Salivary Gland Injury: Cause & Diagnosis
Dermal filler complications, such as salivary gland injury, are becoming more of an issue due to the increase of popularity of filler treatments in the lower two-thirds of the face.
More specifically, the trend of jawline & chin treatments has drastically increased over the past couple of years.
If you are performing these types of dermal filler treatments you must understand one of the main complications that can appear in this area of the face.
What Causes Salivary Gland Injury?
The cause of salivary gland injury can be broken down into 2 main factors:
1. Equipment used in the procedure
Salivary gland injury is typically caused by the use of a cannula.
The region along the jawline & chin is treated as a cannula only area by most clinicians.
Cannulas can cause this injury as they often expose structures to a lot of shearing force as they are pushed through tissue layers.
2. The anatomy of the treatment area.
The glands are vulnerable when treating the subzygomatic area, the gonial angle, and jawline.
The parotid fascia covers the glands and extends into the neck over the platysma surface.
Above the fascia is the hypodermic fat.
The passage of the instrument should be in the hypodermic fat. This lies directly adjacent to the layer of fascia covering the surface of the gland.
You can see therefore that the parotid and submandibular glands would be particularly vulnerable if the instrument was to penetrate a little too deep.
During its movement, the instrument may snag on the surface of the glands causing trauma to its surface.
In more severe injuries, it may be possible to damage the parotid duct and the branches of the facial nerve which passes through the gland.
These structures are deeper within the gland and an experienced injector should know they are in the wrong place before they go in too deep.
Diagnosis Of A Salivary Gland Injury
The diagnosis of salivary gland trauma is often difficult the first time you have to deal with this complication.
The patient usually presents with swelling of various degrees over the parotid gland or the angle of the jaw/neck.
This is often consistent with a normal post-procedure inflammatory side effect.
On examination of the client, you should notice the area is painless, non-tender and there is an absence of bruising.
These are the key aspects which clinically differentiate the pathology from a haematoma or inflammation.
In some cases the diagnosis becomes more obvious when the history reveals that the swelling noticeably worsens before and during eating.
The swelling usually subsides fairly quickly after eating and returns to a baseline level within a few hours as the saliva is reabsorbed or drains away.
We can now tell what has likely occurred.
The instrument has penetrated beyond the subcutaneous fat through the parotid fascia.
While passing along this space it has created tears in the surface of the gland.
During salivary gland stimulation, saliva will spill out of the gland to fill the potential space between the gland and the fascia.