Mandibular Advancement Device (MAD) therapy in edentulous patients with obstructive sleep apnea: dental implant fixed MADs vs. CPAP.

Obstructive sleep apnea (OSA) is a major medical problem, estimated to affect
up to 15-30% of the adults in the USA. Characterized by repetitive obstructions
of the upper airway during sleep, OSA results in fragmented sleep and excessive
daytime sleepiness. Consequences of untreated OSA are serious and include
cardio- and cerebrovascular disease, diabetes mellitus, depression, glaucoma
and increased all-cause mortality. It is also related to an increased risk of
involvement in motor vehicle crashes and a decreased quality of life (QoL).
Major risk factors for OSA include male gender, higher age, obesity, smoking
and craniofacial abnormalities.

In the Netherlands approximately 41 percent of the individuals older than 65
years are completely edentulous. As a result of morphological changes, a higher
incidence of OSA is reported in (partial) edentate individuals compared to the
general population. The exact prevalence of edentulousness in OSA patients is
unknown, however this number is likely to be significant and increasing due to
the aging population and current rise of obesity.
Continuous positive airway pressure (CPAP) therapy is the current gold standard
in OSA therapy next to lifestyle alterations. Although CPAP therapy is widely
used in OSA management, it is accompanied with high non-adherence rates up to
80% due to side effects and wearing discomfort. Oral appliance therapy (e.g.
mandibular advancement device therapy) is a viable and effective treatment
alternative, however requires sufficient dentition for device retention. This
results in oral appliance therapy not being usable in up to one third of all
OSA patients due to dental limitations. Due to the low CPAP compliance rates,
the potential risks of untreated OSA and the lack of other suitable therapies
there is an unmet clinical need of effective treatment strategies for
edentulous OSA patients.

Very limited evidence is available regarding the outcomes of treatment with
MADs or CPAP in edentulous OSA patients. Some case studies showed the potential
effectiveness of dental implant retained mandibular advancement device (MAD)
therapy in edentulous OSA patients, tackling the major obstacle of poor device
retention. An MAD is an intra-oral prosthesis which holds the mandible in a
forced protrusive position during sleep, resulting in an increased pharyngeal
airway space. Implant retained MADs could potentially tackle the problem of
poor device retention in edentulous OSA patients and become a viable treatment
option for these patients.
Our hypothesis is that MAD treatment retained on maxillary and mandibular
overdentures fixed with 2 mandibular dental implants and 4-6 optionally
maxillary implants (based on most recent implantology guidelines NVOI) is an
effective treatment strategy in edentulous OSA patients in terms of sleep apnea
reduction, wearing comfort/side effects and compliance.

The main purpose of this pilot study is to assess the feasibility and potential
efficacy of implant retained mandibular advancement device (MAD) therapy on a
small scale in edentulous patients with mild to moderate OSA in comparison to
CPAP therapy (current standard) in terms of sleep apnea reduction.

Additionally, both treatment will be evaluated in terms of therapy compliance,
side-effects, quality of life and complications (e.g. hypertension, depression
symptoms). The outcomes of this exploratory study can be used for larger scale
hypothesis testing clinical trials on implant retained MAD therapy in
edentulous OSA patients.

Randomized controlled parallel two-group pilot study

Participants in this study will be randomly allocated using a block
randomization method in one of the two treatment groups:

- Treatment A (intervention)
Mandibular Advancement Device (MAD) therapy; MAD retained on upper and lower
overdentures fixed with 2 mandibular dental implants (or pre-existing dental
implants). In case of overdenture related complaints during the MAD treatment
work-up (e.g. retention problems), treatment can be upscaled with the placement
of 4-6 maxillary implants placement (if absent before treatment) to improve
retention as part of the regular implant retained overdenture treatment
protocol (NVOI Implantology Guidelines 2015).

- Treatment B (control-group)
Continuous Positive Airway Pressure (CPAP) therapy using the standard treatment
protocol.

Both dental implant retained overdentures, MAD- and CPAP-treatment are
well-established treatment that are widely used in daily clinical practice.
Burden and risks associated with participation in this study are dependent on
the allocated treatment group. General (potential) side effects of MAD therapy
include discomfort of the jaw, sensitivity of the maxilla and a dry mouth.
Termination of the MAD use would result in quick relief of the above mentioned
symptoms.
Dental implant placement (if required) is a routine surgical procedure. All
patients undergoing such a procedure are at risk for the general complications
associated with dental implants, comprising of infection (peri-implantitis) and
bleeding related to the procedure. In case of such events, patients might
require additional treatment.