Occlusal technique l Oral radiology MCQs

Occlusal technique in dental x-ray l Oral radiology MCQs for dental students 

IMPORTANT POINTS TO REMEMBER

1. It is also called as called ‘sandwich radiography’. Occlusal radiographs are made using an extreme bisecting angle technique in which the primary beam is directed perpendicular to the imaginary bisector of angle formed between long axis of the tooth and long axis of the film.
2. Mandibular cross-sectional view: Also known as ‘mandibular true occlusal radiograph’. The film packet is placed in mouth in such a way that its short axis is in line with the median plane. The central ray is directed along the median plane so as to be perpendicular to the film packet.
3. Mandibular anterior topographic view: The film packet is placed between the teeth in such a way that the pebbled surface is towards the mandibular teeth. The tube is adjusted to direct the central rays through the tip of the chin in midline at −55° angle to plane of the film packet.
4. Mandibular lateral topographic view: The long axis of the film is parallel to the facial surfaces of posterior teeth and the film is placed as posteriorly as possible. The head is positioned so that the occlusal plane of the mandibular teeth is perpendicular to the horizontal plane and the median plane is vertical.
5. Pediatric mandibular occlusal view: A size 2 film is used for projection with embossed dot towards mandibular teeth and the short axis of the film is parallel to median plane. The central ray is directed through the child’s chin at −55°.
6. Maxillary cross-sectional view: The film packet is placed in mouth with its short axis in line with the median plane. the tube head is adjusted so that the central ray is directed along the median line and at an angulation of +65° to pass through the bridge of the nose to the film packet.
7. Maxillary anterior topographic view: The film is placed horizontally with the pebbled surface towards the maxillary teeth and the long axis crosswise in the mouth. The central ray is aimed towards the centre of the film passing through the tip of the nose of patient with a vertical angle of +45° and horizontal angle of 0°.
8. Maxillary lateral topographic view: The film is placed so that its long axis is parallel to the facial surfaces of posterior teeth and the film extends laterally approx 0.5 mm to the buccal cusps. The X-ray tube head is positioned to the side of the patient 2 cm below the outer canthus of eye and directed towards centre of the film with a vertical angle of +60°.
9. Vertex occlusal view: The film packet is positioned carefully in mouth with its short axisin line with the median plane and the film is placed far enough distally to include all the teeth perpendicular to the plane of the film in midline.
10. Maxillary pediatric occlusal view: The film packet is placed in child’s mouth in such a way that the long axis of the film is perpendicular to the sagittal plane. The central ray is directed through the midline of the arch towards the centre of the film with vertical angulation of +60°.
11. Occlusal view for maxillary tuberosity: The occlusal film is placed against the maxillary teeth and stabilized with pressure from patient’s finger the central ray is directed 1 inch behind the supraorbital ridge 45° downward and forward to sagittal plane through the temporal fossa, between temporal bone and zygomatic arch into the maxillary tuberosity.
12. Modified occlusal view for maxillary sinus: The occlusal film is placed in mouth so that the pebbled surface is towards maxillary teeth. The central ray is projected through the intra orbital foramen towards the centre of the film with vertical angulation of +75° to +85° depending upon the slope of forehead.
13. Mandibular lateral oblique occlusal view: The film packet is placed laterally towards the side of interest with pebbled surface towards the mandibular teeth. The patient’s head is supported and rotated away from the side of interest with the chin slightly raised. The central ray is directed from below and behind the angle of mandible through the submandibular gland at −20° vertical angle.
14. Reverse topographic anterior mandibular view: This technique is used when a patient has trismus or the teeth have been wired together and the mouth cannot be opened. The occlusal film is placed under the patient’s chin so that the short axis of the film is parallel to sagittal plane. The central ray is directed from mid of forehead perpendicular to the bisector of the angle formed by the teeth and the film.

MCQ on intraoral radiographic technique (Occlusal technique) for dental x-ray

1. In occlusal radiography film is placed in

a. Anterior maxillary arch

b. Anterior mandibular arch

c. Between maxillary and mandibular arch

d. All of the above

2. The general occlusal film dimensions are

a. 57 × 76 mm

b. 57 × 96 mm

c. 56 × 30 mm

d. 1000 mm

3. Indication for occlusal radiography includes

a. Patient with reduced mouth opening

b. Patient who is unable to tolerate periapical film

c. Examination of floor of maxillary sinus

d. All of the above

4. Maxillary occlusal radiography has

a. Topographic view

b. Cross sectional view

c. Oblique view

d. All of the above

5. Upper oblique occlusal projection correctly shows

a. Posterior part of the maxilla

b. Upper posterior teeth on one side

c. Both of the above

d. None of the above

6. The central rays in vertex occlusal view passes from

a. Ala of nose

b. Bridge of nose

c. Vertex of skull

d. Infraorbital rim

7. Reverse topographic anterior mandibular view is indicated in

a. Pedo patient

b. Interdental wiring

c. Mandibular tumour

d. Impacted mandibular molar

8. Which action precludes overlap of the cusps onto the occlusal surface for bitewing images?

a. Position aiming cylinder at +10 degrees.

b. Point central ray perpendicular to occlusal plane.

c. Utilize bitewing tab or loop instead of a holding device.

d. Direct central ray between first and second mandibular premolars.

9. Which is the appropriate vertical angulation of the aiming cylinder for a cross-sectional maxillary occlusal projection?

a. +10.

b. +45.

c. +65.

d. +90.

10. Which projection is used to evaluate soft tissue for the presence of a sialolith?

a. Lateral maxillary occlusal.

b. Anterior mandibular occlusal.

c. Cross-sectional maxillary occlusal.

d. Cross-sectional mandibular occlusal.