2. Radiographic Anatomy
Skeletal System
Skull

3. Educational Objectives
By the end of this lecture you should be able to:
Identify the anatomical parts of skull on diagrams and radiographs.
Identify the different sutures of the skull
State the surface land marks of skull and explain its importance in radiographic positioning
Explain how to hang skull radiographs on the view box

4. References
1. Text book of radiographic positioning and related anatomy; by
Kenneth L.Bontrager,6th edition.
2. Introduction to Human Anatomy and Physiology: by Eldra
Pearl Solomon:W.B.Saunders Company
3. Handbook of Anatomy and physiology for Students of Medical
Radiation Technology: Mallett.M:Jaspar
Websites

5. 8 Cranial bones (cranium)
Skull
8 Cranial bones (cranium) +
14 Facial bones

6. Cranial bones (8)  Skull Cap (Calvarium): ● 1 Frontal
● 2 Parietal (R,L)
● 1 Occipital
 Skull Base (floor):
● 2 Temporal (R,L)
● 1 Sphenoid
● 1 Ethmoid

7. Facial bones (14) 2 Maxillary 2 Zygomatic 2 Lacrimal 2 Nasal
2 Palatine
2 Inferior nasal conche
1 Vomer
1 Mandible

8. Skull views
Lateral Aspect
Anterior Aspect

9. Skull views
Superior Aspect
Inferior Aspect

10. Frontal View
The frontal bone forms part of the roof of the orbital cavities, it contains two hollow spaces (sinuses) which communicate with the nasal cavities. The frontal bones articulate with the parietal bones, sphenoid, zygomatic, lacrimal, nasal and ethmoid bones. At birth the frontal bone consists of two parts separated by the (frontal suture) but union is usually complete by the 8th year of life.
Frontal

11. Frontal View
Two bones form the sides of the vault just behind the frontal bone on each side of the median plane. They articulate with each other at the sagital suture, with the frontal bone at the coronal suture, with the occipital bone at the lambdoid suture, and with the temporal bone at the squamous suture.
Parietal

12. Frontal View
These two bones lie on each side of the head below the parietal bones; each one is divided into five parts: (1) Squamous part, (2) Mastoid process: can be felt behind the ear , contains large number of air sinuses which become areated only in adults.(3) Tympanic part : in front of the mastoid and below the squamous, form part of the osseous part of EAM. (4) Styloid process, (5) Petrous part of temporal bone: forms part of the base of the skull ,contains organs of hearing and equilibrium and IAM. Which transmits the facial nerve and vestibulocochlear nerve. It contains also the carotid canal which trasmits ICA. And the jugular foramen which transmits the IJV.
Temporal

13. Frontal View
Two small bones placed side by side between the frontal process of the maxillae and form by their junction the bridge of the nose.
Nasal

14. Frontal View
Form part of the nasal septum together with the perpendicular plate of the ethmoid bone and articulate with the nasal bones. The nasal septum is often deviated to one side in most of the people and has both bony and cartilagenous element.
Vomer

15. Frontal View
Form the prominence of the cheek and part of the lateral walls of the orbit and articulate with the temporal bone to form the zygomatic arch.
Zygoma

16. Frontal View
Form the upper jaw, the two parts together, the lower part present the alveolar process (contains sockets for upper teeth) the maxillae contain the largest air sinus in the face : maxillary sinus on each side which communicates with the nasal cavity.
Maxilla

17. Form the lower jaw, it is composed of two bodies united at the symphysis menti, two rami project upwards from the posterior part of the body, the point of junction is the angle of the jaw. The mandible is the strongest bone of the face and only movable bone of the skull. It articulates with the temporal bone to form TMJ
Mandible

18. Frontal View Frontal Parietal Temporal Zygoma Vomer Nasal Maxilla
Mandible

19. Frontal View

20. Lateral View

21. Lateral View
Frontal

22. Lateral View
Parietal

23. Lateral View
Temporal

24. Lateral View
Nasal

25. Lateral View
Zygoma

26. Lateral View
Maxilla

27. Lateral View
Mandible

28. Lateral View
The sella turcica present a saddle –shaped depression lying on the superior surface of the middle part of the sphenoid bone. It supports the pituitary gland. The parts of the sella turcica are: (1) Anterior clinoid processes, (2) Dorsum sellae = posterior clinoid processes, (3) Lamina dura which cover the floor of sella, (4) Sphenoid air sinuses.
Sphenoid

29. Lateral View
Occipital

30. Lateral View
Mastoid Process
(part from temporal bone)

31. Lateral View
External Auditory Meatus

32. Lateral View Frontal Parietal Sphenoid Nasal Zygoma Temporal Occipital
Maxilla
Mandible
Mastoid Process

33. Lateral View

34. Superior View
Frontal

35. Superior View
Parietal

36. Superior View
Temporal

37. Superior View
Vomer

38. Superior View
Sphenoid

39. Superior View
Forms the back of the head , its inner surface is concave and contains the occipital lobes of the brain and the cerebellum, it forms part of the base of the skull.
Occipital

40. Superior View
Foramen Magnum

41. Superior View Frontal Vomer Sphenoid Parietal Temporal Foramen Magnum
Occipital
The base of the skull is formed maily by 4 bones: (1) occipital bones, (2) Palatine bones, (3) Sphenoid bone, (4) Ethmoid bone.

42. Sutures

43. Sutures
Sagittal

44. Sutures
Frontal
(Coronal)

45. Sutures
Squamous

46. Sutures
Lambdoid

47. Sutures
Sagittal
Frontal
(Coronal)
Squamous
Lambdoid

48. Sutures
Frontal
Sagittal
Lambdoid
Superior Aspect

49. Skull Landmarks 1. Vertex 2. External Occipital Protuberance (E.O.P.)
3. External Auditory Meatus
4. Outer Canthus Of Eye.
5. Infra-orbital point
6. Nasion
7. Glabella

50. Skull positioning lines1
The Anthropological line
The Isometric “Baseline” which runs from the inferior orbital margin to the upper border of the external auditory Meatus (EAM) 1
The Orbital- Meatal Line
The original “Baseline” which runs from the Nasion through the outer Canthus of the eye to the centre of the external auditory Meatus. 2
( Note: there is a difference of 10 to 15 degrees between the Orbital- Meatal line and the anthropological line.) 2

51. Skull Landmarks The Interpupillary line3
The Interpupillary line
The line connects the centers of the orbits and is at 90 degree to the median Sagittal plane. 3 4
The Auricular Line
This line passes at 90 degrees to the anthropological line through the centre of the external auditory meatus. 4

52. Skull Landmarks

53. Skull Landmarks

54. Cranial Topography Glabella: raised triangular area bet. eyebrows.
Nasion: depression at the bridge of the nose.
Acanthion: nose and upper lip meet
Tragus: cartilage. flap covering ear opening.
Top of ear attachment (TEA): side frames of eyeglass rest (level of petrous ridge).
Gonion: angle of mandible.
Inion: prominent point of EOP.

55. Skull Series: Basic Projections
PA 0º
PA axial 15º
AP axial
Lateral

56. Skull Series: Basic Projections
PA axial 15º

57. Skull Series: Basic Projections
AP axial

58. Skull Series: Basic Projections
Lateral

59. THANK
YOU