Frequency of awake bruxism behaviour in orthodontic patients: Randomised clinical trial: Awake bruxism behaviour in orthodontic patients.

INTRODUCTION: The influence of aligners on the activity of the masticatory muscles is still controversial, especially regarding the behaviour associated with awake bruxism (AB). OBJECTIVE: To compare the frequency of AB behaviours between patients treated with aligners and fixed appliances. METHODS: The sample comprised 38 Class I patients (mean age 22.08 years), divided by simple randomisation into two groups: OA group; orthodontic aligners (n 19) and FA group; fixed appliance (n 19). The frequency of AB was investigated by the ecological momentary assessment using an online device (mentimeter), during 7 following days at different timepoints, before and after appliance placement and in the 2nd, 3rd, 4th and 6th months of orthodontic treatment. These variables were also evaluated: level of anxiety by the State-Trait Anxiety Inventory, stress by the Perceived Stress Scale, catastrophising related to pain and degree of hypervigilance by the Pain Vigilance and Awareness Questionnaire, and the presence of facial pain evaluated by the DC/TMD. RESULTS: There was no difference between groups in the frequency of AB behaviours, with mean of 53.5% for group OA and 51.3% for FA. The most frequent behaviour was slightly touching the teeth, and in FA group, there was a significant reduction in this behaviour soon after appliance placement. The groups did not differ concerning the degree of anxiety, stress, catastrophising, hypervigilance and facial pain. CONCLUSION: The orthodontic treatment performed with aligners or fixed appliances did not influence the frequency of AB during the 6 months of treatment. REGISTRY OF CLINICAL TRIALS: (REBEC): RBR-9zytwf.

Dental and skeletal characterization of the BR-1 minipig.

This study was designed to characterize the development of oral structures in the BR-1 minipig and to compare these data with literature reports on domestic swine and other minipig lineages. Twelve male minipigs were anesthetized and given physical and radiographic examinations. The presence and chronology of tooth eruption from 3 to 15 months of age were assessed, and the radiographic results were interpreted by two certified researchers, who obtained a high index of agreement (kappa>0.81). The eruption chronology was similar to that reported for domestic swine and other minipig lineages. The results indicate that it is possible to use the BR-1 minipig in dental research.

Radiographic techniques for medical-dental research with minipigs.

Techniques were developed to obtain standardised intra- and extra-oral radiographs in minipigs for use in medical-dental research. Twelve male minipigs (BR-1 Minipigs) were chosen at random. Two animals each at 3, 5, 7, 9, 12 and 15 months of age were anaesthetised and subjected to radiographic examinations to assess six techniques. Three intra-oral and three extra-oral techniques, standardised for humans, were used with variations of the angle of incidence of the X-ray beams, focus-film distance and exposure time. Two film positioners were developed for the intra-oral techniques. Two examiners then chose the radiographs with the least image distortion, greatest clarity and least superimposition of images. For each technique, the suitable angle of incidence of the X-ray beams, the focus-film distance and exposure time that produced the highest quality radiographs were standardised.