The Open Anterior Design



No Material in the Incisor Region Allows Mouth Breathing, Prevents Gagging

Some OSA appliances have acrylic covering the incisor regions of the upper and lower teeth. The Luco Hybrid OSA Appliance does not. There is a very good reason for this. There are 4 reflexes that are stimulated with OSA appliances (just as your knee jumps uncontrollably when hit the right way).

Jaw-Hypoglossal Reflex:  Stimulation of Protrusion of the Tongue

This reflex is stimulated when the lower jaw is moved downward (as with the pads on the appliance) and forward (the wings of the appliance). The reflex occurs with stimulation of the genioglossus muscle ( a fan shaped muscle whose action is to protrude the tongue forward).  When the tongue protrudes forward, it must have somewhere to go. When the anterior is closed, the tongue presses hard against the acrylic covering the incisors potentially causing discomfort of the tongue and shifting of the teeth forward.

Massater-Hypoglossal Reflex: Inhibition of Retrusion of the Mandible (and Tongue)

The vertical opening of the appliance is critical. The thickness of the pads determines the amount of vertical opening. This opening causes stretching of the massater muscle (cheek muscle) and stimulation of the massateric nerve. This stimulation of the massateric nerve inhibits or blocks the contraction of the hypoglossal muscle. The primary function of the hypoglossal muscle is retrusion of the mandible or movement back into the throat. Inhibition of this allows the jaw and tongue to rest comfortably forward between the incisors. Patients with deep overbites may need to be open more than those with normal overbites to allow for stimulation of this reflex.

Lingual-Hypoglossal Reflex: Inhibition of Retrusion of the Mandible (and Tongue)

Mechanical stimulation of the tongue can inhibit or stimulate the tongue, depending upon where the tongue is stimulated. At rest, the tongue should be lightly touching the incisive papilla, just behind the upper central incisors (this is the area you burn when biting into hot pizza!). The tongue stimulates the incisive nerve and all is well. If the incisive papilla is covered, this stimulation does not occur and the tongue may look for an alternate place to rest or press on the appliance in an effort to reach the incisive papilla. On the Luco Hybrid OSA Appliance, the upper casting allows this tongue/papilla contact. It also provides its own stimulation as the tongue rubs across it, behind the papilla. this stimulation results in the tongue moving forward in the mouth (out of the throat) by inhibiting the muscles that retrude the mandible.

Glossopharyngeal-Hypoglossal ReflexStimulation of protrusion of the Tongue

Stimulation of the Glossopharyngeal nerve at the lateral border along the posterior one-third of the tongue induces protrusion of the tongue. The ball clasps on the lower Luco Hybrid are strategically placed on the back inside of the 2nd bicuspids and back inside of the 1st molars. When the clasps are engaged between the teeth, the wire portion is left to protrude 1-1.5mm out from the teeth.  The lateral border of the tongue contacts these clasps stimulating this reflex protrusion of the tongue. Patients often report when the appliance is initially inserted that the feel something “rough” in this area. The wires are not sharp as it is not the end they feel, but the side. After 2-3 days, they patients no longer notice the wires as this reflex has been activated and the tongue is staying forward during sleep.

To fully utilize these reflexes an appliance cannot have coverage of the incisors as the reflex forward movement of the tongue will have no where to go. Many articles claim that lack of coverage of the incisors will allow the incisors to shift. Because the Luco Hybrid appliance stimulates these reflexes, the tongue postures between the teeth and prevents any tooth movement. When these reflexes are not respected, the tongue can put significant pressure on the teeth causing shifting even when covered due to this reflex action of the tongue. The tongue can generate 510 grams of force! It only takes about 15 grams of force to move a tooth. If the tongue is pressing on an appliance hard enough, the teeth under will tip outwards. This is basic physics: Action = Reaction.

Lastly, there is one final reflex we are all familiar with: the gag reflex. Patients who have a pronounce gag reflex often cannot tolerate OSA appliances’s cast framework and open design reduce the gag reflex significantly allowing even patients with a strong gag reflex to benefit fo rm this treatment.

The Luco Hybrid OSA Appliance was carefully designed not just to pull the jaw forward, but to respect the musculature, TMJ, teeth and supporting structures as well as the reflexes as discussed above. It is clinically proven and fully FDA cleared as a Class II medical device.