Orofacial Development 3 rd W IU the STOMODIUM

Orofacial Development

3 rd W. IU the STOMODIUM is bet. 3 prominences Of the brain above& Primitive Heart below

4 th W. IU STOMODIUM surounded by 5 prominences

The 2 mandibular processes(1 st arch) give: lower jaw , lower lip, chin &lower portion of the cheeck The 2 MNP(frontonasal); philitrum of the lip, pre-maxilla& primary palate The 2 LNP(frontonasal); alae of the nose& lateral part of the check The 2 maxillary processes(1 st arch); lateral of upper lip, Maxilla &check related&2 ndary palate *In the groove Bet. Max. &LNP develops nasolacrimal duct

The lateral nasal processes form the: A. nostrils. B. philtrum. C. stomadeum. D. ala of the nose. The medial nasal processes form the: A. nostrils. B. philtrum. C. stomadeum. D. ala of the nose.

DEVELOPMENT of the JAWS • • Originate from neural crest cells Mandible is 2 nd bone ossify Maxilla 3 rd bone ossify They develop from the 1 st pharyngeal arch • By intramembranous ossification • (dermal)

MANDIBLE • Meckel, s cartilage (1 st arch) • 6 W. I U from Ear to mid as guide line

V 3 divides in to lingual medial& inferior alveolar lat. IA at mental foramen divides into incisive&mental

Devlopment of the body At the mental foramen primary center of OSSIFICATION fore each side start, gives trough of the body around the incisive nerve& inferior alveolar. Ant. To the symphysis, post. to the lingula. cartilage disappear except from…. Development of the alveolar process starts when the tooth germ of the deciduous teeth develop then the bone surround the germ separated by bony septa into sockets&inferior alveolar canal. The process grows rapidly at tooth eruption

Development of the ramus: 3 -secondary cartilages from chondrocranium

GROWTH of MANDIBLE It is the leading factor in the facial • growth. 1 -2 ndary cartilage • growth(condylar) 2 -development of alveolar process • 3 -subperiostial apposition& • resorption (enhanced by the functional units)

Development of TMJ

MAXILL: -2 PARTS a- pre maxilla(MNP) b-maxilla proper (maxillary process)

Maxilla proper: Intramemb. by a center at the canine area around infra-orbital nerve in addition to; Alveolar process, palatal process& maxillary sinus Pre-maxilla: Palato-facial center at ASA above B_ Prevomer center AT 8 W. UI PRE. &MAXILLA UNIT Acessory cartilages: -1 -molar process 2 alveolar plate 3 -midline

PALATE: -Single oro-nasal cavity occupied by tongue separated only anteriorly by: 1 -PRIMARY PALATE(MNP) 2 -2 ndary PALATE starts as 2 palatine shelves(vertical)

tongue drop , then shelves grow horizontal & fuse with each other & nasal septum by medial edge epithelium which is designed to die &repaced by mesenchymal cells to ossify. posteriorly develops soft palate

1 -What is the origin of the mandible? • a) Branchial arch I • b) Branchial arch II • c) Branchial arch III • d) Branchial arch IV • e) Not of the branchial arch origin

2 -WHICH OF THE FOLLOWING IS NOT A CORRECT PAIRING OF EMBRYONIC STRUCTURE AND ADULT DERIVATIVE? • a- Maxillary processes: secondary palate. • b- Primary palate: upper incisor teeth. • c- Second pharyngeal arch: mandible. • d- Lateral lip: lateral nasal process.

3 -An oblique facial cleft is formed: • a- Due to the rupture of the buccopharyngeal membrane. • b- When the maxillary process fails to fuse with the mandibular processes. • c- When the maxillary process fails to fuse with the lateral & medial nasal process. • d- When the medial nasal process fails to fuse with the maxillary process

4 -Which of the following does contribute to the formation of the upper lip? • a- Lateral nasal process. • b-Two maxillary processes & medial nasal process. • c- Medial nasal process. • d- First branchial arch. 5 - The palatal shelves (palatine processes): • a- Are covered by endoderm. • b- Are derived from the primary palate. • c- Must assume a vertical position for palate closure to occur. • d- Are derived from the first branchial arch.

Figure from Ten Cate’s Oral Histology, Ed. , Antonio Nanci, 6 th edition

DEVELOPMENT of THE TONGUE MUSCLES From the occipital somite innervated by te hypoglossal except platoglossus MUCOUS MEMBRANE From the pharyngeal arches hence the innervation the ant. 2/3 lingual(1 st. ) general chorda tympani(2 nd. ) taste. Posterior 1/3 general& taste 9 th (3 rd. ). including valate papillae Vallecula + epiglitis internal laryngeal th

The mucous membrane: - Ant. 2/3 rds(1 st • arch) 2 LINGUAL SWELLINGS+tuberculum impar Post. 1/3 rd(3 rd&4 th arches) COPULA (hypobranchial) fuse at foramen cecum

Thyroglossal duct cyst

Lingual thyroid

DEVELOPMENT of THYROID GLAND Proliferation of epithelium of the pharynx at foramen cecum. Descend as bilobed diverteculum infront of the pharynx, at the thyroid cartilage aquied amedian ithmus and 2 lobe the duct disappear and the 4 th bouch forms ultimobranchial body gives XC. cells Persistant ducts leads to thyroglossal cyst or fistula

• A patient present with an asymptomatic soft, fluctuant swelling of the angle of mandible anterior to sternocleidomastoid muscle which he stated to be present since his childhood days. Regional lymph nodes are nonpalpable with normal radiographic pictures of the area and normal blood and urine examination. Aspiration of swelling shows yellow-brown fluid. Most probable diagnosis in the condition is: • A- thyroglossal duct cyst B- salivary gland tumor C- branchial cleft cyst D- lymphadenoma

A patient presented with asymptomatic, • smooth, circumscribed red area in midline anterior to circumvallate papillae on the dorsum of tongue with microscopic evidence of epithelial hyperplasia. The most probable diagnosis of the condition is: A-geographic tongue B-hairy tongue C-median rhomboid glossitis D-lingual thyroid

Oral-facial clefts Due to failure fusion of the processes •

Cleft Palate

Cleft Lip

Unilateral upper lip cleft is due to failure of fusion of: a) Medial nasal processes b) Maxillary and lateral nasal processes c) Maxillary and medial nasal processes on one side d) Maxillary and mandibular processes e) Medial and lateral nasal processes unilateralla.