Whiplash-related injuries and manifestations, typically neck pain, following car collisions are known to potentially disable individuals with a high and increasing cost to society. There is limited knowledge regarding the temporomandibular joint (TMJ) sequelae following whiplash trauma. Previous studies are typically based on retrospective data and few follow-ups are prospective and controlled in design. Furthermore, previous follow-ups have not included magnetic resonance (MR) imaging, which is a prerequisite for verification of TMJ status. The aims of this prospective long-term study were (i) to determine frequency of inaccurate recall of TMJ symptoms in patients with a history of whiplash trauma, and (ii) to evaluate incidence, prevalence and progression of TMJ pathology, verified with MR imaging, and TMJ symptoms in patients after whiplash trauma, compared with the natural course in matched volunteers. We studied 60 consecutive patients who had neck symptoms following a rear-end car collision and were seen at a hospital emergency department. Bilateral TMJ MR imaging and clinical examination were performed at inception and at follow-up on average 15 years later. A self-administered questionnaire regarding TMJ symptoms (pain, dysfunction, or both) and a subsequent interview were performed at inception, at the one-year, and 15-year follow-up. Fifty-seven patients (95%) participated in all three examinations (85% for MR imaging examinations). Concurrently, 53 volunteers matched by age and sex followed the same protocol. Fifty volunteers (94%) participated in all three examinations (89% for MR imaging examinations). Ethics approval of the study protocol and informed consent from all participants was obtained. The calculated agreement between each patient’s inceptive and retrospective reports on TMJ symptoms yielded a kappa value of 0.41 (95% CI 0.18-0.64). Sixteen patients (40%) had inaccurate recall one year after whiplash trauma. There was no statistically significant difference in TMJ symptoms reported by the patients to be present before whiplash trauma compared with matched volunteers at inception. Prevalence of TMJ symptoms increased significantly with whiplash trauma and the increase remained stable throughout the 15-year study period, which contrasted to the natural course in volunteers. After one year the difference in prevalence between patients and volunteers was 54% versus 21% (p=0.0003) and after 15 years 49% versus 18% (p=0.0017). There was no statistically significant difference between patients and volunteers in prevalence of TMJ disc displacement either at inception (63% versus 53%) or at 15-year follow-up (63% versus 55%). TMJ disc displacement was significantly more prevalent in symptomatic volunteers compared with asymptomatic volunteers (89% versus 31%, p=0.0002). Incidence or progression of MR imaging verified TMJ pathology did not differ between patients and volunteers. This prospective 15-year follow-up concludes - that future studies on TMJ sequelae following whiplash trauma should be prospective in study design with examinations conducted in close proximity to whiplash trauma. This allows for reliable baseline status and potential bias of inaccurate recall of symptoms is minimized. - that future controlled studies on TMJ pathology in patients should include control groups of not only asymptomatic but also symptomatic volunteers in order to avoid potentially biased conclusions. - that one of three patients exposed to whiplash trauma can be expected to develop TMJ symptoms beyond that which corresponds to the natural course in volunteers. This finding and previously reported impairment of jaw function in patients with symptoms after whiplash trauma points to the need for including TMJs and related muscles in routine medical examinations of patients with symptoms following whiplash trauma. - that adult individuals presenting with no or mild TMJ symptoms seldom show development or aggravation of TMJ pathology and there is no or little indication for TMJ treatment of these adult individuals. This is in contrast to the higher progression of TMJ pathology previously reported for adult patients with TMJ symptoms, which requires treatment.

Master of Science / Most studies of condylar movement are based on the movement of an arbitrary condylar point. As the condyle is a 3-dimensional body which undergoes complex rotations and translations in function, the movement of one point in the vicinity of the condyle may not accurately represent condylar movement. The aims of this investigation were to determine in human subjects, during open-close and excursive jaw movements, the movement patterns of arbitrary and anatomical condylar points; and whether the trajectory of a single selected point can accurately reflect the movement of the condyle. In 44 subjects, condylar point movements were recorded with an opto-electronic tracking system (JAWS3D), which recoded the position of three light-emitting diodes attached to each dental arch. The primary point, selected to represent movement of the condyle, was 15 mm medial to the palpated lateral condylar pole, parallel to the Frankfort horizontal plane. Additionally, four points were selected along orthogonal axes in the sagittal plane, and four in the horizontal plane: each was 5 mm from the primary point. In two subjects, the mandibular condyles were imaged by computerised tomography (CT) and the lateral and medial poles, most superior, anterior and posterior points of their condyles were selected. The trajectories of each point were compared for each subject for the mandibular movements listed above. Variability in both path form and dimension was noted between the subjects for all mandibular movements. For example, in an open-close mandibular movement the condylar point translation varied in the antero-posterior direction between 1.8-22.8 mm, and in the supero-inferior direction between 4.5-12.1 mm. For each subject, the pathway of each point was different in form and dimension from that subject’s other condylar points for the open-close, and ipsilateral lateral mandibular movements. For the open-close movement, in only four of the 44 subjects were the arbitrary point traces similar in form within a subject; and the tracings of each subject’s condylar points showed, on average, a 3.2 mm difference in maximal horizontal (i.e. antero-posterior) translation and 2.9 mm in maximal vertical (i.e. supereo-inferior) translation. For contralateral lateral mandibular movements, the path form and dimension in the sagittal plane of the condylar points were similar within a subject; however the lateral component showed variability in path length for the different points within a subject. The pathways of the condylar points for a protrusive movement displayed the most similarity within a subject, with an average of 0.4 mm variation in maximal horizontal or vertical displacement between each subject’s arbitrary condylar points’ tracings. The anatomical condylar points of the two subjects showed variability between and within each subject. For these two subjects the trajectories of the arbitrary condylar points moved in directions similar to the anatomical points of all movements except for the ipsilateral lateral mandibular movement, where in one subject, the arbitrary condylar points moved posteriorly, inferiorly and laterally whereas the anatomical points moved anteriorly, inferiorly and laterally. There is much variability in both form and dimension for mandibular condylar movement between human subjects. There is also considerable variability within subjects in the form and dimension of condylar point movement, whether arbitrary or anatomical, depending on the point selected. By inference therefore, a single condylar point cannot accurately reflect the movement of the mandibular condyle, except perhaps for a protrusive mandibular movement. Multiple mandibular points are therefore required to describe the motion of the condyle. In an ipsilateral lateral mandibular movement, for example, an arbitrary point may move in a completely different direction to the mandibular condyle, and so anatomically derived condylar points should be utilised to assess accurately condylar movement.

Doctor of Philosophy / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au

Master of Dental Surgery / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 160-170) Also available in print.

Thesis--Albert Ludwigs University, Freiburg im Breisgau, 1998. / Includes index.

Thesis (doctoral)--Karolinska Institutet, 1987. / Extra t.p. with thesis statement inserted. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 157-170).

Thesis--Albert Ludwigs University, Freiburg im Breisgau, 1998. / Includes index.