1. Intraoral Radiographic Examination

2. Intraoral Radiographic Examination The intraoral radiographic examination is a radiographic inspection of teeth & intraoral adjacent structures. It requires the use of intraoral film, which placed inside the mouth.

3. Types of Intraoral Radiographic Examinations: There are three common types of radiographic examination that use intraoral film: Periapical examination. Interproximal examination. Occlusal examination.

4. Shadow Casting Principles 1.The source of radiation should be as small as possible. 2.The distance from the radiation source to the object should be as long as possible. 3.The distance from the object to the image receptor should be as short as possible. 4.The object & the image receptor should be parallel. 5.The primary x-ray beam should be perpendicular to both object & image receptor.

5. Periapical Examination Main Indications: 1.Detection of apical infection/inflammation. 2.Assessment of the periodontal status. 3.After trauma to the teeth and associated alveolar bone. 4.Assessment of the presence and position of unerupted teeth. 5.Assessment of root morphology before extractions. 6.During endodontics. 7.Preoperative assessment and postoperative appraisal of apical surgery. 8.Detailed evaluation of apical cysts and other lesions within the alveolar bone. 9.Evaluation of implants postoperatively.

6. Ideal Film Positioning Requirements 1-The tooth under investigation and the film packet should be in contact or, if not feasible, as close together as possible. 2-The tooth and the film packet should be parallel to one another. 3-The film packet should be positioned with its long axis vertically for incisors and canines, and horizontally for premolars and molars with sufficient film beyond the apices to record the apical tissues. 4-The X-ray tube head should be positioned so that the beam meets the tooth and the film at right angles in both the vertical and the horizontal planes. 5-The positioning should be reproducible.

7. The Paralleling Technique. Intra-oral Radiographic Techniques The Bisected Angle Technique..

8. Bisected Angle Technique 1. The film packet is placed as close to the tooth under investigation as possible without bending the packet. 2. The angle formed between the long axis of the tooth and the long axis of the film packet is assessed and mentally bisected. 3. The X-ray tube head is positioned at right angles to this bisecting line with the central ray of the X- ray beam aimed through the tooth apex. 4. Using the geometrical principle of similar triangles, the actual length of the tooth in the mouth will be equal to the length of the image of the tooth on the film.

10. Beam Angulation A-Vertical angulation of the X-ray tube head. B-Horizontal angulation of the X-ray tube head.

17. Positioning Techniques A-Using film holders: Bisected Angle Instruments (BAI); closely resemble the paralleling technique holders and consist of the same three basic components — film holding mechanism, bite block and an X-ray beam-aiming device — but the film is not held parallel to the teeth.

18. B-Using the patient’s finger :

19. Advantages of the Bisected Angle Technique 1.Positioning of the film packet is reasonably comfortable for the patient in all areas of the mouth. 2.Positioning is relatively simple and quick. 3.If all angulations are assessed correctly, the image of the tooth will be the same length as the tooth itself and should be adequate (but not ideal) for most diagnostic purposes.

20. Disadvantages of the Bisected Angle Technique 1.The many variables involved in the technique often result in the image being badly distorted. 2.Incorrect vertical angulation will result in foreshortening or elongation of the image. 3.The periodontal bone levels are poorly shown. 4.The shadow of the zygomatic bone frequently overlies the roots of the upper molars. 5.The horizontal and vertical angles have to be assessed for every patient and considerable skill is required. 6.It is not possible to obtain reproducible views. 7.Coning off or cone cutting may result if the central ray is not aimed at the centre of the film, particularly if using rectangular collimation. 8.Incorrect horizontal angulation will result in overlapping of the crowns and roots. 9.The crowns of the teeth are often distorted, thus preventing the detection of approximal caries. 10.The buccal roots of the maxillary premolars and molars are foreshortened.

21. Paralleling Technique 1. The film packet is placed in a holder and positioned in the mouth parallel to the long axis of the tooth under investigation (magnification,loss of definition target-film distance long PID). 2. The X-ray tube head is then aimed at right angles (vertically and horizontally) to both the tooth and the film packet. 3. A film holder must be used to hold the film parallel with the long axis of the tooth. The patient cannot hold the film. The technique is reproducible. This positioning has the potential to satisfy four of the five ideal requirements of shadow cast principles.

24. Film Packet Holders A device used for holding the film packet parallel to the teeth that also prevents bending of the packet. A bite block or platform. An X-ray beam-aiming device. This may or may not provide additional collimation of the beam.

