1. RT 233 Skull Radiography introducing Zygomatic Arches

2. REVIEW: http://wn.com/Cranial_Facial _bones#/videos http://wn.com/Cranial_Facial _bones#/videos

3. Zygomatic Arches This is just getting more and more fun ! ! ! 1 Anatomy of Zygomatic Arches 2 Essential Projections 3 Pathology of Zygomatic Arches

4. Anatomy of Zygomatic Arches Bones Involved, anatomical landmarks 1

5. The squamous portion of the temporal bone is the thin upper portion. It forms a part of the side of the cranium and has a prominent arched process called the zygomatic process. The zygomatic process projects anteriorly articulating with the zygomatic facial bone, this completes the zygomatic arch. On the inferior border of the zygomatic process is the rounded eminence called the articular tubercle. The articular tubercle forms the anterior boundary of the mandibular fossae. The mandibular fossa receives the condyle of the mandible to form. Anatomy of Zygomatic Arches

8. Anatomy of Zygomatic Articulations 1) zygomatic process- temporal bone 2) Mandibular condyle 3) Articular tubercle 4) zygomatico-temporal sutures 5) zygoma

9. Possible Indications for Zygomatic Arch Imaging 1.Car accident 2.Sports injury 3.Domestic violence, child or elder abuse 4.Blunt trauma 5.Fall 6.Gunshot

10. 2 Essential Projections SMV, Tangential, modified Townes

11. Submentovertical (SMV) Tangential Anteroposterior (AP) axial (modified Towne) Essential Projections: Zygomatic Arches

12. Submentovertical Zygomatic Arches Patient position – Seated upright or supine – If supine, elevate thorax Part position – Hyperextend neck to place IOML parallel with IR plane (as much as possible) – Rest head on vertex – MSP perpendicular to IR plane

13. Submentovertical Zygomatic Arches CR – Perpendicular to IOML – Enters MSP of throat at level 1 inch (2.5 cm) posterior to outer canthi – Center IR and CR Collimated field – 8 x 10 inches (18 x 24 cm)

19. SMV

21. SMV projection

22. Tangential Zygomatic Arches Patient position – Seated upright with back against vertical Bucky – Supine with trunk elevated

23. Tangential Zygomatic Arches Part position – Hyperextend neck and rest head on vertex – IOML as parallel with IR plane as possible – Rotate MSP of head 15 degrees toward side being examined – Tilt top of head 15 degrees away from side being examined – Center zygomatic arch to IR

24. Tangential Zygomatic Arches  CR  Perpendicular to IOML  Centered to zygomatic arch at a point 1 inch (2.5 cm) posterior to outer canthus  Centered to IR  Collimated field  8 x 10 inches (18 x 24 cm)

32. AP Axial (Modified Towne) Zygomatic Arches  Patient position  Seated upright or supine  Part position  MSP perpendicular to midline of grid  OML perpendicular to IR plane May use IOML and increase CR angle to ??°

33. AP Axial (Modified Towne) Zygomatic Arches  CR  Angled 30 degrees caudad to enter glabella approximately 1 inch (2.5 cm) above nasion  If IOML used, angle 37 degrees caudad  Center IR and CR  Collimated field  8 x 10 inches (18 x 24 cm)

39. What about the beautiful images you’ve been seeing? Exciting new transitions It’s up to you.

40. 3 Pathology of Zygomatic Arches LeFort Fractures, Tripod Fractures,

41. FRACTURES SITES

42. TRIPOD FRACTURE Radiographic signs of facial fractures Indirect Signs The most common mechanism producing facial fractures is auto accidents. About 70 % of auto accidents produce some type of facial injury, although most are limited to soft tissue. The face seems to be a favorite target in fights or assaults, which are the next most common mechanism. The remainder of facial fractures are produced by falls, sports, industrial accidents and gunshot wounds. Less than 10 % of all facial fractures occur in children, perhaps because of the increased resiliency of a child's facial skeleton. The most common patterns of midfacial fractures are summarized in the table below. Probably the most common facial fracture is the tripod or zygomaticomaxillary complex fracture, so called because it involves separation of all three major attachments of the zygoma to the rest of the face. The tripod fracture, also called the zygomaticomaxillary complex or malar fracture, is composed of a set of three (actually 4) fractures. The first portion of the tripod fracture involves the maxillary sinus including the anterior and postero-lateral walls and the floor of the orbit. The second portion involves the zygomatic arch. The third portion involves the lateral orbital rim, usually including the lateral orbital wall, or the fronto-zygomatic suture. The term is actually not accurate as there is a fourth suture that can be involved: between the sphenoid and zygomatic bones.maxillary sinuszygomatic arch

43. LeFort Fractures

44. LeFort Fractures, Type I, Type II

45. Type III LeFort

46. ___________ Fractures

47. _____________ Zygomatic Arches

48. Isolated Zygomatic Arch Fractures

49. Where is the fracture?

50. Waters view

51. What ???

52. Name this fracture:

55. What is the bone just posterior to the lacrimal bone?

57. What’s Your Message? ZYGOMATIC ARCHES