Occlusal Appliances
Occlusal guards have several purposes. The guards can protect the teeth from wear such as attrition, interrupt oral habits such as clenching, redistribute forces of sore and sensitized teeth, and establish a comfortable occlusal position in a patient who has substantial complaints of bite discomfort.
There are several appliances that dentists have used over the years, some good and some not-so-good. The first and most successful is the full arch flat plane stabilization splint or appliance. This appliance is the least likely to cause harm.
The primary indication for a stabilization appliance is for the patients with moderate levels of attrition, dentin exposure on several teeth, and cheek ridging with moderate bilateral tenderness in the jaw closers on palpation.
The purpose of the occlusal splint is to protect the teeth from further attrition damage, try to reduce the pressure on the sore teeth, and possibly change the patient’s parafunction behavior.
Related Reading: How to Perform an Occlusal Analysis
How an Occlusal Stabilization Appliance Works
The device works “to serve as a behavioral changing device that makes the patient aware of any oral parafunction.” A full arch hard acrylic stabilization appliance is usually fabricated for the maxillary arch or mandibular arch. They are a non-repositioning, flat-surface appliances that cover all teeth and has equal, bilateral posterior tooth contact. Most times, it incorporates anterior tooth guidance during any excursive movement.
When stabilization appliances are used in painful cases, they are commonly adjusted to the jaw closure position of maximum intercuspation or habitual closure. This position is also referred to as muscular contact position (MCP) or centric occlusion (CO).
Stabilization appliances are generally worn during sleep and one to two hours during the day to allow the patient time to practice keeping the teeth apart (e.g. instruct the patient not to consciously ever bring their teeth together on the appliance during the day).
The patient should reduce the time using the appliance after they experience relief of their jaw pain symptoms is evident. They may need to continue use if there is ongoing wear of the occlusal surface of the appliance, indicating a strong clenching or bruxing habit.
Because acrylic is far softer than enamel, single arch oral appliances have been used to reduce the chances of further wear, chipping or cracking of the teeth in both arches.
The diagnoses that would link with this treatment procedure or protocol includes:
- Localized myalgia where the etiology is fully or partially present due to clenching
- Localized capsulitis or arthritis where the etiology is fully or partially present due to clenching
- Severe attrition due to bruxism
- Trigeminal neuropathic pain in teeth where the suspected etiology is tooth clenching
- Unstable occlusion (uneven or lacking of posterior balanced occlusal contacts)
Related Reading: How to Diagnose Masticatory Muscle Disorders
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Partial Coverage Dental Devices
Partial coverage dental devices come in two flavors. One is the lower posterior only occlusal coverage devices that are connected with a lingual bar. The other is the anterior bite plane devices that covers only two to four anterior teeth.
Both devices certainly disrupt the patient’s ability to close together and are, therefore, alter the clenching behavior. Unfortunately, similar to full arch splints described above, the patient can habituate to the device and starts to clench or brux again.
The general and consistent rule of thumb is that no passive occlusal appliance, regardless of its shape or form, will stop the motor behavior of the jaw. The second problem with partial coverage devices is that they have the real potential to alter the patient’s jaw position and cause unpredictable shifts in the occlusion (i.e. open bites).
Related Reading: Trigger Point Mapping: Theory & Step-by-Step Technique
Mandibular Repositioning Appliances
Appliances that deliberately alter the position of maximum intercuspidation are not recommended for use. These appliances are called mandibular repositioning appliances. They typically have ramps on and/or indentation in the surface of the appliance in order to drive the jaw into the new (forward or anterior) position.
These devices may help a patient avoid jaw clicking, but they will produce a posterior open bite since they are supposed to be used 24/7. This produces a shortening of the lateral pterygoid, and if the patient is held in this position for very long, they cause remodeling of the condyle and mandible. This causes the mandible to permanently stay in the forward position.
Over 65% of the time in these disk displacement cases, the clicking will return after several weeks to months so now the patient faces the original clicking jaw joint and a splint induced malocclusion.
Related Reading: Internal Derangements of the Temporomandibular Joint
Occlusal Stabilization Therapy
There are a variety of clinical situations (e.g. an unstable or inadequate position of maximum intercuspation) where it is necessary to perform more permanent occlusal stabilization treatment.
This treatment can involve the following methods to improve the number or distribution of posterior tooth contacts:
- Occlusal surface bonding on posterior teeth which are not in contact
- Equilibration of a specific tooth or multiple teeth
- Restoration of teeth to shorten or lengthen them
- Orthodontic movement of teeth
- Orthognathic surgical movement of part or all of the jaw
The goal of this therapy is to increase and balance the forces on the posterior teeth. Usually this treatment is only done after the jaw is non-painful or has stopped growing if the original instability is secondary to a jaw growth disorder (condylar hypermobility).
The diagnoses that would link with this treatment procedure or protocol include:
- Unstable occlusion (uneven or lacking of posterior balanced occlusal contacts)
- Patient should not have pain or trismus associated with the unstable occlusion
- Patient is usually treated with an occlusal stabilization splint to reduce pain or trismus before occlusal stabilization therapy
Related Reading: Closed Lock Mobilization: TMJ Exercises & Stretches
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