Development of face
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The document covers the development of branchial arches and facial structures during embryogenesis, detailing their origins, components, and eventual anatomical formations. It highlights the role of mesodermal segmentation in forming six distinct branchial arches, which give rise to various craniofacial structures and their associated syndromes. Additionally, it discusses the inductive activities of organizing centers responsible for the formation of facial features and notes potential craniofacial defects due to developmental anomalies.
Development of face
- 1. 1.1. BRANCHIAL ARCHESBRANCHIAL ARCHES 2.2. DEVELOPMENT OF FACEDEVELOPMENT OF FACE
- 2. BRANCHIAL ARCHESBRANCHIAL ARCHES Develop during the late somite periodDevelop during the late somite period i.e. 4i.e. 4thth week I.Uweek I.U The mesoderm of the ventral foregut regionThe mesoderm of the ventral foregut region gets segmentedgets segmented Six distinct bilateral mesenchymal swellingsSix distinct bilateral mesenchymal swellings BRANCHIAL ARCHESBRANCHIAL ARCHES Develop during the late somite periodDevelop during the late somite period i.e. 4i.e. 4thth week I.Uweek I.U The mesoderm of the ventral foregut regionThe mesoderm of the ventral foregut region gets segmentedgets segmented Six distinct bilateral mesenchymal swellingsSix distinct bilateral mesenchymal swellings BRANCHIAL ARCHESBRANCHIAL ARCHES
- 3. Development of Branchial ArchesDevelopment of Branchial Arches
- 5. Branchial arches separated on the externalBranchial arches separated on the external aspect of the embryoaspect of the embryo BRANCHIAL GROOVESBRANCHIAL GROOVES
- 6. Correspond internally with outpouching ofCorrespond internally with outpouching of the elongated pharynxthe elongated pharynx PHARYNGEAL POUCHESPHARYNGEAL POUCHES
- 7. Each pair of Branchial arches contain aEach pair of Branchial arches contain a basic set of structures.basic set of structures. 1. Cartilage component.1. Cartilage component. 2. Muscular component.2. Muscular component. 3. Vascular component.3. Vascular component. 4. Nervous component4. Nervous component..
- 9. Cartilage componentCartilage component :: Adapt to form Bony, Cartilagenous orAdapt to form Bony, Cartilagenous or Ligamentous structuresLigamentous structures Muscle componentMuscle component:: Give rise to special visceral musclesGive rise to special visceral muscles composed of straited muscle fibers.composed of straited muscle fibers. Vascular componentVascular component:: Provides necessary blood supply.Provides necessary blood supply.
- 10. Nerve componentNerve component :: Nerve fibers of special cranial nervesNerve fibers of special cranial nerves Enter mesoderm of branchial archesEnter mesoderm of branchial arches Initiate muscle development in the mesodermInitiate muscle development in the mesoderm Migrate and adapt to the brachial archesMigrate and adapt to the brachial arches
- 11. 11stst BRANCHIALBRANCHIAL ARCHARCH (Mandibular arch)(Mandibular arch) Precursor of both the jaws:Precursor of both the jaws: Maxilla + MandibleMaxilla + Mandible Initially gives rise to a large mandibularInitially gives rise to a large mandibular prominence.prominence. Gives rise to a small maxillary prominenceGives rise to a small maxillary prominence which extends cranioventrally.which extends cranioventrally. MaxillaMaxilla
- 13. COMPONENTS OF 1COMPONENTS OF 1stst ARCHARCH 11.. CartilageCartilage :: MECKEL’S CARTILAGEMECKEL’S CARTILAGE --Arises 41--Arises 41stst – 45– 45thth Day I.UDay I.U --It provides a template for subsequent--It provides a template for subsequent development of the mandible.development of the mandible.
- 14. Derivatives of Meckel’s CartilageDerivatives of Meckel’s Cartilage:: -- Mental Ossicle (Endochondral Oss.)-- Mental Ossicle (Endochondral Oss.) -- Head and neck of Malleus.-- Head and neck of Malleus. -- Short crus of the Incus.-- Short crus of the Incus. -- Ant. Ligament of the Malleus.-- Ant. Ligament of the Malleus. -- Sphenomandibular Ligament.-- Sphenomandibular Ligament.
