Functional evaluation of the mandible was performed by measuring active mandibular movements (Fig 1). For mandibular depression, participants were asked to open their mouths as much as they could without pain. The distance between central incisors of the mandibular row of teeth and the maxillary row of the obturator was recorded. For mandible protrusion, they pushed their lower jaws forward as far as they could and the distance between the upper and lower jaws were recorded. For mandibular deviation, participants pushed their lower jaws first left and then right, and lateral mandibular excursions were measured from upper incisal midline to lower midline. All measurements were performed with the help of a 20-cm ruler and recorded in cm 16.~Facial anthropometry was measured on photograph. A digital camera mounted on a tripod at 110 centimeters in height and a distance of 100 centimeters was used to take photographs 17. Participants' position was standardized on a previously marked cross on the floor. Those who wear glasses were asked to remove the glasses, and the participants with long hair were asked to tie their hair from the top. They were asked to assume a relaxed standing position when the photographs were taken. A small white square sticker 2 cm × 2 cm was placed on the forehead and on the flat surfaces of the right and left cheeks, with the camera lens perpendicular to the square. The purpose of the sticker was to be able to express linear measurements as centimeters rather than pixels while measuring the 3 sides of facial anthropometric landmarks using the Image J program 18. All participants were photographed at front and right and left sides. The measured anthropometric variables were as follows: physiognomic face height, morphological face height, lower face height, face width, mandible width, right upper facial depth, left upper facial depth, right lower facial depth, left lower facial depth, right midfacial depth, left midfacial depth, biocular width, cheek width (distance between inferior insertion of ear), and mouth width. Landmarks are shown and measured variables are defined in Fig 2 19,20. Face golden ratio was used to determine face shape and facial index was used for face phenotype. Face golden ratio was the ratio of physiognomic facial height to the face width, and facial index was the ratio of morphological face height and maximum face width.
Fifty-eight participants with AIS and 45 healthy controls were included in the study. Active mandibular movements including depression, protrusion, and left-right deviation were assessed with a ruler. Facial anthropometry was measured on facial shape on photograph, and phenotype and asymmetry were determined from the acquired anthropometric facial data. Neck mobility was evaluated in movements of flexion, extension, right-left lateral flexion, and right-left rotation using a standard flexible tape. The Fremantle Neck Awareness Questionnaire was used to assess neck awareness. Neck pain in the previous week was measured with a Visual Analog Scale.