Occlusal radiography (Sandwhich radiography) Flashcards
Indications for occlusal radiography
This technique is used to examine large areas of upper and lower jaw, palate and floor of mouth. This is a supplementary radiographic technique that is usually used in conjunction with periapical or bitewing radiographs
To locate retained roots of extracted teeth
To examine the cleft palate
To determine boundaries of maxillary sinuses
To locate supernumerary, unerupted or impacted (canine/third molar) teeth.
To locate foreign bodies in either jaws.
To locate salivary stones in Wharton’s duct in the floor of mouth.
To locate and evaluate the extent of lesions (e.g.. cyst, tumor, tori, etc.) in the maxilla and mandible.
Edentulous patients
Extent and location of fractures in the mandibe and maxilla
Film size
57 mm + 76 mm
Basic principles
Film is positioned with white side facing the arch i.e. being exposed.
Film is placed between the occlusal surfaces of the maxillary and mandibular teeth.
Film is stabilized when patient gently bites* on surface of film.
For maxillary occlusal films the patient’s head must be positioned so that the upper arch is parallel to the floor and mid-sagittal plane is perpendicular to the floor.
For mandibular occlusal films the patient’s head must be reclined and positioned so that the occlusal plane is perpendicular to the floor.
Classification of occlusal projections
(Maxillary occlusal view)
Cross sectional view- Ray directed through the bridge of the nose just belwo the nasion forming an angle of 65 degrees
**Topographic view (anterior)- **Ray directed through the tip of the nose forming an angle of 45 degrees
Topographic view (lateral)- Vertical angulation of 60 degrees which is 2 cm below the canthus of the eye
Classification of occlusal projections
(Mandibular occlusal view)
Cross sectional view- Midline through FOM, 3 cm below the chin at 90 degrees to the receptor
**Anterior view- ** - occlusal plane is 45 degrees above the horizontal
**Lateral view- **Beneath the chin, 3 cm posterior to the point of chin and 3 cm lateral to the midline
Maxillary cross sectional view
(MAIN INDICATIONS)
Periapical assessment of the upper anterior teeth, especially in children but also in adults unable to tolerate periapical films
Detecting the presence of unerupted canines, supernumeraries and odontoma
As the midline view, when using the parallax method for determining the bucco/palatal position of unerupted canines
Evaluation of the size and extent of lesions such as cysts or tumors in the anterior maxilla
Assessment of fractures of the anterior teeth and alveolar bone.
it is especially useful in children following trauma because film placement is straightforward.
Maxillary lateral view
(MAIN INDICATIONS)
Periapical assessment of the upper posterior teeth, especially in adults unable to tolerate periapical films
Evaluation of the size and extent of lesions such as cysts, tumors or osteodystrophia affecting the posterior maxilla
Assessment of the condition of the antral floor
As an aid to determining the position of roots displaced inadvertently into the antrum during attempted extraction of upper posterior teeth
Assessment of fractures of the posterior teeth and associated alveolar bone including the tuberosity
Mandibular cross sectional view
(MAIN INDICATIONS)
Detection of the presence and position of radiopaque calculi in the submandibular salivary ducts
Assessment of the bucco-lingual position of unerupted mandibular teeth
Evaluation of the bucco-lingual expansion of the body of the mandible by cysts, tumours or osteodystrophies
Assessment of displacement fractures of the anterior body of the mandible in the horizontal plane.
As a middle view, when using the parallax method for determining the buccal/palatal position of unerupted/impacted canines.
Mandibular topographic anterior view
(MAIN INDICATIONS)
Periapical* assessment of the lower incisor teeth, especially useful in adults and children unable to tolerate periapical films
Evaluation of the size and extent of lesions such as cysts or tumors affecting the anterior part of the mandible
Assessment of displacement fractures of the anterior mandible in the vertical plane.