- 16. 2.2. Musculature Derived from 1Musculature Derived from 1stst archarch:: -- Muscles of Mastication.-- Muscles of Mastication. -- Mylohyoid Muscle.-- Mylohyoid Muscle. -- Ant. Belly of Digastric.-- Ant. Belly of Digastric. -- Tensor Tympani.-- Tensor Tympani. -- Tensor Veli Palatini Muscles.-- Tensor Veli Palatini Muscles. 3.3. Arterial ComponentArterial Component:: -- Part of Maxillary and Ext.Carotid.Art-- Part of Maxillary and Ext.Carotid.Art
- 17. 4.4. Nerve components:Nerve components: -- Mandibular division of Trigeminal.N-- Mandibular division of Trigeminal.N ( Vth Cranial Nerve)( Vth Cranial Nerve) -- Sensory component supplies-- Sensory component supplies : Mandible and covering mucosa.: Mandible and covering mucosa. : Mandibular teeth including Gingiva.: Mandibular teeth including Gingiva. : Mucosa of ant. 2/3 of Tongue.: Mucosa of ant. 2/3 of Tongue. : Floor of the mouth.: Floor of the mouth. : Skin of the lower third of Face.: Skin of the lower third of Face.
- 18. (Hyoid Arch)(Hyoid Arch) Components:Components: 1.1. CartilageCartilage :: Reichert’s CartilageReichert’s Cartilage (45(45thth – 48– 48thth I.U)I.U) -- Greater part of the third ear ossicle.-- Greater part of the third ear ossicle. -- Stapes, Malleus and incus.-- Stapes, Malleus and incus. -- Styloid process of the temporal bone.-- Styloid process of the temporal bone. -- Stylohyoid ligament.-- Stylohyoid ligament. -- Lessor horn of sphenoid.-- Lessor horn of sphenoid. -- Cranial part - Body of Hyoid.-- Cranial part - Body of Hyoid. -- Segments of the facial canal.-- Segments of the facial canal. 22ndnd BRANCHIALBRANCHIAL ARCHARCH
- 20. 2.2. MusclesMuscles :: -- Stapedius-- Stapedius -- Stylohyoid-- Stylohyoid -- Post. Belly of Digastric.-- Post. Belly of Digastric. -- Mimetic muscles of face.-- Mimetic muscles of face. -- Levator Veli Palatini.-- Levator Veli Palatini.
- 21. 3. Nerve3. Nerve :: -- Facial / VII Cranial nerve.-- Facial / VII Cranial nerve. -- Special sensory component-- Special sensory component - Chorda tympani nerve- Chorda tympani nerve (Ant 2/3(Ant 2/3rdrd of Tongue)of Tongue) 4. Artery4. Artery :: -- Stapedial artery-- Stapedial artery - Transient i.e. disappears during fetal life.- Transient i.e. disappears during fetal life.
- 22. Muscles
- 23. Nerves ass. with Branchial arches
- 25. Anomalies associated withAnomalies associated with branchial archesbranchial arches Deficient development of the branchial archesDeficient development of the branchial arches result in syndromes according to the archresult in syndromes according to the arch involved.involved. First arch syndromes :First arch syndromes : - Agnathia- Agnathia - Microstomia- Microstomia - Treacher Collins syndrome (mandibular dysostosis)- Treacher Collins syndrome (mandibular dysostosis) - Pierre Robin syndrome (micrognathia+cleft palate)- Pierre Robin syndrome (micrognathia+cleft palate)
- 26. Trecher Collins syndromeTrecher Collins syndrome
- 27. DEVELOPMENT OF FACEDEVELOPMENT OF FACE Development of the head depends uponDevelopment of the head depends upon inductive activities ofinductive activities of 2 organizing centers2 organizing centers -- Prosencephalic-- Prosencephalic -- Rhombencephalic-- Rhombencephalic
- 29. Prosencephalic organizing center :Prosencephalic organizing center : -- Derived from prechordal mesoderm-- Derived from prechordal mesoderm that migrates from the primitive streak.that migrates from the primitive streak. -- Situated at the rostral end of the-- Situated at the rostral end of the notochord below the fore brain.notochord below the fore brain.
- 30. -- Induces the formation of :-- Induces the formation of : Visual apparatusVisual apparatus Inner ear apparatusInner ear apparatus Upper third of faceUpper third of face
- 31. Rhombencephalic organizing centerRhombencephalic organizing center :: -- Caudal in relation to the Prosencephalic-- Caudal in relation to the Prosencephalic centre.centre. Induces the formation ofInduces the formation of:: -- Middle and lower third of the face.-- Middle and lower third of the face. -- Middle and external ears.-- Middle and external ears.
