Taming Destructive Forces 

Using a Simple Tension Suppression Device

James P. Boyd, DDS Wesley Shankland, DDS, MS, PhD 

Chris Brown, DDS, MPS Joe Schames, DMD 

(about the authors)

ABSTRACT: "Bruxism" historically has been casually defined as "the clenching and/or grinding of the teeth". Since there can be no teeth grinding without the jaws first being clenched, a re-definition of bruxism is presented: "Jaw clenching, with or without forcible excursive movement, where the intensity of  the clenching dictates the severity of teeth grinding". Traditional inter-occlusal splint methods of treating bruxism have been unpredictable because  their specific design addresses lateral movement (grinding), when it is the degree of intensity of vertical movement (clenching) which dictates severity of symptoms. A new method and device (a simple modification of pre-existing concepts) which suppresses clenching intensity by exploiting the nociceptive trigeminal inhibition reflex while preventing canine and posterior tooth occluding, is presented. 

Individuals with a far less than ideal jaw relationship and/or occlusal scheme may be completely asymptomatic, while others who have ideal jaw relationships and occlusal schemes chronically suffer from debilitating headaches, face and jaw pain (TMD). Etiological research continues to show that essentially, it doesn't matter what a person has, or where it is...what matters is, what one does with what one has.(1) 

Dentistry typically acknowledges that the activity responsible for these symptoms is bruxism. However, the current standard treatment for bruxism, i.e., a splint or nightguard, may not be entirely effective at resolving the patient's symptoms. The problem lies not in dentistry's mis-treatment, but of its mis-conception of the diagnosis, i.e., "bruxism". This lack of understanding of the true nature of bruxism has resulted in the current standard of care for chronic TMD: management of symptoms(1,2,3). 

Dentistry has stipulated that treatment with an inter-occlusal splint will result in one of three scenarios: the patient may improve; remain unchanged; or get worse(4,5). The reality is, treatment outcome using an traditional occlusal splint alone for patients with significant myofascial pain is no better than placebo(6). When treating TMD surgically, those patients with uncontrolled nocturnal bruxism are considered to have a poor prognosis(7). After elective orthognathic surgery, some procedures fail due to previously un-acknowledged, but suddenly destructive, bruxism. A patient cannot be

informed of the risk of the potential adverse outcome if the provider himself doesn't fully understand the true nature of bruxism.

To gain an upper hand on bruxism, a better understanding of the term and therefore, the condition itself, is necessary. Bruxism is not a condition of the teeth. Teeth don't cause an activity, but are merely being affected by an activity(8). Dentistry is essentially the art and science of how healthy teeth occlude with each other. Therefore, dentistry may reflexively treat a condition it is presented with by addressing the health of the teeth, and their scheme of occlusion(9). However, signs and symptoms of bruxism result from the occluding of teeth, specifically, the intensity of occluding.  The resultant scheme of occlusion may modify and direct the forces generated during the occluding.  Dentistry stipulates the occluding, and attempts to treat the resultant symptoms by altering the occlusion.

Bruxism is a function of clenching. The intensity of clenching dictates the severity of grinding. There is no teeth grinding unless the jaws are first clenched together. The jaws must be clenched together intensely enough to provide adequate resistance to alternating lateral pterygoid activity, which then "grinds" the teeth in excursive movement. As the intensity of temporalis contraction (clenching) increases, resistance to mandibular lateral movement is increased, thereby increasing the efforts of the lateral pterygoids and strain on the TMJs. Therefore, as the intensity of clenching increases, the abilityto move the mandible laterally (grinding) decreases. Ultimately, the most intense clenching would prevent any grinding of the teeth at all, which provide a stable and protected environment for the temporomandibular joints . With this observation, the appropriate definition of bruxism becomes apparent:"Jaw-clenching, with or without forcible excursive movements". The patient who presents with severely worn teeth, obviously a result of vigorous grinding, may have no symptoms to report, because they never exert adequate clenching intensity to become symptomatic (just enough to rub the teeth together). Another with no indication of occlusal wear, but who complains of severe headaches and neck pain and has no TMD signs or symptoms, clenches intensely in centric position. Only by recognizing bruxism as a function of clenching can these patients be accurately diagnosed.  

 

In a  study of chronic tension-type headache patients without signs or symptoms of  TMD, temporalis contraction (clenching) during sleep was shown to be, on average, fourteen times more intense than in asymptomatic control subjects(10). Clenching in centric and balanced position maintains a stabilized TMJ environment. However, the typical patient with chronic TMD (headaches, face and jaw pain, tooth wear) will forcibly grind their teeth to an excursive position, and then clench in that position ("grinding to a clench"), placing severe and often damaging strain on the TMJ(s)(11). There exists a dynamic relationship between the temporalis' and lateral pterygoids, from which signs and/or symptoms may result. The intensity of the temporalis activity combined with the degree of lateral pterygoid activity (if any), dictates the presentation of headache, TMD, or tooth wear.

Ultimately, in order to treat and prevent bruxism, clenching intensity must be suppressed. Unfortunately, the traditional inter-occlusal splint, while decreasing resistance to lateral movement thereby relieving lateral pterygoid contraction and TMJ strain, provides improved resistance to the temporalis, allowing clenching to persist, or intensify(12).

 By reducing the resistance created by tooth contacts in excursive movement (A), a splint 

allows the lateral pterygoids to contract less intensely.  Therefore, TMJ system strain is less, thereby relieving symptoms.  However, the evenly distributed occluding forces on the same splint (B) provides a more efficient clenching surface.  Therefore, temporalis intensity can 

maintain or increase, thereby maintaining or increasing symptoms.

The success or failure of the traditional inter-occlusal splint is a function of the intensity of clenching. If clenching intensity persists or increases after using a splint, TMD treatment becomes TMD management.

