Health risk from occlusal interferences in females.

The purpose of the present study was to test the effect of elimination of occlusal interferences on the incidence of requests for treatment of symptoms in the head and cervicobrachial region. One hundred and twelve females 45 years of age or under, were randomly divided into a treatment group (n = 54) and a control group (n = 58). The former underwent occlusal adjustment and the latter grinding that did not affect occlusal contacts. The treatments were repeated every 12 months over a period of 4 years. The outcome variable was a spontaneous request for treatment. Statistical analyses included chi-square tests for categorical variables and a t- or Wilcoxon ranked sum test for continuous variables. Poisson regression was used to compare the risk of seeking treatment between the groups. The cumulative incidence rate of treatment requests was 2/54 in the treatment group and 11/58 in the control group. The relative risk was 5.12. The 95 per cent confidence limits were 1.14 and 23.1, respectively. The difference between groups was statistically significant (P = 0.0336). Systematic elimination of occlusal interferences significantly reduced the incidence of requests for treatment of symptoms in the head and cervicobrachial region. This is in contrast with the view that there is no, or at best, an insignificant health risk from occlusal interferences.

Duration of surgical-orthodontic treatment.

OBJECTIVE: To study the duration of surgical-orthodontic treatment with special reference to patients' age and the type of tooth movements, i.e. extraction vs. non-extraction and intrusion before or extrusion after surgery to level the curve of Spee. MATERIAL AND METHODS: The material consisted files of 37 consecutive surgical-orthodontic patients. The files were reviewed and gender, diagnosis, type of malocclusion, age at the initiation of treatment, duration of treatment, type of tooth movements (extraction vs. non-extraction and levelling of the curve of Spee before or after operation) and type of operation were retrieved. For statistical analyses two sample t-test, Kruskal-Wallis and Spearman rank correlation tests were used. RESULTS: Mean treatment duration of the sample was 26.8 months, of which pre-surgical orthodontics took on average 17.5 months. Patients with extractions as part of the treatment had statistically and clinically significantly longer treatment duration, on average 8 months, than those without extractions. No other studied variable seemed to have an impact on the treatment time. CONCLUSION: The present small sample size prevents reliable conclusions to be made. However, the findings suggest, and patients should be informed, that extractions included in the treatment plan increase chances of longer duration of surgical-orthodontic treatment.

Familial occurrence of signs of temporomandibular disorders in headache children and their mothers.

OBJECTIVE: Earlier studies have provided evidence of genetic inheritance of headache, especially migraine, but no familial occurrence has been found regarding temporomandibular disorders (TMD). In adults, headache and TMD have been found to be associated with each other, but studies on children are few. The aim of the present study was to test the hypothesis that there is no association between signs of TMD in 13-year-old headache children and their mothers. MATERIAL AND METHODS: The study population was a nested case-control study of the population-based Finnish Family Competence Study originally consisting of over 1000 families. A structured questionnaire was sent to the families of 6-year-old children. A clinical examination was performed in 96 children with headache and 96 pairwise controls. At the age of 13 years, 75 of these same 96 children with headache and 79 of 96 headache-free controls participated in pediatric and stomatognathic examinations. Moreover, the mothers (n=154) filled in a structured headache questionnaire and participated in the stomatognathic examination. RESULTS: No association between mother's and child's TMD signs was found. There was a significant association between signs of TMD and both migraine and tension-type headache in children. In mothers, the association was significant only between migraine and TMD signs. CONCLUSIONS: Familial occurrence of signs of TMD cannot be found in headache children and their mothers.

Psychological factors and responses to artificial interferences in subjects with and without a history of temporomandibular disorders.

OBJECTIVE: It has often been suggested that psychological factors play a role in temporomandibular disorders (TMD). However, reports on psychological factors in TMD patients and controls have been equivocal. In a previous double-blind randomized controlled study, subjects with a TMD history showed more clinical signs and subjective symptoms and adapted less well to the artificial interferences than subjects without an earlier TMD history. In the present study, we analyzed the associations of psychological factors with symptom responses and adaptation to interferences. MATERIAL AND METHODS: Before the intervention, the subjects filled in questionnaires dealing with personality traits, level of psychological and somatic stress symptoms, coping strategies, and health beliefs. Every day during the 2-week follow-up period, the subjects rated the intensity of their symptoms on 9 modified visual analog scales (VAS). RESULTS: Health hardiness, positive socialization history and inhibition of aggression were associated with weaker symptom responses and better adaptation to true artificial interferences. Some personality characteristics in subjects with an earlier TMD history tended to associate with higher symptom reporting despite the type of intervention. CONCLUSIONS: Psychological factors appeared significant for the symptom responses to artificial interferences, and they seem to play a different role in responses in subjects with an earlier TMD history compared to those without.

Subjective reactions to intervention with artificial interferences in subjects with and without a history of temporomandibular disorders.

In a previous double-blind randomized controlled study, subjects with a history of temporomandibular disorder (TMD) reacted to artificial interference with more signs of TMD than did subjects with no TMD history. In the present study, we analysed the subjective reactions of these individuals on several symptom scales. Every day during the 2-week follow-up period, the subjects rated the intensity of their symptoms on 9 VAS scales (occlusal discomfort, chewing difficulties, tender teeth, fatigue in the jaws, headache, facial pain, opening difficulty, bruxism, ear symptoms). Subjects with a history of TMD and true interferences reported stronger symptoms than subjects with no TMD history and placebo interferences. The most prominent symptoms were occlusal discomfort and chewing difficulties. The difference in outcome between the groups with and without a TMD history suggests that there are individual differences in vulnerability to occlusal interferences. It is likely that the etiological role of occlusal interferences in TMD has not been correctly addressed in previous studies on artificial interferences.

Effect of artificial occlusal interferences depends on previous experience of temporomandibular disorders.

Studies on artificial interferences in subjects with no temporomandibular (TMD) history have shown adaptation to the interference within a fairly short period of time. The role of occlusal factors in the etiology of TMD has therefore been questioned. The results might have been different, however, if subjects with a prior TMD history had been included in the study groups. To test this assumption in a randomized double-blind clinical set-up, we included healthy women without (n = 26) as well as with (n = 21) an earlier TMD history. Both groups were randomly divided into true and placebo interference groups. Artificial interferences were introduced in the true interference groups and simulated in the placebo groups. The subjects were followed for 2 weeks, after which the interferences were removed. The subjects without a TMD history showed fairly good adaptation to the interferences, but the subjects with a TMD history and true interferences showed a significant increase in clinical signs compared to the other groups. We suggest that the etiological role of occlusal interferences in TMD may not have been correctly addressed in previous studies with artificial interferences and allow no conclusions as regards TMD etiology.