facial/oral lec 1 Flashcards
What are the two divisions of the skull?
- Neurocranium
- Viscerocranium
What are the 4 unpaired bones of the neurocranium?
- Ethmoid
- Sphenoid
- Frontal
- Occipital
What are the 2 paired bones of the neurocranium? (4 total)
- Parietal
- Temporal
What are the 4 parts of the frontal bone?
- Zygomatic process
- Orbital portion
- Nasal portion
- Coronal suture
How does hydrocephalus relate to the coronal suture?
Hydrocephalus happens in children, who do not have coronal suture yet – lack of suture allows swelling of head
What are the 6 main parts of the sphenoid bone?
- Lesser wings: on top of optic canal
- Greater wings: part of orbit, articulate with frontal and temporal bones
- Medial pterygoid process
- Lateral pterygoid processes
- Pterygoid hamulus: point of attachment for muscles and ligaments
- Sella turcica/hypophyseal fossa: between two lesser wings, location of pituitary gland
Functions of sphenoid bone? (4)
- Gives skull rigidity
- Optic canal: optic nerve
- Foramen ovale: trigeminal nerve – mandibular branch
- Foramen rotundum: trigeminal nerve – maxillary branch
Parts of ethmoid bone? (5)
- Crista galli: superior portion, protrudes into cranial cavity and attaches dura mater
- Perpendicular plate: superior part of nasal septum
- Middle nasal conchae
- Superior nasal conchae
- Cribriform plate: small holes for smell nerves
What is falx cerebri?
Dura mater between the two hemispheres
What are the 2 unpaired bones of the viscerocranium?
- Mandible
- Vomer
What are the 6 paired bones of the Viscerocranium? (12 total)
- Maxilla
- Nasal
- Palatine
- Lacrimal
- Zygomatic
- Inferior nasal conchae (only nasal not part of ethmoid)
What is the only moveable bone of the skull? When does it fuse?
- Mandible
- During first year after birth
Parts of mandible? (7)
- Mental symphysis + protuberance (where fuses)
- Alveolar process (attaches teeth)
- Lingula (helps locate mental and mandibular foramen – mental nerve = part of mandibular trigeminal nerve)
- Ramus (attaches masseter and medial pterygoid)
- Coronoid process (attaches temporalis – anterior ramus)
- Condylar process (part of TMJ – posterior and superior ramus)
- Mandibular notch (between the two processes)
What is micrognathia? What does it affect?
- Undersized jaw
- Affects swallowing, articulation, may cause tongue to fall back into throat or stick out of mouth
What are the 5 maxillary bones visible from an anterior view?
- Frontal process (meets frontal bone)
- Infraorbital foramen (maxillary trigeminal nerve)
- Zygomatic process
- Nasal spine and notch
- Alveolar process/ridge (teeth)
What are the 3 maxillary structures visible from a medial view?
- Maxillary sinus
- Palatine process
- Alveolar process/ridge
What are the 4 maxillary structures visible from an inferior view?
- Bilateral palatine process
- Intermaxillary suture (cleft palate)
- Transverse palatine suture
- Premaxilla (cleft lip)
What are the small L-shaped bones called? What are its three parts? What does it compose (2)?
- Palatine bone
- Horizontal plate (posterior ¼ of hard palate), perpendicular plate, nasal crest
- Composes lateral wall + floor of nasal cavity and posterior wall of orbit
Which nasal conchae is independent? What is between the three conchae?
- Inferior = independent
- In between = superior, middle, and inferior meatuses
Functions of the conchae?
Warming, humidifying, and cleaning incoming air
What does the vomer divide? What does it form? When does it start and stop growing?
- Divides nasal cavity
- Forms inferior and posterior nasal septum
- Starts growing during fetal stage, may continue until puberty
What does the complete nasal septum consist of? (3)
- Vomer
- Perpendicular plate of ethmoid bone
- Septal cartilage
What does the vomer provide a connection to? (3)
- Sphenoid bone
- palatine bone
- maxillary bone
What forms the zygomatic arch?