Suppression of temporalis contraction (clenching) can be achieved by exploiting the nociceptive trigeminal inhibition reflex, also known as the jaw-opening-reflex (13,14,15). Direct pressure stimulation of the mandibular incisor's periodontal ligament activates a reflex loop which suppresses the temporalis' contraction intensity (conversely, anesthetization of the mandibular incisors PDL's allows clenching intensity to increase (16)). Historically, an anterior deprogrammer (such as a Lucia jig) or an anterior-point-stop (17), has been advocated to establish and record optimal condylar position (CR) and to suppress acute muscular symptoms on a short term basis. Each are effective in clenching suppression in centric positions. However, for the deprogramming jig, excursive movements of the mandible can allow for a mandibular canine to contact the device, allowing for ipsilateral near-maximal clenching (18) and joint strain.   Protrusive movement of the mandible with the anterior-point-stop allows for occluding of the posterior teeth, again allowing for high intensity clenching. Clearly, all mandibular excursive positions, not just centric, must be considered when attempting to suppress temporalis clenching.

Modifying an anterior point stop by extending the point contact both anteriorly and distally provides clenching suppression in all mandibular movements (a prefabricated, retrofitable device is available commercially through NTI-TSS, Inc.) (19) 

Used primarily during sleep, a modified AMPS (anterior midline point stop)  reduces voluntary clenching intensity to one-third of maximum (20). As described by Okesen (17), the modified AMPS design allows for the best "musculoskeletally stable" (CR) position of the condyles, while suppressing hyperactive musculature. Additionally, by providing for no unilateral canine or posterior contacts, as can happen with a full-coverage splint due to contortion of the mandible in excursive movement (10), the modified AMPS allows for the least amount of potential joint strain in any excursive or protrusive movements, thereby allowing for optimal joint healing an remodeling (21).

Two misconceptions of  a modified AMPS are not uncommon: posterior teeth may supra-erupt, and mandibular incisor(s) may intrude.  In order for a posterior tooth to supra-erupt, it must go unopposed for a considerable amount of time, long enough to allow bone growth at the apex (approximately six weeks is necessary for bone growth). Since it is impossible to masticate with a modified AMPS in place, the daily stimulation of the posterior teeth prevent any adverse drifting or supra-eruption (22).  As for incisal intrusion, a constant low-grade force must be maintained for a considerable amount of time before intrusion can occur. Even in the most extreme circumstances, clenching forces persist for only minutes, not nearly enough time to allow for permanent orthodontic movement or intrusion. Even in the case of the clinician's oversight, where the discluding element of the modified AMPS (which

provides the point stop) is not perpendicular to the long axis of the mandibular incisor (it should be), the patient will report a tenderness to the tooth immediately after the first night of use, and will resist wearing the device until addressed by the dentist, long before there is any orthodontic tipping movement.

Although the modified AMPS device itself does not cause any orthodontic movement, it can allow for optimal positioning of the mandible, due to its providing  for the most musculoskeletally stable condylar position. This is most noticeable in the patient whose condyles happen to seat more posteriorly and superiorly in the fossa as the patient's symptoms resolve. As the condyle seats more posteriorly and superiorly, the mandible "pivots" typically at the last molars, with the anterior mandible rotating inferiorly and posteriorly. The patient's original degree of incisal overlap during CO dictates to what degree, if any, of resulting anterior open bite. Interestingly, when informed of the odds of this scenario occurring, patients are usually surprised if they perceive that the practitioner has placed the importance of their current jaw relationship above their chronic pain.  Following any repositioning of the condyles, some degree of occlusal equilibration may be necessary.

Although the modified AMPS requires slightly less fabrication time than the traditional methods of splint fabrication and delivery (which typically require impressions, models, lab-fees, and the potential for numerous adjustment appointments), the commercially available pre-fabricated devices require one simple chair-side procedure where the device can be retro-fitted and delivered in a 20-minute appointment and a follow-up appointment.  Compared to the bulky and often irritating traditional splint, the relatively smaller size of a modified AMPS and its secure fit provide for excellent patient compliance, while specifically addressing and suppressing the source of the patient's discomfort.

The NTI-tss: 

a) ...b) ...c)    a) Prefabricated matrix  b) Retro-fitted by reline with acrylic  c) Sculpted and finished 

The Authors

James P. Boyd, DDS      - Director of Research, Senior Clinical Instructor:           White Memorial Medical Center’s Craniofacial Pain / TMD Clinic, Los Angeles            http://www.DrJimBoyd.com

Wesley Shankland, DDS, MS, PhD     - Immediate past president American Academy of Head, Neck and Facial Pain           http://www.drshankland.com

Chris Brown, DDS, MPS     - President, American Academy of Pain Management

Joseph Schames, DDS     - Clinic Director:  White Memorial Medical Center’s Craniofacial Pain / TMD Clinic, Los Angeles 

REFERENCES:  (clicking on the number to returns to its location in the article above) 1 .  Management of Temporomandibular Disorders and Occlusion. 2nd edition, p. 160. Okeson, JP. 1989 CV Mosby Co., St  Louis. 2 . Current Controversies in Temporomandibular Disorders, edited by McNeil. Quintessence, 1991 3. Temporomandibular Disorders: Guidelines for Classification, Assessment, and Management, edited by McNeil.  Quintessence, 1990 4 . Hansson TL, "Orthopedic Appliances" in Current Controversies in Temporomandibular Disorders, edited by McNeil. Quintessence, 1991 5 . Perspectives in Temporomandibular Disorders, edited be GT Clark, WK Solberg, p. 180. Quint. 1987 6.  Dao TT, "The efficacy of oral splints in the treatment of MPD of the jaw muscles: a controlled clinical trial" Pain,  1994 Jan 7 . Temporomandibular Disorders: Guidelines for Classification, Assessment, and Management, P. 94 edited by  McNeil. Quintessence,

