Trigger point injections (TPIs) are a minimally invasive treatment modality commonly used in the management of orofacial pain associated with myofascial trigger points. These are hyperirritable spots found within taut bands of skeletal muscle or fascia, which are usually tender to palpation and cause referred pain, muscle dysfunction, and localized discomfort. TPIs aim at relieving pain, improving muscle function, and restoring normal movement by targeting specific areas.
Mechanism of Action
The pain-relieving mechanisms of TPIs are largely unknown; there are a variety of theories related to its potential mechanism:
Mechanical Disruption: The tip of the injection needle is destructive to the individual muscle fibers comprising the trigger point, thus providing a basis for relaxation of the taut band.
Chemical Modulation: Agents administered locally with injections like saline, local anesthetics (lidocaine or bupivacaine), and corticosteroids reduce localized inflammation and interference with pain-conducting activity.
Neuromodulation: The injection may restore the dysfunctional motor endplates that are associated with trigger points, thus reducing abnormal muscle firing and hypertonicity.
Indications for Orofacial Pain
Trigger point injections are most useful in the management of pain associated with:
Myofascial pain syndrome (MPS)
Temporomandibular disorders (TMDs) that have a muscular component
Headaches (tension-type headaches or migraines with myofascial triggers)
Bruxism-related muscular pain
Postural strain to orofacial muscles
Neck and upper back muscular dysfunction contributing to referred orofacial pain
Procedure
Patient Assessment: The clinician determines the presence of trigger points by physical examination, usually by palpating the taut band of muscle and locating areas of maximal tenderness or referred pain.
Preparation: The skin over the trigger point is cleaned, and the patient placed in a comfortable position.
Injection Technique:
A fine-gauge needle minimizes discomfort
The needle is inserted into the trigger point, usually eliciting a localized twitch response, which may be viewed as a positive sign of adequate placement.
A small volume of anesthetic, saline, or corticosteroid is injected, or dry needling is performed without any injectate.
Post-Injection Care: Patients are encouraged to stretch the muscle gently, apply heat or cold as needed, and maintain good posture to optimize the therapeutic effect.
Benefits
Rapid pain relief in many cases
Improved range of motion and muscle function
Non-invasive alternative to surgery or systemic medications
Minimal downtime and quick recovery
Complications and Risks
While generally safe, TPIs can have some risks, including:
Localized discomfort or soreness at the injection site
Bruising or minor bleeding
Infection (rare with proper aseptic technique)
Temporary numbness if anesthetic spreads to adjacent nerves
Pneumothorax (rare but possible when injecting in areas near the thorax)
Adjunctive Therapies
To enhance the effectiveness of TPIs, they are often combined with other treatments such as:
Physical therapy (e.g., stretching, strengthening, and massage)
Behavioral interventions to decrease stress or maladaptive habits such as bruxism
Pharmacologic interventions (e.g., muscle relaxants, NSAIDs)
Lifestyle modifications, including ergonomic corrections and improved sleep hygiene
Clinical Considerations
Trigger point injections are highly technique-sensitive and require a good understanding of orofacial anatomy to be both accurate and safe. Contributing factors such as malocclusion, parafunctional habits, and psychosocial stressors must also be assessed and addressed by the clinician for complete treatment.
In summary, trigger point injections are a valuable tool in the management of orofacial pain, offering targeted relief for patients suffering from myofascial pain syndromes and related conditions. Proper assessment, technique, and follow-up care are essential to achieve optimal outcomes and improve patients’ quality of life.
Course Features
- Lecture 1
- Quiz 1
- Duration 90 minutes
- Skill level All levels
- Language English
- Students 113
- Certificate Yes
- Assessments Yes
Requirements
- BDS MDS
Features
- TMJ, tmj joint, dentistry and tmj, temporomanidubular joint, orofacial pain
Target audiences
- all dental practitioners