Upload
others
View
6
Download
1
Embed Size (px)
Citation preview
Development of Face & Abnormalities of Face
รศ.ดร.จริยา อ าคา เวลบาทAssoc Professor Dr Jariya Umka Welbat
Department of Anatomy
Faculty of Medicine, KKU
09/10/64 1
References:
09/10/64 2
09/10/64 3
During week 3 of embryonic development, an oropharyngeal membrane initially appears at the site of the future face. It is comprised of ectoderm and endoderm – externally and internally, respectively.During the 4th week, the oropharyngeal membrane begins to break down in order to become the future oral cavity, and sits at the beginning of the digestive tract.
Development of the Face
The five primordial appear around the stomodeum or primitive mouth early in the fourth week.
09/10/64 4
The frontonasal prominence (local swelling), formed by the proliferation of mesenchyme ventral to the forebrain, constitutes the cranial boundary of the stomodeum.
The paired maxillary prominences of the first brachial arch from the lateral boundaries, or discs, of the stomodeum.
The paired mandibular prominences of the same arch constitute the caudal boundary of the stomodeum.
09/10/64 5
Mesenchyme proliferates at the margins of these placodes, producing horse-shaped elevations, the sides of which are called the medial and lateral nasal prominences (swelling).
The nasal placodes now lie in depressions called nasal pits.
The maxillary prominences enlarge owing to the proliferation of mesenchyme and grow medially toward each other and the medial nasal prominence.
The medial migration of the maxillary prominences moves the medial nasal prominences toward the medial plane and each other.
The development of the face occurs mainly between the fourth and eighth weeks
By the end of the fourth week, bilateral oval thickenings of the surface ectoderm, called nasal placodes, have developed on each side of the inferior part of the frontonasal prominence.
Lower jaw and lip form first.
09/10/64 6
Each lateral nasal prominence is separated from the maxillary prominence by cleft, or furrow, called he nasolacrimal groove.
By the end of the fifth week, the auricles of the external ears have begun to develop.
Each maxillary prominence has emerged with the lateral nasal prominence along the line of the nasolacrimal groove.
This establishes continuity between the side of the nose (formed by the lateral nasal prominence) and the cheek region (formed by the maxillary prominence).
09/10/64 7
During the sixth and seventh weeks, the medial nasal prominences merge with each other and the maxillary prominences.
As the medial nasal prominences merge with each other, they form an intermaxillary segment.
This segment give rise to (1) the medial portion or philtrum of the lip, (2) the premaxillary part of the maxilla and its associated gigiva (gum), and (3) the primary palate.
09/10/64 8
09/10/64 9
09/10/64 Jariya Umka Welbat 10
09/10/64 11
Prominence Derivatives
FrontonasalForehead, bridge of nose, medial and lateral nasal prominences
Medial nasalPhiltrum, primary palate, upper 4 incisors and associated jaw
Lateral nasal Sides of the nose
Maxillary (1st pharyngeal arch)Cheeks, lateral upper lip, secondary palate, lateral upper jaw
Mandibular (1st pharyngeal arch) Lower lip and jaw
Pharyngeal arches
Ectoderm
Mesenchyme core: artery, nerve & cartilage
◦ Original mesenchyme
From mesoderm in 3rd week: skeletal, musculature vascular endothelium
◦ 4th week neural crest cells: mesenchyme in the head and neck
Differentiates and produces the prominences of the first arch
Endoderm
09/10/64 12
First or Mandibular Arch
Skeleton◦ Malleus and incus
Muscles: from 4th Somitomere◦ Muscles of mastication (e.g. masseter)
Nerve: Trigeminal (V) Aortic Arch: Maxillary Artery 1st Pharyngeal Pouch: Auditory tube (eustachian
tube) and tympanic cavity (distal end) 1st Pharyngeal Groove: External auditory meatus
(exterior ear opening)
09/10/64 13
1409/10/64
Skeleton◦ Stapes◦ Styloid process◦ Lesser horn of the hyoid bone
Muscles: from 6th Somitomere◦ Muscles of facial expression
Nerve: Facial (VII) 2nd Aortic Arch: Hyoid artery, Stapedius artery 2nd Pharyngeal Pouch◦ Suprstonsilar fossa: component of the palatine tonsils
1509/10/64
Second or Hyoid Arch
09/10/64 16
Excess tissue in frontonasal prominence: Frontonasal Dysplasia
09/10/64 17
➢ Broad nasal bridge, hypertelorism, cleft nose, median cleft lip.
➢ Ocular (orbital) hypertelorism increase in the interorbital distance.
➢ Can be associated with other defects (e.g. tetralogy of Fallot in Heart).
Excess tissue in frontonasal prominence: Frontonasal Dysplasia
Mediancleft lip and bifid nose
Bifid nose results when the medial nasal prominences do not merge completely; the nostrils are widely separated and the nasal bridge is bifid. In mild forms of bifid nose, a small groove is present in the tip of the nose.
09/10/64 18
Absence of intermaxillary process
Absence of the intermaxillarysegment with hypotelorism. The midline rectangular defect indicates the site of the deficient intermaxillary segment with absent prolabium, incisors, and primary palate. There was consequent clefting of the secondary palate. Absent intermaxillary segment with hypotelorism signifies a high likelihood of holoprosencephaly.
http://imaging.consult.com/chapter/S1933-0332%2808%2973604-8#facial_clefts
09/10/64 19
Facial clefts: median cleft lip and median cleft face
http://imaging.consult.com/imageSearch?