1990 8. Management of Temporomandibular Disorders and Occlusion. 2nd edition, p. 159. Okeson, JP. 1989 CV Mosby  Co., St. Louis 9.  Wilkinson, TM, "The Lack of Correlation Between Occlusal Factors and TMD" in Current Controversies inTemporomandibular Disorders 10. Clark, GT "Waking and Sleeping EMG Levels in Tension-Type Headache Patients" J. Orofacial Pain, Vol. 11, #4, 1997 11. Hannam AG, "Musculoskeletal Biomechanics in the Mandible" in Current Controversies in Temporomandibular Disorders, 12. Clark GT, Beemsterboer PL, Rugh JD: "Nocturnal massester muscle activity and the symptoms of masticatory dysfunction"              J Oral Rhabil 1981;8:279-286 13. Stohler CS, Ash MM: "Excitatory response of jaw elevators associated with sudden discomfort during chewing"  J Oral  Rhabil 13:225,

1986 14. Sessle BJ: in Roth GI, Calmes R: Oral Biology, p. 61, The CV Crosby Co, St. Louis, 1981 15. Management of Temporomandibular Disorders and Occlusion. 2nd edition, p. 37. Okeson, JP. 1989 CV Mosby Co., St. Louis 16. Williamson EH, Lundquist DO: "Anterior guidance: its effect on eletromyographic activity of the temporal and  masseter  muscles"             J Pros Dent 49:816,1983 17. Management of Temporomandibular Disorders and Occlusion. 2nd edition, p. 403. Okeson, JP. 1989   CV Mosby Co., St. Louis 18. Gibbs C, "EMG activity of the superior belly of the lateral pterygoid muscle in relation to other jaw muscles"            J Pros Dent 1984, 51:691-701 19. "NTI Tension Suppression System", NTI-TSS, Inc., manufacturer, Mishawaka, Indiana. FDA marketing allowance            July, 1998, "For the prevention of chronic tension and temporal mandibular joint syndrome that is caused by chronic           clenching  of the posterior mandibular and maxillary teeth by the temporalis muscle. The device is custom made for the           individual".  1-(877)- 4-NTI-TSS,  http://www.nti-tss.com 20. "Effect of a prefabricated anterior bite stop on electromyographic activity of masticatory muscles." J Prosthet Dent, 

            82(1):22-6 1999 Jul 21.  Schames, et. al.  "Therapeutic motion of the joint" , submitted May 2000 to the Journal of Pain Management. 22.  Kinoshita et al "The effect of hypofunction on the mechanical properties of the periodontium in the rat  mandibular first             molar." Arch Oral Biol, 27(10):881-5 1982

The Butterfly DeprogrammerThis page is technical and meant to be read by dentists

The butterfly deprogrammer is an extremely simple device, fabricated in about 20 minutes at chairside, for the immediate relief of recurrent tension headaches and the acute symptoms of temporomandibular dysfunction.  It is useful as an aid in the diagnosis of TMD, and in the fabrication of a functional laboratory processed splint.  It allows the general dentist to obtain a relaxed centric mandibular relation in which the condyles are located superiorly in their fossae without forceful manipulation. This manually made appliance can be fabricated for the immediate relief of serious temperomandibular symptoms, however, if the patient can wait for several weeks, a laboratory processed NTI device will bring about the same relief without the chairside time. The butterfly is something of a legacy device because it, along with the Lucia Jig preceded laboratory processed appliances of their type for many years.

The butterfly does not cover the maxillary occlusion and thus allows the practitioner to retrieve an accurate, totally relaxed bite registration while the patient is wearing the appliance.  This bite registration can be used to mount study models for further treatment planning and for the fabrication of a uniquely comfortable bruxing guard.  Most important, this form of therapy is non invasive and completely reversible.

Because it is quick and easy to make, inexpensive and well accepted by patients, the butterfly deprogrammer is an excellent first step in the empirical diagnosis and treatment of TMD.  It is made with light cured composite used in the fabrication of provisional bridges and crowns (Triad from Dentsply), but could be fabricated from cold cure acrylic directly in the patient's mouth.  The light cured variety is given its initial cure in the mouth by hand held VLC unit and its final cure in the light curing oven.  

I first learned about the concept of deprogramming as an aid in the treatment of the symptoms of TMD in 1981 while attending a seminar given at Walter Reed Army Hospital by professor Peter A. Neff, who was at that time the chairman of occlusion at Georgetown University.  The original deprogrammer is built using a stone model of the maxillary teeth.  A vacuum formed splint is fabricated to cover the maxillary occlusion, and further modified with clear cold cured acrylic.  The acrylic is used to create a small bite ramp (now called a disoccluding element) which makes contact at only one point, in the midline of the lower incisors.  All posterior teeth are disocclude by two or three millimeters.  This disocclusion, and single

point contact on the mandibular incisal midline is maintained through all protrusive mandibular movements.  

The rational for this form of treatment for TMD is well explained in lay terms in my page on TMJ.  I hope you will take the time to read this page.   Not all dentists will agree with me, but I have had great success using the butterfly deprogrammer if the patients are given a good explanation of its purpose and the type of results that are expected.  The relief of symptoms is the result of a forced relaxation of the muscles of mastication, which in turn brings about relief of pressure on all anatomic structures including the TMJ, the muscles of mastication, the teeth and supporting structures.  Deprogramming frequently brings about a shift in the position of the lower jaw leaving the joints in a more relaxed functional position which probably corresponds fairly closely to Dawson's definition of centric relation.  The position thus obtained may correspond to the patient's centric occlusion, but frequently does not.  The point here is that the condyles occupy a more centric and relaxed position in the fossae.  This position is reproducible without forceful manipulation by the dentist.  The patient simply taps the lower incisors lightly on the point of plastic several times and holds this position gently while a polysiloxane bite registration paste is injected between the teeth.  Injection of the bite registration is possible because there should be approximately 2 to 3 mm between the upper and lower teeth when the patient is occluding on the deprogrammer. 

