TMD/Facial Pain and Forward Head Posture
Differential diagnosis is a key component in any successful dental treatment, and that key is especially applicable in patients who demonstrate head, neck, and facial pain. One such dysfunction that has been shown to contribute to head, neck, and facial pain, is temporomandibular joint disorder (TMD), where successful diagnosis often proves to be vital for successful intervention and treatment.1,2
TMD has been shown to manifest itself as pain and hypertonicity in the muscles of mastication, and in the muscles of the head, neck-jaw complex, as demonstrated by increased electromyographic activity.3-7 TMD and associated head neck and facial pain is most frequently treated by dentists, physical therapists, and psychologists.8 Traditionally, dentists have utilized oral appliances to treat TMD.9-13 Physical Therapists have commonly used a variety of TMD treatment procedures including exercise, heat, cold, ultrasound, electrical stimulation, biofeedback, soft-tissue techniques, massage, and mobilization/manipulation.14-16 The interventions of both dentist and physical therapist may result in resolution of symptoms, but desired outcomes may often elude both patient and practitioner. The dentist has only partial success in cases where TMD and cervical problems exist together, whereas the physical therapist cannot resolve cervical problems if adjacent TM disorders are ignored.17
Postural Contribution to TMD
The dental profession is aware of the relationship of head, neck, and jaw posture.18 Many authors have suggested that postural problems may lead to pain and dysfunction, while others postulate that Forward Head Posture (FHP) is associated with temporomandibular disorders (TMD).18,19 However, postural considerations are often overlooked by the dental profession in the diagnosis and treatment of facial pain and TMD.
TM joint dysfunction with postural abnormalities appear prevalent in patients presenting at a hospital based TMD/Facial pain center. The existence of a relationship between neck pain and TMD is an important relevant finding.20,21 It is the goal of the dentist and physical therapist to normalize posture and align the masticatory and cranio-cervical system within an individual patient’s adaptive capacity. The relationship between the masticatory and cervical muscles is important when considering the effects of head posture and the resting position of the mandible.22,23 Researchers have noted changes in the activity of the masticatory musculature with changes in head position.24-26 Forward head posture (FHP) consisting of slumped/rounded shoulders with concomitant extension of the upper cervical spine, causes the head to shift anteriorly beyond its normal axis (see illustration in Figure 1). This posture may alter the neuromuscular influences on the entire masticatory system, thus influencing the resting position of the mandible.27 Forward Head Posture (FHP) has an immediate effect on mandibular closure.28,29
In FHP, the supramandibular muscles may pull the mandible toward the maxilla and cause a decrease in the resting freeway space, as well as a more retruded position.30 This posture causes the suprahyoid and posterior cervical musculature to shorten isometrically, while the infrahyoid muscles are stretched.31,32 consequently decreasing or eliminating the freeway space. The effects of this abnormal position may lead to an excessive amount of tension in the muscles of mastication and the supporting structures. “Clinically, patients with FHP are at greater risk of developing swallowing impairment, impingement of the glenohumeral joints, reduced costal cage expansion during inhalation, and lower extremity problems related to hyperpronation (eg., ankle sprains, shin splints, and patellofemoral pain).”33
Functional restoration is best accomplished with a combination of postural alignment and an active exercise program to recondition musculature. The authors have been involved in the development of two devices that promote postural realignment and active stretching and strengthening of affected muscles. These devices are named the Occivator® and Posture-JacTM, respectively, and are manufactured by Posteocentric Systems, Mastic Beach, NY (www.posteocentricsys tems.com).
The main objective of postural realignment is to lift the occiput up and away from the cervical spine. An upward pull on the head from the occipital area results in a forward and upward movement of the head relative to the neck (as distinguished from straight vertical traction).34 The authors report the following therapeutic effects from using the Occivator® realignment device (see illustrated usage in Figure 2):
- Lifting of the occiput up and forward results in:
- Subcranial decompression
- Occipito-atlantal distraction
- Occipital extensor stretch
- Active effort strengthens the occipital flexors
- Facilitates neutral alignment of the lower cervical spine (i.e., from forward to neutral posture)
- Restores physiologic “tripodism”
- Normalizes load on the intervertebral discs
- Provides enhanced form/force closure (i.e., clinical stability) to the C3-6 region through physiologic nuchal ligament tension
- Decreases torque on the neck
- Stretches the sternocleidomastoid and scalene muscles
- Facilitates neutral alignment of the shoulder/scapular/thoracic region
- Scapulae are realigned down and back (i.e. depressed and retracted)
- Sub-acromial space is increased
- Stretches the upper trapezius and levator scapulae muscles
- Stretches the anterior chest wall (i.e., pectoralis major, minor, and fascias).
- Normalizes the thoracic kyphosis through an extension force
- fStrengthens the lower scapular stabilizers (i.e. mid/lower trapezius, rhomboids, and serratus anterior muscles.
- Cervical traction (i.e., opening of the intervertebral foramina)
- Self-mobilization of the vertebral column (O-A, A-A, C2-7, T1-12, L1-5).
It is important to evaluate for and address the common postural imbalance referred to as forward head/rounded shoulders posture. This postural malady is ubiquitous, affecting individuals as a result of aging, trauma, occupational factors, osteoporosis, emotional stress, etc. It consists of extension, or backward bending of the head, flexion or forward bending of the neck/upper back, and rounding of the shoulders.
On a physiologic basis, musculature reconditioning must accomplish the following effects: