Dental Impressions and Bite Registration
Dental impressions with alginate or other desired medium are taken of both the maxillary and mandibular full arches. The impression should adequately capture the dentition and a good deal of the periodontium both facially and lingually. Alginate impressions should be poured immediately for optimal accuracy. Among dental laboratories which accept digital workflow, the arches may be scanned and the bite registration with the teeth together may also be scanned in.
Next, a bite registration needs to be taken so the dental laboratory technician can relate the maxillary arch to the mandibular one. This registration should be taken with the patient at the 50% protrusive level. Some of the previously mentioned protrusion gauges have attachments that serve as bite forks to facilitate the bite registration process. Whether one uses blue mousse or thermacryl as their bite registration of choice, either one can flow into these attachments providing a degree of rigidity. This makes the registration more durable during packaging and handling at the lab. It is best to add the Blue Mousse® onto the bite fork extraorally with a thin layer on either side. Return the bite fork still attached to the gauge to the mouth (gauge set at 50% maximum protrusive). Have the patient’s incisors seat back into the gauge. The mousse will intermingle with the teeth. Additional mousse can be added with a syringe tip to fill in voids, gaps or bulk up the registration in select areas (Figure 9).
George gauge with bite fork and bite registration capturing the patient at 50% protrusive.
As an alternate if no gauge is available, a light curable Triad™ ball can be formed and can serve as a bite jig. The patient can be guided to bite into the jig at 50% maximum protrusive. Instruct the patient to bite only partially through it, thus leaving 1-2 mm between the upper and lower molars. This space will be filled in by the registration paste later. Light cure with a hand held curing device. Remove the acrylic jig and continue to light cure the lingual aspect until fully cured. Replace the jig back into the mouth and inject blue mousse bite registration paste covering exposed occlusal surfaces of both arches. Once set, remove and disinfect. Both the jig and the bite registration will be sent to the dental laboratory (Figure 10).
Bite registration taken with the patient’s jaw in the 50% protruded position by way of an acrylic jig.
Regardless of method used, return the jig or bite fork registration to the mouth. Have the patient sit in the chair for 5-10 minutes. If the patient can tolerate this protruded position, continue with the MAD fabrication process. If the patient cannot tolerate this position at all, MAD may not be the right treatment for their OSA. But note that some forms of MAD allow the dentist to decrease the degree of protrusion so this from the original 50% protrusive captured at the fist appointment.