Why Deprogram?

An anterior midline contact produces minimal temporalis contraction intensity and minimal joint strain, and tends to allow the TM Joints to translate slightly forward to rest against the eminence.   Furthermore, an attempt to brux against an anterior midline disoccluding element produces sore lower incisors, which discourages further bruxing. Thus deprogramming is a simple trick to produce a forced relaxation of the temporalis, masseter and pterygoid muscles allowing the TM Joints to rest in a functionally comfortable position in the fossa.  The butterfly deprogrammer, followed by a bruxing guard built using the new functional (deprogrammed) bite registration can bring about immediate and permanent relief of pain in a majority of TMD cases.  Symptoms relieved include a reduction in tension headaches, ear aches and the neck stiffness associated with parafunction.  Sensitive teeth and "phantom toothaches" in otherwise healthy teeth frequently respond to this form of treatment.  Crepitus and popping of the temperomandibular joints may be lessened or relieved.  

The deprogrammer accomplishes three goals

1. The deprogrammer should bring about nearly immediate relief of acute symptoms.  In general, pain is reduced or eliminated within one or two hours of insertion of the deprogrammer.  Muscle relaxants, analgesics or other drugs are generally unnecessary.

2. The butterfly deprogrammer helps to confirm the diagnosis of TMD, and the appropriateness of jaw repositioning as a treatment.  I have found that in cases where the butterfly deprogrammer does not bring about sufficient relief from pain, the construction of a functional appliance will be of little benefit.   While this does not mean that jaw repositioning therapies are entirely inappropriate, it does imply that the practitioner should be wary and rule out other causes for the patient's pain before proceeding with expensive therapies.  

3. The butterfly deprogrammer brings about relaxation of masticatory structures, and allows for the determination of a functional centric jaw relation and the construction of a "deprogrammed" bite appliance.  Any symptoms of TMD that have been relieved by the use of the deprogrammer should be also be corrected by a properly fabricated deprogrammed bruxing guard.  Unfortunately, bruxing guards, even deprogrammed guards, do not always relieve tension headaches since the patient can still clench against the guard.   Even so, patients often experience a reduction in the frequency and intensity of tension headaches.

In the end, the ability to register an accurate functional centric jaw relation without the use of fully adjustable articulators, face bow transfers or passive manipulation by the dentist is probably the most important advantage of using this simple appliance.

Fabrication of the butterfly deprogrammer

The advent of light cured composites that do not shrink or distort upon curing has made it possible to build the butterfly deprogrammer at chairside.  I use the Triad system (Dentsply).  The composite most suited to this appliance is the VLC provisional crown and bridge material.  It is tooth colored and comes in ropes of convenient length.  Its putty-like consistency and its slight stickiness allow it to be molded (with lubricated fingers) without sagging or falling away from the teeth provided that the teeth and palatal gingiva are fairly dry.  One half rope is sufficient to build the appliance for most patients.  

1. First ask the patient to close their teeth together in their normal centric occlusion.  Note the depth of  the bite and the alignment of the upper and lower midlines.  Also note the degree of overjet.  This will give you a general idea of the position and height of the bite ramp.  (This will be in contact with the lower midline, or if the lower teeth are very uneven, the point will be broadened to contact several lower incisors.)  The bite ramp will open the bite two or three millimeters.  

2. Dry the patient's upper teeth thoroughly with the air syringe.   SEVERE undercuts such as those found under a pontic or under extremely tilted teeth should be blocked out with soft wax.  Lubricate your own gloved fingers with petroleum jelly, or with the patient's own saliva, or with the model separating medium that is supplied with the Triad system.

3.

Begin by applying 1/2 rope of uncured tooth colored provisional crown and bridge material to the palatal gingiva and the lingual aspects of the dried teeth. Start just distal to the second bicuspid on both sides.  Be sure to press it into all embrasures and undercuts on the palatal aspects of the teeth. 

4. Try not to bring the material over the occlusal surfaces of the teeth.  Any material covering the occlusion will be trimmed away later.  Continue pressing the material anteriorly and around the palatal of the arch, in a horseshoe shape.  There should be ample material in  1/2 rope to leave a substantial bulk built up on the lingual aspects of the teeth, and over the palatal gingiva.

5. Now begin to bring some of the bulk forward toward the midline.  It should be built up into a pointed ramp which in most cases lies in the midline between the maxillary central incisors.

The ramp will make contact with the lower anterior midline, provided that the lower incisors are not too uneven. 

6. The point should be broadened into a plane contacting as many incisors as necessary to prevent the ramp from locking the lower teeth into any fixed lateral position, or otherwise interfering in any way with the free movement of the lower jaw as it slides over the ramp. The finished ramp should completely disocclude all posterior teeth during all functional jaw movements.  Most of the time, the length of the disoccluding element should allow for a minimum freeway space, however, relief of tension headache sometimes requires an elongation of the disoccluding element beyond the minimum required to provide for a minimum freeway space.  Sometimes as much as 2 to 3 mm.

7. After initial shaping, the appliance can be light cured right in the mouth.  Since I do all my fillings in light cured composite, I use high powered  PAC lights which shorten my curing time considerably.  In any case, It is necessary to cure the material only to a medium stiffness so that it can be removed from the teeth, and then replaced and cured further.  This step allows for a well adapted appliance that is not locked into undercuts.  When the deprogrammer can be removed from the mouth, and then replaced  several times without distorting,  it is ready to be placed in the light curing oven.  Cure the appliance in the oven for about 5 minutes.  

8. After curing in the light oven, cool the deprogrammer under running water and reinsert it into the patient's mouth.

Check to see if the posterior teeth are disoccluded when the patient bites on the ramp.  Upon occasion, the shift in the position of the mandible can be so great that one side or the other of the posterior teeth can still make contact in some excursions.  If this happens, the ramp can be modified  after it is cured. 

