Lecture 1: Abnormal A&P Flashcards
What is a cleft?
An abnormal opening (fissure) in an anatomical structure that is typically closed
Failure of parts to fuse at midline
All structures are present, but not fused or developed normally
Prevalence is 1:600 live births in USA
Embryological Development
Development of lip and alveolus/alveolar ridge 6-7 wks
Development of palate 8 -9 wks
Tongue begins to drop down 7-8 wks
Fusion of hard palate and velum is complete by 12 weeks
Causes of Cleft
Embryologic under-development
Cell migration delay
Cell disruption
Chromosomal disorders
Genetic disorders
Maternal factors: older age, utero factors, maternal malnutrition
Environmental teratogens (cigarette smoke, Dilantin, thalidomide, valium, lead, corticosteroids)
Classifications of Clefts
Normal, complete (into nostril), incomplete, bilateral
What is the Primary Palate?
Primary palate = lip and alveolus/alveolar ridge (structures anterior to the incisive foramen)
Types of clefts of the primary palate
Complete (thru to incisive foramen) or incomplete (e.g. lip only)
Unilateral or bilateral
What is the secondary palate?
Secondary palate = hard palate & velum
Types of secondary palate clefts
Complete (uvula to incisive foramen) or incomplete (bifid uvula into velum)
With or without cleft lip
Types of sub mucous clefts
Overt – ID thru intraoral exam -Chapter 12
Bifid uvula
Zona pellucida (bluish area in middle of velum; “v” at rest)
Posterior hard palate notch
Occult – hidden on nasal surface (via nasoendoscopy)
Types of facial clefts
Oblique and Midline
Types of Oblique facial clefts
Unilateral or bilateral
Affects skeletal & soft tissue
Begins at mouth>lateral, horizontal, upward (extreme disfigurement)
Types of midline facial clefts
Mild Cause cranial base anomalies Encephalocele Absent corpus callosum Associated w/ other midline anomalies Bifid nose Frontonasal dysplasia Hypertelorism Holoprosencephaly
