Assessment of occlusal interferences

Mandibular function, temporomandibular disorders, and headache in prematurely born children

OBJECTIVE

To evaluate mandibular function, signs, and symptoms of temporomandibular disorders (TMDs) and headache in prematurely born 8- to 10-year-old children, and to compare the findings with matched full-term born controls.

MATERIAL AND METHODS

Seventy-three preterm children were selected from the Medical Birth Register--one group comprising 36 extremely preterm children born before the 29th gestational week, the other group 37 very preterm children born during gestational weeks 29 to 32. The preterm children were compared with a control group of 41 full-term children matched for gender, age, nationality, and living area. The subjective symptoms of TMD and headache were registered using a questionnaire. Mandibular function, signs, and symptoms of TMD and headache were registered. TMD diagnoses were set per Research Diagnostic Criteria for temporomandibular disorders (RDC/TMD).

RESULTS

No significant differences between groups or gender were found for TMD diagnoses according to RDC/TMD or for headache. The preterm children had smaller mandibular movement capacity than the full-term control group, but when adjusting for weight, height, and head circumference mostly all group differences disappeared.

CONCLUSIONS

Prematurely born children of 8 to 10 years of age did not differ from full-term born children when considering diagnoses according to RDC/TMD, signs, and symptoms of TMD or headache.

TMD in Consecutive Patients Referred for Orthognathic Surgery

Objective: To answer the question whether temporomandibular disorders (TMD) were more common in a group of individuals referred for orthognathic surgery than in a control group. The null hypothesis was that neither the frequency of signs and symptoms of TMD or diagnosed TMD would differ between the patient group and a control group.

Materials and Methods: A sample of 121 consecutive patients referred for orthognathic surgery at the Department of Oral Maxillofacial Surgery, Malmö University Hospital, Sweden, was interviewed and examined regarding signs and symptoms of TMD and headaches. A control group was formed by 56 age- and gender-matched individuals attending the Department of Oral Diagnosis, Faculty of Odontology, Malmö University, Sweden, and Public Dental Health Clinic in Oxie, County of Skane, Sweden. TMD diagnoses were used according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD).

Results: The patient group showed more myofascial pain without limited opening, disc displacement with reduction, and arthralgia according to RDC/TMD than the control group. The patient group also had more symptoms and signs of TMD in general.

Conclusions: The null hypothesis was rejected because patients who were to be treated with orthognathic surgery had more signs and symptoms of TMD and higher frequency of diagnosed TMD compared with the matched control group.

A study of the incidence of overeruption and occlusal interferences in unopposed posterior teeth

OBJECTIVES

To determine the incidence and extent of overeruption in unopposed posterior teeth; to determine the incidence of occlusal interferences associated with unopposed posterior teeth; and to detect an association between the extent of overeruption and the presence of occlusal interference.

DESIGN

The study was a single centre clinical retrospective analysis. Setting The setting was in the Combined Care Clinic of Leeds Dental Institute. The patients were undergoing routine restorative care by final year undergraduate dental students during 2000.

SUBJECTS AND METHODS

All patients over18 years of age with one or more unopposed posterior tooth, were invited to participate. A sample group of 120 subjects were recruited. A clinical occlusal examination was carried out and the presence of initial retruded contact position (RCP) contacts and excursive interferences were recorded. Study models were made and digitally scanned.

OUTCOME MEASURES

Measurements of overeruption from the curve of Spee were made from the images obtained, by a single observer. Reliability of the measurements was assessed by means of a Bland Altman Plot. The presence and site of RCP contacts and excursive interferences were recorded by a single observer. Reliability of the measurements was assessed by means of Kappa scores. The association between overeruption and the presence of occlusal interference was examined using Spearmans Correlation Coefficient.

RESULTS

A total of 120 subjects were recruited, with a total of 155 unopposed sites. Eighty-one of the sites belonged to male subjects, 74 to female subjects. The mean age of the group was 50.9 years, Standard deviation 13.9 Eighty-three per cent of sites displayed overeruption (95% CI 78-90), ranging from under 0.5 mm to 5.4 mm. The reliability of the observations was found to be good. A total of 51.6% (95% CI 44-60) of unopposed teeth were involved in RCP contacts or excursive interferences. Thirty-two sites were involved in more than one contact or interference. The intra-examiner agreement was found to be good, using Kappa. The findings of the Spearman's correlation, show that if an association exists between overeruption and occlusal interference, it is weak, and of no statistical significance.

CONCLUSIONS

Eighty-three per cent of unopposed teeth are likely to overerupt, and the extent of the overeruption may be marked. The incidence and extent of overeruption is of clinical significance, not only in terms of treatment planning to prevent undesirable vertical movement, but also in the restoration of the edentulous space. The reliability of observations made in the study was found to be good, justifying the methodology. Fifty-one point six per cent of unopposed teeth are likely to be involved in RCP contacts or excursive interferences. The incidence is of clinical significance when planning the restoration of unopposed teeth, or the associated edentulous space. Only a weak statistical association was demonstrated between the degree of overeruption and the presence of occlusal interferences.

Symptoms and signs of temporomandibular disorders in girls with normal occlusion and Class II malocclusion

Mandibular function, headaches, and symptoms and signs of temporomandibular disorders (TMD) were studied in one group of girls with a well-defined normal occlusion (n = 60) and another group with class II malocclusion (n = 123). Frequent headaches and temporomandibular joint clicking, muscle tenderness to palpation, pain on mandibular movement, awareness of tooth clenching, and grinding were commoner in the class II malocclusion group. Awareness of tooth clenching had the largest influence on the odds for symptoms and signs of temporomandibular disorders (TMD) in a logistic regression analysis. Occlusal variables that increased the odds for symptoms and signs of TMD were large overjet, frontal open bite, few occlusal contacts, lateral sliding retruded-intercuspal contact position, crowding, and non-working side interferences. We concluded that normal occlusions have lower odds for symptoms and signs of TMD, whereas some occlusal characteristics, more frequently found in the class II malocclusion group, increased the odds for symptoms and signs of TMD.

Reliability of the evaluation of occlusal contacts in the intercuspal position

Reliability of clinical measurement is essential to any clinical discipline. This investigation assessed intraexaminer and interexaminer reliability achieved in identifying contacting teeth in the intercuspal position. Shim stock and an articulating film were compared in the evaluation of occlusal contacts of 337 antagonist occlusal pairs in 24 young adults by two examiners. Results were compared by use of a simple proportion of agreement and, when possible, the Kappa statistical test that corrects for chance agreement. Shim stock displayed better reliability than articulating film and appeared suitable for clinical measurement of occlusal contacts in intercuspal position.

Short-term effect of occlusal adjustment on craniomandibular disorders including headaches

The aim of this study was to assess the short-term effect of occlusal adjustment on craniomandibular disorders. Fifty patients were randomly selected and divided into a treatment (T) and a control (C) group. The initial clinical examination and the follow-up were made by one observer and the occlusal adjustment by another. There were no significant differences between groups with regard to frequency of headaches, facial pain, pain on mandibular function, or duration of headaches and facial pain. Fifty-two percent of the patients in the treatment group and 20% of the patients in the control group reported reduced subjective symptoms overall at follow-up examination. The improvement was statistically significant within the T group and significantly greater than in the C group. There was no significant change within or between groups with regard to frequency of headaches, facial pain, or pain on mandibular movements. There was an almost significant difference between groups after treatment with regard to changes in the number of tender muscles. The results of this study indicate that occlusal adjustment provides a general subjective improvement of craniomandibular disorders.