- 32. Oral development in embryo is demarcatedOral development in embryo is demarcated extremely early in life by the appearanceextremely early in life by the appearance of theof the prechordal plateprechordal plate (14(14thth day)day) ++ EndodermalEndodermal ThickeningThickening Oropharyngeal MembraneOropharyngeal Membrane
- 35. Oropharyngeal membrane is aOropharyngeal membrane is a temporarytemporary bilaminar membrane which functionsbilaminar membrane which functions as:as: 1.1. Site of junction of ectoderm andSite of junction of ectoderm and endoderm.endoderm. 2.2. Demarcates the stomodeum from theDemarcates the stomodeum from the rest.rest. i.e. initial demarcation ofi.e. initial demarcation of thethe future mouth.future mouth.
- 36. Cranial portionCranial portion EmbryoEmbryo Caudal portionCaudal portion Rapid development of the cranial portionRapid development of the cranial portion than the caudal portion.than the caudal portion.
- 38. This differential rates of growth results in theThis differential rates of growth results in the formation offormation of pear-shapedpear-shaped embryonic disc.embryonic disc. -- Cranial/Head region forming the-- Cranial/Head region forming the expanded portion of the pear.expanded portion of the pear. Further, the 3 germ layers show specificFurther, the 3 germ layers show specific development by the middle of the 3development by the middle of the 3rdrd week in the cranial portion as compared to 4-5week in the cranial portion as compared to 4-5 wks in the caudal portion.wks in the caudal portion.
- 39. Therefore during 5Therefore during 5thth to 8 wks.to 8 wks. - Head constitutes nearly half the- Head constitutes nearly half the total body size.total body size. This explains theThis explains the ““Cephalo-caudal growth gradient”Cephalo-caudal growth gradient”
- 40. The face derives from five prominences thatThe face derives from five prominences that surround a central depression,surround a central depression, --The Stomodeum--The Stomodeum ( Future mouth)( Future mouth) Prominences:Prominences: ---- Single median FrontonasalSingle median Frontonasal -- Paired Maxillary + Mandibular-- Paired Maxillary + Mandibular
- 41. Frontonasal prominenceFrontonasal prominence :: Surrounds the forebrainSurrounds the forebrain sprouts lateral optic diverticulasprouts lateral optic diverticula EyesEyes
- 42. TheThe frontal portionfrontal portion of the prominenceof the prominence b/wb/w the eyes forms thethe eyes forms the Forehead.Forehead.
- 43. At the infero-lateral corners, thickenedAt the infero-lateral corners, thickened ectodermalectodermal nasal placodesnasal placodes arisearise
- 44. TheseThese placodesplacodes induced by the underlyinginduced by the underlying olfactory nervesolfactory nerves InvaginateInvaginate Demarcate the medial andDemarcate the medial and lateral nasallateral nasal prominences.prominences. Nasal pitsNasal pits Precursors toPrecursors to Anterior naresAnterior nares
- 46. Next, is the union of the facial prominencesNext, is the union of the facial prominences by either of the 2 belowby either of the 2 below developmental events.developmental events. 1. Merging of the frontonasal, maxillary1. Merging of the frontonasal, maxillary and mandibular prominences.and mandibular prominences. OROR 2. Fusion of the central maxillonasal2. Fusion of the central maxillonasal components.components.
- 48. Merging is completed as a result ofMerging is completed as a result of proliferation of the underlyingproliferation of the underlying mesenchymemesenchyme into the intervening grooves.into the intervening grooves. The above is guided by the disintegration ofThe above is guided by the disintegration of thethe contacting surface epitheliumcontacting surface epithelium b/w theb/w the processes termed asprocesses termed as Nasal finNasal fin
- 49. FailureFailure of normal disintegration ofof normal disintegration of nasal finnasal fin Due toDue to:: 1. Cell death1. Cell death 2. Mesenchymal2. Mesenchymal transformationtransformation Leads to cleft of upper lip and anterior palate (Due to prevention of merging of mesenchyme of max. and medial nasal processes)
- 51. Midline merging of median nasal prominencesMidline merging of median nasal prominences forms :forms : Philtrum of upper lipPhiltrum of upper lip Median tubercle.Median tubercle. Tip of the nose.Tip of the nose. Primary palate.Primary palate.
- 52. Post. Merging of Medial nasal processesPost. Merging of Medial nasal processes Median primary palateMedian primary palate PremaxillaPremaxilla Future site of 4 upper incisorsFuture site of 4 upper incisors
- 54. Midline merging of the pairedMidline merging of the paired mandibular prominencesmandibular prominences Lower jaw + Lower lipLower jaw + Lower lip -- First to get definitely established-- First to get definitely established..
