YOUR DELIVERABLES Your agency is to provide the court with a professional written report that includes: 1. Background information about the physics principles that apply to an automobile collision [forces & motion, work & energy, friction, conservation of momentum, kinematics]. 2. Detailed calculations that determine: a. The coefficient of kinetic friction between the tires and the road for both the car and the truck. b. The speed of each vehicle just after the collision c. The speed of each vehicle just before the collision 3. A detailed opinion (conclusion) about which driver was at fault. The opinion must be justified using scientific principles and the detailed calculations that you have provided.
The present study attempts to determine whether the onset of swallowing is affected by bilateral lingual and inferior alveolar nerve anesthesia and by raising the occlusal vertical dimension by wearing an occlusal bite plate. Twenty young male volunteers were selected and asked to chew and swallow corned beef and a corned beef and liquid mixture in their usual manner before and after modifications were made. Oral and pharyngeal swallowing was investigated using videofluoroscopic examination in the lateral plane. Eight objective indicators, including oral containment time, swallowing threshold, and pharynx-to-swallow intervals were estimated. Oral containment time, total sequence duration, total number of chews, and total number of swallows of the two test foods were significantly different before and after the modifications. Individual pharynx-to-swallow intervals also varied. The results indicate that modification of the masticatory condition affects the onset of swallowing and that changes in the onset varied among the participants.
The aim of our study was the evaluation of seasonal influences on development and evolution of temporomandibular disorders (TMD). In a retrospective study based on data from 1997 and 1998, we analyzed the monthly number of patients at the Department of Prosthodontics. The total number of first time examinations during these two years was 11,747. Nine hundred and sixty-one (961) patients showed symptoms frequently found in TMD. These patients were submitted to a special TMD diagnosis based on the criteria of a validated craniomandibular index questionnaire. In 568 patients (group A1), a TMD was confirmed, in the other 393 patients (group A2), the disorder could not be confirmed. Dividing up the numbers of patients into summer and winter half years, we found statistically significant relationships between patient numbers and season in TMD patients (A1) as well as in all patients (group B). The distribution of the monthly numbers of TMD patients with its maximum in winter, however, was characteristically different from that of all patients with the maximum in summer. The number of TMD patients per month was significantly correlated to the mean daily sunshine duration per month. Parallels could be drawn to seasonal variations of symptoms in Seasonal Affective Disorders (SAD). As the mechanisms which influence the emergence of psychologically impacted disease in TMD patients might be comparable to SAD, we propose that a similar therapy may be applied.
The aim of the present study was to investigate the relationship between noncarious cervical lesions (NCCL) and dental premature contacts (PC). Following examination of 1,974 teeth from 77 patients referred to the Department of Oral Medicine, Faculty of Dentistry, Mashad University of Medical Science, Iran, a total of 167 teeth were identified to have the criteria set for noncarious cervical lesions (regarded as NCCL group). Also, 167 teeth exhibiting no such lesions were selected randomly from the same population (regarded as control group). The results indicated that within the NCCL group, the frequency of noncarious cervical lesions differed significantly among the various teeth; the first premolar teeth showed the greatest number of cervical lesions, followed by the canine teeth, and the second molar teeth had the least number of lesions. A similar trend was detected in the total number of premature contacts among the seven types of teeth. The results revealed a highly significant and positive correlation between the incidence of NCCL and the PC. The NCCL group and the control group differed significantly in the number of premature contacts in centric relation (CR) and working side, but not in balancing and protrusion.
This retrospective series was intended to determine whether morphological disk findings in open and closed mouth magnetic resonance imaging (MRI) may be correlated with the time curves in axiography. In this series, 45 temporomandibular joints of 33 patients were subjected to a retrospective evaluation. Magnetic resonance images obtained with closed and open mouth and joint movements assessed by electronic axiography were analyzed. Disk morphology in MRI was classified as normal, partly flattened, partly thickened, or completely thickened. For the axiographic tracings, time curves of the free movements of the respective joint were developed and evaluated. Data obtained were analyzed for any potential correlation using scatter plots and discriminance analysis. No correlation between these data was found suggesting that the axiographic time curves do not provide for any conclusions with regard to disk morphology. Apart from patient history and a thorough clinical evaluation, recording of jaw movements, but also using MRI continues to be of particular value in the diagnostic assessment of anterior disk displacement.
