TMJ Surgery: The Use of oral orthotics (splints) in managing “TMJ”

`One of the most basic non-surgical management tools in the armanentarium of providers managing patients in this field is the occlusal orthotic (bite splint).  From a surgical standpoint, the sole purpose of the oral orthotic is to separate the teeth and prevent the condyle of the mandible from seating and loading the articular disc/capsule of the TMJ.  Some non-surgical providers will maintain patients on occlusal orthotics for months or years, often changing “splints” to meet an ever changing or exclusive management philosophy of the provider. (Provide ways for jaw muscles to relax, “deprogram” muscles from the interference of the influence of the way the teeth contact, etc.)

In their defense, orthotics or splints have been shown to be an effective way to manage joint pain in meta-analysis of the dental literature on the subject. (1)  However, the problem often becomes one of difficult practical options for the patient.  And, what about people with multiple missing teeth ?….

The fundamental question in management should be what happens if the orthotic is discontinued, say, during the act of chewing function.  If joint pain and instability are corrected while the orthotic is worn, this is a good thing.  However, most patients can not or will not be able to wear the devices continuously during everyday life.  Likewise, they can not be worn indefinitely during chewing and loading function as they are very inefficient and cumbersome to eat with.   When pain returns during routine chewing loading of the joint or attempted mouth opening, it just might be that mother nature is giving one a clue that all is not well.  Rarely do non-surgical providers incorporate the use of MRI or other specifically sensitive imaging testing to assess their treatment.  This is unfortunate.
Our non-surgical protocols are to place patients in orthotics that adapt to the lower jaw.  The position of the lower jaw is determined by a radiograph called a tomogram, which is a thin cut image of the joint.  The orthotic is constructed and the teeth separated enough to provide a centered  condyle/fossa position with a significant increase in joint space compared to when teeth are in contact.  This generally requires a slight forward posturing (edge/edge incisor tooth  position) of the mandible.  We ask our patients to wear the orthotic 16-18 hours a day for a month, including night time.  We construct one for the lower jaw because they do not interfere with speech function as much as maxillary (fit to the upper teeth) orthotics or splints.  They can be tolerated better at work or school.  Also, the mandible can be manipulated slightly to decompress a painful and compromised joint.  We do not want the  patient to alter the diet nor eat with the orthotic in place.  It is during this time that we want to ascertain how this joint will function during routine chewing function and loading.  After all, painless joint stability during eating is the goal of any therapy.  If a patient improves with the orthotic but joint instability and pain progressively returns during routine mastication loading, this is significant.

If symptoms do not improve after one month of orthotic wear, we will examine the patient with MRI imaging in the dental occluded position,and  open mouth position, with and without the orthotic.

In general, the decision to suggest TMJ surgery to a patient comes when MRI imaging reveals a significant derangement or  impingement along with a joint that continues to be significantly unstable in all examined range of motion.  Patients will continue to complain of significant pain and jaw  incoordination  when eating, despite wearing the splint for significant hours each day.  Comparison of the images with the teeth in their natural occlusion position  together and the splint in the mouth gives the provider an idea of how effective the splint is in overcoming  various orthopedic pathologies in the joint  when teeth come in contact or the mouth opens.

In reality, A TMJ derangement or this physical impingement problem is not too dissimilar to the concept of impingement syndrome of the shoulder where different curvatures of the achromion (equivalent to socket/fossa of the shoulder joint) and the head of the humerus (condyle of the upper arm) pinch down on the rotator cuff of the shoulder joint in various degrees and position of the  shoulder/arm rotation and abduction.

For surgical patients, I obligate surgery  patients to wear the surgical orthotic continuously for one month post operatively.  This does two things.  When the disc/capsule of the joint is repaired, the critical area of repair receives the maximum amount of physical force in the joint region when the teeth engage.  To that end, we do not want this region of the TMJ disc/capsule loaded until tensile strength of the repair site is assured.  (generally 4-6 weeks).  Likewise, since the joint is a synovial (fluid making) joint, there will likely be a post operative effusion temporarily (fluid in the joint) from the operation.  Taking loads off the joint during this time improves patient comfort based on their feedback along with MRI data (see below).

Finally, a word about bruxism.  Bruxism or jaw/teeth clenching or grinding  is a human fact of life, first described by ancient Egyptian physicians and the famous Greek physician Galen long before the time of Christ.  It can be physically apparent to any of us during stress or other emotionally charged periods of consciousness.  For many, it can occur at night during sleep and is a common physiologic reflex that is, for most, uncontrollable.  In orthopedic surgery, certain lifestyle considerations are taken into account when specific types of joint surgeries are performed.  With jaw joint surgery, long term bruxism can not go uanappreciated in the surgery patient and it is our advice to patients to consider the use of the orthotic at night indefinitely, to protect against joint loading that can be higher and occur for longer periods of time then when we eat a meal.

1.  Forssell H, Kalso E et al:  “Occlusal treatments in temporomandibular disorders:  a qualitative systematic review of randomized controlled trials.”  Pain 1999, 83:  549-60.

2. rinchuse D and McMinn, J:  “Summary of evidence based systematic reviews of temporomandibular disorders “  Am J Orthod Dentofacial orthopedics, 2006;  130a;  715-720.

3.  Guidelines for Diagnosis and Management of Disorders Involving the Temporomandibular Joint and Related Musculaskeletal Structures.  The American society of Temporomandibular Joint Surgeons.  2004 (See ASTMJS.org)

Tags: Add new tag, jaw joint, orthopedic surgery of jaw, TMJ Surgery