treat severe OSA and in some CSA cases.
Dental practitioners need to be familiar with basic sleep disorders and understand the basic theory of how sleep affects oral health. Sleep patterns differ across different ages and practitioners can identify risk factors associated with different age groups and how it affects craniofacial development.