M2 work by pushing or pulling your lower jaw forward. By doing this, your tongue is kept in a position that does not block your airway. This reduces the risk of snoring or that your tongue may obstruct your  airway during sleep. If this device is helping you, the sound of snoring should be gone entirely or lessened.

As with all treatments, not everyone gets the same benefit from oral appliances. For some, the OSA and snoring go away completely, while for other people, other forms of treatment are needed. Oral appliances are more likely to work if you have mild or moderate sleep apnea; more recent evidence supports use for some people with severe sleep apnea as well. If your sleep apnea gets better when you lie on your side (compared to sleeping on your back) and if you are not overweight, you are also more likely to benefit from this appliance. If you have central sleep apnea (a less common condition than OSA), then oral appliances are unlikely to be helpful. Until you have been properly fitted for an oral appliance and tried it, no one can know how well it will work for you.

CPAP (Continuous Positive Airway Pressure) is a reliable treatment for sleep apnea. Immediate results are typically seen with CPAP regardless of how bad the sleep apnea is. An oral appliance will usually improve your sleep apnea, but may not completely control it. If you have moderate or severe OSA, CPAP is more likely to work to correct your sleep apnea than an oral appliance. 

However, an oral appliance may be a better option than no treatment at all if you cannot tolerate CPAP. M2 are also not the main therapy if you have significant heart disease or are very sleepy during the day. In these cases, CPAP is the best treatment. A sleep specialist can provide guidance regarding the most appropriate therapy for you. For more information see the ATS Patient information series piece on “Continuous Positive Airway Pressure for Adults with Obstructive Sleep Apnea” at www.thoracic.org/patients.

If fitted well, the oral appliance should be comfortable during the night. However, because it acts to push your jaw forward, some people feel discomfort when first using the appliance. This discomfort tends to improve as you use it more. If discomfort happens, it is usually in the joint at the back of your jaw, just in front of the ear (the temporomandibular joint). This discomfort should go away when you take the appliance out in the morning.

Also, oral appliances may cause increased saliva in your mouth, or make your teeth feel tender. These symptoms usually settle down quickly the more you use the device. Over time, there may be tooth movement, changes in your bite, or problems with the joint and muscles of your jaw. It is important to have regular follow-up visits with the dentist who supplied you with the appliance to detect and manage problems early.