Pentti Kirveskari

Occlusal adjustment and the incidence of demand for temporomandibular disorder treatment

STATEMENT OF PROBLEM Contrary to clinical opinion, the structural risk from dental occlusion in temporomandibular disorders has been questioned or considered to be insignificant in clinical practice. PURPOSE This study tested the effect of elimination of occlusal interference through occlusal adjustment, on the incidence of temporomandibular disorders. MATERIAL AND METHODS In a controlled clinical trial of 146 healthy children and adolescents, half of the subjects underwent occlusal adjustment aimed at elimination of the presumed structural risk, and the other half underwent mock adjustment. Adjustments were repeated every 6 months over a period of 4 years. The outcome variable was the incidence of temporomandibular disorders, operatively defined as request for treatment of symptoms characteristic of the disorders with presence of clinical signs demonstrated in the muscles of mastication and/or jaw joint. RESULTS The cumulative incidence rate was 9/67 in the mock adjustment group and 1/60 in the real adjustment group, for a relative risk of 8.06. The difference between groups was statistically significant (p = 0.019). CONCLUSIONS Elimination of the presumed structural risk from the dental occlusion appeared to significantly reduce the incidence of temporomandibular disorders in a select group of young subjects.

Association between craniomandibular disorders and occlusal interferences

No theoretical model explaining craniomandibular disorders has been generally accepted, despite the large number of studies on its etiology. This article suggests that one reason for the lack of a well-structured causal explanation could be associated with the study design most often used: cross-sectional studies of samples representative of a base population. Variation in the number of interferences was increased among the subjects by eliminating occlusal interferences annually in the treatment group (n = 53). The control group (n = 46) underwent placebo treatment. A double-blind design was used throughout the 3-year study. A cross-sectional analysis in the third year disclosed a significant association between the number of interferences and the signs of craniomandibular disorders. The results suggest that the absence of interference-free subjects in nonselected samples can be one explanation for the lack of association reported in most studies.

Association between craniomandibular disorders and occlusal interferences in children

The association between clinical signs of craniomandibular disorders (CMD) and occlusal interferences was studied longitudinally in two cohorts of children, 5 and 10 years of age at baseline, representing the nonpatient population. They were followed up for 5 years. The range of active participants was 96 to 106 in the younger group, and 64 to 74 in the older group. The subjects were seen annually for registration of signs of CMD and for the presence of interferences, and for a real or placebo occlusal adjustment. The double-blind study design was applied. Baseline data showed no association between the variables studied; parts of data from second and third examinations disclosed significant associations; and fourth, fifth and sixth examinations disclosed a consistent pattern of significant associations.

Association of functional state of stomatognathic system with mobility of cervical spine and neck muscle tenderness

Clinical signs of craniomandibular disorder, the mobility of the cervical spine, and neck-shoulder muscle tenderness were assessed or measured in a nonpatient sample of 57 and a patient sample of 76 subjects. Examinations performed after a 1-year interval showed that the frequency of signs of craniomandibular disorder had remained virtually unchanged. The functional state of the stomatognathic system was significantly associated with both mobility of the cervical spine and neck-shoulder muscle tenderness.

Changes in Headache After Treatment of Mandibular Dysfunction

To analyse the effect of treatment of mandibular dysfunction on headache, 35 patients with migraine, 20 patients with combination headache and 36 patients with muscle contraction headache were studied in a clinical double-blind trial. Patients in the treatment group received occlusal adjustment and those in the placebo group mock occlusal adjustment. After eight months and four months, respectively, the neurologist evaluated the treatment outcome. The frequency of headache was reduced in 79% and the intensity in 53% of patients suffering from muscle contraction headache or combination headache in whom the adjustment of the dental occlusion had been successfully accomplished. The difference from the placebo group was statistically significant. The decrease in headache frequency as calculated from the headache diaries correlated with the decrease in the index of clinical signs of mandibular dysfunction.

Effect of occlusal adjustment on mandibular dysfunction A double-blind study

A group of headache patients who also had many signs and symptoms of mandibular dysfunction were randomly assigned to treatment and placebo groups. All 48 patients in the treatment group received occlusal adjustment and 19 of them also splint therapy. In the placebo group all 43 patients received mock adjustment. The changes in symptoms and signs of mandibular dysfunction were evaluated after 8 months in the treatment group and after 4 months in the placebo group, in a double-blind design. Placebo treatment and real treatment were equally effective in relieving symptoms of mandibular dysfunction, but there was significantly more reduction in signs of dysfunction in the treatment group than in the placebo group. When tested statistically, this reduction appeared to be independent of the use of splints as an aid to treatment. It can be concluded that the elimination of occlusal disturbances was an effective treatment for mandibular dysfunction.

The role of occlusal adjustment in the management of temporomandibular disorders

The use of occlusal adjustment as a treatment for temporomandibular disorders has been questioned because of lack of evidence that occlusal factors play an etiologic role; lack of evidence that this irreversible treatment modality has sufficient efficacy, when reversible modalities are available; the self-limiting character of the disorders; and the possibility of adverse effects. However, controlled clinical trials have yielded results that are difficult to explain unless occlusal factors have a causal role in temporomandibular disorders. Controlled clinical trials also suggest an effect for occlusal adjustment on chronic headaches and on chronic neck and shoulder pain in comparison with conventional treatments. Moreover, no adverse effects of properly conducted occlusal adjustments have been reported. In view of the possibility that occlusal factors have a causal role in temporomandibular disorders, research efforts on the role of occlusion should be intensified, and teaching should be revised accordingly.

Response to occlusal treatment in headache patients previously treated by mock occlusal adjustment

Headache patients who had received mock occlusal adjustment and who, after the placebo treatment, were judged to have moderate to severe mandibular dysfunction were offered further treatment. The present study reports the results of occlusal treatment in 19 patients who were willing to undergo further treatment. Statistically significant reduction after occlusal treatment (occlusal adjustment, aided in some cases by temporary use of occlusal splints) was observed in clinical signs (P less than 0.05) and subjective symptoms (P less than 0.01) of mandibular dysfunction and in the frequency of headache (P less than 0.05). The results are complementary to our earlier clinical studies and corroborate the conclusion that improvements after occlusal treatment exceed those after placebo treatment.

Globus hystericus: globus syndrome?

In a double-blind study, 22 patients with typical globus symptoms were investigated by both otolaryngological and odontological methods. All the patients underwent thorough hematological, endoscopic and radiological examinations. They were randomly divided into a treatment group and a placebo group and underwent either simple occlusal adjust or mock adjustment, respectively. The result of occlusal adjustment was assessed immediately after completion of treatment. The effect of treatment on globus symptoms was assessed 2 to 3 months later in a double-blind study. Binomial tests showed that there was a significant association between the success of occlusal adjustment and disappearance of the globus symptom. A new name for this disease is proposed: the globus syndrome.

Crown Size of Permanent Teeth in Icelanders

Mesiodistal and buccolingual crown diameters were measured from casts of 1010 dentitions of schoolchildren from Northeast Iceland. Their teeth proved to be larger than in Europeans generally, being exceeded only by Australian Aborigines, some American Indian populations, and American Negroes. In comparison with Ohio Caucasians of Northwest European origin Icelanders showed clearly larger dimensions, less sexual dimorphism, and a different pattern of dimorphism. Crown indices were also distinctly different in Icelanders and Ohio Caucasians.