25. FILM HOLDERSFILM HOLDERS

26. Copyright © 2005 by Elsevier Inc. All rights reserved. Assembling the XCP (Extension-Cone Paralleling Instruments), Anterior Assembly

27. Positioning Techniques Patient position. Film position. Beam adjustment. Machine adjustment.

28. Film Position With Film- holder

29. Film Positioning with Film Holder

30. Modifications In Technique 1-Shallow Palate; parallelism between the film & the long axis of the tooth is difficult to accomplish in a patient with a shallow palate (low palate vault), tilting of the bite block occurs, which result in the lack of parallelism between the film & the long axis of the tooth. If this tilting not exceed 20˚angle the radiograph is acceptable. But if its more than the 20˚ angle the modification is necessary; –Cotton rolls; two cotton rolls can be used one placed on each side of the bite-block; the periapical coverage is reduced. –Vertical angulation; can be increased by 5-15 angle more than the XCP instrument indicates, however image distortion occurs.

31. 2. Bony Growth: a torus is a bony growth in the oral cavity. A maxillary torus palatinus seen along the midline of the hard palate. Torus mandibularis seen along the lingual aspect of the mandible. Maxillary torus; the film must be placed on the far side of the torus (increase the film- object distance). Mandibular torus; the film must be placed between the tori & the tongue (increase the film-object distance).

32. 3. Mandibular Premolar Region: the anterior floor of the mouth area can be very sensitive region, when periapical film placements cause discomforted to the patient in the mandibular premolar region. Film placement; the film must be placed under the tongue to avoid the impinging on the muscle attachment & the sensitive lingual gingiva. Film; the lower edge of the film can be gently curved or softened to prevent discomfort. Bending of the film must be avoided.

33. Advantages of The Paralleling Technique 1. Geometrically accurate images are produced with little magnification. 2. The shadow of the zygomatic bone appears above the apices of the molar teeth. 3. The periodontal bone levels are well represented. 4. The periapical tissues are accurately shown with minimal foreshortening or elongation. 5. The crowns of the teeth are well shown enabling the detection of proximal caries. 6. The horizontal and vertical angulations of the X-ray tube head are automatically determined by the positioning devices if placed correctly. 7. The X-ray beam is aimed accurately at the centre of the film — all areas of the film are irradiated and there is no cone cutting. 8. Reproducible radiographs are possible at different visits and with different operators. 9. The relative positions of the film packet, teeth and X-ray beam are always maintained, irrespective of the position of the patient’s head. This is useful for some patients with disabilities.

34. Disadvantages of the Paralleling Technique 1. Positioning of the film packet can be very uncomfortable for the patient, particularly for posterior teeth, often causing gagging. 2. Positioning the holders within the mouth can be difficult for inexperienced operators. 3. The anatomy of the mouth sometimes makes the technique impossible, e.g. a shallow, flat palate. 4. The apices of the teeth can sometimes appear very near the edge of the film. 5. Positioning the holders in the lower third molar regions can be very difficult. 6. The technique cannot be performed satisfactorily using a short focal spot to skin distance because of the resultant magnification. 7. The holders need to be autoclavable or disposable.

35. Bite-wing Radiography 1.Interproximal caries. 2.Over-hang filling. 3.Level of crestal bone between the teeth. 4.Interproximal calculus.

36. Bite-wing Radiography Principles: 1.The film is placed in the mouth parallel to the crown of both upper & lower teeth. 2.The film stabilized when the patient bites on the bite-wing tab or bite-wing film holder. 3.The central ray of the x-ray beam is directed through the contacts of the teeth, using a +10 degree vertical angulation.

39. Technique: 1.Position the patient upright in the chair so that the upper arch is parallel to the floor & the mid- sagittal plane is perpendicular to the floor. 2.Remove all objects from the mouth e.g. (dentures, retainers, chewing gum) & the eyeglasses must be also removed. 3.Film positioning; ask the patient to slowly bite on the bite-wing tab or bite-block of the film holder. 4.Set vertical angulation at +10 degrees. 5.The x-rays should be directed perpendicular to the curvature of the arch.

40. Modifications in the Technique Edentulous Spaces: may cause a problem with bite-wing film placement. A cotton roll must be placed in the area of missing tooth or teeth to support the bite- wing tab or film holder. Failure to support the bite-wing tab or film holder results in a tipped occlusal plane on the resulting radiograph. Bony Growths: the film placed between the tori & the tongue & then exposed.