Trans-Oral
Parotidectomy

The accessory parotid gland is deep to the facial nerve and closer to the mucous membrane inside the cheek/mouth. When a tumor grows in an accessory gland, it is usually deep to the facial nerve and therefore safer to access it through the mouth. Most often, if one hand is placed on the cheek skin, and the other hand’s index finger is inside the mouth, the mass can be felt between them. When detected early, these tumors tend to be mobile and can be very safely removed through the mouth. These tumors are generally found at an earlier stage because the cheek tissue is thin, and they can be easily seen or felt.

The trans-oral approach to the accessory parotid gland tumors allows most of the surgery to be done in the area deep to the facial nerve. At the CENTER, we always use a facial nerve monitoring system to improve the safety of the facial nerve, as well as nerve stimulation to accurately map out the anatomy of the facial nerve in the vicinity of the tumor. Once the facial nerve branches in the area surrounding the tumor and the parotid duct have been identified, the tumor can be removed. A thorough understanding of the anatomy is crucial in being able to do this surgical approach appropriately.

The parotid gland’s deepest portion is behind and deep to the jawbone muscle. On occasion, tumors start in this area and grow inward. This area is confined by the jawbone (to the side), spine (in the middle), and the ear bone/skull base (on the back), so the tumors that develop here can only grow in a forward direction, which is towards the throat. Once they grow large enough, they either get close to the mucous membrane of the soft palate (back of the roof of our mouth) or can push the palate, in which case we can see a bulge in the palate when we look inside the mouth.

The parotid gland’s deepest portion is behind and deep to the jawbone muscle. On occasion, tumors start in this area and grow inward. This area is confined by the jawbone (to the side), spine (in the middle), and the ear bone & the skull (on the back), so the tumors that develop here can only grow in a forward direction, which is towards the throat. Once they grow large enough, they either get close to the mucous membrane of the soft palate (back of the roof of our mouth) or can push the palate forward, which can be seen as a bulge in the palate when we look inside the mouth.

The incision is closed in multiple layers with absorbable sutures. These sutures don’t have to be later removed. The tumor is thoroughly inspected once removed. The capsule surrounding the tumor is also checked.

The tumor may be sent to the pathologist during surgery for immediate examination to see what type it is. This is done if the tumor has not already been biopsied before the operation, or if it has suspicious features (areas that are very hard, or has roots attaching it to the muscles, etc.). This usually takes 20 minutes, and the results are called into the operating room.

Why can’t all tumors in the parotid be removed via the trans-oral parotidectomy approach?

Mainly because of the facial nerve. Tumors that are inside the main parotid gland are usually in very close proximity to the facial nerve or immediately on one or a few nerve branches. As such, the surgeon would have to find the branches of the facial nerve first before removing the tumor. From inside the mouth, it is not possible to see the full facial nerve anatomy inside the parotid gland.
The approach angle through the mouth (Red Triangle) not only does not give access to that part of the gland (jawbone and muscles in the way), but would require passing through the area of the facial nerves to get to the tumor. If this approach is from the outside, the tumor would be superficial to the facial nerve and thus much safer.