9. It generally does not have enough retention yet to remain in place, but it should fit into the embrasures and over the palatal gingiva , and not rock or cause pressure that the patient finds uncomfortable.

10. In order to make the appliance snap snugly into the palatal aspects of the patient's teeth, it is usually necessary to reline it.  

There are a number of options for this step, but I use the Triad LiteLine gel.  Dentsply sells this material to fabricate removable appliances on plaster models.  Two tubes come with the light, so anyone who uses the triad system usually has some on hand.

11. A dab of the gel is placed into each tooth indent in the appliance, the patient's teeth are wet with water or saliva, and the appliance is replaced on the teeth.  Intraoral curing of this material is done with the VLC light through both the plastic of the appliance and through the teeth.  Note that the Lite-Line material gets hot while curing, however I have never found this to present a problem. 

Removal of the appliance from the patient's mouth is accomplished by inserting a heavy instrument such as a crown remover between the palatal tissues and one of the posterior flanges of the appliance and pulling.  I have never actually had to deploy the spring in the crown remover to supply a shock to remove the appliance.

Once removed, the appliance is trimmed, polished and the patient instructed in its use.  The patient should be able to insert the appliance by lining up the ramp with the incisal midline and snapping it in.  Removal is accomplished by slipping a fingernail under a posterior palatal flange and pulling down.

Within a few minutes of inserting the deprogrammer, the dentist may notice that the position of the lower jaw begins to shift as the muscles relax.  

In extreme cases, the entire mandible may tilt and shift to one side necessitating a change in the position and length of the ramp so that it again occludes with the mandibular midline and all posterior teeth are out of occlusion.  This is easily accomplished by applying Triad bonding agent and additional composite to the ramp.  

How to use the butterfly deprogrammer

The butterfly deprogrammer should relieve the symptoms, confirm the diagnosis and assist in the construction of a permanent bruxing appliance.  I consider the butterfly deprogrammer to be a disposable appliance, so I generally tell the patient that it is to be worn only during the course of active phase I dental treatment.  It may be worn while sleeping and at other critical times of day when the patient is likely to be bruxing or clenching.  Since it is a "throw away" appliance, it may be modified and "refitted" to accommodate changes in the dentition during the weeks or even months it may take to do fillings and produce an overall state of good oral health.  

It should be worn continuously for the first 24 hours except when eating or performing dental hygiene.  After that, the deprogrammer may be worn while sleeping and at times when the patient is likely to

be bruxing or clenching her teeth, such as while working at a computer terminal, driving a vehicle, or concentrating on a task.  Patients generally learn quickly when to wear the appliance.  If the deprogrammer has been properly constructed, the patient's symptoms should be reduced or eliminated within 24 hours.  In most cases, symptoms abate within one hour.  The relief can be so dramatic that patients don't seem to mind the appearance and they quickly learn to speak while the programmer is in place.

Three days of conscientious use of the butterfly deprogrammer should be enough time to evaluate the case.  A majority of cases will clear completely while a few will have no demonstrable relief from symptoms.  It can be assumed that any symptoms relieved by the deprogrammer will be permanently relieved by a deprogrammed bite guard, and the decision of whether to proceed or to refer will be based upon the dentist's clinical judgment modified by the patient's informed consent.  If the deprogrammer produces little benefit, proceeding with a guard or other jaw repositioning therapies may be ill advised. 

Update: Since the introduction of the NTI-TSS device, many dentists have become familiar with the concept of deprogramming.  Over the past few years, many dentists have come to the conclusion that a deprogrammer, such as the butterfly deprogrammer presented here, may be used as as a permanent appliance for the suppression of bruxing and the treatment of TMD.  The disoccluding element (the point that makes contact with the lower incisors)  has been found to replicate an alternative incisal bite which allows the joint to be seated in a natural loading position.  The advantage that deprogrammers have over and above even a deprogrammed bruxing appliance is that they tend to reliably reduce or eliminate tension headaches as well as symptoms of TMD.

Taking and using a bite registration

The patient should be allowed to wear the deprogrammer on and off for several days prior to taking a bite registration.  Just before the bite is to be registered, the patient should wear the deprogrammer continuously all day until the appointment time.  We usually schedule this appointment for the first thing in the morning instructing the patient to sleep with the deprogrammer in place and remove it only to eat and brush the teeth.  Otherwise, the patient's posterior occlusion should be disoccluded for as long as possible before the appointment. 

With the deprogrammer in place, have the patient sit in an upright position and gently tap the lower teeth against the bite ramp a few times.  NOT HARD!  when the dentist is satisfied that the position of contact of the ramp with the lower teeth is stable and reproduced with each tap, have the

patient hold the lower teeth gently against the ramp.  Now begin injecting the Blue Mousse (or Regisil) between the teeth starting on the posterior teeth on one side, and continuing anteriorly being sure to overlay the buccal cusp tips and incisal edges of all teeth while injecting around the arch to the posterior teeth on the other side. 

With the deprogrammed bite in hand, remove the deprogrammer and take alginate impressions of upper and lower teeth to send to the lab.  Ask them to mount the teeth using the Regisil bite, and not to change the vertical dimension when building the bruxing guard.  I prefer a hard acrylic flat plane guard for heavy bruxers, although the newer Thermoflex or nylon materials make fitting the guard much easier since warm water softens the plastic and allows the appliance to self adjust to any discrepancies in the exact fit to the teeth.  In situations involving intractable hard bruxing, however, flexible plastic may be too easily indented to retain a flat plane over the long haul. 

 

 

 

  

 

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The Basics of Occlusal Splint Therapy

Written by Tim J. Dylina, DDS, FAGDMonday, 01 July 2002 00:00

Treatment of occlusal-related disorders is often a challenge for both the dentist and the patient. These disorders are

often difficult to diagnose, as the presenting symptoms can be variable. Occlusal splint design and function can be

considered an example of the art and science of dentistry. Once the cause of occlusal-related disorders is identified,

this reversible, noninvasive therapy provides both diagnostic information and relief without the problems that often

accompany other approaches to care, ie, surgery and extended drug therapy.

