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Flashcards in Face and Palate Deck (68)
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1
Q

time of development of the face

A

4-8 weeks in utero

  • eyes, ears, nose
2
Q

time of formation of palate

A

6-10 weeks in utero

  • soft palate developing till 12 weeks
3
Q

what is the earliest bone laid down in the skull

A

the mandible (approx 6-7 weeks)

one of the earliest in the skeleton

4
Q

what are the 2 severities of defects in face and palate formation

A

can be major defects
- are incompatible with life

can be minor defects
- can be surgically corrected

5
Q

the process of face and palate formation is

A

Highly coordinated and pre-programmed

6
Q

how common are face and palate development abnormalities

A

1 in 700 births have some form of congenital malformation

More severe defects tend to occur 4-8 weeks (early facial developments)

Relatively minor problems develop later (8-12 weeks)
- Cleft lip and palate

7
Q

what do the frontal nasal processes develop from

A

tissues surrounding forebrain

Develop separately from 1st pharyngeal arch (tissue around maxilla and mandible)
- Usually defects affect one or the other but not both at the same time

8
Q

what are pharyngeal arches

A

ridges/outgrowths of tissues

devolved from gills of fish
- common in embryogenesis of all vertebrates

9
Q

pharyngeal arches in humans

A

4 pairs of well developed arches

  • 5 is short ridge
  • 6 is debatable

Mesenchymal core (mesoderm and neural crest) covered ectoderm, separated by clefts and inside has endoderm separated by pouches

Each arch has a central rod of pre-cartilaganous/ cartilaginous mesenchyme then transformed into adult skeletal structures
- Striated muscles transformed into muscles of face

Each arch supplied by major artery and has specific CN nerve derived from

10
Q

pharyngeal arch structure

A

Mesenchymal core (mesoderm and neural crest) covered ectoderm, separated by clefts and inside has endoderm separated by pouches

Each arch has a central rod of pre-cartilaganous/ cartilaginous mesenchyme then transformed into adult skeletal structures
- Striated muscles transformed into muscles of face

Each arch supplied by major artery and has specific CN nerve derived from

11
Q

1st pharyngeal arch

A

Mandibular

Trigeminal Nerve CNV, Muscles of Mastication, Malleus, Incus, Meckel’s Cartilage

  • Forms mandible
  • – Second bone to start to ossify in skeleton
  • — Intramembranous ossification – bone laid down in mesenchyme around it

Mandibular, part maxilla, ear

12
Q

2nd pharyngeal arch

A

facial nerve CNVII, muscles of facial expression, hyoid

13
Q

3rd pharyngeal arch

A

glossopharyngeal Nerve CNIX, Stylopharyngeus, Common Carotid Artery, Hyoid

14
Q

4th and 6th pharyngeal arches

A

Vagus Nerve CNXII, Muscles of Pharynx and Larynx, Aortic Arch, Laryngeal Cartilages

15
Q

how many prominences does the face develop from

A

5 prominence surrond stomadaeum

grow and develop and fuse in midline to form face

16
Q

what is the stomadaeum

A

central depression in developing skull which leads on to be the mouth

17
Q

what are the 5 prominences of facial development

A

frontnasal
- overlies developing forebrain

paired maxillary
- from 1st pharyngeal arch

paired mandibular
- from 1st pharyngeal arch

18
Q

what does the frontal nasal prominence develop into

A

Forehead; bridge of nose
- Lateral aspects – circles – nasal placode

Grow and enlarge in fifth embryonic week
Olfactory epithelium

19
Q

what does the medial nasal prominence develop into

A

Midline nose (grow towards midline and form septum)

philtrum upper lip (fuse with maxillary prominences that are going towards midline)

20
Q

what does the lateral nasal prominence develop into

A

Alae (wings/lateral aspect) of nose (fuse to form)

21
Q

what does the maxillary prominence develop into

A

Cheeks

lateral upper lip (corners of mouth – where fuse with mandibular prominence)

22
Q

what does the mandibular prominence develop into

A

Lower lip and jaw (fuse in midline, location where they fuse – chin can lead to cleft or dimple in chin not fused)

23
Q

what forms the nasal lacrimal duct and lacrimal sac

A

6th week – groove between lateral nasal prominence and maxillary process

24
Q

what term is used for the precursor of the ear

A

auricular helix

25
Q

how many parts does the palate form from

A

2

26
Q

process of developing palate (5)

A

at 6 week the nasal and oral cavities are continuous
- open space

end of 7 weeks – Medial nasal processes expand inferiorly to join to form form intermaxillary process

  • gives rise to philtrum of lip and primary palate
  • –contains 4 incisor teeth
  • —premaxilla
palatal shelves (7-8 weeks) separate them 
 - derive from Maxillary prominences, from 1st Pharyngeal arch (lateral palatal shelves form secondary palate)

Thin palatal shelves grown downwards from maxillary prominences (approx. 7 weeks)

  • Then rotate up towards midline – go horizontal
  • –Fuse around midline
  • —Can see primary palate (premaxillary) and secondary palate
  • —Maxilla and palatine bones laid down in tissue

