Radiography for Children

Radiographs: Supplemental Data Base Radiographs for children are a component of the supplemental data base; not a component of the defined data base. Consequently, the exposure of radiographs on a child is based on a documented need for a specific radiograph in order to render a thorough diagnosis. The decision to expose radiographs should only be made after a thorough clinical examination by the dentist. Exposure of radiographs is not a routine procedure or a component of any standard protocol. Only a dentist can determine when and what radiographs are required. This decision cannot be delegated. When radiographs are required, an informed consent from the child’s parent is required. The “adequate information” of an informed consent would include explaining to the parent the justification for exposing the radiographs for which consent is requested.

Radiation Safety Parents are increasingly concerned regarding radiation exposure of their children…as they and we should be. There is credible scientific evidence of a small increase in cancer risk in individuals exposed to radiation levels encountered in diagnostic imaging procedures. This is particularly important in children whose tissues are more radiosensitive in general and whose life expectancy provides a longer time to develop cancers resulting from radiation exposure. Health professionals account for 50% of the annual per capita radiation exposure in the United States.

Radiation Safety: Image Gently An initiative was launched nationally in 2007 by the Society for Pediatric Radiology to establish an “Alliance for Radiation Safety in Pediatric Imaging.” The alliance now includes over 80 organizations committed to change clinical practices through an education and awareness campaign called Image Gently. The various dental specialty organizations have joined the effort, and in September of 2014 dentistry as a profession officially joined the movement. An Image Gently website has been developed to provide information to parents, and includes answers to frequently asked questions. The website is at:

Image Gently Webpage

Six-Step Plan to Minimize Radiation Exposure to Children in the Dental Office 1.Select radiographic views that match a patient’s individual need for diagnosis and are not merely a routine. 2.Use the fastest image receptor possible: E or F film or comparable digital storage system. 3.Collimate the x-ray beam to only expose the area of interest. 4.Always use a thyroid collar. 5.Child –size the exposure. Do not use adult exposure times. 6.Use cone beam CT only when absolutely necessary, as results in higher dose exposure.

Lead Apron with Thyroid Collar

Criteria for Exposing Radiographs on a New Patient In the primary dentition, bitewing radiographs should be exposed, but only if the proximal surface of the posterior teeth cannot be clinically visualized. In the transitional dentition (after the eruption of the first molar) bitewings and a panoramic radiograph should be exposed. Contacts between the primary posterior teeth become tighter as a result of the mesial eruptive force of the first permanent molar, closing more tightly the inter-proximals spaces between primary molars, making them more difficult to clinically visualize. A panoramic film in the early transitional dentition (age 6) permits the determination of any developmental anomalies such as congenitally missing or supernumerary teeth. Individual periapicals are indicated in both the primary and transitional dentitions based on the need to evaluate specific circumstances, e.g. required extraction of a tooth, endodontic procedures, or trauma to a tooth.

Criteria for Exposing Radiographs at the Periodic Oral Examination The periodicity of examining a child subsequent to their initial examination as a patient is based on the caries risk of the child, as well as the developmental milestones. A discussion of assessing caries risk will occur in our next Minicourse on Preventive Dentistry. Development milestones, and the implication for radiographic assessment, will be discussed in our Third Year course, PDO 834. Based on caries risk assessment and development, children are generally re-examined (recall appointment) at 3, 6, 12, or 18 month intervals. Children at low risk for dental caries may only require bitewing radiographs infrequently, every months. Children at high risk for dental caries may require bitewing radiographs at 6 month intervals, or until their risk for caries has declined.

Common Radiographic Images Bite-wing: To visualize proximal tooth surfaces unable to be visualized clinically in order to determine the existence of dental caries on the proximal surfaces. The crowns of the teeth and only part of the root is visualized. Occlusal carious lesions are diagnosed clinically, not radiographically. Periapical: To visualize the entire tooth, including the root apex. Necessary when a tooth is indicated for extraction, for assessing trauma, and for endodontic procedures. Panoramic: To visualize the entire dentition as well as the supporting craniofacial complex. Occlusal: To visualize the maxillary or mandibular anterior segment of the arches in order to view present and developing teeth. Most frequently used in the primary dentition.

