NMDA Journal Summer 2019

nmdental.org 17 If you haven’t heard, the recent buzzword across the entire healthcare industrial complex lately is “sleep medicine,” and pertaining to us dentists is “sleep dentistry.” This, contrary to what it sounds like, is not a dentist’s version of sleep walking nor doing dental work in your sleep; nor is it doing dentistry when the patient is asleep. Sleep dentistry addresses the role a dentist can and should play in all of our patient’s overall health by identifying the signs and symptoms of sleep apnea or sleep related breathing disorders. The role that sleep plays in our day-to-day lives and health is huge, which shouldn’t sound surprising because it is an activity that should take up approximately one-third of our lives. It is easy to say that the physiologic systems that are vital to overall health that occur during normal, healthy sleep comprise at least, if not more, than one-third of the whole equation to keep one’s body“healthy.” We don’t think of sleep being as important as other “vital” health needs, but compare lack of sleep with lack of food. The body can function without food for days and weeks on end; without sleep the body starts to break down and lose its ability to function properly much faster. The main physiological process that we are addressing when we are talking about“sleep den- tistry”is breathing or the lack thereof. So, let’s discuss the ways that we as dentists can help get our patients get their normal healthy sleep by both identifying the signs and symptoms of sleep related breathing dis- orders, understanding the effects on the body that happens if these are overlooked, and working together with physicians and other healthcare providers to get them the help and treatment they need. Healthy Sleep Let us all first understand what our sleep is and also what it does for our health. First off, let’s remember that we need to be breathing normally during our sleep to actually stay asleep. It is best for the majority of our breathing to be nasal breathing, so air ideally goes in through our nasal turbinates. This process aids in converting oxygen to nitric oxide, a key vasodilator. This air passes through the relaxed soft tissue structures of our airway and into our lungs. Our sleep is comprised of different sleep stages and cycles. There are four stages of a single sleep cycle and we should complete about 6–7 sleep cycles; non-REM sleep has 3 stages, which comprises 75% of total sleep, and REM which makes up the remaining 25%. Within non-REM sleep, there is stage 1, 2, and 3 with the most crucial stage to reach being the stage 3 or deep sleep. This should be 25% of our total, normal sleep cycle, and it is when our body systems are going into their prime reset mode. After these stages one enters into REM sleep; this is where we get our “dreaming” sleep, and it is also where our memory centers are processing all of our brain’s input into long-term memory storage. All of these stages make up one sleep cycle and there should be about 6–7 cycles per night of sleep. A huge part of our sleep physiology is our body’s hormone regulation and chemistry checks and balances. Human growth hormone (HGH) is released during sleep. Anti-diuretic hormone is released, which is why bed-wetting (especially in children) is often a sign that proper sleep is not being achieved. Hormones that control hunger and digestion such as leptin and ghrelin are regulated in sleep; during lack of sleep, leptin levels are decreased and ghrelin is increased leading to more unnecessary feelings of hunger. Other key systems that are regulated and promoted during sleep are our immune systems and memory centers. One large area of research has identified a significant role of cumulative lack of sleep correlating to dementia. During our REM sleep our body is able to clear our brain of built up excess beta- amyloid proteins from a process called a meningeal wash. When this wash does not occur, the proteins accumulate and inhibit normal brain signaling and conduction. This would normally be the time that your memory would be taking all the input that your brain took in for the day and files it away into long-term memory, but without REM sleep these memories never make it to long-term memory. Unhealthy Sleep Now let’s discuss the primary way that this normal process of sleep is being disrupted. The big word here is sleep apnea. There are two types of sleep apnea, obstructive sleep apnea and central sleep apnea. Ob- structive is where the airway is partially or completely blocked by the individual’s own soft tissue anatomy thus preventing the individual from breathing adequately. Sidenote: This is not “holding your breath” during sleep! This is the type of apnea that can be addressed by den- tists with oral appliances, orthodontics, and oral surgery to open the airway. Central apnea is the unexplained phenomena of the brain sim- ply not giving the signals to the muscles to breath during sleep, even though the airway may be clear and open. Central apnea needs to be treated with a CPAP to force air into the lungs. It is important to note that these are not mutually exclusive diagnoses as patients can have both types of apnea. You may be wondering are we more concerned about sleeping or are we concerned about breathing? Let’s look at the whole equation this way: We need to be sleeping in order to get through each stage of our sleep. Each of those stages has a purpose where something chemically and physiologically important is happen- ing, and they all happen chronologically. And in order to stay sleeping we need to breathe. If you stop breathing then your body will wake itself up in order to get a breath in. In general, an obstruction (or lack of central signal) leads to apnea which leads to hypoxia which leads to sleep arousal which leads to a disturbance in the sleep cycle. 18% of men and 8% of women from ages 30–70 have some form of OSA. Only about 10% of these people have been diagnosed. Sleep Apnea Facts These are some statistics of the population in the US and sleep apnea: 18% of men and 8% of women from ages 30–70 have some form of OSA. (*National Healthy Sleep Awareness Project American Academy of Sleep Medicine, September 2014). Only about 10% continues on page 18 