Jaw Lever

Project  / Project number: 995  /  Status:



The challenge

After a severe stroke the client was left with complete paraplegia and trismus meaning his jaw is locked closed, unable to be opened without the help of a therapist.

For therapy reasons, and for oral hygiene, it is necessary to open the jaw forcibly on a daily basis. Plastic devices are available to do this but were nothing like strong enough to open this client’s jaw. As a result, the therapist was opening his jaw using a standard practice of forcing a stack of tongue depressors between his teeth. This was hazardous as well as time consuming.

The challenge was to create a device that was easy to use and strong enough to open the jaw but without damaging the client’s teeth.


The solution

Two pieces of ash were connected at a central pivot point. On one side the ash pieces met and on the other they were separated and connected together with a bolt and wing nuts allowing the device to function like a jack, opening the jaws when the wing nut is tightened.

Ash was found to be the best material to avoid damaging the client’s teeth but with the necessary strength to open the jaw.  Fittings are in stainless steel allowing the device to be sterilised between uses. A pair of devices were manufactured as shown above.

The benefit

The device increases the speed and ease of this daily task and decreases the risk to the client.

Engineer: John

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