Deranged development of the frontonasal process and/or failure of adjacent processes to merge successfully results in a coherent series of malformations. Insufficiency of the frontonasal and medial nasal processes may result in hypoplasia or absence of the nose and intermaxillary segment, with a roughly rectangular defect in the middle one third of the upper lip, absence of the incisors, absence of the primary palate with a cleft in the secondary palate, and hypotelorism. This is one common manifestation of holoprosencephaly.
09/10/64 20
Median cleft lip
http://health.allrefer.com/health/cleft-palate-resources-cleft-lip-repair-series-4.html
09/10/64 21
True midline cleft of the upper lip and philtrum with hypertelorism. True midline cleft lip signifies the high likelikhood of midline craniofaciocerebraland optic dysraphism(incomplete closure of a raphe; defective fusion, particularly of the neural tube).
http://imaging.consult.com/chapter/S1933-0332%2808%2973604-8#facial_clefts
09/10/64 22
Right unilateral common cleft lip and palate. The cleft extends into the base of a widened nostril. The intermaxillary segment is distorted.
09/10/64 23
https://www.google.com/search?biw=1920&bih=969&tbm=isch&sa=1&ei=4l2lXZqHNcv1rQHm1aKADw&q=biilateral+cleft+lip&oq=biilateral+cleft+lip&gs_l=img.12...644471.651822..687139...1.0..0.88.782.10......0....1..gws-wiz-img.wnpSQzd9Uxc&ved=0ahUKEwiagNzeyJ3lAhXLeisKHeaqCPAQ4dUDCAc#imgdii=TQlJ8F5M5nK9xM:&imgrc=ZYXl1lNFV4OFlM:
09/10/64 24
Bilateral common cleft lip and cleft palate with discordant forward growth of the intermaxillary segment.
The normal canthi, alae nasi, and lateral thirds of the lip and jaw indicate normal formation and merging of the maxillary and nasolateral processes.
The abortive prolabium, premaxillary segment, and central incisors attach to the vomer and project well anterior to their expected position, because failure to merge the facial processes led to discordant growth of the maxillary and intermaxillary segments.
Bilateral common cleft lip and palate prior to (C) and
following (D) surgical repair. There is near-symmetric
restoration of the nose and upper lip, with some residual distortion caused by scar.
09/10/64 25
Oblique facial clefts
http://imaging.consult.com/imageSearch?
❖ Obliques facial clefts
are produced by failure
of the maxillary
prominence to merge
with its corresponding
lateral nasal prominence.
❖When this occurs, the
nasolacrimal duct is
usually exposed to the surface
09/10/64 26
Discordant growth of the two divided processes may then result inoffset of the premaxillary segment from the maxillary segment, awidened nostril, a depressed ala nasi, and an anomalous nasalseptum. Failure to merge the nasolateral process with the maxillaryprocess results in an oblique facial cleft extending from the innercanthus of the eye into the nose
Facial clefting. Bilateral oblique oroocular clefts with bilateral common cleft lip.
09/10/64 27
This cleft may occur in association with bilateral common cleft lip and/or palate. Failure to merge the maxillary with the mandibular process, unilaterally or bilaterally, results in a transverse facial cleft, also designated “wolf mouth” or macrostomia.
Facial clefting. Unilateral transverse facial cleft and macrostomia in an infant girl.
09/10/64 28
Cebocephaly: a monkeylike deformity of the head, with the eyes close together and the nose defective.
09/10/64 29
Development of Nasal cavity
รศ.ดร.จริยา อ าคา เวลบาทAssoc Professor Dr Jariya Umka Welbat
Department of Anatomy
Faculty of Medicine, KKU
09/10/64 30
09/10/64 31
Nasal cavity
6th week nasal pit: nasal sacThe beginning of 6th week to the end of 7th week nasal fin, oronasal membrane7th week primitive choaca, primary palate
PalatePrimary palate7th week Primary palate: intermaxillary process
premaxillary part8th & 9th week Secondary palatemaxillary process: palatine
self or lateral palatine process9th week – 12th weekpalatine selves + primary
palate = secondary palate
Nasal septum & concha
Nasal septum: ectoderm & mesoderm of frontonasal & medial nasal processesdefinitive choanaNasal concha: superior, middle and inferior
Maxillary sinuses:nasal sac ➔ are small at birth.
These sinuses grow slowly until puberty and are not fully developed until all the permanent teeth have erupted in early adulthood.
Paranasalair sinus
Paranasalair sinus
- The ethmoidal sinuses (middle meatus) small before the age of 2 years and do not begin to grow rapidly until 6 to 8 years of age. At approximately 2 years of age, the two most anterior ethmoidal cells grow into the frontal bone, forming a frontal sinus on each side. Usually the frontal sinuses are visible in radiographs by the 7th year.
- Sphenoidal sinuses are present at birth.- The most posterior ethmoidal cells grow into the sphenoid bone at approximately 2 years of age, forming two sphenoidal sinuses.
Paranasalair sinus
Growth of the paranasal sinuses is important in altering the size and shape of the face during infancy and childhood and in adding resonance to the voice during adolescence.
Olfactory area
5th weekNasal placode: 1˚neurosensory cell➔ Olfactory epithelium
cribiform plate
6th-16th weeknasal pit ➔ respiratory epithelium
1˚neurosensory cell
2˚neurosensory cell in olfactory bulb
Axon of 2˚neurosensory cell: olfactory tract
09/10/64 40
Vomeronasal organ (of Jacobson)
Atavistic remnants in human, vomeronasal organ are well developed
in mammals and are considered to be olfactory chemoreceptor
organs that aid the sense of smell, reproduction and feeding.
09/10/64 41
09/10/64 42