The goal of this article is to familiarize “physicians of the masticatory system”1 with the basic principles of occlusal

splint therapy for treating temporomandibular disorder (TMD), bruxism, and some forms of headache.

WHAT IS OCCLUSAL SPLINT THERAPY?

Figure 1. A stabilization appliance

allows freedom of movement for the

teeth and the condyle, but is guided

by the anterior teeth.

Occlusal splint therapy may be defined as “the art and science of establishing neuromuscular harmony in the

masticatory system by creating a mechanical disadvantage for parafunctional forces with removable appliances.”2 A

properly constructed splint facilitates a mutually protected occlusion3 (Figure 1).

WHAT TYPES OF SPLINTS ARE AVAILABLE?

The types of splints currently employed in occlusal splint therapy include permissive, nonpermissive, hydrostatic, and

soft rubber (silicone) splints. The permissive splints4 allow the teeth to glide unimpeded over the biting or contact

surface. These include bite planes (anterior deprogrammer, Lucia jig, anterior jig) and stabilization splints (Tanner,

centric relation, flat plane, and superior repositioning).

Figure 2. An anterior repositioning

appliance (nonpermissive) locks the

teeth and mandible in a forward

position.

The nonpermissive splints have ramps or indentations that limit the movement of the mandible. Examples include an

anterior repositioning appliance (ARA) and a mandibular orthotic repositioning appliance (MORA) (Figure 2).

Soft rubber splints and hydrostatic splints (Aqualizer, Jumar Corp) function by separating the teeth. Soft rubber

splints, however, do not provide the characteristics necessary for successful splint therapy. These splints can

exacerbate bruxism,5 possibly due to premature posterior contacts related to the fact that these splints cannot be

balanced.

HOW DO SPLINTS WORK?

Splints provide diagnostic information, allow muscles in spasm to relax, protect the teeth and jaws from the adverse

effects of bruxism, and normalize periodontal ligament proprioception. These devices can also allow repositioning of

the condyles and jaws into centric relation (CR).2

Providing Diagnostic Information

Figure 3. Wear facets on the splint

indicate parafunctional habits.

Occlusal splints provide diagnostic information in different ways. The restorative dentist can determine the envelope

of function, potential neutral zone impingements, parafunctional habits, and anterior guidance requirements, as well

as obtain information about vertical dimension from patients who wear a splint. A study of patients with nocturnal

bruxism revealed that 13% exhibited isometric clenching, 71% exhibited bilateral clenching, 13% exhibited unilateral

excursion, and 3% exhibited protrusive movement6 (Figure 3). The treating clinician can predict from this information

that a large precentage of patients requiring restorative treatment may exhibit lateral parafunctional forces that could

damage the natural and prosthetic dentition. Cusp shapes, sizes, angulations, and depths can be evaluated and

properly designed if this information is available prior to treatment.

Temporomandibular (TM) status may also be obtained and a working diagnosis verified or discarded. An example is

the individual diagnosed with a muscular TM joint that does not achieve total muscle relaxation with treatment. This

can indicate a more advanced joint disorder than originally diagnosed. This author considers splint wear mandatory

prior to extensive restorative therapy.

Muscle Relaxation

The literature has shown that tooth interferences to the CR arc of closure activate the lateral pterygoid muscles7;

posterior tooth interferences during excursive mandibular movements cause hyperactivity of the closing muscles8;

and conversely, that the elimination of posterior excursive contacts by anterior guidance significantly reduces elevator

muscle hyperactivity.9 Even small (50 µm) occlusal interferences can initiate changes in coordinated muscle activity.10

Headache is observed in many TMD patients.11,12 The effectiveness of splint therapy in reducing head and neck pain

and muscle hyperactivity is well documented.13-16 A specific anterior deprogrammer known as the nociceptive

trigeminal inhibition (NTI) appliance has recently been approved by the FDA for the prevention of medically

diagnosed migraine headache pain.17 Occlusal splints promote muscle relaxation by providing a platform for the teeth

that allows for equal distribution of tooth contacts, immediate posterior tooth disclusion in all movements (with anterior

guidance), and reduced stress on the joint. Neuromuscular harmony that follows provides for optimal function and

comfort.

Protecting Teeth and Jaws From Bruxism

Bruxism has been defined as “the grinding or clenching of teeth at other times than for the mastication of

food.”18 Certain authors have suggested it is only a nocturnal activity.19 A CR-balanced splint can provide protection

from the potentially adverse effects of this parafunctional activity.

Studies examining the occurrence of bruxism have reported prevalence ranging from 6.5% to 88%.20 The forces

generated during bruxism can be as much as six times the maximal force generated by normal chewing.21 Since the

average force generated by normal chewing is 162 pounds per square inch,22 patients who brux should be identified

and treated as required. Identification involves examination of the teeth, supporting tissues, muscles of mastication,

and TM joints. Signs or symptoms of bruxism should be countered with a nocturnal CR-balanced splint prior to and

after any restorative intervention.

It is important to remember that splints do not prevent bruxism, rather, they distribute the force across the masticatory

system. These appliances can decrease the frequency but not the intensity of the bruxing episodes.6

An interesting study by Nitzan suggested another pathologic mechanism.23 Cellular hypoxia can take place when

capillary perfusion pressure is above 25 mm Hg. Needles were inserted into the superior joint space of dental

students during maximal clenching, both with and without a flat plane appliance in place. Pressures exceeding 200

mm Hg were observed when clenching without the splint, but pressures were less than 25 mm Hg when clenching

with the splint. With compression of the vessels, the affected area has reduced blood flow, which will adversely affect

normal function and wound healing.

