IMPORTANT DATES - Answers +*3 weeks* in utero = 3 mm in length + invagination/stomodeum
development
+*4 weeks* in utero = rupture of buccopharyngeal membrane
+*5-6 weeks* = odontogenesis
+*6 weeks* in utero = lips form
+*6-12 weeks* in utero = hard palate forms
+*3 months* in utero = 61 mm in length
+*4-6 months* in utero = primary crown development
+*Birth-3 years* = permanent crown development
+*11-13 years* = permanent 2nd molar emergence (may stop fluoride)
Mesial Drift - Answers -involves attrition, contacts, and *transseptal fibers*
(1) over time, attrition occurs through normal wear and the contact is lost
(2) the tooth will then drift mesially until contact
(3) *transseptal fiber* will shorten during drift
Embryonic Development of the Face - Answers A. Zygote
B. Stomodium Development (3rd Week)
C. Budding
D. Frontal Process
E. Globular Process
F. Fusion of Maxillary/Mandibular Processes
G. Embryonic Development of the Palate
H. Tongue Development
Tiny Tubular Embryo - Answers =first configuration of the embryo (tube w/i a tube)
,Diagrammatic Identifications: Cephalic End (head), Caudal End (tail), Outside of the body, Soft
organs origin (between the outer tube boundary and inner tube edge), Primitive Digestive
System (inner tube)
Ectoderm (Primary Embryonic Layer) - Answers -Outer layer
-Forms:
(1) *c*avities (nasal + oral)
(2) *to*oth (enamel organ)
(3) *nervous system*
Mesoderm (Primary Embryonic Layer) - Answers -Middle layer
-Forms:
(1) *s*keleton
(2) muscles
(3) blood
(4) *so*ft organs
Endoderm (Primary Embryonic Layer) - Answers -Inner layer
Forms:
(1) *D*igestive system (stomach, intestines, etc.)
Frontal Process - Answers = the front of the head (top of the head)
-Forms:
(1) nasal septum
(2) primitive palate aka premaxilla (anterior part of the hard palate, between canine & first
premolar there is a fusion line)
*also forms Globular Process*
Stomodeum Development - Answers -@ *3 weeks*
-primitive oral cavity via *invagination*
, Invagination - Answers pushing in of the ectoderm
Evagination - Answers pushing out of the ectoderm
Rathke's Pouch - Answers -forms via *evagination* of the ectoderm
-*primitive pituitary gland*
Buccopharyngeal Membrane - Answers 1. Location: the most posterior portion of the primitive
mouth (*between the ectoderm of stomodeum and endoderm of the primitive gut*)
2. Timing: @ *4th week* the membrane ruptures and connects with the primitive gut
*palatine tonsils* form superiorly
Budding - Answers -associated with the midline
-formation of the 4 Branchial Arches (aka Pharyngeal Arches)
*Branchial Arch I* →
*Maxillary Process*:
(1) upper cheek
(2) lateral portions of the upper lip (aka not tubercle)
(3) posterior portion of the hard palate
*Mandibular Process*:
(1) lower cheek
(2) lower lip
(3) mandible
(4) body of the tongue
Branchial Arch II-IV → Root of Tongue
Maxillary Process - Answers -from Branchial Arch I (aka Pharyngeal)