Radiological diagnosis in periodontology
Introduction :
Simply performing a clinical examination is sometimes insufficient to make a correct diagnosis of periodontal disease; the practitioner must be able to use all the additional examinations that help to clarify the definitive diagnosis without, however, replacing the clinical examination.
Radiography is one of the very useful complementary examinations in the practice of dental surgery in general and in periodontology in particular given the very valuable data it provides us on the state of the dental organ and the peripheral organs surrounding it.
Advantages and limitations:
Radiography allows us to assess the state of the mineralized tissues of the dental organ: enamel, dentine and especially the clinically inaccessible calcified periodontal tissues; the alveolar bone with its different structures and in rare situations the cementum. These tissues appear on the image in the form of a so-called radiopaque (white) image whose intensity is proportional to the degree of mineralization of the tissue. Soft tissues such as the gum, pulp and periodontal ligament being non-mineralized tissues appear as a so-called clear (black) radiographic image and therefore invisible in the image, except for the periodontal ligament and the pulp; these two tissues are housed in a space bordered by a radiopaque tissue (the dentine around the pulp and the alveolar bone for the periodontal ligament) so we can clearly appreciate their size but not their content.
The different oral x-ray procedures:
Depending on the placement of the X-ray when taking the X-ray, a distinction is made between intraoral and extraoral X-rays.
- Intraoral radiography:
- The retroalveolar image:
It is a small film of 2×3 cm or 3×4 cm placed in the mouth behind the dental organ that can include between 2 to 4 teeth and placed either along its length or width. It is a shot that gives an excellent image of the dental organ although limited in the number of visible teeth and little or no visibility of the peripheral organs (sinus cavities or lower dental canal). The entire dental formula can be visualized by increasing the number of shots up to 10, 12 or 14 juxtaposed shots.
Among the requirements of a good retroalveolar image we have the fidelity of the image which must reproduce the dental organ in its real dimensions and to achieve the satisfaction of this requirement two methods of producing the image are proposed:
- Parallel or orthogonal technique:
The film is carried by a rigid support placed parallel to the axis of the tooth and connected to the cone that carries the X-rays perpendicularly. This is a technique that gives an excellent image that most faithfully reproduces the dimensions and structures of the dental organ.
- Given the difficulties of sometimes placing the support parallel to the axis of the tooth, a technique called BISELECTR uses this technique, which consists of directing the X-ray beam not perpendicular to the axis of the tooth or to that of the support but rather to that of the bisector of its two axes and which is estimated by the practitioner’s gaze.
Whatever method is used, it is imperative to include the entire dental organ in the field of action of the X-rays; concerning the clinical crown there will be no difficulty in filming it but as for the apex of the teeth it is necessary to include the axis connecting the wing of the nose to the orifice of the ear in the irradiation zone.
- The occlusal cliché:
It is a 4×5 cm image that gives us an occlusal image of the maxilla in order to visualize the dental structures in the vestibulo-buccal direction. The film is placed intra-orally on the occlusal surfaces of the teeth.
- The interproximal or bite-wing shot:
a small film is carried by a bitten support and placed behind the teeth in an intercuspation position.
exhibiting the least degree of distortion
Allowing the visualization of the maxillary and mandibular bony septa at the same time
Apical areas located outside the evaluated area
It is the technique of choice for the evaluation of intraosseous lesions and the visualization of inadequate restorations and carious lesions.
- Extraoral radiography:
- Panoramic X-ray or orthopantomography:
This is a commonly used cliché in dental surgery:
allows to obtain information in 2 dimensions
gives an overview of:
– all dental arches
– the relationship of the teeth with the peripheral structures: maxillary sinuses, nasal cavities, dental canal, etc.
– the temporomandibular joint
Panoramic radiography is useful for:
- detection of abnormalities in maxillary development
- detection of pathological lesions of teeth and jaws, as well as fractures
- assessment of the distribution and severity of bone destruction in periodontal disease
- In children, it is indicated to assess dental age.
- Tomography of the Temporomandibular Joints:
widely used for the study of ATMs in open and closed mouths.
it visualizes the condyle and the bony surfaces satisfactorily.
- Computed tomography or CT scan:
This test provides an image in the 3 dimensions of space
Although it is a fundamental examination in a pre-implant assessment , the scanner has very limited indications in the diagnosis and evaluation of the treatment of periodontal diseases.
It is mainly indicated in:
– traumatology
– tumor and inflammatory pathologies
– cranial malformations.
- Magnetic resonance imaging “MRI”:
The images are made using a magnetic field
Based on the information sent back to the body, a computer system will create a digital image which will be printed on film.
This exam allows:
- to study the anatomy of the facial mass: bones, muscles, vessels, teeth, etc.
- to determine craniofacial malformations, tumor and inflammatory processes ,
- to detect cervicofacial adenopathy.
Radiological diagnosis in periodontology
Early cavities in children need to be treated promptly.
Dental veneers cover imperfections such as stains or cracks.
Misaligned teeth can cause difficulty chewing.
Dental implants provide a stable solution to replace missing teeth.
Antiseptic mouthwashes reduce bacteria that cause bad breath.
Decayed baby teeth can affect the health of permanent teeth.
A soft-bristled toothbrush preserves enamel and gums.