T2 L23 Congenital abnormalities of face Flashcards
Where is the oropharyngeal membrane?
Between maxillary prominences
How is stomatodeum formed?
Breakdown of oropharyngeal membrane
What does stomatodeum form?
Opening to oral cavity
What is frontonasal prominence formed by?
Proliferation of mesenchymal neural crest cells that are ventral to forebrain.
What does the frontonasal structure form?
Forehead
Bridge of nose
Medial and lateral nasal prominences
What do 2 nasomedial structures form?
Philtrum
Primary palate
Upper 4 incisors and associated jaw
What do 2 nasolateral structures form?
Sides of nose
What do 2 maxillary structures form?
Cheeks
Lateral upper lip
Secondary palate
Lateral upper jaw
What do 2 mandibular structures form?
Lower lip
Jaw
Describe formation of the palate
Nasal cavity is initially continuous with oral cavity
Fusion of media nasal prominences to form intermaxillary segment (primary palate)
Maxillary prominences expand medially to form palate shelves which advance medially to fuse superior to the tongue
Developing mandible expands to increase size of oral cavity.
What does the mandibular pharyngeal arch form?
Maxillary nerve Meckel's cartilage Maxillary prominence Mandibular prominence Artery becomes terminal portion of maxillary which is a branch of the external carotid.
What does Meckel’s cartilage form?
Malleus and incus
What does maxillary prominence of arch 1 form?
Maxilla
Zygomatic bone
Part of temporal bone
What does the hyoid pharyngeal arch form?
Facial nerve
Reichert’s cartilage
Stapedial artery
Hyoid artery
What does Reichert’s cartilage form?
Stapes
Styloid process
Stylohyoid ligament
Upper body and lesser horn hyoid bone
What does pharyngeal arch 3 form?
Glossopharyngeal nerve
Artery becomes common carotid artery and proximal portion of internal carotid artery
Lower body and greater horn of hyoid
What does pharyngeal arch 4 form?
Vagus nerve
Vascular derivatives:
- right: proximal portion of subclavian artery
-left: aortic arch
What is a thyroglossal duct cyst?
Forms along path of thyroid descent
How does a thyroglossal fistula form?
Spontaneous rupture of thyroglossal cyst –> draining sinus (thyroglossal fistula)
What is the treatment for a thyroglossal fistula?
Surgery: sistrunk’s operation
What is a branchial fistula?
Rare, congenital abnormality arising from abnormal persistence of branchial apparatus remnants
May need surgery if there are recurrent infections
What is a ranula?
Cyst that forms on floor of mouth due to blockage of salivary glands
Make an incision so saliva can drain into mouth
What is an external angular dermoid?
Common subcutaneous tumour of the face covered by trapping of epithelium under the skin
Cosmetic procedure to remove it as it will continue to enlarge
What is a cystic hygroma?
Malformation of lymphatic system where lymph doesn’t drain well
