Occlusal splint maintenance, TMJ sound, and EMG recording in diagnosis and treatment of patients with bruxism and TMD. Sven E Widmalm, DDS, Odont. Dr. Specialist of Stomatognathic Physiology
Pdf and doc files of the hand-outs are available at http://sitemaker.umich.edu/widmalm • Questions are welcome at firstname.lastname@example.org • Info about how to reach me is posted in Blue and Green Clinics.
Occlusal Splints • You know already how to make a MI occlusal splint and the basics about why we make them. I will emphasize some important points in splint management. • I will give short descriptions of TMJ sound and EMG recording methods and a few examples of how those techniques can be of value in patients who need occlusal splints.
Signs of bruxism • Masseter hypertrophy • Non-functional wear facets
Bruxism is the most common reason for making a splint in Student Clinics.
A maxillary MI Occlusal Splint is the type used most often in this school.
It may be preferable to make a mandibular splint if the patient needs to use one during day time. Explain the pros and cons with maxillary and mandibular splints and let your patient decide.
Mandibular advancement splints to be used for repositioning a disk and keep it in a normalized position are not made in Student Clinics.
Careful, often time consuming adjustments, are important. • It is easier for the patient to relax the jaw muscles in a supine position. • Use a “horse shoe” formed holder for the articulating paper. • If you do not have that type - use type B – not type A.
Consider before making a splint • Counseling, behavioral therapy, relaxation training etc. may work as well or even better than a splint. • Age dependant wear is natural and does not require splint protection. • Correctly made restorations seldom need to be protected by splints.
Splints may not be harmless • Occlusal splints may cause serious side effects if left unsupervised even if they were made to fit well and had a good design.
Sindelar BJ. Edwards S. Herring SW showed in animal studies that prolonged splint wear can induce remodeling and even injury of TMJ tissues. • “The most striking change was the presence of a degenerative osseous defect on the medial side of the mandibular condyle in half of the splinted animals.
Non-conservative splints may be especially dangerous if used more than a few months without supervision.
Before starting BS treatment • Complete the Occlusal Examination Form • Provisional diagnosis signed by instructor • Symptomatic treatment plan signed by instructor • Be sure the patient can come back at least 3-4 times during the next 3-4 weeks • Be sure you have time to see the patient at least 3-4 times during the next 3-4 weeks
Important points in splint management • A splint should be checked at least once during the first 10 days after delivery. If adjustments are needed and performed a new visit within 1-2 weeks has to be scheduled. • Patients with TMD should preferably be recalled after 2-6 months. Other splint patients need to be seen 1-2 times per year. • No patient should be told to have the splint for the rest of his/her life. • At the recall visit you should consider if the patient may cease using a splint.
If there still is a treatment need you should discuss alternative therapies. • Do not make the patient dependant on the splint by turning the splint into a crutch. • Many students believe that splints are made primarily to protect teeth from wear and fillings from cracking in patients with bruxism. However, a majority of our patients may also have signs and symptoms of TMD. • Results of treatment have to be noted in the records. • Notes about diagnoses, alternative tx choices, need for referrals, and treatment results are important.
Relining • A new splint should never be relined at delivery unless it is an “emergency case” and a splint has to be delivered. It should be replaced by a heat-cured splint as soon as possible. • Relining with cold cure acrylic may cause monomer allergy. • If possible take instead a new impression and make a new splint. • TRIAD clear gel is a good choice if you have to reline.
Instructions to splint patients • Written instructions are important because oral are often incomplete and may be forgotten or misunderstood by the patient. A signed consent form can protect you from false accusations of insufficient instructions. (See the form in the hand-out package).
Specially designed examination forms are of great help to avoid forgetting making important notations in the patient record. • When screening you often do not have more than ~ 10 minutes and may use a short one page form such as the one to the left. • Before starting treatment of a patient with TMD S&S you need to make a much more complete examination that make take 45 – 60 minutes, sometimes more – even for an experienced clinician. Use a form such as the 10 page form to the right.
TMJ sounds • Healthy TMJs with normal function and without degenerative or arthritic changes are clinically silent. The examiner does not hear any clicking or crepitation at auscultation. • Audible TMJ sounds are considered to be cardinal signs of TMJ dysfunction and pathology. • TMJ sounds may occur in patients without pain or any other S&S of TMD and are then usually not treated unless disturbing because of being very loud.
TMJ sound/vibration recording is useful in patients with • Disk Displacement • Arthritic Changes
Widmalm, S. E., Westesson, P. L., Kim, I. K , Pereira, F., Lundh H. & Tasaki, M. 1994 Temporomandibular joint pathosis related to sex, age, and dentition in autopsy material. Oral Surgery, Oral Medicine, Oral Pathology, 78, 416 - 425.
Widmalm, S. E., Westesson, P. L., Brooks, S. L., Hatala, M. P. & Paesani, D. (1992) Temporomandibular joint sounds: Correlation to joint morphology in fresh autopsy specimens. American Journal of Orthodontics & Dentofacial Orthopedics, 101, 60 - 69.
Careful use of sound and EMG recording may help to detect dysfunction and pathologic changes at an early stage before it is too late for treatment.
Methods used for TMJ Sound/Vibration Recording • Palpation. • Auscultation with stethoscope. • Patient Report. • Electronic recording with microphones. • Electronic recording with skin contact transducers.
Palpation • Palpation has a limited value. You may feel low frequency vibrations and the movements of joint components with your fingers but that is not hearing. Sounds cannot be palpated with fingers. You listen with your ears. • You cannot store palpation findings in a way that you can make reliable comparisons between sessions and observers. • Diagnoses based only on palpation may be directly misleading and lead to false conclusions about type and location of disk dysfunction.
Auscultation • The ability to hear differs between examiners. You may hear sounds that are not audible for others. Therefore you cannot compare observations in a reliable way. • You cannot store auscultatory findings in a way that you can make reliable comparisons between sessions and observers. • Diagnoses based only on auscultation may be directly misleading and lead to false conclusions about type and location of disk dysfunction.
People are different • Hearing sound is one thing. Describing what you heard is a totally different story and difficult if not impossible for most people. Classifications such as clicking and crepitations are by necessity very crude and do not make it possible to relate with certainty the sound characteristics to different types of pathology. Even if people could hear sounds the same way they may not be able to describe them in a way that other examiners always understand what they heard.
Few people hear sounds the same way. Hearing ability deteriorates with age and may be quickly impaired in those exposed to loud environmental noise.
Players in baseball, tennis, golf can hear the difference between bad and good hits. • TMJ sounds differ too depending on joint conditions but you may need an objective electronic recording to detect and analyze differences.
Patient Report • In the research I have been involved in we found the patient reports to be more reliable than recordings with auscultation.
One of several reasons • The TMJ is very close to the ear canal.
Electronic Recording • Electronic recording has significant advantages as compared to auscultation and palpation but may lead to false conclusions if used without good knowledge about TMJ anatomy, acoustics, and signal analysis.
Sano, T., Widmalm, S. E., Westesson, P. L., Takahashi, K., Yoshida, H., Michi, K., & Okano, T.1999 Amplitude and frequency spectrum of TMJ sounds from subjects with and without other TMD signs/symptoms. Journal of Oral Rehabilitation, 26, 145-150.
Widmalm S.E., Williams, W.J., Djurdjanovic D & McKay D.C. 2003 The frequency range of TMJ Sounds. Journal of Oral Rehabilitation, 30, 335-346.