Bruxism can be defined as the grinding of teeth for non-functional purposes. Some authors refer to nocturnal grinding as bruxism while the term bruxomania is given for grinding during the day time.
Para function is abnormal function, as in bruxism. Bruxism (tooth grinding, occlusal neurosis) is a habit of grinding, clenching, or clamping the teeth. The force generated may damage both tooth and attachment apparatus. It should be emphasized that bruxism occurs during vertical (clenching) and horizontal (grinding) nonfunctional movements of the mandible. It may occur during sleep (nocturnal bruxism) or during waking hours (diurnal bruxism). Parafunctional tooth contacts tend to be repetitive and of greater force and duration than the more random and fleeting functional tooth contacts.
1. Psychological and emotional stresses have been attributed as one of the causes of bruxism.
2. Occiusal interference or discrepancy between centric relation and centric occlusion can predispose to grinding.
3. Pericoronitis, and periodontal pain is said to trigger bruxism in some individuals.
a. Occlusal wear facets can be observed on the teeth.
b Fractures of teeth
c. Mobility of teeth.
d. Tenderness and hypertrophy of masticatory muscles.
e. Muscle pain when the patient wakes up in the morning.
f. Temporomandibular joint pain and discomfort can occur.
History and clinical examination in most cases is sufficient to diagnose bruxism. Occlusal prematurity can be diagnosed by use of articulating papers. Electromyographic examination can be carried out to check for hyperactivity of the muscles of mastication.
Many cases of bruxism are associated with emotional and psychological disturbances. Thus appropriate psychological counseling by a psychiatrist maybe initiated. Hypnosis, relaxing exercises and massage can help in relieving muscle tension. Occlusal adjustments have to carried out to eliminate prematurities. Night guards or other occlusal splints that cover the occlusal surfaces of teeth help in eliminating occlusal interference, prevent occlusal wear and break the neuromuscular adaptation.
Bruxism may have been established during the dental history. Not all patients are aware of parafunctional activity, and therefore, an interview with the patient rarely provides reliable diagnostic information vis-a-vis parafunction. It has been estimated that only a few patients (20%) know they engage in parafunction. Most patients deny the activity, but when asked to duplicate jaw movements associated with parafunction, they will duplicate them easily. Stressful lifestyles, heavy occlusal wear facets on nonfunctional tooth surfaces, fractured cusps, tooth mobility, hypercementosis, tenderness and or hypertrophy of masticatory muscles, and limited mandibular opening are frequent bedfellows of parafunction, and their presence in a given case could have diagnostic ramifications.
Occlusal adjustment for bruxism. It is axiomatic that the muscles of mastication be free of myospasm or other functional disorders before occlusal adjustment is performed. Spastic, splinted muscles occur in response to noxious or injurious tooth contacts and result in neuromuscular patterns of jaw movement that avoid the offending tooth contact(s). These same contacts may be the target contacts of occlusal adjustment, and it is pointless to adjust an occlusion when target contacts cannot be recorded. Stressful life-styles or events commonly provide a psychic background for myospasm.
Occlusal analysis for bruxism. Ideally, the occlusal analysis should be carried out on an adjustable articulator with the maxillary cast mounted on the hinge axis on an anatomical articulator, and the mandibular cast should be mounted in centric relation. Alternatively, the analysis may be performed in the mouth. In either case, occlusion contacts should be recorded along the operator-guided, patient- generated, movements of the mandible that originate in centric relation.
How Is Force Control Achieved for a Periodontal Patient with bruxism?
Force control in a patient with occlusal traumatism may be achieved by occlusal adjustment of the natural dentition (occlusal adjustment), removable appliance therapy (night guards), removable and fixed provisional splint therapy, orthodontics, and fixed restorative dentistry. This chapter will discuss general guidelines for occlusal adjustment and appliance therapy tor cases of moderate chronic periodontitis with occlusal traumatism that can usually be managed effectively with these two traditional forms of force control.
What Are Occlusal Adjustment and Occlusal Appliance Therapy?
