Craniofacial Complex Flashcards

1
Q

Functional Matrix

A

The functional relationship between soft tissue and skeletal units.

Size, shape, structure integrity, and location of each components results from secondary and compensatory responses to the operational demands of the functional matrix.

Consider biology, environment, and behavior.

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2
Q

Chondocranium

A

Base of the skull.

  • Develops first during embryology
  • Derived from endochondrial ossification
  • Forms supportive platform on which remainder of skull develops
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3
Q

Dermatocranium

A

Creates the brain case.

  • Develops second during embryology
  • Derived from intramembranous ossification
    • Fontanelle are reminants of the membrane at birth
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4
Q

Splanchnocranium

A

Contributes to facial structure.

  • Formed last during embryology.
  • Derived from intramembranous ossification.
  • Does not complete formation until the end of puberty.
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5
Q

Primary Neurulation

A
  • During 3rd week of development:
    • Transition from bi-laminar disc to tri-laminar disc.
    • Longitudinal band of ectodermal cells expands to form the neural plate.
    • Neural plate continues to expand and folds in the middle forming the neural groove.
    • Neural groove deepens as neural folds on either side approach each other at the dorsal midline.
  • During 4th week of development:
    • Neural folds begin to fuse centrally.
    • Fusion proceeds both caudally and rostrally forming the neural tube.
    • As neural tube forms, it seperates from overlying ectoderm and sinks into underlying mesoderm.
      • Leaves behind a group of cells from the crest of each neural fold ⇒ future neural crest cells.
    • Future neural crest cells migrate out of the neural folds, seperating the ectoderm from neural tube.
      • Controlled by Hox Genes
    • Neural tube expands forming the three primary vesicles:
      • Prosencephalon ⇒ forebrain
      • Mesencephalon ⇒ midbrain
      • Rhombencephalon ⇒ hindbrain
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6
Q

Rhombomeres

A

The part of the neural tube that develops behind the rhombencephalon (hindbrain) develops a series of bulges ⇒ rhombomeres.

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7
Q

Neural Crest Cell

Migration

A

During 4th to 5th week of development:

Neural crest cells associated with specific rhombomeres migrate into the ventrolateral aspect forming the pharyngeal arches.

Six paired outpocketings:

1st pharyngeal arch: rhombomeres 1, 2, and 3

2nd pharyngal arch: rhombomeres 3 and 4

3rd pharyngal arch: rhombomeres 6 and 7

4th pharyngal arch: rhombomere 5

5th pharyngal arch: often never develops or degenerates quickly

6th pharyngal arch: rhombomere 5 (cannot be seen externally)

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8
Q

Pharyngeal Arches

A

Pharyngeal arches

  • Composed of mesoderm
  • Each arch is associated with a specific:
    • cranial nerve
    • muscle group
    • artery
    • skeletal or cartilaginous derivative
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9
Q

First Pharyngeal Arch

Derivatives

A
  • Cranial nerves:
    • V2: maxillary division of trigeminal nerve
    • V3: mandibular division of trigeminal nerve
  • Muscle:
    • Muscles of mastication
    • Tensor tympani
    • Tensor veli palatini
  • Cartilage & Skeletal Elements:
    • Part of sphenoid
    • Incus
    • Malleus
    • Maxilla
    • Mandible
    • Zygomatic
    • Squamous portion of temporal bone
  • Vessels:
    • Maxillary artery
  • Other structures:
    • Mucous membranes of anterior 2/3 of tongue
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10
Q

Second Pharyngeal Arch

Derivatives

A
  • Cranial nerves:
    • VII: facial
  • Muscle:
    • Muscles of facial expression
    • Posterior belly of digastric
    • Stylohyoid
    • Stapedius
  • Cartilage & Skeletal Elements:
    • Stapes
    • Styloid process
    • Stylohyoid ligament
    • Lesser horns of hyoid
  • Vessels:
    • Stapedial artery
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11
Q

Third Pharyngeal Arch

Derivatives

A
  • Cranial nerves:
    • IX: glossopharyngeal
  • Muscle:
    • Stylopharyngeous
  • Cartilage & Skeletal Elements:
    • Greater horn of hyoid
  • Vessels:
    • Common carotid
    • Proximal internal carotid
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12
Q

