Resource Reading: Chapter 17 – pp. 158 – end of chapter

 In the anterior area, the size 1 film is used and always placed in a VERTICAL direction.  In the posterior area, the size 2 film is used and is always placed in a HORIZONTAL direction.

 There are 5 Basic rules: ◦ Receptor Placement ◦ Receptor Position ◦ Vertical Angulation ◦ Horizontal Angulation ◦ Film Receptor Exposure

Anterior Film Placements  Place the film directly behind the teeth you are trying to capture.  Maxillary canine – A  Maxillary Central and lateral incisors – B  Mandibular canine – C  Mandibular lateral and central incisors - D

Posterior Placement  Place the film directly behind the teeth you are trying to capture.  Maxillary premolar shot – A  Maxillary molar shot – B  Mandibular premolar shot – C  Mandibular molar shot - D

 An easy way to tell if the film is placed correctly is to make sure that the bite block is projecting out over/under the occlusal or incisal surfaces of the the teeth you are trying to capture.

 The receptor must be positioned to the long axis of the tooth.  The receptor and XCP must be positioned away from the teeth and toward the middle of the oral cavity. The mandibular molars are the only exception to this.

 The central ray should be directed perpendicular (at a right angle) to both film and tooth.  Vertical angulation refers to the “up & down” movement of the cone.

 The central ray of the x-ray beam must be directed through the contact areas of the teeth.  Horizontal angulation refers to the “left to right” movement of the cone.

 The end of the cone MUST line up with the placement ring of the of the Rinn.

 Failure to do so will result in what is called a “conecut”.  This concept will discussed more later in the course (Chapter 20)