Key to Past 25 years TN MGR Med Univ Questions - Development of Face Chapter

Development of face

Meckel’s cartilage: 

Place where it is found; cartilage of which arch; the week at which it is formed – from which structure – forms which structures – at which week - how it acts as a scaffold for the mandible and the persistence of the cartilage in adult as the inner ear bones- how mandible develops from this including the type of ossification

Development of Maxilla & Mandible:

Maxilla: head development – begins/ends at which week – mesenchymal prominence - development of medial and nasal process- descent and movement of the process – concept of premaxilla, primary palate, secondary palate – descent of tongue – fusion of processes – mechanism involved – clinical significance of non-fusion – clefts of maxilla – Diagrams Mandible: week of initiation in IUL – Meckel’s cartilage formation - Place where it is found; cartilage of which arch; the week at which it is formed – from which structure – forms which structures – at which week - how it acts as a scaffold for the mandible and the persistence of the cartilage in adult as the inner ear bones- how mandible develops from this including the type of ossification – Growth of mandible – development of lingual, nerve innervation's and blood supply

Development of mandible: 

Week of initiation in IUL – Meckel’s cartilage formation - Place where it is found; cartilage of which arch; the week at which it is formed – from which structure – forms which structures – at which week - how it acts as a scaffold for the mandible and the persistence of the cartilage in adult as the inner ear bones- how mandible develops from this including the type of ossification – Growth of mandible – development of lingual, nerve innervation's and blood supply - Diagrams

Development of middle third of face: 

4^th week IUL - facial prominence's – 1^st pharyngeal arches appear - Maxillary prominence - mandibular prominence - frontonasal prominence - nasal (olfactory) placodes - nasal pits - nasal prominence – lateral - medial - nasolacrimal groove  - nasolacrimal duct- lacrimal sac – formation of cheeks and maxilla. Nose- 5 facial prominence's - the frontal - medial nasal prominence - lateral nasal prominence. Skin development – innervation's – Reichert Cartilage - Diagrams

Derivatives of second pharyngeal arch: 

Hyoid arch- Reichert’s cartilage- stapes, styloid process of the temporal bone, stylohyoid ligament, and ventrally, the lesser horn and upper part of the body of the hyoid bone.  Muscles of the hyoid arch - stapedius, stylohyoid, posterior belly of the digastric, auricular, and muscles of facial expression. The facial nerve, the nerve of the second arch, supplies all of these muscles. Diagrams

Development of tongue: 

4 weeks in the form of two lateral lingual swellings and one medial swelling, the tuberculum impar - first pharyngeal arch - copula, or hypobranchial eminence - a third median swelling, formed by the posterior part of the fourth arch - laryngeal orifice – relationship with arytenoid swellings  - lateral lingual swellings - increase in size – tuberculum impar and merge - body of the tongue. Tongue mucosa - from the first pharyngeal arch - sensory innervation's - terminal sulcus. Root of tongue and the 2^nd, 3^rd and 4^th pharyngeal arch.  tongue muscles - myoblasts  - occipital somites - hypoglossal nerve. Sensory, motor and taste supply to tongue. Two diagrams. 

(A Special Thanks to Colleagues at Ragas Dental College & Hospital, Chennai)