# Thermography as a Method to Detect Dental Anxiety in Oral Surgery
## 2 Materials and Methods
### Procedures  
The thermal recordings were performed in a controlled environment: the temperature was maintained in a range from 18 to 25 \({}^{\circ}\)C and the humidity was controlled. The door room was closed, the room was sound-proofed and no one was allowed to enter during the thermal registration except for the staff selected. All topical applications such as ointments and cosmetics and all objects like jewelry and glasses were removed from all the relevant areas of the face. The room was free from any secondary infrared sources such as an incandescent lamp or direct sun-light and the cameras were placed perpendicular to patients' face at a distance of 30 cm. The thermal recording of the patient was divided into two steps. The first step called the BASELINE was used to acquire a starting temperature. During this step the patient sat on the dentist's chair and no stimuli were given. Only the patient and the thermal camera operator were present in the room. This recording started as soon as the patient entered the room and ended two minutes later. The second step was called the VISIT. This thermal recording started as soon as the dentist entered the room and continued during the anamnestic and clinical examination and the explanation of the treatment plan. For all the patients, a single dentist, unaware of the aim of the study, performed the examinations. On the face of each subject five ROIs centered on the nose, ear, cheek, forehead, and chin were taken into consideration. A temperature was recorded for each ROI. At the end of the thermal recordings a difference of temperature for each ROI between the temperature recorded during the BASELINE step and the temperature recorded during the VISIT step was calculated and averaged, respectively. After the medical examination the patient filled out the Italian version of the MDAS questionnaire 20 to assess the presence and severity of dental anxiety. This is a five-item scale measuring dental anxiety on a five-point Likert scale and generating a total score ranging from 5 (not anxious) to 25 (extremely anxious). The cut-off of 19 points may identify patients with high dental anxiety.  
In order to classify the patients, the following criteria were considered: (1) a difference of temperature between 0.1 \({}^{\circ}\)C and 0.3 \({}^{\circ}\)C, relating to an average difference of temperature of 0.2 \({}^{\circ}\)C, identified a non-significant difference of temperature attributable to patients with no dental anxiety; (2) a difference of temperature between 0.3 \({}^{\circ}\)C and 0.9 \({}^{\circ}\)C, relating to an average difference of temperature of 0.6 \({}^{\circ}\)C, identified a significant difference of temperature attributable to patients with a medium dental anxiety; and (3) a difference of temperature between 1 \({}^{\circ}\)C and 2 \({}^{\circ}\)C, relating to an average difference of temperature of  
Figure 2: Regions of interest (ROIs).  
1.5 \({}^{\circ}\)C, identified a significant difference of temperature attributable to patients with high dental anxiety.  
For the MDAS score the following criteria were used: (1) a score from 5 to 10 points identified patients with no dental anxiety or with a mild dental anxiety, categorized as non-significant dental anxiety (Group 1); (2) a score from 11 to 18 points identified patients affected by moderate dental anxiety (Group 2); and (3) a score from 20 to 25 points identified patients affected by severe dental anxiety (Group 3).