Occlusal adjustment is the reshaping of occlusal surfaces of teeth by grinding to create harmonious contact relationships between upper and lower teeth. This process is also known as occlusal equilibration or selective grinding. The term odontoplasty is commonly used to describe the act of occlusal adjustment/occlusal equilibration/selective grinding. The guiding principle of occlusal adjustment are the preservation and refinement of supporting cusp tips in centric occlusion and the elimination of lateral interfering centric and excursive contacts. Wear facets are also eliminated by vertical grooving and rounding of edges to reduce the tooth contact surface area during parafunction.
Pain or tenderness in the masseter, temporalis, or lateral pterygoid muscles, hypertrophy of the masseter muscles, limitation in opening the jaws, and/or subconscious resistance to movement of the mandible in hinge-axis and border movements are signs of myospasm in bruxism. The application of heat to the affected muscles, and the use of an anterior bite-plane appliance for 1-2 weeks is usually all that is required to deprogram avoidance patterns and ultimately relieve the myospasm. Patients who are refractory to this noninvasive therapy may have a more serious form of myofascial pain dysfunction (MPD) syndrome or other temporomandibular joint (TMJ) disease. Patients with refractory pain and dysfunction will require care by a specialist and should be referred for treatment as soon as possible.
Occlusal appliance therapy for bruxism
1. The primary function of appliance therapy in periodontal patients with bruxism is force control in secondary occlusal trauma, Additional benefits from occlusal appliances in periodontitis patients include splinting of teeth in the appliance, control of super-eruption, and anchorage for minor tooth movement. Typically, the force control appliance will provide full occlusal coverage of either the maxillary or mandibular teeth. The decision over which arch will be chosen for appliance therapy will be affected by Angles classification, the location of teeth that might require splinting, and the location of teeth that need to be controlled for super-eruption. Wrought wire clasps and the anterior Hawley appliance wire are unnecessary unless the appliance is modified to accomplish anchorage for orthodontics. The occlusal scheme for full occlusal force control appliances is maximum cuspal contact on the flat occlusal surfaces of the guard in centric relation and all excursions. Because there are no indentations for cusp interdigitation, full occlusal appliances do not have a centric occlusion. As such, they have been proven to be effective in the long- term maintenance of muscle “deprogramming.” They are not recommended for initial deprogramming of splinted muscles of mastication.
2. In patients who have a normal periodontium and demonstrate heavy occlusal wear of parafunctional origin, or who have a history of fracturing restorations or teeth, an occlusal night guard may be prescribed as an ablative shield. Force control may not be as much of an issue in these patients as tooth protection, particularly in cases where teeth have normal amounts of periodontal support. This appliance allows the patient to continue engaging in parafunctional activity without additional occlusal wear. Instead of irreversible tooth wear as a consequence to bruxism, the appliance is ablated.
3. In patients who have mild MPD and where muscle deprogramming is required before occlusal adjustment, an anterior bite plane may be constructed covering the lingual surfaces of the six maxillary anterior teeth. A Hawley labial wire is commonly included in the appliance to stabilize tooth position. A lingual platform establishes occlusal contact with the six mandibular anterior teeth, increases the occluding vertical dimension, and “discludes” all posterior teeth. The net effect of this appliance is that noxious tooth contacts are prevented while the patient wears the appliance. The expected outcome should be the reduction of myospasm in the muscles of mastication.
Because anterior bite plane appliances are reasonably simple to fabricate and usually require less chair time to adjust than the full occlusal appliances, it is tempting to use these appliances for long-term force control in bruxism . One consequence of this approach may be the extrusion of unopposed teeth and unexpected additional occlusal problems. It is recommended that anterior bite-plane appliances be used only for short-term muscle deprogramming.
Force control in bruxism has been a tradition in the treatment of periodontitis. Initially, it was believed that forces acting on teeth produced gingival recession and attachment loss and that periodontal therapy was incomplete unless these forces were eliminated or at least controlled. Today, the paradigm is that occlusal trauma and marginal periodontal diseases are probably distinct clinical entities. Occlusal trauma is treated with force control and periodontitis is treated by infection control.
The sequence of treatment for bruxism is critical. Effective treatment of marginal periodontal inflammation may decrease some of the signs and symptoms of occlusal trauma. In addition, reactive repositioning (closure of open contacts) may take place after inflammatory disease control. There is also evidence that untreated inflammatory disease may impact negatively on the repair of occlusal trauma. In some cases, occlusal therapy may not be necessary after inflammation control.
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