Side Effects of MAD Therapy

MAD therapy may have a number of side effects that some patients may experience. Excess salivation is often reported early after delivery of a MAD while the appliance is in place. With time this subsides. Some patients report that areas where the appliance contacts the tissues causes some discomfort, for instance the teeth or the gingiva. Sore jaws are a side effect, mostly occurring upon awakening, but is most often transient.²⁷

Additionally, the MAD can be reported as being over-retentitve, not retentitve enough, causing sore cheeks internally, or causing teeth to feel loose. Most of these effects are minor and can be readily resolved with minor adjustment of the MAD.

The most common side effect reported are bite changes. This can include posterior open bite (POB) changes or, due to advancement forces, mandibular incisors may be directed labially while the maxillary incisors can be pushed palatally.²⁷ The bite changes can be short-term or long term. After a night of wearing a MAD, it is normal for the patient to feel that their teeth do not interdigitate just right when they bite together. Sustained contraction of the lateral pterygoid muscles is the mechanism behind this. This may resolve on its own in twenty minutes after removal of the MAD in the morning. Alternatively, some MAD products come with a bite tab or an acrylic bite pad (sometimes referred to as morning repositioner) that can be worn for 5-10 minutes upon wakening to facilitate in “resetting the bite.”

Long-term occlusal changes can occur and it is best to expect them and inform the patient that this will happen. These bite changes may be permanent even if the MAD is discontinued. An 11 year follow up study using the Klearway MAD in 77 patients determined that the mandibular arch expands significantly and both overbite (2.3 ± 1.6 mm) and overjet (1.9 ± 1.9 mm) decreased.²⁸ The dental changes seemed to progress over time. However, in this study there was no realignment tab used in the morning.

A retrospective study of 167 OSA patients treated with either a Klearway MAD or a Herbst appliance showed that 7.1% had POB at baseline and eventually 17.9% developed a POB, however only about 1 in 4 patients noticed this change.²⁹ Additionally, 10.8% of the cohort met criteria for TMD before MAD delivery. These symptoms increased but by the fourth follow up diminished down to 2.4%.

Both the dental professional and the patient should recognize that bite changes can happen. Due to the side effect of our training, there is a tendency to overreact to bite changes as the end of the world. However, returning to the topic of OSA, we should realize that if left untreated, OSA will cause significant morbidity and mortality to the patient with a significant negative impact on their quality of life. Let us therefore weigh the pros and cons: bite change vs. morbidity/ mortality.

Hence a good written consent form should be developed in the dental office indicating the reason for the treatment, risks of MAD treatment, and risk of not treating OSA. The need for a follow up sleep study after MAD delivery should be emphasized. The consent should be signed. The form should also include limitations in MAD treatment in improving OSA. The definition of success was defined earlier.