Normalizing Periodontal Ligament Proprioception

The attachment of a tooth to the osseous (alveolar) housing is via the periodontal ligament. Contained within this

collagenous structure are sensors (proprioceptive fibers) that perceive force. Messages received from the ligament

are transmitted through nerve fibers to the central nervous system, triggering muscle patterns that protect the teeth

from overload. Using an animal model, Hannam and coworkers24 found that stimulation of pressure receptors in the

periodontal ligament led to a jaw-opening reflex. Hellsing demonstrated that muscle changes occur with tooth contact,

and that periodontal afferent feedback (sensory nerve feedback) must be responsible for this rapid adaptation.25 An

occlusal splint functions to dissipate the forces placed on individual teeth by utilizing a larger surface area covering all

teeth in the arch. Once fabricated, a splint must be continually adjusted to re-establish equal contact, balance the

load, and allow for muscle symmetry.

Allowing Condylar Seating in CR

CR is defined as “the relationship of the mandible to the maxilla when the properly aligned condyle/disc assemblies

are in the most superior position against the emminentia irrespective of tooth position or vertical dimension.”1

Figure 4. The properly aligned

condyle/disc assembly. Physiologic

function is dependent on the

component parts being in position

when loading occurs.

Figure 5. The articular disc and its

attachments maintain their

physiologic position as the lateral

pterygoid obtains full extension.

CR can be a starting point for determining the relationships of the teeth, discs, bones, ligaments, and muscles (Figure

4). The condyle/disc assembly is allowed to seat in CR (Figure 5) when the superior belly of the lateral pterygoid

muscle obtains its full extension due to minimal positioning muscle hyperactivity, which dictates tonic muscle activity

as opposed to any type of muscle hyperactivity. The TM joints are load bearing,26-28 specifically during parafunctional

activities and forceful mastication or biting. During loading, the elevator muscles (mainly the temporalis and masseter)

can exert maximal force with a totally relaxed lateral pterygoid and a disc that is physiologically located. When the

lateral pterygoid is triggered to hyperactivity through occlusal stimuli, the disc is pulled anteriomedially toward  the

origin of the muscle, resulting in displacement. In this case the disc, condylar head, ligaments, and muscle are under

excessive loading and are susceptible to damage. Chronic and acute overloading of the condyle/disc assembly when

not in normal physiologic position contributes greatly to the development of TMD.

A properly balanced splint results in an occlusion associated with relaxed positioning elevator muscles, allowing the

articular disc to obtain its antero-superior position over the condylar head. Splint therapy can utilize CR as the

physiologic treatment position. This is contraindicated in situations where inflammation of the joint results in pain. The

condyles may have to be in an anterior-inferior joint position until the inflammation subsides and CR is achievable.

The literature supports repositioning into CR. Curtis and coworkers29 demonstrated that splints designed to provide a

lateral deviation to the centric arc of closure resulted in bone density changes in the condyles of monkeys. The

monkeys positioned in CR did not experience changes in the condyles. Pressure may be associated with cartilage

breakdown and arthritis in the condylar heads.30

WHICH TYPE OF SPLINT SHOULD BE USED AND WHEN?

The type of splint utilized is dependent on the diagnosis. A careful medical/dental history along with a comprehensive

examination is necessary for all patients, but especially those with facial pain, TMD, or bruxism.

If the patient reports bruxism and headaches but no TMD, the use at night of a full-coverage splint, in which acrylic

covers an entire arch of teeth, is often adequate to protect the teeth. Muscle relaxation is an added benefit that often

relieves or eliminates tension headaches. The choice of the arch for which the splint is fabricated is dictated by the

type of bruxism habit. If the patient clenches isometrically, a full-coverage maxillary guard with all of the teeth in

contact is appropriate. With isometric clenching, the maxillary anterior teeth would not be covered on a mandibular

splint, and since no movement takes place, this force would not be properly distributed using this type of splint. If the

patient demonstrates parafunctional movement in lateral and protrusive directions, a splint for the mandibular teeth

will be effective. With parafunctional movement laterally, a mandibular splint that does not touch all of the anterior

teeth is acceptable (it must touch the cuspids for guidance, but to extend it to touch the incisor teeth would be

uncomfortable and unsightly). Pressure is not transferred to only the posterior teeth because movement is so

dynamic. If there is a question regarding the extent of mandibular nighttime movement, a maxillary splint is preferred.

Figure 6. An 8-mm splint eliminated

headache pain; a 4-mm splint did

not.

The occlusal thickness of the splint has been addressed in the literature. Manns et al14 showed that splints that

increased vertical dimension 4.4 mm and 8.2 mm were more effective in producing muscular relaxation in patients

with bruxism and myofascial pain dysfunction patients than 1-mm splints. Piper31 suggested a 12- to 15-mm distance

(incisal edge to incisal edge) to decrease clenching efficiency. These studies suggest that a minimum of a 4-mm

increase in vertical dimension is necessary to protect bruxing patients. If the patient is wearing a splint 4 mm in

thickness and still experiences muscular soreness, headache, and/or facial muscle tightness immediately after

waking, splint thickness should be increased incrementally until symptoms disappear, indicating that the appropriate

splint thickness has been determined (Figure 6).

For TMD patients, the selection of a splint is dependent on the diagnosis of the disorder. For the specific diagnosis of

TMD, the Piper Classification31 is helpful. The use of medications and other treatment approaches is beyond the

scope of this article.

Figure 7. An anterior deprogrammer

is utilized to separate the teeth for

muscle relaxation.

Bite plane therapy may be used when a muscle disorder is suspected (Figure 7). Muscle disorders are initiated by

hyperocclusion; bite planes separate the teeth, allowing the muscles to relax. These appliances should not be worn

for longer than 24 to 48 hours continually, as they cover the maxillary anterior teeth, and intrusion/supra-eruption of

posterior teeth could occur from lack of contact. Full-coverage stabilization splints, which are flat plane splints

covering the entire dental arch, are also acceptable, and may be the treatment of choice for unreliable patients. In

general, muscle disorders are effectively treated with appropriate splint therapy (bite planes and stabilization

appliances).