Fourth Pharyngeal Arch

Derivatives

A
  • Nerves:
    • CN X: vagus
    • Superior laryngeal nerve
  • Muscle:
    • Pharyngeal constrictors
    • Cricothyroid
    • Levator veli palatini
  • Cartilage & Skeletal Elements:
    • Laryngeal cartilages
  • Vessels:
    • Proximal right subclavian
    • Arch of aorta
  • Other structures:
    • Mucous membrane of posterior 1/3 of tongue
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13
Q

Sixth Pharyngeal Arch

Derivatives

A
  • Nerves:
    • CN X: vagus
    • Recurrent laryngeal nerve
  • Muscle:
    • Intrinsic muscles of the larynx
  • Cartilage & Skeletal Elements:
    • Laryngeal cartilages
  • Other structures:
    • Mucous membranes of posterior 1/3 of tongue
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14
Q

Branchial Clefts & Pouches

A

Connective tissue between the pharyngeal arches form:

Branchial clefts externallyectoderm

Branchial pouches internallyendoderm

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15
Q

First Branchial/Pharyngeal Pouch

Derivatives

A
  • Mucosa of eardrum
  • Tympanic cavity
  • Auditory tube
  • Mastoid antrum
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16
Q

Second Branchial/Pharyngeal Pouch

Derivatives

A
  • Tonsilar fossa
  • Surface epithelium of palatine tonsils
17
Q

Third Branchial/Pharyngeal Pouch

Derivatives

A
  • Thymus
  • Inferior parathyroid glands
18
Q

Fourth Branchial/Pharyngeal Pouch

Derivatives

A

Superior parathyroid glands.

19
Q

Development of the Face

A

Brain, eyes, and stomodeum recognizable by week 4.

Complete by 7th week of development.

Involves interaction of numerous embryonic tissues:

  • Neural tube
  • Paraxial Mesoderm
  • Endoderm of pharynx
  • Cranial ectoderm

Five facial prominences responsible for development of facial features:

  1. One frontonasal
    • elevation of the margins of the nostrils
    • sides develop into the medial and lateral nasal prominences
  2. Two maxillary
    • Migrate medially and merge with frontonasal prominence.
      • nose
      • upper lip
      • palate
  3. Two madibular
    • Merging of madibular prominences
      • lower jaw
      • lower lip
      • lower cheek
      • chin
20
Q

Development of the Palate

A

During 7th week of development.

Initially widely seperated.

Merging of frontonasal and maxillary prominences.

  • Median palatine process drived from frontonasal prominence.
  • Lateral palatine process drived from maxillary prominences.

By the time of birth, a tiny gap or complete union may exist.

Interruption of migration or failure to fuse results in cleft lip/palate.

21
Q

Postnatal Growth

A
  • Sexual dimorphisms account for 90% of development/maturation.
    • Females complete development earlier than males.
  • Behavior and environment influences ~ 10% of development/maturation.
  • Majority of focus resides with brain development.
    • Facilitates early learning
      • Observation
      • Cultural knowledge
22
Q

Fontanelle Closure

A

Skull’s basic morphology established at birth.

Fontanelle faciliate continued growth and expansion of skull and passage through birth canal.

Fontanelles are 38% closed by end of 1st year and 96% closed by end of second.

  • Posterior fontanelle closes at 2-3 months.
  • Sphenoidal fontanelle closes at ~ 6 months.
  • Mastoid fontanelle closes after 6-18 months.
  • Anterior fontanelle closes between 1-3 years of age.
23
Q

Development of Dentition

A
  • Teeth develop independently during embryology but functions together morphologically
  • Eruption & exfoliation timeline patches development/puberty.
24
Q

Skull

Characteristics and Functions

A
  • Formed by the articulation between the cranium and mandible.
    • 22 bones
      • 6 unpaired
      • 8 paired
    • 6 ear bones
  • Most complex region of skeleton
  • Functions:
    • Foundation for sight, smell, taste, and hearing.
    • Framework for masticatory apparatus
25
Q

Cleft Lip & Palate

(CL/P)

