Resonance FInal

What is a teratogen?

any agent that can cause birth defects or increase their risk by interfering with normal fetal development

Teratogens associated with cleft lip/palate

cigarette smoke, certain drugs including phenytoin, valium, corticosteroids, and lead pollution

characteristics of Wolf-Hirschhorn syndrome

• deletion or missing portion of short arm of chromosome 4

• cleft palate is common, distinctive facial appearance linked to a greek helmet

• hypertelorism

• dysplastic ears and periauricular tag

• occasional hearing loss

what syndrome?

Wolf-Hirschhorn Syndrome

Treacher Collins syndrome characteristics

• mutations on the long arm of chromosome 5

• frequently occuring cleft

• pronounced micrognathia

• downward slanting of the palpebral fissures

• colobomas of the lower eyelids

• middle ear anomalies

• communication deficits related to conductive hearing loss and micrognathia

what syndrome?

Treacher Collins syndrome

Moebius syndrome

• absence or udner development of abducent nerve (CN VI) and facial nerve (CN VII)

what syndrome?

Moebius syndrome

hemifacial microsomia

• facial asymmetry due to unilateral hypoplasia of the face, malar, maxillary, and/or mandubular processes

pierre robin sequence

• micrognathia that may be due to crowding in utero or may be genetic as part of a syndrome

what syndrome

hemifacial microsomia

what syndrome?

Pierre Robin Sequence

velopharyngeal insufficiency

• caused by an abnormal structure

  • speech therapy will NOT fix this because it is structural

velopharyngeal incompetency

occurs when there is poor velar mobility. there is typically enough tissue but the velum is not moving properly to close the gap. this is typically neurophysiological and can be managed with a prosthetic device.

velopharyngeal mislearning

Functional issue where abnormal articulation or faulty placement causes nasal emission or hyper natality, even though there is no structural abnormality. This typically requires speech therapy to correct.

migration

the cranial neural crest cells travel from the neural tube to their specific target destinations within the developing embryo

proliferation

Once the cells arrive at their target destination in the facial region, they proliferate (multiply) so that the facial structures can begin to take shape

differntiation

This is an ongoing process where the cells specialize to form specific tissues, such as skin, muscle and cartilage and development. The cartilage is replaced by bone

submucous cleft

congenital defect that affects the underlying structures of the pallet while leaving the oral surface Macosa intact

overt submucous cleft palate

Can be seen on the oral service and diagnose through a standard intraoral examination. Physical signs include a Bifi or hypoplastic uvula or a zone pellucida, bony notch in the midline of the posterior border of the hard palate.

bifid

split

hypoplastic uvula

underdevelopedx

zone pellucida

bluish translucent area in the middle of the velum caused by thin mucosa and lack of underlying muscle mass

what side does a uniltaeral cleft usually occur on with the primary palate?

left side

What is a cranial neural crest cell?

primary cells from which the tissues of the face are derived

how do cranial neural crest cells function?

3 main phases of development:

1. migration: travel from neural tube at different rates to their specific target destinations within the embryo

2. proliferation: once the cells arrive at their target destinations in the facial region, they rapidly multiple so that the facial structures can begin to take shape

   1. differentiation: the cells undergo a ongoing process of specialization to form specific tissues, such as skin, muscle, and cartilage (which is later replaced by bone)

factors affecting vp closure?

• velum lentgh

• pharyngeal depth

  • muscular function and integrity

levator veli palatini

pulls velum superiorly and posteriorly to posterior pharyngeal wall

levator veli palataini is innervated by?

CN X

musuclus uvulae

Shortens and bronze uvula to help it close against posterior pharyngeal wall

innervation of musculus uvulae

CN X

palatoglossus

if tongue is fixed, pulls soft palate down (opposes levator)

if palate is fixed, the palatoglossus ____

raises back of tongue

palatopharyngeus

guide food into pharynx for swallowing, may also help lower soft palate

3 layers of pharyngeal tube

1. epithelial mucosa

2. aponeurosis/fascia

3. muscular:

   1. superior pharyngeal constrictor

   2. middle pharyngeal constrictor

      1. inferior pharyngeal constrictor

salpingopharyngeus

help draw lateral walls of pharynx upward and medially

tensor veli palatini

tense and lower palatl aponeurosis help open Eustachian tube (pop ears)

innervation of tensor veli palatini

CN V Trigeminal

4 pairs of muscle involved in velopharyngeal closure

• levator veli palatini

• superior pharyngeal constrictor

• musculus uvulae

• palatopharyngeus

what are some ways a person can prevent craniofacial anomolies?

avoiding terotogens and maintaining proper nutrition and health

endogenous causes of clefts

chromosomal, genetic, syndromes

exogeneous causes of clefts

teratogens, maternal nutritional deficiencies

complete cleft lip

Extends entirely through the lip, the nasal floor and the alveolus reaching all the way back to the incisive foreman

incomplete cleft lip

Only affects the lip and does not involve the alveolus

passavants ridge

shelf-like projection from the posterior pharyngeal wall that occurs inconsistently in some individuals during vp activities

sagittal pattern

least common pattern of closure, involves high degree of lateral pharyngeal wall movement moving inward toward midline

coronal pattern

achieved primarily through the anterior posterior movement of the beam to the posterior wall. Very little lateral pharyngeal wall movement.

circular pattern

Close your functions more like a true sphincter involving a combination of both anterior posterior wheeler movement in lateral pharyngeal wall movement