Chapter 3- Clefts

Cleft

An abnormal opening or fissure in an anatomical structure

congenital

present at birth

T/F Clefts can be acquired

T- through ablative surgery such as tumor removal

Development of the lip begins at

7 weeks gestation

Development of the palate begins at

9 weeks gestation

The lip and palate are done developing at

12 weeks (3 months)

development starts at

incisive foramen

Fusions moves in a

anterior then posterior motion

Prior to palate formation, the tongue

in a superior and posterior position in the nasopharynx

Prior to the mandible dropping, the palatal shelves are

in a vertical position on each side of the tongue

The palatal shelves form the

hard palate

The oral surface forms ______ the nasal surface of hard palate

before

endogenous factors

genetic factors

Exogeneous factors

environmental factors

Recurrence risk for clefts

3-5%

Highest risk for clefts based on racial background

Native Americans

Possible exogeneous factors contributing to clefting

teratogens, maternal nutrition deficiencies, physical interference/crowding in utero

Genetic/environmental factors delay the migration of

neural crest cell migration and, therefore, lip and palatal shelf movement

• delay causes the fetus to miss the normal period of fusion at the suture lines

dysplasticity

lack of normal development due to suture lines not fusing

on what side are clefts more common

left

Primary palate consists of the

alveolus and lip

Secondary palate consists of the

hard palate, velum, uvula

Primary palate cleft can affect these functions

Specific articulation errors

Resonance affected

Possibly hypernasality

Secondary palate cleft effects on structure

Absent velar aponeurosis

Altered insertion of the levator velar muscles (cleft muscles of Veau)

Abnormalities in nasal septum

Secondary palate cleft effects on function

Velopharyngeal insufficiency (speech and resonance affected)

Feeding problems and nasal regurgitation

Eustachian tube malfunction

Submucous cleft

the nasal surface (or just the uvula) is incomplete

Characteristics of submucous cleft (only need one to idenitfy)

Bifid or hypoplastic (small or underdeveloped) uvula

Zona pellucida: Thin, bluish area in the middle of the velum

Notch in the hard palate where the posterior nasal spine should be, if the submucous cleft extends into the hard palate

muscles of Veau

Levator muscles insert on the posterior border of the hard palate rather than in the middle of the velum (looks like a tent)

Submucous cleft types

overt and occult

Submucous effect on structure

depends on severity - ranges from minor abnormality (uvula) to altered insertion of muscles (muscles of Veau)

Types of facial clefts

Oblique

Midline (median)

Facial clefts can be caused by

Genetic defects

Amniotic bands

amniotic bands

Inner membrane of the amniotic sac ruptures, causing fibrous and sticky amnion tissue (bands) to float in the waters of the uterus. Bands can entangle a body part, reducing blood supply

Cleft lip/palate prevalence

fourth most common birth defect and most common congenital defect of the face

Cleft prevalence is one in _______ in the US

600

Cleft lip occurs twice as often in

males

cleft palate occurs twice as often in

females

submucous cleft may become symptomatic following

adenoidectomy

Cheilorraphy

lip repair

Palatoplasty

palate repair