- 55. Lateral merging of maxillary andLateral merging of maxillary and mandibular prominences.mandibular prominences. Commisures of mouthCommisures of mouth
- 58. All the regions of the face grow inAll the regions of the face grow in proportionproportion to each other and equally.to each other and equally. i.e. anyi.e. any malproportioningmalproportioning at this time mayat this time may form a basis forform a basis for craniofacial defects.craniofacial defects.
- 59. Various Cranio- facial defectsVarious Cranio- facial defects Acephaly (Absence of head) Anencephaly (Absence of brain) Acrania (Absent skull) Acalvaria (Roofless skull) Cranioschisis (Fissured cranium) Premaxillary agenesis (Median cleft lip/palate) Premaxillary dysgenesis (Bilateral cleft lip/palate) Agnathia (Absent mandible)
- 60. Specific structuresSpecific structures :: -- Nose-- Nose -- Cheeks-- Cheeks -- Lips-- Lips -- Tongue-- Tongue
- 61. NoseNose :: Complex structure with contributionsComplex structure with contributions from :from : -- Frontal prominence --- Frontal prominence - BridgeBridge -- Merged MNP --- Merged MNP - Median ridgeMedian ridge + Tip+ Tip -- Lateral nasal Prominence --- Lateral nasal Prominence - AlaeAlae -- Cartilage nasal capsule --- Cartilage nasal capsule - SeptumSeptum + Nasal conchae+ Nasal conchae
- 62. From frontonasal process From median nasal processFrom median nasal process
- 63. LipsLips :: 1.1. Upper lipUpper lip :: As the maxillary, lateral and nasalAs the maxillary, lateral and nasal processes fuse and the nares come close toprocesses fuse and the nares come close to each other the upper lip forms from theeach other the upper lip forms from the -- Maxillary process-- Maxillary process -- Frontanasal process-- Frontanasal process
- 65. The mesodermal basis of lateral partThe mesodermal basis of lateral part Maxillary processMaxillary process The mesodermal basis of median partThe mesodermal basis of median part Frontonasal processFrontonasal process
- 66. The ectoderm of the max. processThe ectoderm of the max. process overgrowsovergrows the philtrum to meet the opposite side.the philtrum to meet the opposite side. Therefore the skin of the entire upper lip isTherefore the skin of the entire upper lip is formed by the maxillary process, andformed by the maxillary process, and innervated by the maxillary nerves.innervated by the maxillary nerves.
- 68. The fused mandibular prominences giveThe fused mandibular prominences give rise to the lower lip and jaw.rise to the lower lip and jaw. Cheeks :Cheeks : After the formation of the lips theAfter the formation of the lips the maxillary and mandibular processes undergomaxillary and mandibular processes undergo progressive fusion to form the cheeks.progressive fusion to form the cheeks.
- 70. TongueTongue :: Ant 2/3Ant 2/3rdrd :: -- Median triangular elevation in the-- Median triangular elevation in the floor of the primitive pharynx ant. to foramenfloor of the primitive pharynx ant. to foramen caecum termed ascaecum termed as Median tongue bed.Median tongue bed. ( Tuberculum Impar)( Tuberculum Impar) -- Mesenchyme of the 1-- Mesenchyme of the 1stst arch give risearch give rise toto 2 distal tongue beds2 distal tongue beds on either side of medianon either side of median tongue bed.tongue bed.
- 71. Median and distal tongue beds rapidlyMedian and distal tongue beds rapidly increase in size and fuse together to formincrease in size and fuse together to form the ant.2/3the ant.2/3rdrd of the tongue.of the tongue. 2 elevations2 elevations copulacopula and theand the hypobranchialhypobranchial eminence form theeminence form the posterior 1/3posterior 1/3rdrd of theof the tongue.tongue.
- 73. External earExternal ear :: 11STST Brachial grooveBrachial groove -- External acoustic meatus-- External acoustic meatus
- 74. • AuricleAuricle derived fromderived from thethe auricular hillocksauricular hillocks i.e. the mesoderm ofi.e. the mesoderm of the 1st and 2ndthe 1st and 2nd Branchial arches.Branchial arches.
- 75. BIBLIOGRAPHYBIBLIOGRAPHY -- G.H.SPERBER (Cranifacial Embryology) -- KIETH.L.MOORE (The Developing Human) -- KIETH.L.MOORE (Altas of Human Embryology) -- WILLIAM.R.PROFFIT (Contemporary Orthodontics)