Combination muscle and disc disorders are identified by joints that click or pop, and  muscle symptoms are also

present. These disorders tend to be more chronic in nature (unless there has been an acute exacerbation), and are

associated with more damage. Stabilization splints are the treatment of choice, as they provide long-term wear that is

usually needed. They also cover the entire dental arch, ensuring that the covered teeth do not move. They must be

worn continually for 24 hours (except when eating) for as long as required to eliminate muscle, disc, ligament, and

tooth symptoms. Three to 6 months of wear is often required. These disorders may be reversible if detected relatively

early and treated appropriately.

Advanced disc and muscle disorders are identified in patients who experience jaw locking and/or noises, painful

joints, and sometimes increasing pain with splint wear. Patients with acute trauma may require an anterior

repositioning appliance for 7 to 10 days to keep the condyle away from the retrodiscal tissues, so inflammation can

subside. These patients often have a long history of joint pain, locking, and instability. Stabilization splints are the

treatment of choice, and must be balanced to accommodate the specific needs of the patient (ie, many patients

require shallow cuspid guidance in lateral or protrusive movements to eliminate joint clicking). Splints may need to be

worn for 6 months to 2 years depending on the patient. These disorders are usually not reversible, but with treatment

patients can experience amelioration of symptoms.

HOW OFTEN SHOULD SPLINTS BE ADJUSTED?

In a study by Holmgren et al6 occlusally induced changes (indentations) were observed every 2 weeks in 61% of

patients. The remaining 39% also demonstrated changes at different times, namely indentations in the acrylic,

indicating some grinding movements or static indentations. This suggests that more than half of splint patients require

postdelivery visits before 2 weeks. A suggested protocol would include adjustments at 24 hrs, 3 days, 7 days, 14

days, 21 days, and 1 month. When no movement on the splint is seen at adjustment appointments and symptoms are

improving, the intervals between adjustments can be extended, and the patient told to call for an appointment if

symptoms worsen. The splint must be continually monitored and adjusted to ensure equal contacts on all teeth, with

immediate disclusion of the posterior teeth in all movements. When muscle relaxation is achieved and/or

inflammation subsides, the position of the teeth on the splint will change. Neuromuscular harmony often returns when

readjustment to the CR position is accomplished. If interferences on the splint are continually eliminated by

rebalancing into CR, the patient will realize long-lasting relief from symptoms.

CONCLUSION

Familiarity with application of splint therapy for patients with occlusal-related disorders can be one approach to

treatment of affected individuals. Proper diagnosis and fabrication of the appropriate device can often result in relief

of symptoms.

References

1. Dawson PE. Evaluation, Diagnosis and Treatment of Occlusal Problems. 2nd ed. St Louis, Mo: Mosby; 1989.

2. Dylina TJ. A common sense approach to splint therapy. J Prosthet Dent. 2001;86:539-545.

3. D’Amico A. Origin and development of the balanced occlusion theory. J South Calif Dent Assoc. 1960;28:317-318.

4. Boero RP. The physiology of splint therapy: a literature review. Angle Orthod. 1989;59:165-180.

5. Okeson JP. The effects of hard and soft occlusal splints on nocturnal bruxism. J Am Dent Assoc. 1987;114:788-

791.

6. Holmgren K, Sheikholeslam A, Rüse C. Effect of a full-arch maxillary occlusal splint on parafunctional activity

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Dent. 1993;69:293-297.

7. Ramford S, Ash M. Occlusion. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1983.

8. Manns A, Rocabado M, Cadenasso P, et al. The immediate effect of the variation of anteroposterior laterotrusive

contact on the elevator EMG activity. Cranio. 1993;11:184-191.

9. Williamson EH, Lundquist DO. Anterior guidance and its effect on electromyographic activity of the temporal and

masseter muscles. J Prosthet Dent. 1983;49:816-823.

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12. Schokker RP, Hansson TL, Ansink BJJ. Craniomandibular disorders in patients with different types of

headache. J Craniomandib Disord Facial Oral Pain. 1990;4:47-51.

13. Manns A, Miralles R, Guerrero F. The changes in electrical activity of the postural muscles of the mandible upon

varying the vertical dimension. J Prosthet Dent. 1981;45:438-445.

14. Manns A, Miralles R, Santander H, et al. Influence of the vertical dimension in the treatment of myofascial pain-

dysfunction syndrome. J Prosthet Dent. 1983;50:700-709.

15. Clark GT, Langham F, Flack VF. Treatment outcome results for consecutive TMJ clinic patients. J Craniomandib

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17. Hornbrook D. A look at a promising device for treating TMJ, migraine pain. Dent Pract Report. 2001; November,

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18. Nadler SC. Bruxism, a classification: a critical review. J Am Dent Assoc. 1957;54:615-622.

19. Zarb GA, Carlsson GE. Temporomandibular Joint Function and Dysfunction. Copenhagen, Germany:

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21. Gibbs CH, Mahan PE, Mauderli A, et al. Limits of human bite strength. J Prosthet Dent. 1986;56:226-229.

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transmission.J Prosthet Dent. 1981;46:443-449.

23. Nitzan DW. Intraarticular pressure in the functioning human temporomandibular joint and its alteration by uniform

elevation of the occlusal plane. J Oral Maxillofac Surg. 1994;52:671-679.

24. Hannam AG, Wood WW, De Cour RE, et al. The effects of working side occlusal interferences on muscle activity

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25. Hellsing G. Functional adaptation to changes in vertical dimension. J Prosthet Dent. 1984;52:867-870.

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29. Curtis DA, Nielsen I, Kapila S, et al. Adaptability of the adult primate craniofacial complex to asymmetric, occlusal

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30. Radin EL, Paul IL, Rose RM. Role of mechanical factors in the pathogenesis of primary

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