Joint splint. Splint for TMJ treatment
Temporomandibular joint dysfunction — is a malfunction of the joint due to misalignment of the jaw, teeth or muscle tension. It can manifest as discomfort and pain when opening the mouth, muscle tension, and clicking. In this article, we will take a detailed look at how one of the tools to improve joint and muscle function — joint splint works.
An articular splint or splint is a removable plastic mouth guard that partially or completely covers the occlusal surface of the teeth of one of the jaws. Each splint is made individually based on impressions of the patient's teeth and depending on the treatment objectives.
How does the splint work?
The splint prevents the teeth from closing in the position the patient is accustomed to, which provokes joint dysfunction and muscle tension. While wearing the splint, the teeth close on it and the patient gradually gets used to the new, more correct position of the jaw: the joint changes position and the muscles relax.
An articular splint is usually used as one of the stages of treatment of dysfunction and solves the following tasks:
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Relaxation of the chewing muscles,
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Determination of the new jaw position,
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Holding the new jaw position,
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Moving the lower jaw to a new position.
In order to determine treatment goals and fabricate the correct splint, the gnathologist performs a joint diagnosis.
Joint Diagnosis for Splint Fabrication
The first thing the doctor needs to determine is whether the joint dysfunction is triggered by muscle tension or improper bowing. The type of splint depends on this. To do this, the doctor performs a number of tests, such as asking you to open and close your mouth, palpating the joint and muscles, and other manipulations.When the cause of dysfunction and the goal of treatment is determined, the doctor begins to find the optimal position of the jaw, in which the patient will be comfortable — the muscles will not be overstretched, the joint will take a new position.
Positions are determined according to the following algorithm:
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Deprogramming. The patient puts on a removable device made of plastic or hard silicone for 30-40 minutes, which prevents the teeth from habitually closing. At this time, the muscles relax and the articular head gets into the correct position.
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Monitoring the position of the joint. Once the new joint position has been found, it needs to be monitored using CT and MRI scans. The doctor needs to make sure that the bony and soft structures of the joint are accurately in the correct position. In order to fix the new position on the MRI image, the patient takes it in a bite guard. The bite guard — is a silicone impression of the patient's upper and lower teeth that replicates the jaw position found in the deprogrammer.
Planning and fabrication of the splint
When a new position has been found and the doctor is satisfied that the joint and muscles are working correctly in that position, a splint must be fabricated to fix that position. There are 2 methods that can be used to plan the splint.
Classical planning
The plaster models of the patient's teeth are placed in an articulator — a device that simulates the movement of the jaws and joint. In it, the doctor finds the new jaw position and draws up the specifications for the fabrication of the splint: at what height the splint will be, and which teeth will be covered.Digital planning
The joint splint can also be planned in 3D modeling programs: Exocad, Avantis. The software allows you to upload CT and MRI images, model the new position of the joint and jaws as well as the articulator, and set the parameters for printing the splint based on the data.
After the specification is ready, the splint can be produced in 3 ways:
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Manually in the articulator. The mouthpiece is molded from silicone in the new position set in the articulator.
A handmade splint -
3D printing. A virtual model of a joint splint can be printed from safe medical plastic on a 3D printer.
Splint printed on a 3D printer -
CAD/CAM milling. Machining of the mouthpiece from a digital model.
Machine-milled splint
Joint splints that are 3D printed or milled tend to be thinner and resistant to staining.
Splint therapy. Splint treatment
The patient must wear the splint virtually 24 hours a day and remove it only when brushing teeth. For effective treatment, it must not be removed even during meals — the jaws must fully adapt to the new alignment while chewing. Sometimes during the treatment process, the doctor will prescribe an adjustment of the splint — slightly resurfacing it in height if the treatment plan requires it.
The splint should be removed when brushing your teeth. It can be cleaned with a regular toothbrush and rinsed under running water.
The average treatment period for splinting is 2-3 months to six months, until the muscles and jaw have adjusted to the new position.
The process of wearing the splint may also include muscle myogymnastics and work with an osteopathic physician.
Splint treatment results
The aim of splint therapy — to find a position in which the joint will occupy the optimal position. It is not always possible to align all joint structures perfectly. However, the main indicator of success of splint therapy — relief from symptoms of dysfunction: pain at rest or on movement, tension, difficulty opening the mouth.
Fixing the results of splint therapy
When the splint has worked, the new jaw position is fixed and the patient is comfortable, it is removed. But since the patient's bite has remained unchanged, the jaw position will soon return to the pre-splint treatment condition or may even worsen.
Hence, the next task — to fix the clamping of the teeth in the new position. To do this, the patient undergoes orthodontic or orthopedic treatment, or treatment in combination. Orthodontic treatment creates a correct bite for the patient. Orthopedic restorations raise the height of the bite and also help to restore proper alignment. If the patient undergoes orthodontic treatment after joint therapy, occlusal onlays may be prescribed for this period to maintain the teeth in alignment.