1. DEVELOPMENT OF TONGUE THYROID GLAND, FACE AND PALATE
By Dr Samina Anjum

2. PHARYNGEAL ARCHES

6. Taste Buds Anterior 2/3 tongue - Cranial nerve VII
Circumvallate papillae - Cranial nerve IX
Posterior 1/3 tongue - Cranial nerve IX
Most posterior part & Epiglottis - Cranial nerve X

7. TONGUE TIE

8. Development of Thyroid
The thyroid gland is the first endocrine gland to develop in embryo.
It begins to form about 24 days after fertilization
It develops from a median endodermal thickening in the floor of a primordial pharynx
Thickening soon forms a small outpouching called thyroid primordium

9. Cont….
As the embryo and tongue grow, the developing thyroid gland descends in the neck, passing ventral to the developing hyoid bone and laryngeal cartilages
For a short time the thyroid gland is connected to the tongue by a narrow tube, the thyroglossal duct, disappears later

10. Cont…
At first the thyroid primordium is hollow but it soon becomes solid and divides into right and left lobes.
The two lobes are connected by the isthmus of the thyroid gland.
Isthmus lies anterior to the developing second and third tracheal rings.

11. Cont… By seventh week it has reached its final site in the neck
The proximal opening of the thyroglossal duct persists as a small pit in the tongue, the foramen cecum
A pyramidal lobe extends upward from the isthmus in about 50% of people
The pyramidal lobe and the associated smooth muscle represent a persistent part of the distal end of the thyroglossal duct

12. Thyroglossal Duct Cysts & Sinuses
Following infection of a cyst, a perforation of the skin occurs forming a thyroglossal duct sinus

14. Lingual Thyroid

15. DEVELOPMENT OF FACE
STOMODIUM: Is the depression between five elevations. Opposed to the primitive pharynx by buccopharyngeal membrane, which will break down later, then stomodeum communicates with the foregut.

22. Craniofascial Defects
Treacher Collin’s syndrome
Robbin’s sequence
Digeorge anomaly
Goldenhar syndrome

23. First Arch Syndrome
Two Major types; both result in extensive facial abnormalites
Treacher Collins Syndrome
Pierre Robin Syndrome

24. Treacher Collins Syndrome
Autosomal dominant trait/teratogens
Malar hypoplasia
Mandibular hypoplasia
Down slanting palpepebral fissures
Malformed external ears

25. Pierre Robin Syndrome Genetic or envoirmental factors
Mandibular hypoplasia
Micrognathia
Cleft palate

26. Digeorge anomaly Disturbance of cervical neural crest migration.
Absence of thymus and parathyroid glands
Immunological deficiency, Hypocalcaemia, Poor prognosis

27. DEVELOPMENT OF PALATE

30. Intermaxillary Segment Forms
Labial Components (Philtrum)
Maxilla Component (Alveolus + 4 Incisors)
Palatal Component (Triangular Primary Palate)

31. Secondary Palate

36. Congenital malformations
1) cleft lip:
a. unilateral cleft lip: results from failure of the maxillary prominence to merge with medial nasal prominence on the affected side

37. b. bilateral cleft lip : results from failure of the maxillary prominences to merge with the medial nasal prominence on both sides
c. median cleft lip: results from failure of the medial nasal prominences to merge and form the intermaxillary segments

38. 2) oblique facial cleft: results from failure of the maxillary prominence to fuse with the lateral nasal prominence

41. Thank You