# Optimization of Image Capture Distance for Facial Thermograms in Dentistry
## 4 Discussion
However, the results of the temperature differences obtained for the front and right views for the different shooting distances were higher (>0.2 \({}^{\circ}\)C), thus indicating that the different distances selected in this study impacted the measurements, which is in agreement with a former published study where the experimental setup was comprised of focusing distances of 0.05 m and 0.15 m with a camera distance of 0.8 m [66]. It is important to bear in mind that acceptable temperature variations of less than 0.2 \({}^{\circ}\)C, as described in previous studies, used cameras with an advanced hardware system [64; 65; 66; 67]. The camera used in the current study was a portable device that could be attached to a mobile phone and had a sensitivity measurement uncertainty of \(\pm\)5 \({}^{\circ}\)C, therefore, the differences observed in the current study for the right side may also be considered as acceptable. In this study, the temperature differences in the front view were greater this 5 \({}^{\circ}\)C, hence it must be acknowledged that the three distances chosen did influence the measurements. This variation in the temperature differences measured at different distances for the various views could perhaps have been due to a number of factors including the examination room factors, camera accuracy, and analysis methods [68]. This study was conducted in strict adherence to follow the recommended guidelines for thermographic imaging. The ambient room temperature and the humidity of the room in this study was maintained at a mean temperature of 22.07 \(\pm\) 0.36 \({}^{\circ}\)C [min: 21.30 C, max: 22.6] and 36 \(\pm\) 5% [min: 30%, max: 50%] [66]. It has been recommended that for better stability, drift, and uniformity, cameras with study hardware should be used [68]. The camera used in this study was from a reputed manufacturer that has previously been used for dental applications and is especially recommended for expected differences in temperature measurement greater than 0.05 \({}^{\circ}\)C and for its feature of portability [59; 67]. The analysis software employed in this study was manufacturer recommended and therefore, concerns arising because of compatibility/sensitivity issues could be ruled out. Although this study was conducted adhering to the recommended guidelines for thermography and with sound methodology, certain limitations may have existed. First, as this study only included healthy volunteers, the true effect of screening an actual oral health condition was not possible. However, it must be kept in mind that the scope of this study was to standardize shooting distances and the effect of influencing factors on the temperature measurements. A further critique that can be made is that only one portable thermography camera was employed in this study. This aspect was designed with intent. In the domain of geriatric dentistry, older adults with complex health and cognitive statuses are treated. These adults are often care-resistant, non-cooperative, aggressive, or immobile, or present with severe physical handicaps. Therefore, the concept of using thermography to identify and screen oral diseases in non-communicative individuals is novel and could greatly ease the entire process of screening and diagnosis as well as avoid cumbersome procedures like employing general anesthesia just for examination and diagnosis. When considering these aspects, it is equally important that the thermography technique employed does not necessitate elaborate equipment or extensive preparations. Therefore, the camera used in this study was selected while considering its features of portability,ease of use as well as its compatibility with a mobile smartphone device. Moreover, its technical specifications recommend it for use in situations where a temperature variation of more than 0.05 \({}^{\circ}\)C is expected.