TOPIC: SPECIALIZED INTRAORAL TECHNIQUES
🌟 IMPORTANT POINTS TO REMEMBER
🔹Mandibular third molar radiography: It can be done by surgical needle holder technique, two-radiograph technique, using film holder and modified X-ray cone position technique.
🔹Gagging is also called retching which refers to the strong involuntary effort to vomit. It can be caused by psychogenic stimuli and tactile stimuli. It can be managed by attitude enhancement, never suggesting gagging, less time for exposure, exposure sequence, diverting attention, local anaesthetic spray, placebo medicine, deep breathing, reducing the tactile stimuli, placing film packet flat, demonstration of film placement, bite-block and film-holding device, music, hypnosis and administration of salt.
🔹Endodontics: Proper endodontic radiography includes special endodontic film holders and two different radiographs for the separation of the root canal. Root length assessment can be done by using a parallel technique.
🔹Children or pediatric patient: Film should be placed in the occlusal plane and the occlusal radiograph taken. Show and tell approach should be followed with patients.
🔹Reverse bitewings: Film packet is placed in buccal sulcus. The child bites on the tab to hold the film packet in the desired place. The X-ray beam is directed extraorally from the opposite side of the mandible 2 cm below the lower border of the mandible.
🔹Shallow palate: Cotton rolls should be placed on each side of bite-blocks to position the film parallel to the long axis of the tooth. To compensate for the tilt, the vertical angulation can be increased by 5–15°.
🔹Bony growth:
- Maxillary tori – The film should be placed on the far side of the torus and then exposed.
- Mandibular tori – They are more difficult to work as compared to maxillary tori. The film is placed between the tori and the tongue (not on the tori) and then exposed.
🔹Lingual frenum: Vertical angulation should be increased in this patient in the range of 40–60°.
🔹Canine overlap: In this case, central rays should be directed from the distal side of the canine.
🔹Restricted mouth opening: It may occur due to inflammation, pain, trauma or damage to the temporomandibular joint (TMJ). When the mouth opening is more than 13 mm, film can be introduced in the oral cavity by means of haemostat.
🔹Periodontal disease: Modification of the technique is done to focus the alveolar crest to see and assess the bone loss in periodontal disease. The X-ray beam should be as horizontal as circumstances permit.
🔹Infection: It may lead to oedema of the muscle of mastication which will result in trismus. Due to this intraoral radiography is painful to the patient. In this case, extraoral or occlusal technique is the only choice.
🔹Premolar area: The Premolar area in the lower mandibular region is very sensitive. In such a case, the film must be placed away from the tongue with the bite-block being placed on the premolar.
🔹Trauma: Dental fractures are best seen on periapical or occlusal view. For facial fractures, extraoral views are needed. In some patients, it may be needed to have radiography in the supine position.
🔹Pregnancy: Although the fetus is sensitive to ionising radiation, the amount of radiation received by dental radiography is extremely low.
🔹Grid measurement: Some dentists use the intraoral grid to evaluate bone levels and for endodontic measurement. Intraoral grids are available as thin radiopaque and radiolucent lines in the vertical and horizontal planes in 1 mm gradation.
🔹Radiopaque media: In endodontics, a radiopaque file is used to determine the root length. Gutta-percha or silver point can be placed in the periodontal soft-tissue pocket to determine periodontal pocket depth.
🔹Object localization: It is used for the localization of foreign objects or an impacted tooth within the jaw. A dental radiograph is a 2-D image; it gives the orientation of the image in either superoinferior or anteroposterior (intraoral periapical view) direction or in buccolingual (occlusal view). Sometimes, it becomes necessary to determine the 3-D position of the object.
🔹Clark technique: It is also called tube shift cone technique, or SLOB technique.
🔹Buccal object rule: This was discovered by Richard in 1952. This rule appears the same as the Clark rule.
🔹Right angle technique: This technique employs two projections of the same object taken at the right angle to each other.
🔹Radiographic wire technique: This technique is used in the case of an edentulous region. When the teeth are not present, radiopaque wires of different shapes are placed in a sheet of wax that is moulded over the edentulous area as a denture base.
🔹Stereoscopy: It is used to determine the location of small intracranial calcifications and multiple foreign bodies.
📌 INDICATION FOR OBJECT LOCALIZATION
- Foreign objects: Many times some foreign objects may get incorporated into the oral cavity. As radiography is a two-dimensional view, the location of the object cannot be understood. So in that case object localization technique is very useful.
- Salivary gland stones: Usually in this case right angle technique is used to locate salivary gland stones.
- Canal position: In endodontics, it is very important to locate the canal and position of the root in the posterior teeth.
- Impacted teeth: To know the exact position of the impacted tooth, object localisation is useful.
- Root piece: It is also used to know the position of root pieces in the jaw.
- Filling material: Many times restorative material gets dislodged and can affect the diagnosis. In that case, object localisation is helpful.
- Broken needle: Many times while giving local anesthesia needles are broken which may get dislodged in the soft tissue.
- Superimposition: If buccal and lingual objects are superimposed, then they can be separately viewed by using the buccal object rule by changing the angulation.
📌 INDICATIONS OF STEREOSCOPY
- It is more useful in evaluating the bony pockets in patients with periodontal disease.
- Morphology of TMJ.
- Root configuration teeth of those teeth that require endodontic therapy.
- Assessment of bone shape when the placement of dental implants is considered.
- Relationship of mandibular canal to the roots of unerupted mandibular third molars.
📌 MULTIPLE CHOICE QUESTIONS (MCQs)
💡 Gagging reflex refers to
a. Retching
b. Clenching
c. Both of the above
d. None of the above
Answer: a
💡 Causes of gagging include
a. Psychogenic stimuli
b. Tactile stimuli
c. Touching of the soft palate
d. All of the above
Answer : d
💡 Management in gagging involves
a. Time limit
b. Diverting attention
c. Mouthwash
d. All of the above
Answer : d
💡 Buccal object rule was discovered by
a. Richard in 1952
b. Elflnso in 1980
c. Stewart in 1951
d. Clark in 1986
Answer: a
💡 The problem with edentulous ridge can be overcome by taking
a. Modified bisecting angle technique
b. Panoramic technique
c. Placement of cotton role
Ad. ll of the above
Answer : d
💡 For Children who cannot tolerate the lingual placement of film, the film is placed in the buccal sulcus, that technique is known as
a. Reverse technique
b. Reverse bitewing technique
c. Reverse periapical view
d. None of the above
Answer: b
💡 Canine overlap is managed by
a. Central rays should be directed from the distal side of the canine
b. Central rays should be directed from the mesial side of the canine
c. Central rays should be directed from the middle of the canine
d. None of the above
Answer: a
💡 For object localization in the edentulous ridge, a technique used is
a. Right angle technique
b. Radiographic wire technique
c. Clark rule
d. Buccal object rule
Answer: b