111 Ch. 26
The Several roles of the bones of the skull:
Protect the Brain.
Form facial skeleton.
Participate in the growth process of the jaws.
SKULL IS COMPOSED OF 22 BONES (SOME SINGLE AND SOME PAIRED).
There are 2 groups that make up the 22 bones;
NEUROCRANIUM- 8 bones surround the brain
VISCEROCRANIUM- 14 bones of the face
Inferior nasal conchae(paired)
composed of the Vomer and Ethmoid bone
Eye orbit rim - formed by
3 Foramens from the anterior view
Supra orbital foramen or notch(nerve and blood supply to the forehead).
Infra orbital foramen( nerve and blood supply to upper lip, lower eyelid and side of nose).
Mental foramen( nerve and blood supply to lower lip and facial anterior gingival).
Coronal suture also called the Frontoparietal suture.
Lambdoid suture also called the paritooccipital suture forms a inverted V.
Sagittal suture(Interparietal suture)- connects the left and right parietal bones.
SOFT SPOT ON BABIES HEAD ( joint for where frontal and 2 Parietal bones join.
3 CRANIAL FOSSAE (BOUNDARIES)
1. Anterior cranial fossa- from the lesser wing of the sphenoid anterior to the frontal bone. Houses the Frontal lobe of the brain
2. Middle cranial fossa- from the crest of the Petrous temporal bone forward to the lesser wing of the sphenoid. Houses the Temporal lobe of the brain.
3. Posterior cranial fossa- from the crest of the Petrous temporal bone back to the posterior of the skull. Houses the Brain Stem(pons and medulla) and the Cerebellum.
PTERYGOID PROCESS made up of 4 parts( projects down from the body of the sphenoid, just behind the maxillae)
Lateral pterygoid plate
medial pterygoid plate
MAXILLAE PROCESS has a body and 4 processes
Alveolar process( forms the socket for the teeth)
Horizontal palatine process
located in the Maxillae.
the largest of the paranasal sinuses.
Anterior nasal spine
lower end of the nasal cavity, in the front.
This is a radiographic landmark frequently used in lateral head films for orthodontics
a bulging by the anterior teeth and sometimes premolars
Posterior bulging behind 3rd molar region. This is were much of the growth occurs. Lack of growth means inadequate room for 3rd molars.
Median palatine suture
accounts for lateral palatal growth
Opening(hiatus) of Maxillary Sinus-
The smaller the opening the more likely sinus problems.
this is the way tears flow down into the nose.
Causing a runny nose when crying
Growth of the Maxillae- occurs from the
Palatal process of the maxillae
Palatal process of the palatine bone ( Problems
: Thumb and Tongue thrust)
Injection sites of the Maxillae
Incisive foramen(between teeth 8 and 9)(Greater palatine nerve branch)
Greater palatine foramen( by 2nd molar)(Greater palatine nerve)
A SINGLE BONE MADE UP OF THREE PARTS.
The horizontal body.
The alveolar process on the top of the horizontal body,
The ramus( the vertical portion of the body) There are two rami on the mandible(right and left).
Injection sites on the Mandible
Mental foramen( by the 2nd premolar)(blood and nerve supply to lower lip and chin)(EXIT)
Mandibular foramen(inside of the rami)(blood and nerve supply for the lower teeth and chin)(ENTER)
Tip of chin
the attachment for one of the muscles of mastication the Temporalis.
External oblique line – shows up radiopacity on x-rays
Growth of the Mandible- occurs in several places
The alveolar process and body increase in width and height.
Lengthening occurs by bone being added to the posterior border of the ramus and taken away from the anterior border. If not enough growth, there will be a lack of room for the 3rd molars
Mental spines(genial tubercles)
attachments for muscles that aid in tongue movement and swallowing.(genioglossus muscle and the geniohyoid muscle).
111 Ch. 26
Den 111 Ch.26