FACIAL AND PALATAL ABNORMALITIES (Exam 1)

Question 1

What are the two developmental mechanisms involved in the proper development of the craniofacial area?

Answer 1

1. Appropriate amount of tissue proliferation (Cell migration) in the region is required to eliminate the space (Cell proliferation)
2. Fusion: Process by which the two regions of tissue that were initially separated grow together

Question 2

What causes a cleft to be formed?

Answer 2

A failure of tissue to merge or fuse together; which leads to a persisted deficit of tissue

Question 3

Embryological basis for clefts may include a failure to fuse due to:

Answer 3

• Excesses tissue (i.e. excess proliferation)
• Deficits of tissue (i.e. under proliferation tissue which could be related to cell death
• Alterations in the shape and size of head or jaw leading to misalignment of the regions of tissue

Question 4

Fusion between maxillary and lateral nasal process forms:

Answer 4

Side of nose

Question 5

Fusion between with maxillary and medial nasal process (IM) will form:

Answer 5

Upper lip

Question 6

The primary palate is formed by:

Answer 6

Maxillary and inter maxillary segment

Question 7

The cheek is formed by:

Answer 7

Maxillary and mandibular process

Question 8

The secondary palate is formed by:

Answer 8

Lateral palatal shelves of maxilla

Question 9

Fusion between both medial nasal =

Answer 9

Midline/tip of nose and INtermaxillary segment

Question 10

IM ->

Answer 10

Primary palate and philtrum of lip

Question 11

Fusion between with each mandibular process forms the:

Answer 11

Chin

Question 12

Fusion of right/left lateral palatal shelves with primary palate and nasal septum forms the:

Answer 12

Complete palate

Question 13

What are the types of facial Anomalies:

Answer 13

1. Midline facial defects can be: Hypoplasia (under developed), Hyperplasia (overdeveloped)
2. Facial clefts can be : Oblique, Lateral (transverse)
3. Palatal clefts and lips
4. Mandibular clefts

Question 14

What is Holoprosencephaly?

Answer 14

Failure of forebrain to divide, which leads to spectrum of cdraniofacial disorders released to a aarrested development of frontonasal tissue to form or proliferate; can be associated with failure of NC migration from forebrain region

Clinical Phenotype: Single to close set eyes (hypotelorism); absent to single nostril; missing premaxilla

Most severe: Single cerebral lobe instead of right and left hemispheres; single nostril (cebocephaly); single eye (cyclopia)

Question 15

Embryological basis for Holoprosencephaly:

Answer 15

The forebrain directs the development of frontonasal process:
- Developmental defects in the forebrain such as a failure of the forebrain to divide, leads to arrested development of frontonasla process

Outcome: midline facial abnormalities

** DEFICIENT AMOUNT OF TISSUE IN MIDLINE**

Question 16

What is Frontonasal Dysplaisa?

Answer 16

(Median Facial Cleft): is a spectrum of conditions associated with the failure of tissue to fuse in midline due to an excess of amount of tissue:

Clinical Phenotype: Spectrum of median craniofacial hyperplasia

• Small eyes (Microphthalmia) eyes wide set (hypertelorism
• Bifid nose or a brand nose with cleft/groove-the nasal tip may be absent
• Cleft of primary and or secondly palate

** EXCESS AMOUNT OF TISSUE IN MIDLINE**

Question 17

Embryological basis for Frontonals displays (Midline Facial Cleft):

Answer 17

Midline defect due to over-proliferation of tissue and or lack of growth inhibition in the frontonasal process following placed formation

Question 18

What is an oblique facial cleft:

Answer 18

Persisten groove from inner eye to the ala of the nose:

Embryological basis: Failure of maxillary process to mere with lateral nasal process and premaxilla

Question 19

What is a Lateral facial Cleft?

Answer 19

Associated with Macrostomia (large mouth)

Embryological basis: Incomplete fusion between the soft tissue of the maxillary and mandibular processes leads to distortion of labial commissures

Question 20

What is congenital Macrostomia?

Answer 20

A rare congenital anomaly seldom occurring alone and is frequently associated with deformities of the structures developing from the first arch. It maybe part of a group of disorders known as Hemifacial microsomes which exhibit defects in first and second arch

Question 21

What is Hemifacial microsomia?

Answer 21

A birth defect that occurs when a part of the face fails to grow and appears small or underdeveloped. The syndrome varies in severity but always includes the maldevelopment of the ear and the mandible. This is the second most common facial birth defect after clefts

Question 22

What is a Primary Cleft?

Answer 22

Clefts anterior to incisive foramen are considered primary (anterior) and may be bilateral or unilateral

Question 23

What is a Secondary Cleft?

Answer 23

Secondary (posterior) Clefts are located posterior to the foramen and may involve the hard and or soft palate

Question 24

What is a complete cleft?

Answer 24

A complete cleft includes the entire definitive palate and may be bilateral or unilateral