BOTOX® and Neuromodulators For Persistent Orofacial Pain & Jaw Disorders – Part 3

BOTOX® in Clinical Practice: Protocol and Considerations

This is part three of a three-part series where I discuss the utility of BOTOX®* and other neuromodulators based on the science and insights from treating patients at our Orofacial Pain practice.

The first two parts in this series, I detailed the primary benefits of BOTOX® and other neuromodulators for treating muscle-based orofacial pain. If you haven’t had a chance to read those segments yet, please check them out to get a full background:

• Part 1
• Part 2

In this third and final segment, I focus on the clinical protocol and key considerations for BOTOX® treatment to achieve and sustain symptom relief.

The Comprehensive Approach

What should be remembered is this: BOTOX® should never stand alone when addressing muscle-based orofacial pain problems.

Since the origins of these problems are rarely due to one specific and identifiable event, identifying and addressing the ongoing risk factors driving the muscle pathologies will ultimately determine the success or failure of BOTOX® therapy. If the muscles being treated continue to be overworked, over-excited, or injured by microtraumas, then the potential for recognized and sustained relief will be limited.

Treatment Protocols

Masseter Muscle

Assuming that the identified jaw muscle problems and associated symptoms of pain, muscle soreness, tension, and guarded jaw motion remain persistent despite first-line therapies having been deployed, the most common area to address with BOTOX® is the masseter muscle.

Having both superficial and deep muscle components, each of the following areas should be considered in the injection protocol. Though there exists no standardized injection location protocol for the masseter muscle, treatment sites typically include one or multiple areas:

• Areas of prominence on contracture
• Knotted areas or what are often called trigger points
• Locations of pain reported by the patient
• Deep and superficial muscle areas

Most commonly, between 20-30 units are utilized in this large and powerful muscle, with 4-6 injection sites.

Temporalis Muscle

Next in line would be the temporalis muscle, another jaw elevator, often overworked by awake and sleep bruxism or other daytime jaw overuse behaviors. This large fan-shaped muscle has three bodies—anterior, middle, and posterior—with injection sites most commonly in the anterior and middle components.

Again, reported pain locations, bulging areas on contracture, and knotted areas are typically the sites injected with a total of 20-25 units. Typically, 4-5 injection sites are common.

Lateral & Medial Pterygoid Muscles

The lateral and medial pterygoid muscles are also considered based on symptoms and physical findings but are less frequently injected. In my experience, both the lateral and medial pterygoids are effectively treated with a series of lidocaine injections, jaw exercises, and reduction of jaw overuse behaviors—therefore, BOTOX® is commonly not necessary.

If needed, injecting the lateral pterygoid with 10 units of BOTOX® at the neck of the condyle is straightforward, but accessing its origin on the pterygoid plate requires some form of EMG guidance. When needed, engaging the medial pterygoids with 10 units from an extraoral approach at the mandibular angle provides predictable benefit.

Essential Patient Communication Points

1. An informed consent is mandatory and should be presented orally and in written form.
2. The patient should understand that the effects of BOTOX® are not immediate due to its mechanism of action and will take between 5-10 days to be recognized at some level.
3. Typically, maximum benefit is perceived at the one-month mark, with symptoms gradually increasing as the three-month mark approaches.
4. It is unusual for one BOTOX® injection session to fully address a patient’s chief complaints, though this does occur occasionally. Two to three sessions is common, with intervals of between 3-6 months.
5. At times, a patient may report after one month that they realized no benefit from the BOTOX® injections. At 3-4 months, those same patients may for the first time realize that the injections did in fact help, as symptoms have escalated for no specific reason.
6. Though facial slimming as a result of muscle atrophy is not common following the first session of masseter injections, some patients do notice a change in the shape of their face, which likely is due to the reduction of lymphatic pooling that is common around taut muscles.
7. It is not common for patients to experience chewing limitations as a result of these 1-3 injection sessions.
8. Occasionally following BOTOX® injections in the masseter muscles, a walnut-sized bulge will emerge within 5 days every time the patient brings their teeth together. This is called paradoxical masseter bulging and is the result of specific muscle anatomy and the injection technique used. Fortunately, it can be addressed by injecting a bit more BOTOX® into the bulge, leading to a resolution in a few days.

Potential Outcomes to Be Discussed

1. Not every patient will respond to BOTOX® injections, and this needs to be discussed ahead of time. If a patient’s pain is of Neuropathic and/or Nociplastic origin, the response may be minimal to non-existent.
2. Though facial slimming and hollowing of the temporal region is not anticipated as a result of 1-2 BOTOX® injection sessions with intervals of 3-4 months, after the third session, subtle changes can begin to be seen. If occurring, it is the result of muscle atrophy and the resultant decrease of muscle bulk. Though many patients desire both pain relief and a less square jawline, others may not desire this consequence. Discussion ahead of the first injections and all subsequent sessions will help minimize this outcome, as injection protocol and volume of BOTOX® used can be modified.
3. Some patients experience profound benefit from BOTOX® injections when everything else has failed over many years of trying. Once this relief has been experienced, a return to their former pain state is an unacceptable option. This scenario inevitably leads to ongoing injection sessions with intervals exactly at 3 months. When this occurs, my sense is that the pain being experienced is similar to that of a migraine but is being experienced in the face and jaw. For these patients, facial slimming and jaw muscle weakness is anticipated and must be part of ongoing discussions and alternative treatment planning for the long term.
4. Care should be taken with patients exhibiting hypermobility problems to avoid loss of muscle tone needed to support the temporomandibular joints.
5. In patients with excessive skin elasticity, repetitive masseter injections can lead to the appearance of undesired ‘jowls.’ In females, this is not desirable, so getting a thorough medical history is key, and maintaining aesthetic conversations is a must.

Conclusion

Unquestionably, BOTOX® and other neuromodulators have added a new dimension to addressing stubborn orofacial pain problems. As with all medication-based treatments, however, there is a need for ongoing familiarity with the scientific literature and conversations with patients under care so that outcomes are being carefully monitored.

To my colleagues: I eagerly seek your insights, reflections, and experiences as we explore this topic in depth. Please feel free to comment below with your thoughts.

*In this article, BOTOX® represents various neuromodulators.