A case for full-coverage hard acrylic non-sleep-apnea dental orthotics.

In the context of human dentition, an orthotic device is “any removable artificial occlusal surface used for diagnosis or therapy affecting the relationship of the mandible to maxilla.”1 Dental orthotics for the treatment of conditions other than sleep apnea, also known as non–sleep-apnea dental orthotics (NADOs), are removable occlusal appliances that completely or partially cover either dental arch. Usually made from hard acrylic, they are also called splints, dental orthotics, orthotic devices, occlusal devices, bite guards, night guards or interocclusal appliances. NADOs are widely used by most general and rehabilitative dental practitioners, as well as those who treat orofacial pain. Many practitioners believe that NADOs are effective in the treatment of temporomandibular disorders, especially of myogenous origin,2,3 but evaluation of the literature on NADOs has not supported this belief,4–6 and all too often the devices are used without any evidence of efficacy.7 The potential for a placebo effect must also be taken into consideration.8 NADOs are also used before and after oral rehabilitation as a diagnostic aid, a treatment aid or a protective device.9–11 They are routinely prescribed to reduce occlusal wear, as in bruxism associated with sleep disorders.12–15 Numerous styles of NADOs are available, and claims of superiority in effectiveness and efficacy for some of these forms have been published.16,17 NADOs made of hard acrylic are available as full-coverage stabilization devices, full-coverage anterior repositioning devices, partial-coverage posterior or anterior devices, and pivoting devices. The most common of these is the full-coverage stabilization device (Fig. 1). Devices of this form can be directly fabricated at chairside or indirectly fabricated (processed in the laboratory). Directly fabricated full-coverage hard acrylic NADOs save both time and money. However, because they are made in situ, the unpleasant aspects of the technique (e.g., taste, tissue irritation, odours) lead to an unfavourable patient response. Indirectly processed full-coverage hard acrylic NADOs require a higher degree of operator skill to ensure accurate fit, not only on the arch for which they are fabricated but also in terms of the preciseness of the interarch relationship. Indirectly processed full-coverage hard acrylic devices (Fig. 1) also potentially maximize the possible mechanism of action for NADO therapy as listed in Table 1 of all the styles available.7,18,19 Furthermore, not only are these indirectly fabricated devices more durable than directly fabricated hard acrylic NADOs, but they are also safe, reliable and reversible. Partial anterior-coverage dental orthotics (PACDOs), another style of NADO, have been used by practitioners for muscle deprogramming when taking interocclusal records for decades (Fig. 2)20 and have become very popular in recent years. Contact inhibition effected by these devices is one of the proposed (although unsubstantiated) mechanisms for muscle deprogramming and relaxation.21 These orthotics have been advocated not only for the treatment of masticatory muscle disorders but also for treatment of neurovascular A Case for Full-Coverage Hard Acrylic Non–Sleep-Apnea Dental Orthotics