mandibular landmarks of radiograph

final bds- omr

1. EKLAVYA DENTAL COLLEGE AND HOSPITAL DEPARTMENT OF ORAL MEDICINE AND RADIOLOGY TOPIC : RADIOGRAPHIC MANDIBULAR LANDMARKS GUIDED BY SUBMITTED BY DR. SWATI GOEL(M.D.S) – HOD AND READER DR. VISHESH YADAV(M.D.S.) – SENIOR LECTURER A. AFSANA FINAL YEAR BATCH 2016-17

2. RADIOGRAPHIC NORMAL ANATOMICAL LANDMARKS OF MANDIBLE

3. RADIOPAQUE STRUCTURES ENAMEL DENTIN CEMENTUM LAMINA DURA ALVEOLAR CREST CANCELLOUS BONE GENIAL TUBERCLES MENTAL RIDGE MYLOHYOID RIDGE INTERNAL OBLIQUE RIDGE EXTERNAL OBLIQUE RIDGE INFERIOR BORDER OF MANDIBLE

4. RADIOLUCENT STRUCTURES PULP PERIODONTAL LIGAMENT SPACE NUTRIENT CANALS LINGUAL FORAMEN SYMPHYSIS MENTAL FOSSA MENTAL FORAMEN MANDIBULAR CANAL SUBMANDIBULAR FOSSA

5. TOOTH STRUCTURE ENAMEL : The densest structure and seen as the outer most radiopaque layer of the crown of a tooth on the radiogragh . DENTIN : It is found beneath the enamel layer and appears radiopaque and comprises most of the tooth structure. It is less radiopaque than enamel. CEMENTUM – it is not usually apparent on the radiograph because the cemental layer is very thin.

6. SUPPORTING STRUCTURE LAMINA DURA ALVEOLAR CREST PERIODONTAL SPACE CANCELLOUS BONE

7. Lamina dura Definition: It is the wall of the tooth socket that surrounds the root. On Radiograph : Thin radiopaque line that surrounds the root. It is continuous with the shadow of the cortical bone at the alveolar crest

8. Double lamina dura - appears if the mesial and distal surfaces of root present in the path of x-ray beam Intact lamina dura around tooth - a vital pulp.

9. Definition: This is the most coronal portion of the alveolar bone found between the teeth. Alveolar Crest On Radiograph : Radiopaque line Located 1.5-2mm below CEJ Appears - A point of bone in anterior teeth; flat in posterior. Recede apically with age Markable resorption with periodontal disease Continuing with lamina dura and forms a sharp angle → Rounding angle indicative periodontal disease

10. Definition: It is the space between the root and the lamina dura and it contains connective tissue fibers, blood vessels and lymphatics . Periodontal ligament space On Radiograph : Thin Radiolucent line Its of uniform thickness and presents around the root. Width of PDL varied by individual, teeth & location; thinner in the middle of the root, slightly widened near the alveolar crest & apex. Its thickness less around – roots of embedded tooth and those lost their antagonists.

11. Periodontal ligament space

12. Definition: This is the spongy bone located between two layers of dense cortical bone Cancellous Bone On Radiograph : It appears predominantly radiolucent with the trabeculae appearing radiopaque in a criss -cross pattern. Anteriorly – trabeculae are thicker, coarser and fewer Posteriorly – trabeculae are fine, and have larger marrow spaces than anterior region.

13. Cancellous Bone

14. Structures of mandible Symphysis Genial tubercle Lingual foramen Nutrient canals Mental ridge Mental fossa Mental foramen Mandibular canal Mylohyoid ridge Submandibular gland fossa External oblique ridge Inferior border of mandible Coronoid process

15. Symphysis It is the suture in the midline of the mandible. It fuses by the end of first year of life, after which it is not radiographically evident. On Radiograph : appears radiolucent line through the midline of jaw

16. Mandibular symphysis In a new born infant Mandibular symphysis fracture

17. Genial Tubercles These are tiny bumps of bone on the lingual side of the mandible, approximately in the midline. serves as attachment for the genioglossus and the geniohyoid muscles. Well visualized on standard occlusal film

18. Genial Tubercles On Radiograph : appear as ring shaped radiopacities below the apices of mandibular incisors

19. Lingual Foramen It is a tiny opening in the bone located on the internal surface of the mandible, near the midline and surrounded by the genial tubercles. On Radiograph : A small radiolucent dot inferior to the apices of the mandibular incisors.

