Panorâmica Dental
Thomas Merino
Panoramic radiography, also called panoramic x-ray, is a two-dimensional (2-D) dental x-ray examination that captures the entire mouth in a single image, including the teeth, upper and lower jaws, surrounding structures and tissues.
An x-ray exam helps doctors diagnose and treat medical conditions. It exposes you to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most often used form of medical imaging.
A panoramic x-ray is a commonly performed examination by dentists and oral surgeons in everyday practice and is an important diagnostic tool. It covers a wider area than a conventional intraoral x-ray and, as a result, provides valuable information about the maxillary sinuses, tooth positioning and other bone abnormalities. This examination is also used to plan treatment for full and partial dentures, braces, extractions and implants.
You may be asked to wear a lead apron as a safety precaution to protect the rest of your body from any radiation exposure that may scatter from the panoramic x-ray beam. You may also be asked to remove your jewelry from the region being imaged, eye glasses and any metal objects that might interfere with the x-ray images.
Women should always inform their dentist or oral surgeon if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Radiation Safety page for more information about pregnancy and x-rays.
A panoramic x-ray machine consists of two sides. An x-ray tube is mounted on one side and the x-ray film or a detector on the opposite side. The patient's head is positioned with chin, forehead and side rests. The patient may be provided with a bite blocker to open the mouth slightly for a clearer picture.
X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. The technologist carefully aims the x-ray beam at the area of interest. The machine produces a small burst of radiation that passes through your body. The radiation records an image on photographic film or a special detector.
The digital format also allows the dentist to adjust and change the contrast, brightness and darkness of the image for better visualization of certain structures and tissues. Images on film cannot be adjusted or changed.
First, you will be situated in the center of the unit where the technician will carefully position and secure your head. The unit can be adjusted to accommodate a patient standing or sitting in a wheelchair. A bite-blocker is then placed in your mouth to ensure proper alignment of the teeth. Correct placement of the teeth and head is important for obtaining a clear image.
You will be asked to remain very still while the rotating arm travels in a semicircle around the perimeter of your head and the images are being taken. This can typically last between 12 to 20 seconds.
A panoramic x-ray does not provide precise and detailed information about each individual tooth or soft tissues, such as the muscles. It is generally used as an initial evaluation of the bones and teeth. Because your mouth is curved, the panoramic x-ray can sometimes create a slightly blurry image where accurate measurements of your teeth and jaw are not possible. If your dentist or surgeon needs more information, a computed tomography (CT) scan or magnetic resonance imaging (MRI) may be ordered. This may include Dental Cone Beam CT, an imaging exam developed specifically for this part of the body.
RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical questions or for a referral to a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you can search the ACR-accredited facilities database.
This website does not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a better understanding of the possible charges you will incur.
Web page review process: This Web page is reviewed regularly by a physician with expertise in the medical area presented and is further reviewed by committees from the Radiological Society of North America (RSNA) and the American College of Radiology (ACR), comprising physicians with expertise in several radiologic areas.
Outside links: For the convenience of our users, RadiologyInfo.org provides links to relevant websites. RadiologyInfo.org, RSNA and ACR are not responsible for the content contained on the web pages found at these links.
Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.
Objectives To gather information on the types of panoramic x-ray equipment used in NHS dental practice and whether dentists satisfy the legal requirements for safety, to determine which practice personnel take panoramic radiographs and to assess the prevalence of the practice of 'routine' panoramic radiography among NHS dentists.
Results 542 dentists returned the questionnaire, a 73.3% response. Panoramic x-ray equipment ranged in age from 27 years old to new, with 42.2% exceeding 10 years in age. The overwhelming majority of GDPs satisfied the requirement for regular maintenance and surveying of equipment. Almost all dentists (95.9%) performed a history and clinical examination prior to panoramic radiography but 42% practised 'routine screening' of new adult patients. A substantial proportion (36.7%) of dentists used unqualified personnel to take panoramic radiographs.
Conclusions While some aspects of this study give reassurance about the prevalence of good practice, widespread panoramic screening and using unqualified staff to take radiographs causes concern. These findings have implications for educators and for those involved in maintaining clinical standards.
All types of radiography in England and Wales have shown a steady rise throughout the past two decades, with a marked proliferation in the use of panoramic radiology. In 1983, Wall and Kendall remarked on the rapid rise in its use,1 while today more than 1.7 million panoramic radiographs are taken annually in NHS general practice.2 These figures underestimate the true numbers as they exclude radiographs exposed in independent practices, hospitals and the Community Dental Services. Recently it was estimated that there are about 3,250 panoramic x-ray sets in the UK.3
While any exposure to x-rays is believed to carry a risk of inducing cancer, dental radiography has generally low doses and associated risks. Nevertheless, the dose from panoramic radiography has recently been estimated at 6.7 μSv,3 and 26 μSv,4 carrying an associated risk of inducing a fatal cancer of 0.21 and 1.9 cases per million examinations respectively.3,4 Such dose and risk levels assume a level of 'good practice' and well-maintained modern equipment. However, higher doses and risks are associated with certain older types of equipment. Those using a circular scanning motion incorporating three centres of rotation produce doses between 3 and 16 times higher than those with an elliptical path of rotation, due to relative 'hot spots' over the mandible and parotid glands.5 A study in France showed the latter type to be the most widely used.6 Furthermore, a survey of panoramic equipment in the UK found that a higher dose than appropriate was being delivered during use of 70% of the panoramic equipment.7
It is a fundamental requirement of radiation protection that all exposures to x-rays as part of diagnosis should be clinically justified for each patient. The guidelines on the use of 'panoral' radiographs devised by the Dental Estimates Board in 1983,8 are in conflict with this philosophy. One of these guidelines states that a fee would be paid by the Board for a panoramic examination for 'Examination of a patient new to the practice, or for a patient for whom a comprehensive radiographic examination has not previously been undertaken at the practice'. There is no evidence to support 'routine' panoramic radiography of patients, and a recent report has recommended selection criteria for use of the technique in primary dental care.9
The Ionising Radiation Regulations (1988)10 and the Guidance Notes11 put certain obligations upon dentists. It is a requirement that all x-ray equipment is regularly maintained and surveyed every 3 years for radiation safety,11 but it is not known how many dentists comply with these requirements. A 'physical director' (the person who exposes the patient) must be adequately trained,10 but anecdotal evidence of nurses and other practice staff taking radiographs suggest that this requirement is not always observed.
While there is some valuable data in existence on the radiation doses delivered during panoramic radiography,1,3,4,5,6 there is little information available on other aspects of panoramic radiographic use in the UK.
The study involved a postal questionnaire of dentists working in 22 Family Health Service Authorities (FHSAs) in England and Wales during 1997. Dental Practice Board data12 on the rates of claims for radiographs per 100 item of service claims classify each FHSA as a 'low', 'medium' or 'high' prescribing area (hereafter termed the 'radiographic prescription profile'). FHSAs were randomly selected from each of the three category groups for inclusion in the study. The number of FHSAs included from each category was determined on the basis of numbers of registered dentists in those FHSAs, so that approximately equal numbers of dentists were surveyed from each of the 'low', 'medium' and 'high' prescribing areas.
c80f0f1006