Reference reading: Chapter 19 Show interproximal caries Show pulp changes Show overhangs Display improperly fitting crowns Shows recurrent caries beneath restorations Show resorption of alveolar bone Is a method used to examine the interproximal surfaces of the teeth (where the explorer doesn’t reach). Considered a method of preventive dentistry. Is a radiographic exam that is used the most frequently in conjunction with dental exams and cleanings. X-ray beams pass through teeth at a 90 degree angle, which creates a more accurate image of structures. The use of paralleling technique creates the illusion of open contacts, giving the appearance that there are spaces between the teeth. ◦ Appears radiolucent (BLACK) Show the crowns of both upper and lower teeth, as well as the supporting alveolar bone, on a single film. The film is placed in the mouth parallel to the crowns of both the upper and the lower teeth The film is stabilized when the patient bites on the bite-wing tab or film holding device. The central ray of the x-ray beam is directed through the contacts of the teeth, using vertical angulation of +10 degrees The Bite-wing tab: this is a sticky tab that is placed on the tube side of the film packet. The patient bites directly on the tab, and therefore establishes a better image because the teeth are fully closed, and there is no bite-block interference. Rinn XCP Bitewing instrument: ◦ Just like the Rinn for periapical films, the Rinn bite-wing holder will position the film, stabilize it, and align the PID for a good diagnostic film. Premolar view: ◦ angle the PID at +10 degrees vertically; ◦ horizontally aim toward center of film, between the premolars and the occlusal plane ◦ Center tab on 2nd premolar Molar view: ◦ angle the PID at +10 degrees vertically, ◦ horizontally aim at contacts of 1st and 2nd molars ◦ Center tab on 2nd molar Size 0 = pediatric patient with primary dentition Size 1 = children with mixed dentition Size 2 = teens and adult patients Size 3 = horizontal bitewings only; not recommended due to overlapped contact results Can be used to examine the level of supporting bone in the mouth. The bite-wing is placed in a vertical, up and down, direction. Mainly used for periodontal patients. A total of 7 projections are used to cover all areas. The whole purpose of the bitewing examination is to see the interproximal areas of the teeth. If horizontal angulation is incorrect, the contacts will be overlapped, and produce a film of poor diagnostic quality. To avoid overlap, direct the CR through the interproximal areas of the teeth. If the vertical angulation is incorrect, the image will be distorted, and also of poor diagnostic quality Edentulous Areas ◦ A cotton roll must be placed in the area of the missing teeth to support the bite-wing tab. ◦ Failure to support the BW tab results in a tipped occlusal plane on the radiograph. Bony Growths (tori) ◦ Mandibular tori may cause a problem in film placement. ◦ The film must be placed between the tori and the tongue, not on the tori. BEFORE PLACING FILM IN PATIENT’S MOUTH: Set exposure factors ◦ (kVp, mA, exposure time) Ask patient to remove all intraoral objects and eyeglasses Check the oral anatomy ◦ Tori? Shallow or narrow palate? ◦ Limited opening? Attempt to retract cheeks and tongue to gauge difficulty during film placement.