20. Nutrient canals These are tube like passages through the bone that contain nerves and blood vessels that supply the teeth. On Radiograph : Vertical radiolucent lines More prominent in anterior region and in edentulous mandible.

21. Mental ridge I t is a linear bony prominence found on the labial Aspect (external portion) of the mandible Extends from the premolar region to the midline and slopes upward turn as it approaches it. It appears as a Radio opaque line below the apices of anterior teeth.

22. Mental fossa This is a scooped out depressed area of the bone located on the external surface of the anterior mandible. On Radiograph : radiolucent area above mental ridge More prominent in anterior region and in edentulous mandible.

23. mental fossa : this represents the depression on the labial aspect of the mandible overlying the roots of the incisors. The resultant radiolucency may be mistaken for pathology

24. Mandibular incisor region mental fossa Lingual foramen Genial tubercle Mental ridge

25. Mental Foramen Its an opening in the bone located on the external surface of the mandible, in the region of premolars. On Radiograph : A small ovoid or round radiolucent area in the apical region of the premolars.

26. Mental foramen

27. Mylohyoid ridge located on the lingual surface of the mandible, extending from third molar area to Premolar region, serves as an attachment for the mylohyoid muscle. On Radiograph : Dense radiopaque band extends downwards and forward from the molar region. It may appear continuous with internal oblique ridge.

28. Internal Oblique Ridge Linear prominence of bone located on the internal surface of the mandible. Extends downwards and forwards from the ramus It may end in the region of third molar or it may continue as the mylohyoid ridge. On Radiograph : Radiopaque band that extends downwards and forwards from the ramus

29. Depending upon the technique used, the internal and external oblique ridges may appear superimposed on one another. When the ridges appear seperate ., then the superior band is external oblique ridge (white arrows) and the inferior radiopaque band (black arrows) is the internal oblique ridge.

30. External Oblique Ridge Linear prominence of bone located on the internal surface of body of the mandible. On Radiograph : Radiopaque band that extends downwards and forwards from anterior border of the ramus. It typically ends in the region of third molar.

31. Submandibular fossa It’s a scooped out depressed area of the bone located on the internal surface of the mandible inferior to the mylohyoid line. It houses the submandibular salivary gland. On Radiograph : Radiolucent area in the molar region below the mylohyoid ridge.

32. Mandibular premolar region A – mylohyoid ridge B - mandibular canal c – submandibular gland fossa d – mental foramen

33. Mandibular molar region A – external oblique ridge B – mylohyoid ridge C – mandibular canal D- submandibular gland fossa

34. Mandibular Canal It is a tube like passage through the bone that travels the length of the mandible. Extends from mandibular foramen to mental foramen. On Radiograph : A radiolucent band outlined by two thin radiopaque lines that represent the cortical walls of the canal. It may appear below or superimposed on the mandibular molar teeth.

35. Inferior border of the Mandible As the name suggests is the lower border of the mandible. Its rarely seen on the periapical projections. On Radiograph : Dense Radiopaque band of bone

36. Coronoid process Marked prominence of bone on the anterior ramus of the mandible. It’s the site for attachment of the muscles of mastication. On Radiograph : A triangular radiopacity superimposed over or inferior to the maxillary tuberosity region. Its seen on IOPA of maxillary molar, not a mandibular periapical radiograph.

37. RESTORATIVE MATERIALS RADIOPAQUE SILVER AMALGAM GOLD STAINLESS STEEL PINS GUTTA-PERCHA ORTHODONTIC APPLIANCES ZINC PHOSPHATE CEMENT RADIOLUCENT SILICATES COMPOSITE PORCELAIN CALCIUM HYDROXIDE

38. AMALGAM GUTTA PERCHA CAST CROWNS ORTHODONTIC APPLIANCES

39. THANK YOU