Occlusal splint
An occlusal splint (also Knirsch (er) , dental or Michigan splint ) is a prosthesis-like plastic overlay adapted to the dental arch for the treatment of myoarthropathies (diseases of the chewing system ). The aim of therapy using an occlusal splint is to remove excessive and incorrect loads on the teeth and jaw joints, for example through teeth grinding .
application
The bite splint is applied to loss of substance by mechanical abrasion ( abrasion ) to the teeth. It should protect the teeth from further loss of substance. The splint can be made for either the upper or lower jaw.
Insufficient support of the chewing surfaces
The splint is often used when the chewing surfaces are not supported when the jaw is closed . This is caused by a misaligned tooth or because the two halves of the dentition do not fit into each other for other reasons. An uneven surface causes increased abrasion of the tooth substance.
Crunching and pressing
In bruxism (grinding / grinding and clenching of the teeth), wear occurs. Grinding and pressing are mostly done unconsciously and mostly at night. The bite splint acts like a protective cover for the teeth. This does not prevent grinding or clenching, but because the splint is softer than the teeth, the splint will be rubbed off when you grind, not the teeth.
Because the splint itself is approx. 1 mm thick, it creates a greater distance between the lower and upper jaw. This changes the resting position and the usual chewing pattern, sometimes the unconscious crunching or pressing is interrupted.
Secondary diseases
Both diseases can cause a number of secondary diseases. These include: craniomandibular dysfunction , headache (misdiagnosed as migraine ) and other pain; in addition, these are supposed to cause tinnitus ( causal relationship unproven); Grinding teeth with associated consequential damage.
Therefore, it is also important to prevent grinding and clenching or to correct the wrong bite.
effect
An occlusal splint only provides symptomatic treatment (if at all) . According to their proponents, they also help, in contrast to braces, when the position of the upper jaw does not match that of the lower jaw. The splint is usually worn at night, in some cases also during the day. It is supposed to reduce the unconscious grinding of your teeth.
The costs are not always borne by the health insurances, because studies have so far not been able to sufficiently prove the effectiveness of this measure.
Manufacturing
To make it, an alginate impression is first taken of the teeth. This is poured with super hard stone . On the model by means of deep-drawing device a hot, approximately 1 mm thick PMMA foil by means of vacuum over the model "pulled". This blank is now cut out and processed by the technician (plus any therapeutic grinding). Now the patient still has to try them on, with additional pressure points and edges being sanded off if necessary.
Materials of different hardness are used to manufacture the splint. The production itself is subject to the same laws of successful technical implementation of dental specifications: Gingival contact is to be avoided, the splint encloses all tooth equators sufficiently for the accuracy of fit or slightly above if these are difficult to define (in some cases not available).
For the desired successful functionality of the splint, the surface ( occlusal ) is of decisive importance; it specifies the movements that can now still be carried out. The method of applying an individualized layer of hard plastic ( acrylate ) to the already prepared splint made of thermoplastic material (the end product is a soft, transparent rubber-like plastic) , which can be adapted to the patient's exact articulation, has proven itself .
The same method is used with mouthguards for boxers or in connection with other injury-prone sports. However, the individual structure can be dispensed with; the thickness of the film used is the thickness required or necessary by the athlete instead of the usual 1–4 mm.
An alternative method of preparation is the CAD / CAM - milling process . The plaster model (see above) is digitized using a 3D scanner and then the patient-specific occlusal splint is digitally created with the aid of dental CAD software (e.g. WorkNC Dental ). The CNC code is then transferred to a milling machine via a CAM module . The splint is then milled with high precision from so-called prefabricated blanks (milling discs) and then polished by hand by a dental technician. Advantages of this production method are the higher quality in the sense of z. B. higher biocompatibility by a lower residual monomer content (lower allergenic potential for the patient, no load of the laboratory personnel by methacrylate vapors) as well as better fit (elimination of the polymerization shrinkage in the laboratory). The high precision of the milled chewing surfaces also reduces manual post-processing by the dentist.
statistics
In 2016, 1.6 million occlusal splints were prescribed in Germany, an increase of 16 percent compared to 2012.
Alternatives
Autogenic training or another psychotherapeutic relaxation method is often recommended in the case of abrasion , and biofeedback is rarely offered.
The NTI-tss splint, which only covers the front teeth, is cheaper than the Michigan splint, which covers all teeth. This splint made of thermoplastic material is adapted to the upper or lower incisors and has only one point of contact with the opposite incisors. This avoids pressing intensity and contact between the canine and molar teeth.
See also
literature
- Heli Forssell, Eija Kalso, Pirkko Koskela, Raili Vehmanen, Pauli Puukka, Pentti Alanen: Occlusal treatments in temporomandibular disorders: a qualitative systematic review of randomized controlled trials. In: Pain. Vol. 83, No. 3, December 1999, ISSN 0304-3959 , pp. 549-560, PMID 10568864 .
Web links
- Online test with sample films to check a possible CMD. ProDente e. V.
- University Dental Clinic Greifswald (PDF)
Individual evidence
- ↑ Fabian Franke: My jaw, a vice, in: Die Zeit No. 5, January 23, 2020.
- ↑ Description with picture of the NTI-tss bite splint