Temporal process (of zygomatic bone) connecting to zygomatic process (of temporal bone)
Define frontal process, maxillary process, and temporal process
- Frontal process: where zygo bone meets frontal + sphenoid bones
- Maxillary process: where zygo bone meets maxillary bone
- Temporal process: where zygo bone meets temporal bone, anterior half of arch
What is the hyoid bone attached to?
nothing! It’s a floating bone
what does the hyoid do for articulation and swallowing muscles?
Serves as anchor point for them
What is the vallecula?
Depression where hyoid bone, tongue, and epiglottis meet
Where are teeth housed? (don’t say mouth lol)
In the alveoli of the mandible and maxilla
How many primary vs permanent teeth do we develop?
- Primary: 20
- Permanent: 32
What is the biting surface called?
occlusal surface
What is the part of the teeth toward the tongue called?
Lingual surface
What is the part of the teeth toward the lips called?
Labial surface
What is the part of the teeth toward the cheeks called?
Buccal surface
What is the part of the teeth toward adjacent teeth called?
Approximal surface
How many incisors do we have? When do they erupt? When are they replaced?
- 4 on top, 4 on bottom
- 6 months
- 6-8 years
How many canines do we have? When do they erupt? When are they replaced?
- 2 on top, 2 on bottom
- 16-20 months
- 9-12 years
how many premolars do we have? any primary? when do they erupt?
- 2 x 4
- no primary
- erupt around 10-11 years
how many molars do adults vs kids have? when do primary vs permanent erupt?
- ADULTS: 3 on top (right), 3 on top (left), 3 on bottom (right), 3 on bottom (left)
- KIDS: 2 on top (right), 2 on top (left), 2 on bottom (right), 2 on bottom (left)
- first: primary 12-15 months, permanent 6 years
- next: permanent around 11-13 years
- third/wisdom: 18-20 years or not at all
diff bw class 1 vs 2 vs 3 occlusion?
- class 1: normal position
- class 2: overbite + receding chin (most common)
- class 3: underbite + protruding jaw (sometimes in down syndrome)
EMBRYOLOGY: Primitive face is made up of 5 swellings. what are they?
- frontonasal prominence
- 2 maxillary prominences
- 2 mandibular prominences
EMBRYOLOGY: what does the frontonasal prominence make up? (5)
- frontal = forehead
- nasal = nose, philtrum, medial upper lip, premaxilla
EMBRYOLOGY: what do the maxillary prominences make up (4)? which arch do they come from?
- upper jaw, lateral upper lip, hard palate, upper cheeks
- arch 1
EMBRYOLOGY: what do the mandibular prominences make up (3)? which arch do they come from?
- lower jaw, lower lip, chin
- arch 1
EMBRYOLOGY: what are nasal placodes? what do they develop into + at roughly how many weeks does this occur?
- thickenings of the ectoderm
- they develop into nasal pits surrounded by medial and lateral nasal prominences (7-10 weeks)
EMBRYOLOGY: what does the naso-optic furrow form?
nasolacrimal duct
EMBRYOLOGY: what does the primary palate (premaxilla) vs secondary palate (hard palate) form from?
- primary: frontonasal prominence
- secondary: maxillary prominences
EMBRYOLOGY: do the two palatal shelves from inferiorly or superiorly?
inferiorly
EMBRYOLOGY: what happens during weeks 7-8 vs weeks 9-11?
- weeks 7-8: tongue descends and palatal shelves elevate and fuse (anterior to posterior)
- weeks 9-11: nasal septum grows inferiorly and fuses with palatine process
EMBRYOLOGY: what happens during week 5 regarding the tongue? which arch does this happen at?
- paired lateral lingual swellings develop surrounding the tongue bud
- median sulcus is formed via merging of lateral lingual swellings
- ultimately forms anterior 2/3 of the tongue
- arch 1
EMBRYOLOGY: which pharyngeal arch does the mandibular arch develop from?
PA 1
EMBRYOLOGY: Midline swellings of Arch 3 form _____
posterior 1/3 of the tongue
EMBRYOLOGY: where does the hypopharyngeal eminence originate from? what does it develop into?
- arches 3 and 4
- develops into the posterior part of the tongue
EMBRYOLOGY: how is the terminal sulcus formed?
- Arch 1 and 3 merge and overgrow Arch 2
EMBRYOLOGY: by which week is distinct tongue structure evident?
week 7
