To Chew Or Not To Chew

A common debate in the industry these days involves that of impression technique and whether or not one should have the patient move their jaw during the process, or keep the jaw stationary with a Bite Block™ in place. For many years our position at Westone has been to have the patient move their jaw with a "chewing" motion in order to replicate the patient's natural jaw positions. However, it appears from the abundance of research on the topic that mandibular movement during the impression taking process causes changes in the ear canal that may contribute to fit problems.

Based on the latest information, we feel that open-jaw impressions using a Bite Block definitely have a place. There are some conditions that certainly warrant an open-jaw impression. These may include patients with a history of feedback/loose fit problems, significant jaw movement, or retention problems. Research also indicates that using a higher viscosity impression material will improve acoustic seal and is the preferred material when taking open-jaw impressions. Our Pink Silicast®, Blue Silicast® and Silicone Singles® are ideal for this application.

In cases involving the fit of musicians (particularly horn players) whose mouth/jaw position is usually in a set position, we would recommend an impression technique that would replicate that specific mouth position. In cases where the patient has a sensitivity and cannot tolerate a tight fit, a closed-jaw impression may be preferable to avoid causing the patient further discomfort.

Our new position? Open-jaw impressions taken with a Bite Block™ are favorable in the majority of fittings. In keeping with our efforts to provide the best for each patient, we may move off of this position on a case by case basis, depending on the physical and acoustic characteristics of each individual patient.

As always, regardless of the technique used, the accuracy of the earmold/earplug fit relies largely on the accuracy of the impression provided to the laboratory.

All of our impression materials as well as Bite Blocks are available through our Online Supply Warehouse.

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