Craniofacial Abnormalities Flashcards
What is oro-facial clefting?
Abnormal development of the lip and palate
What types of clefting can we have?
Cleft lip +- palate
Cleft palate
What gender is more likely to get cleft lip?
What side of the face is more common?
Males
Left
What % of cleft lip is associated with syndromes?
10%
Explain the process in the face during development
Have brachial arches present.
Frontonasal process at the top bound by the maxillary and mandibular processes below.
The cardiac bulge sits underneath this.
Within the frontonasal process there is a thickening of the ectoderm called the nasal placodes.
These start to sink into the underlying mesenchyme.
What happens during development within the frontonasal process?
As the nasal pits form due to sickening of the nasal placed, thickening occur around the nasal pit called the medial and lateral nasal processes.
Below this are 2 maxillary processes and a continuous mandibular process.
Within 6 weeks, the medial nasal process moves towards rehab midline and the lateral nasal processes bound the nasal pits.
Explain what origin each of these have:
1) Upper lip
2) Alae and sides of nose
3) Cheek
1) Medial nasal processes in middle, maxillary processes laterally
2) Lateral nasal processes
3) Maxillary processes, lateral nasal processes
How does the palate form?
Palate is derived from primary and secondary palate.
The primary palate gives rise to the middle portion of the lip (philtrum) and the incisor teeth.
Secondary palate gives rise to the rest of the hard and soft palate and the maxillary dentition.
The primary palate is is derived from the merged medial nasal processes.
The secondary palate is derived from the maxillary processes.
The maxillary process gives rise to palatine shelves.
These sit either side of the tongue and then elevate above the tongue and grow towards each other in the midline.
They fuse in the midline and the nasal septum above and the primary palate anteriorly to form the secondary palate.
This takes place within 6-10 weeks of development.
What is a conditional knock-out?
Lacking function of a gene in certain tissues.
What can go wrong in the formation of the palate?
The shelves could fail to form
Shelves can fuse inappropriately with other regions of the embryo
They can fail to elevate above the tongue
They can fail to grow towards each other in the midline
They can fail to fuse when they meet each othe
How do we manage patients with facial clefts?
Main objectives of treatment is to improve appearance, maximise function of speech, hearing and swallowing.
Want to enhance well-being and self esteem.
It involves a team approach.
Lip repair = within 3 months of life
Placate repair = within 9 months of lip as we dont want to limit maxillary growth.
When would a clefting patient need a alveolar graft and why?
Prior to canon eruption.
This graft will allow canine eruption through the bone, periodontal support, stabilises maxillary segment, allows orthodontic space closure if laterals absent, suppers the alar base and closes fistulae.
What is an osteotomy and when is it needed?
Need an advancement of the maxilla and set back of mandible to correct the class 3 malocclusion.
How many CLP and CP are associated with syndromes?
CLP = 10%
CP = 30%
What are the main 2 causes associated with non-syndromic clefting?
FGF signalling pathway
Transcription factors