Lec 2 PDF - Skull Anatomy

 SKULL 2 Dr. Ruba Ahmad Alslehat Dr. Syeda Uzma Zahra  Reference ◦Snell’s clinical anatomy by regions. 10th edition  Norma lateralis The parietal bones form the sides and roof of the cranium. The skull is completed at...

 SKULL 2 Dr. Ruba Ahmad Alslehat Dr. Syeda Uzma Zahra  Reference ◦Snell’s clinical anatomy by regions. 10th edition  Norma lateralis The parietal bones form the sides and roof of the cranium. The skull is completed at the side by the: 1. Squamous part of the occipital bone 2. Parts of temporal bone: The squamous Tympanic Mastoid process Styloid process Zygomatic process 4. The greater wing of the sphenoid 5. The ramus and body of the mandible lies inferiorly.  Temporal bone ◦ Parts of temporal bone: 1. Squamous part 2. Tympanic part 3. Mastoid process 4. Styloid process 5 1 5. Zygomatic process 6 5 4 6. Petrous part (only this 2 3 4 3 part is not shown in norma lateralis )  Temporal bone Squamous part Zygomatic process Mastoid process  Temporal bone Tympanic part Styloid process Petrous part Squamous and Petrous parts of temporal bone  Zygomatic arch ◦ The zygomatic process of temporal bone articulates with the temporal process of the zygomatic bone to form the zygomatic arch o It’s posterior root passes above the 4 external auditory meatus and joins the 3 1 2 supramastoid crest. 1. Temporal process of zygomatic bone 2. Zygomatic process of temporal bone 3. Supramastoid crest 4. Zygomatic arch  Temporal lines The superior temporal line gives attachment for the temporal fascia. The inferior temporal line is for the attachment of temporalis muscle  Superior temporal line Inferior temporal line The temporal fossa lies below the inferior temporal line. The zygomatic arch divides the lateral side of the skull into the temporal fossa and infratemporal fossa. Temporal fossa  Norma lateralis Pterion(H-shaped ) ✓ It is the thinnest part of lateral wall of the skull. ✓ It is formed between frontal, parietal, greater wing of sphenoid and temporal bones. ✓ It overlies the anterior division of middle meningeal artery and vein. ✓ Trauma to this area results in epidural bleeding.  Mastoid antrum ◦ is an air space in the petrous portion of the temporal bone, lying posterior to the middle ear and connected to it. ◦ Function ◦ voice resonance, acoustic insulation and reduce the mass of the cranium.  Suprameatal triangle Posterior margin of external auditory Function : This is an important landmark For performing a cortical mastoidectomy.  Mandible The mandible (lower jaw) is the largest and strongest bone of the face. It articulates with the skull at the temporomandibular joint The mandible consists of a more horizontal, horseshoe-shaped body and a pair of vertical rami. The body of the mandible meets the ramus on each side at the angle of the mandible The ramus of the mandible has an anterior coronoid process and a posterior condyloid process, or head. A short neck is inferior to the head. The mandibular notch separates the coronoid and condyloid processes.  Mandible The mental foramen is inferior to the second premolar tooth; it transmits mental nerve and vessels. The upper border of the body of the mandible is the alveolar part; in the adult, it contains 16 sockets for the roots of the teeth. The base is the lower border of the body of the mandible. Mandible Oblique line Mental foramen Mental protuberance Ramus Condyloid process Coronoid process  Mandible The mandibular foramen is on the medial surface. This transmits the inferior alveolar nerve and vessels. The lingula is a projection in front of the mandibular foramen for the attachment of the sphenomandibular ligament The foramen leads into the mandibular canal, which opens on the lateral surface of the body of the mandible at the mental foramen The incisive canal is the forward continuation of the mandibular canal beyond the mental foramen and below the incisor teeth.  Mandible The mental spines (genial tubercles) are on the midline medial surface of the body of the mandible. The mylohyoid line is an oblique ridge that runs backward and laterally from the area of the mental spines to an area below and behind the third molar tooth. The submandibular fossa, for the superficial part of the submandibular salivary gland, lies below the posterior part of the mylohyoid line. The sublingual fossa, for the sublingual gland, lies above the anterior part of the mylohyoid line. Mandible 1- Head 1 5 2- Neck 3 4 2 3- Pterygoid fovea 4- mandibular notch 5- Coronoid process 6- Lingula 7- Mandibular foramen 8- Mylohyoid line 9- Submandibular fossa 10 10- Sublingual fossa 11- Mental protuberance 12 13 12- Mental foramen 11 13- Oblique line Mandible Mandible Mandibular notch Mandibular foramen Neck Sublingual fossa Submandibular fossa Digastric fossa Masseter muscle insertion site Mylohyoid line ‫شكراً‬