Mandibular movements recordings by a mono vision system.

To examine the mandible's movements, vision analysis was employed and performed with the digital camera which featured 1920 x 1080 resolution and was fixed on an aluminium extension arm attached to a headset worn by the subject.The camera was aligned parallel to the subject's face at a distance of 0.3 meters. The study used two 10 mm x 5 mm reference markers, which were accurately reproduced on the camera recorded images. In line, one marker was put on the medial cleft above the upper lip, and the other one was positioned below the first one in a straight line, in the middle of the chin. Then, the patient was asked to open maximally and close the mouth twice.To establish the mandible's trajectory, the line was drawn between the positions of the two markers to connect the two points. The line's parameters were calculated only during initial measurements and were constant throughout the study.

The maximum mouth opening value calculated as the difference in the distance between the markers before registration and during the maximum opening.

The value of the maximum deviation of the lower marker in relation to the upper one in the frontal plane.

The value of normalized displacement calculated by dividing the sum of squared errors in movement trajectory on the transverse axis by the number of measurements taken during analysis time.