# Content Analysis of YouTube Videos That Demonstrate Periapical Radiography
## 4 Discussion
One of the few issues commonly identified from the videos was the omission of removing the metallic objects from the patient's head and neck region. Straightly speaking, the metallic earrings or eyeglasses do not affect the image quality for many of the intraoral radiographs as they are often outside the field of view. However, they would become detrimental if the patient would subsequently take other radiographs such as occlusal or panoramic radiographs. Our prior study indeed found that some instructional videos on panoramic radiography showed metallic earrings on the resultant image, thus obscuring the region of interest [14]. Each clinic has its own standard operating procedure, but the authors perceived that it is a good practice to instruct patients to remove the metallic objects from the patient's head and neck region on a routine basis before undergoing dental radiographic examinations. This routine practice is especially useful for junior students who may become unaware of the metallic objects during subsequent radiographic examinations. Many of the surveyed videos focused on the assembly of the receptor holder and its positioning within the oral cavity, whereas omitting the scene or explanation on choosing a correct radiation dose according to patient's body size and tooth type to be imaged. Optimized radiation dose may not be very critical with regards to image quality for clinics using phosphor plates, as they can still produce good quality radiographic images at exposure times lower or higher than the standard, rendering a much reduced chance of under- and over-exposure [17]. However, the principle of \"as low as reasonably achievable\" (ALARA) advocates against an unnecessary increase in the radiation dose [18]. The principle has now evolved into \"as low as diagnostically achievable being indication-oriented and patient-specific\" (ALADAIP), implying that correct setting of the radiation dose according with the aid of the body size and tooth type controls is of paramount importance especially for pediatric patients [19]. From the radioprotective perspective, the instructional videos should demonstrate the selection of proper radiation dose from the control panel. Another common issue was not showing the orientation dot on the film or phosphor plate to be placed on the occlusal side. The original intention of the orientation dot is to indicate which side of a radiographic film is the surface during viewing. The physical dot should be raised on the surface side. One drawback of the dot is that its presence will obscure the image, and that is why it should be placed on the occlusal side, so that the periapical region including root apices and surrounding structures will be preserved. For intraoral sensors and phosphor plates, the issue of determining the surface during viewing is not applicable, as the digital images are viewed directly on the computer screen. If an operator wrongly flips or rotates a digital image on the computer screen, the digital orientation dot cannot provide any clues, unless the operator has made customized rules during radiographic taking (e.g., the dot should always be placed towards the mesial side); however, then it would have a chance to obscure the periapical region. The authors were unclear which digital imaging systems still incorporated the orientation dot or mark, but it should be placed on the occlusal side when present. It is important to make the patient feel as comfortable as possible during periapical radiography. Besides the operator's technique and experience, the design of the image receptor and the receptor holder would also affect the patient comfort level [20; 21]. The intraoral sensor is rigid and bulky, whereas the traditional film packet and phosphor plate are thin but the edges are relatively sharp. The pressure exerted against the floor of the mouth or the lingual sulcus during taking mandibular periapicals may particularly cause discomfort to the patients.