A total of 201 completely edentulous subjects taken consecutively from the waiting list of the Royal Dental Hospital of Melbourne were examined. Data were obtained from the dental history and anamnestic and clinical examinations. Analysis revealed that parafunctional habits were prevalent among complete denture wearers, and that elderly complete denture wearers potentially present more signs and symptoms of craniomandibular disorders than do younger subjects.

A review of the literature on bruxism--a condition which has been clinically recognized since the late nineteenth century--is presented. It will be seen that there is not complete agreement on the definition of this activity, and its aetiology and treatment remain controversial.

A total of 201 completely edentulous patients awaiting treatment for new complete dentures at the Royal Dental Hospital of Melbourne were examined for signs and symptoms of craniomandibular disorders, and a history was taken regarding their dentures. Statistical analysis by means of Student's t-test showed that the only reliable indicator of craniomandibular disorder was the patient's sex, i.e. female subjects tend to show more symptoms of craniomandibular disorders than male subjects. When regression and multiple regression analyses were applied, it was found that subjects with a history of fewer sets of complete dentures worn appeared to be correlated with an increase in the number of signs and symptoms of craniomandibular disorders. However, this correlation had a weak predictive power, although it was significant enough to indicate that such a relationship could exist in the general population.

Three hundred and seventy casts with 652 registrable proximal surfaces adjacent to crown preparations were examined for iatrogenic damage to hard tissue surfaces. The incidence of damage was high and recommendations for prevention and treatment of such damage are made.

The movements of the mandible during the chewing of gum have been studied using a closed circuit television movement detector. The shape of the cycle was studied in three planes. initially at right angles. and the shape of the cycle in the transverse and sagittal planes, variations in velocity within cycles. and the period of contact as reported by other workers, confirmed.Small protrusive and lateral movements were observed in the initial opening phase from contact in most cycles. and in final closing into the intercuspal position. A small slide was also seen in the intercuspal zone.