Periapical Flashcards
Patient felt pain when having cold and hot drinks PA of teeth 45 and 44 given Good pre-operative PA is important. List 5 things that the PA can tell (5)
The quality of any restoration present
Extent of caries in relation to the pulp
Calcifications in the pulp chamber and crestal bone level
Three-dimensional anatomy of the tooth and its surrounding alveolar anatomy into a two-dimensional image.
Additional root canals
Improve perception of the spatial relationship of the root apices to their relevant surrounding structures
Root canal length
How to position the xray beam and film when taking a periapical using parallel technique
The x-ray receptor is supported parallel to the long axis of the teeth, and the central ray of the x-ray beam is directed at right angles to the teeth and receptor. This orientation of the receptor, teeth, and central ray minimizes geometric distortion and presents the teeth and supporting bone in their true anatomic relationships.
For maxillary projections, the superior border of the receptor generally rests at the height of the palatal vault in the midline.
For mandibular projections, the receptor should be used to displace the tongue posteriorly or toward the midline to allow the inferior border of the receptor to rest on the floor of the mouth away from the mucosa on the lingual surface of the mandible.
b. What is the problem of the x-ray film for permanent canine and how to correct it?
The x-ray film may not be able to fit within the arch of the maxilla or mandible which may lead to bending of the film and results in distortion hence we need a small film size (size 1 instead of size 2)
In addition to the periapical given, one more x-ray is needed to identify the location of the impacted canine, what is that?
Occlusal X-ray Or another periapical which is slightly shifted mesially or distally
Parallax technique, explain and draw diagram
The main principle utilizes the relative positions of radiographic images of two separate objects change when the projection angle at which the images were made is changed. If the tube is shifted and directed at the reference object (e.g., the apex of a tooth) from a more mesial angulation and the object in question also moves mesially with respect to the reference object because the object lies lingual to the reference object. If the tube is shifted mesially and the object in question appears to move distally, it lies on the buccal aspect of the reference object. These relationships can be easily remembered by the acronym SLOB: same lingual, opposite buccal.
Radiolucency around the crown of the impacted canine, give 2 differential diagnoses
Dentigerous Cyst Unicystic Ameloblastoma Adenomatoid odontogenic tumors
Why does radiolucency around the crown of the impacted canine suggest Dentigerous Cyst
In most cases, dentigerous cysts involve the permanent impacted teeth Radiographically, dentigerous cysts typically show a well-defined unilocular radiolucent area close to the crown of an unerupted tooth. The radiolucent space should be at least 3 to 4 mm in diameter. Due to its slow-growing pattern, it expands to the outer cortical boundary of the involved jaw. A critical diagnostic fact is that this type of cyst attaches at the cementoenamel junction.
Why does radiolucency around the crown of the impacted canine suggest Unicystic Ameloblastoma
The predominant radiographical patterns of unicystic ameloblastoma are unilocular, scalloped macromultilocular, pericoronal, interradicular, or periapical expansive radiolucencies
Why does radiolucency around the crown of the impacted canine suggest Adenomatoid odontogenic tumors
Radiographically, in approximately 75% of cases, these tumors appear as a corticated circumscribed unilocular radiolucency surrounding an impacted tooth. In addition, internal radiopaque foci develop in two-thirds of cases