A
  • One of the most common birth defects
  • Polygenic/multifactorial inheritance
    • 20-50% genetic
    • most AD, some AR, rarely X-linked
    • variable expression
    • Examples of single mutations:
      • Van der Woude Syndrome: IRF6 on chromosome 1
      • Treacher Collins Syndrome: TCOF1 on chromosome 5
      • Apart syndrome: FGFR 2 on chromosome 10
  • Risk factors:
    • maternal smoking and teratogens
    • maternal alcohol
    • Folic acid deficiency
    • Certains medications
      • Retinoids
      • Anticonvulsants
      • Steroids
  • Health effects:
    • difficulty feeding, low weight, malnutrition
      • use Haberman feeder bottle
    • ear infections
    • difficulty hearing
    • abnormal tooth development
    • difficulty speaking
26
Q

CN I

A

Olfactory

  • CNS source:
    • Forebrain
  • Cranial exit:
    • Foramina of Cribriform plate
  • Function:
    • Special sense of Olfaction
27
Q

CN II

A

Optic

  • CNS source:
    • Forebrain
  • Cranial exit:
    • Optic canal
  • Function:
    • Special sense of vision
28
Q

CN III

A

Occulomotor

  • CNS source:
    • Midbrain
  • Cranial exit:
    • Superior orbital fissure
  • Function:
    • Motor to extraocular muscles
      • superior, inferior, and medial rectus
      • inferior oblique
      • levator palpebrae superioris
29
Q

CN IV

A

Trochlear

  • CNS source:
    • Midbrain
    • Only one that emerges dorsally
  • Cranial exit:
    • Superior orbital fissure
  • Function:
    • Motor to extraocular muscle
      • superior oblique
30
Q

CN V

A

Trigeminal

CNS source:

Pons

  • Ophthalmic (V1)
    • Cranial exit:
      • Superior orbital fissure
    • Function:
      • Sensory:
        • cornea, skin of forehead, scalp, eyelids, nose, mucosa of nasal cavity, paranasal sinuses
  • Maxillary (V2)
    • Cranial exit:
      • Foramen Rotundum
    • Function:
      • Sensory:
        • skin of face over maxilla, upper lip, maxillary teeth, mucosa of nose, maxillary sinuses, palate
  • Mandibular (V3)
    • Cranial exit:
      • Foramen ovale
    • Function:
      • Sensory
        • skin of face overlying mandible, lower lip, mandibular teeth, TMJ, mucosa of mouth, anterior 2/3 of tongue
      • Motor
        • muscles of mastication, mylohyoid, anterior belly of digastric, tensor veli palatini, tensor tympani
31
Q

CN VI

A

Abducens

  • CNS source:
    • Pons
  • Cranial exit:
    • Superior orbital fissure
  • Function:
    • Motor to extraocular muscle
      • Lateral rectus
32
Q

CN VII

A

Facial

  • CNS source:
    • Pons
  • Cranial exit:
    • Internal auditory meatus ⇒ Facial canal ⇒ Stylomastoid Foramen
  • Function:
    • Special sense of taste
      • anterior 2/3 of tongue
    • Sensory
      • skin of ear
    • Motor
      • muscles of facial expression
      • salivary, nasal, and lacrimal glands
33
Q

CN VIII

A

Vestibulocochlear

  • CNS source:
    • Pons
  • Cranial exit:
    • Internal auditory meatus
  • Function:
    • Special sense of hearing and balance
34
Q

CN IX

A

Glossopharyngeal

  • CNS source:
    • Medulla
  • Cranial exit:
    • Jugular foramen
  • Function:
    • Special sense of taste
      • Posterior 1/3 of tongue
    • Sensory
      • Posterior tongue, middle ear, pharynx, carotid body, carotid sinus
    • Motor
      • Stylopharyngeus muscle
      • Parotid gland
35
Q

CN X

A

Vagus

  • CNS source:
    • Medulla
  • Cranial exit:
    • Jugular Foramen
  • Function:
    • Special sense of taste
      • Epiglottis
    • Sensory
      • External ear, pharynx, larynx, thoracic and abdominal organs
    • Motor
      • Thoracic and abdominal organs
      • Muscles of pharynx and larynx
36
Q

CN XI

A

Spinal Accessory

  • CNS source:
    • Medulla
  • Cranial exit:
    • Jugular Foramen
  • Function:
    • Motor
      • Trapezius and sternocleidomastoid
37
Q

CN XII

A

Hypoglossal

  • CNS source:
    • Medulla
  • Cranial exit:
    • Hypoglossal canal
  • Function:
    • Motor to the tongue