craniofacial (prof mossey 1)

Question 1

what are the pre and post-natal craniofacial growth examples?

Answer 1

• Neural growth pattern
• Skeletal growth pattern
• Cephalocaudal gradient

Question 2

what are the types of growth in the craniofacial complex?

Answer 2

• Cranial vault
• Cranial base
• Nasomaxillary complex
• Mandible

Question 3

what are the names of the 3 distinct cranium?

Answer 3

• Desmocranium
• Chondrocranium
• Viscerocranium

Question 4

what are the role of the 6 fontanelles?

Answer 4

• membrane covered
• intra-membranous ossification
• facilitate birth
• posterior, sphenoid and mastoid fuse early
• anterior (superior) persists until 1.5 years

Question 5

describe cephalometrics

Answer 5

the measurement of cranial facial aspects

Question 6

describe cephalocaudal

Answer 6

refers to the dominance of the neural growth in the early stages of fetal growth and then the postnatal growth is dominated by skeletal elements

Question 7

describe hydrocephaly

Answer 7

• ballooning up of the brain
• CSF in ventricles

Question 8

describe microcephaly

Answer 8

• brain is reduced in size
• e.g. zika virus

Question 9

describe craniosynostoses

Answer 9

• premature fusion due to genetic mutation e.g. FGFR-2
• is the opposite to hydrocephaly, this is where there is premature fusion of the cranial bones and the cranial sutures, as a result that there is increased intracranial pressure which causes the protrusion of the eyeballs as a feature of cranial sinus doses

Question 10

describe crouzen syndrome

Answer 10

patient has a sutra fusion which is a early surgical operation

Question 11

How is phenotype in craniosynostoses determined?

Answer 11

by which sutures are fused early

Question 12

what is an example of cranial sinus doses?

Answer 12

Apert syndrome

Question 13

describe sagittal fusion

Answer 13

sagittal fusion early results in a bulging of the skull in abnormal places because the neural growth will continue

Question 14

describe trigoncephaly

Answer 14

determined by where the sutures fuse

Question 15

describe cloverleaf skull

Answer 15

example of craniosynostosis doses temporal fusion

Question 16

Describe synchondroses

Answer 16

areas in which growth continues to happen

Question 17

describe condrocranium

Answer 17

• centres of ossification on either side of synchondrosis
• endochondral mechanism - cartilage grows rapidly & replaced by bone
• cartilage interposed between large sections of bone, which form of the ethmoid, sphenoid and basioccipital bones

Question 18

what role does homeobox genes have?

Answer 18

a) craniofacial shape and patterning
b) patterning of the dentition

Question 19

describe homeobox genes

Answer 19

• homeotic “master” genes
• Encoding for transcription factors
• involved in patterning, induction, apoptosis
• control of epithelial/mesenchymal interaction

Question 20

How do homeobox genes work?

Answer 20

• through the neural crest cells (NCC)
• Ectomesenchyme of first branchial arch derived from the NCC
• migration directed by homeobox genes

Question 21

describe morphogenetic cascade

Answer 21

the basic morphogenetic processes of initiation, segmentation, patterning, migration and differentiation are medicated via a series of extracellular signalling molecules in a cascade of cellular events

Question 22

What are the timing of palatal closure?

Answer 22

• Week 6, Day 44: primary palate fusion
• Week 7, Day 54: palatal shelves elevate
• Week 8, Day 58: secondary palate fusion

Question 23

describe meckels cartilage

Answer 23

a precursor of the mandible, this is an embryonic structure that has no role whatsoever in postnatal growth, there are initial site of osteogenesis which begin to protect the nerves: IAN

Question 24

How is homeobox genes relevant to craniofacial development?

Answer 24

Control and direct the processes of resorption deposition

Question 25

Which teeth appear first?

Answer 25

The first teeth that appear are the normal incisors followed by the lower central incisors then lateral lower incisors and then the upper incisors, then we go from first decidious molars to second decidious molars, very pattern orientated developmental process

Question 26

What can you still see in still births?

Answer 26

Even in a still birth u can see all the decidious teeth have developed, the first permanent molar begins to ossify around about the time of birth, although it doesn’t erupt until the age of 6

Question 27

describe the mechanisms of different component parts

Answer 27

Coronoid process has muscular attachments, angular process which is dominated by muscular attachments, body of the mandible which contains the nerves, chin unit which is called the mentalis muscle attaches there, and the alveolar process which contains the teeth as they develop

Question 28

Primary growth centres

Answer 28

Responsible for anteroposterior lengthening of cranial base. It is under genetic and epigenetic control meaning there is predetermined growth. There is also transverse growth by transverse sutures between these bones

• Sphenooccipital
• Intersphenoid
• Sphenoethmoidal

Question 29

Circum-maxillary sutures

Answer 29

Allows downward and forward growth of the skull

Question 30

Frontal propulsion

Answer 30

Is caused by the increasing demands by the body such as mastication and respiration. Enables it to move downwards and forwards and sutural growth at the back

Question 31

condylar cartilage

Answer 31

Separates to protect the neurovascular bundle. It plays an important role as a stress absorber during function and enables functional join movements.
Condylar growth also occurs in a V- shape

Question 32

What is normal development of the dentition ?

Answer 32

1) Lower incisors
2) lower lateral incisors
3) Upper incisors
4) 1st deciduous molars
5) Canines
6) 2nd deciduous molars

Question 33

describe permanent teeth

Answer 33

Begin to develop in the palatal/lingual side.

Question 34

MSX1 and MSX2

Answer 34

Important in the initiation, patterning, and morpho-differentiation of tooth buds in tooth development (Muscle specific homeobox genes)

Question 35

Mesenchymal growth factor genes

Answer 35

Information for craniofacial development is expressed through these

Question 36

Hemifacial microsomia

Answer 36

Abnormal smallness of one side of the face caused by bursting of an embryological artery known as the stapedial artery