Growth and expansion of mandible to accommodate tongue

27
Q

basics of how nasal septum formed

A

Downgrowths of frontal nasal prominence
- Fuse in midline

Divide into L and R nasal cavities

28
Q

stomadaeum

A

Primitive mouth

Structure 5 prominences form around

29
Q

medial nasal prominences develop into

A

philtrum of upper lip and tip of nose

30
Q

what forms the alae of nose

A

maxilla fused with lateral nasal prominences

31
Q

5 prominences of facial development and 2 additional features used to show stage

A

frontal nasal prominence

mandibular prominence

maxillary prominence

medial nasal prominence

lateral nasal prominence

nasal pits and developing eye

32
Q

what do the lateral palatal shelves come from

A

maxillary process

- open space between them can see into nasal cavity from oral cavity

33
Q

what fuse to form the inter-maxillary process (distal to the primary palate)

A

medial nasal processes

34
Q

stages in palatine development

A

palatal shelves grow down, towards you

palatal shelves begin to fold up horizontally
- coming closer together

palatal shelves nearly at midline

palatal shelves start to fuse in midline
- incisive foramen where they fuse together towards the primary palate/premaxilla region

35
Q

where could palatal development go wrong

A

fusion not occur
- cleft palate

can be linked to mandible growth as it’s growing simultaneously

36
Q

complete or partial failure of facial development can lead to

A

facial cleft

37
Q

facial cleft affecting one side

A

unilateral

38
Q

facial cleft affecting both sides

A

bilateral

39
Q

4 impacts of life facial clefts can impact

A

Feeding

Speech

Hearing

Social integration

40
Q

how common is facial clefts

A

1 in 700 births

can be connected to a syndrome (300 syndromes) most oro-facial clefts are not

41
Q

cleft lip

A

Failure of fusion of maxillary prominence with the mesial nasal processes

  • Maxillary prominence coming in to form the secondary palate
  • Medial nasal process forms the primary palate and philtrum of lip
  • -See cleft formed in between

Uni or Bi lateral

Can extend to incisive foramen

42
Q

medial cleft lip

A

Failure of the two medial nasal processes to fuse with each other
- rare

43
Q

cleft palate

A

Failure of 2 palatal shelves fuse together in midline

44
Q

what can effect the distribution of cleft lip and palate

A

sex, familial distribution, geography

45
Q

isolated cleft lip prevalence

A

more common on left

more prevalent in males

46
Q

isolated cleft palate prevalence

A

more in females

- later elevation of palatal shelves in females (week 8 over 7)

47
Q

cause of oro-facial clefts

A

Multi-factorial
- Identical twins don’t form the same

Related factors

  • Environment
  • Smoking
  • Alcohol
  • Viral infection
  • Certain drugs
  • Some vitamin A analogues
48
Q

diagnosis of cleft lip

A

ultrasound from week 13

usually picked up in 20 week midterm scan
- and definitely picked up 72hrs post-partum

49
Q

diagnosis of cleft palate

A

harder to see on ultrasound pre birth

50
Q

treatment of cleft lip and palate

A

Can be repaired surgically

cleft lip surgery
- 3-6 months
cleft palate surgery
- 6-12 months

51
Q

advise on cleft lip/palate treatment

A

Advised early on

  • Feeding issues – unable to form seal
  • Hearing issues – higher ear infections chance
  • Dental development – can have impact
  • Speech development
52
Q

time of cleft lip surgery

A

3-6 months

53
Q

time of cleft palate surgery

A

6-12 months

54
Q

additional treatment that might be required for cleft lip and palate babies (2)

A

Speech and language therapy

Orthodontic treatment
depending on the development of adult dentition

55
Q

sutures

A

joints between bones in skull
- juvenile further apart

strong fibrous joints

limited to no movement

56
Q

ossification of bones of calvarium

A

intramembranous ossification

57
Q

intramembranous ossification

A

laid down directly into membrane

grow and start to replace the membranes

58
Q

fontanelles

A

membrane tissue remains (yet to be ossified)

movement/flexibility can happen here

  • will continue to grow and replaced by sutures
  • – fibrous bone connections
59
Q

mental symphysis

A

2 forming sides of mandible

can start to fuse but see split still

60
Q

closed mental symphysis

A

single mandible

symphysis completely closed
- one mandible

by one year old

61
Q

open mental symphysis

A

see 2 parts of mandible

visible split in middle

62
Q

what can happen to sutures with advanced age

A

Sutures can fuse completely and disappear

63
Q

antemortem tooth loss

A

Evidence of healing

Tooth sockets filling in, alveolar bone removed with tooth

64
Q

post mortem tooth loss

A

No healing/turnover of bone

Open tooth socket

65
Q

denture pain if most alveolar bone is lost

A

dentures sit close to mental foramen

- sit on nerve = pain

66
Q

bone in life

A

Constant turn over
- Old removed
- New laid down
Micro fractures repaired

Don’t use it you lose it
- Astronauts/bed ridden lose bone density and resor

No mechanical stimulation as loss of teeth
- Alveolar bone resorbed

67
Q

why wide obtuse angle of mandible in juvenile

A

Wide obtuse angle in juvenile
- Ramus not finished growing

Need to widen to accommodate adult dentition
- To create space for developing adult teeth

68
Q

angle of mandible comparison between males and females

A

females More obtuse than males

Changes in puberty 
- Males undergo larger growth spurt 
-Larger muscle mass
----Pull more on bone 
More robust mandible 

Mandible grows more in men

  • Square chin and jaw
  • Ridges on bone due to enlarge muscles of mastication