Kinematics ofmandibular advancement devices(MADs):Why do some MADs move the lower jaw backward duringmouth opening?

Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep apnea.MADs function by advancing the lower jaw to open the upper airway.To increase patient comfort,most patients allow the mouth to be opened.However,not all systems maintain the lower jaw in a forward position during mouth opening,which results in the production of a retrusion that favors the collapse of the upper airway.Furthermore,the kinematic behavior of the mechanism formed by the mandible-device assembly depends on jaw morphology.This means that,during mouth opening,some devices cause lower jaw protrusion in some patients,but cause its retraction in others.In this study,we report the behavior of well-known devices currently on themarket.To do so,we developed a kinematic model of the lower jawdevice assembly.Thismodelwas validated for all devices analyzed using a high-resolution camera system.Our results show that some of the devices analyzed here did not produce the correct behavior during patient mouth opening.

3D kinematicmandiblemodel to designmandibular advancement devices for the treatment of obstructive sleep apnea

Mandibular advancement devices(MADs)are one of the treatments used for Obstructive sleep apnea(OSA).MADs try to maintain the mandible in an advanced position to keep the upper airways open when sleeping.To achieve this goal,most current MADs limit the mouth opening to a few millimetres.The study of the kinematic behaviour of the patient’s jaw is essential in order to design devices that allow greater aperture ranges.For this purpose,a 3D multibody model that reproduces jaw movement has been developed in this work.To this end,the movement of the lower incisor has been determined by means of a vision system and reflective markers.In addition,the kinematics of the temporomandibular joint has been modelled.Next,the device is designed and printed using a cam-follower mechanism.This way,the cam profiles and the followers are optimally designed and positioned for each patient depending on the physiognomy of the jaw and the opening and advancing movement prescribed by the specialist.

Changes in sleep parameters following biomimetic oral appliance therapy: A case report

BACKGROUND Mandibular advancement devices(MADs)are used to treat mild to moderate obstructive sleep apnea(OSA),but there is a risk that the underlying condition can worsen in the long-term.Therefore,this case report is based on biomimetic oral appliance therapy as an alternative to MADs,which was found to be beneficial in the treatment of a case with severe OSA.CASE SUMMARY An overnight sleep study was undertaken in a 50-year-old male with excessive daytime sleepiness that lead to a diagnosis of severe OSA as the apnea-hypopnea index(AHI)was found to be 32.8/h.Since the patient was unable to comply with continuous positive airway pressure therapy and declined surgical intervention,treatment with a MAD was initiated.Approximately 10 years later,another sleep study was performed with no MAD in the mouth,which revealed an AHI of 67.9/h.In view of the deterioration in sleep quality,the patient sought alternative treatment and elected on biomimetic oral appliance therapy,using a mandibular repositioning nighttime appliance(mRNA appliance®,Vivos Therapeutics,Inc.,United States).After 10 mo,another sleep study was performed with no device in the patient’s mouth,which revealed an AHI of 11.8/h,a mean oxygen saturation of 94%and a mean oxygen desaturation index of 5.3%while sleeping.Finiteelement analysis of the pre-and post-treatment study models of the upper jaw showed localized size increases of 15%-17%in the premolar regions and 15%-23%in the molar regions.CONCLUSION In adults with severe OSA that are unable to accept continuous positive airway pressure or surgical treatment,biomimetic oral appliance therapy may be preferable over MADs since biomimetic oral appliance therapy may be able to prevent worsening of sleep parameters by remodeling the nasomaxillary complex.Long-term follow up studies are required to verify these novel findings.

Clinical consequences and economic costs of untreated obstructive sleep apnea syndrome

Objective: To provide an overview of the healthcare and societal consequences and costs of untreated obstructive sleep apnea syndrome.Data sources: PubMed database for English-language studies with no start date restrictions and with an end date of September 2014.Methods: A comprehensive literature review was performed to identify all studies that discussed the physiologic, clinical and societal consequences of obstructive sleep apnea syndrome as well as the costs associated with these consequences.There were 106 studies that formed the basis of this analysis.Conclusions: Undiagnosed and untreated obstructive sleep apnea syndrome can lead to abnormal physiology that can have serious implications including increased cardiovascular disease, stroke, metabolic disease, excessive daytime sleepiness, work-place errors, traffic accidents and death.These consequences result in significant economic burden.Both, the health and societal consequences and their costs can be decreased with identification and treatment of sleep apnea.Implications for practice: Treatment of obstructive sleep apnea syndrome, despite its consequences, is limited by lack of diagnosis, poor patient acceptance, lack of access to effective therapies, and lack of a variety of effective therapies.Newer modes of therapy that are effective, cost efficient and more accepted by patients need to be developed.