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. 2017 Apr 17;96(8):895–901. doi: 10.1177/0022034517704375

Table.

Summary of Methods.

Activity [Location] Purpose Application
Initial visit [UB] Collected:
● Informed consent
● Dental impressions
● DC/TMD examination results, completed forms
● Head CT
Permitted:
● Protection of subjects’ rights
● Fabrication of oral appliances used in dynamic stereometry
● Group categorization (±DD) using DC/TMD, inclusion/exclusion criteria
● 3-dimensional craniomandibular anatomy for numerical modeling
Imaging visit 1 [PIC] Collected bilateral MR images of TMJs (1.5 T machine) Permitted group categorization (±DD) using DC/TMD
Imaging visit 2 [PIC] Collected bilateral MR images of TMJs and reference system (using surface coils) Characterized 3D TMJ anatomy for dynamic stereometry
Laboratory visit 1 [UB] Recorded
● Jaw tracking with reference system during static and dynamic jaw tasks
● Masseter and temporalis EMG bilaterally and bite forces during biting tasks
Trained subject for ambulatory masseter and temporalis EMG
Combined:
● Jaw tracking with MR images for dynamic stereometry to determine:
● Q, ΔD, x, y (to calculate ED)
● Eminence shapes (for numerical modeling)
● Subject- and muscle-specific EMG/bite-force data to determine T20 N for laboratory visit 1
Subjects self-recorded EMG unilaterally in their natural environments for 3 days, 3 nights
Laboratory visit 2 [UB] Collected ambulatory EMG equipment and data
Recorded masseter and temporalis EMG bilaterally and bite forces during biting tasks (repeated)
Inspected and filtered completed ambulatory recordings
Determined T20 N for laboratory visit 2; averaged T20 N results for 2 visits and applied to ambulatory EMG for calculation of DF
Data analysis [UB, UMKC, UZ] Tested for ±DD group differences using:
● TMJ ED (from dynamic stereometry and numerical modeling)
● Jaw muscle DF (from ambulatory EMG recordings and T20 N)
● MBS (ED2 × DF)

CT, computed tomography; ΔD, distance of stress-field translation, mm; ±DD, with/without disc displacement; DC/TMD, diagnostic criteria for temporomandibular disorders; ED, energy density; EMG, electromyography; MBS, mechanobehavioral scores; MR, magnetic resonance; PIC, private imaging center; Q, cartilage volume, mm3; T20N, average threshold of EMG activity for 20 N of bite force; TMJ, temporomandibular joint; UB, University at Buffalo School of Dental Medicine; UMKC, University of Missouri–Kansas City School of Dentistry; UZ, University of Zurich School of Dental Medicine; x, product of aspect ratio and compressive strain3; y, velocity of stress-field translation, mm/s.