Bitewing Radiographs

A #0 film is the size used for exposing bite- wings on a child in the primary dentition. As the first permanent molar erupts at age 6, it is advisable to use the larger #2 bitewing film. Child’s head is positioned so that ala-tragus is parallel with the floor. Film is positioned in the floor of the mouth between the tongue and lingual aspect of the mandible. The bite-tab is positioned on the occlusal surfaces of the posterior teeth. The child is instructed to close slowly. The X-ray cone is positioned such that it parallels the bite-wing film and is at a vertical angle of +10°.

Bitewing Radiograph

Diagnosing Dental Caries on a Bitewing Radiograph

Periapical Radiographs Paralleling Technique Rinn XCP positioning instruments for paralleling technique to expose periapical view. Bisecting Angle Technique

Rinn Snap-A-Ray Universal Sensor Holder for Digital Radiography

Rinn Snap-A-Ray Holder for Conventional Film

Posterior Periapical Radiographs Using Rinn Snap-A-Ray Holder

Periapical Radiograph

Posterior Periapical to Evaluate Eruption of First Permanent Molar Ectopic Eruption

Maxillary Occlusal Radiograph Occlusal plane parallel to the floor. #2 film placed with long axis left to right, and with anterior edge of the film extending approximately 2 mm beyond the incisal edge. Patient instructed to bite lightly on the film. Central ray of the film directed to the apices of the central incisors. Vertical angle of X-ray cone is a +60°.

Maxillary Occlusal to Identify a Developmental Anomaly Gemination

Maxillary Occlusal on an Asymptomatic 4 Year Old Child Mesiodens

Mandibular Occlusal Radiograph Film placement for the mandibular occlusal is identical to that of the maxillary. Film placement should be 2mm in front of incisal edge mandibular incisors. Child’s head positioned so that occlusal plane is at -45° angle. The cone is aligned at a -15° angle.

Digital Systems Some digital systems utilize solid-state detector technology such as charge-coupled devices or complementary metal oxide semiconductors for image acquisition. These systems are not ideal for children as young children do not tolerate the wired sensors well. A phosphor-based digital system is more ideal for the child patient. The phosphor plates have no wire to the computer and resemble intraoral film in every way.

Panoramic Radiograph Panoramic radiographs can be helpful with anxious children as the radiograph is obtained without placement of film in the mouth. However, remaining immobile for the required 15 seconds of the exposure may be challenging. While not a substitute for intra-oral films, the panoramic radiograph does provide a comprehensive view of the teeth and supporting cranio- facial cranio-facial complex. Typically, a panorex is exposed at age 6-7. It provides little data of diagnostic value prior to that age. That is the reason insurance carries will not pay for a panorex prior to the eruption of the first permanent molars at age 6-7. The major weakness of the panoramic image is that it does not provide the detail required for diagnosing dental caries.

Panoramic Radiograph

Behavior Management Tell.Show.Do : TELL and SHOW the child what you are going to DO. For young children, the X-ray cone can be referenced as a “nose,” or “elephant’s trunk.” Let the child hold the film/sensor. Never ask the child if you may do it…they could say “No;” an answer to be honored. Work as rapidly as possible. Do not say “this will not hurt”…if could be somewhat uncomfortable. Have the X-ray cone properly positioned before placing the film in the mouth. Have the child focus on an object straight ahead so that s/he does not follow your movements. Use DESCRIPTIVE praise. For the uncooperative child, “expose” at least one film and tell the child will finish at the next visit.

X-ray versus Radiograph X-rays have short wave lengths, size of an atom. Obviously, x- rays cannot be seen. Cause ionisations (removing or adding electrons to atoms.) Affect photographic film the same way as light: turn it black. Absorbed; stopped by metal and bone. Pass through healthy body tissue. These properties make x-rays useful in medical diagnosis and treatment. This is a radiograph; it is not an x-ray!