DEN 103: EXAM 2 (11/5) QUESTIONS
WITH VERIFIED ANSWERS. A+ GRADE
2025/2026.
IMPORTANT DATES - ANS +*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 - ANS -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
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,Embryonic Development of the Face - ANS 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 - ANS =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) - ANS -Outer layer
-Forms:
(1) *c*avities (nasal + oral)
(2) *to*oth (enamel organ)
(3) *nervous system*
Mesoderm (Primary Embryonic Layer) - ANS -Middle layer
-Forms:
(1) *s*keleton
(2) muscles
(3) blood
(4) *so*ft organs
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, Endoderm (Primary Embryonic Layer) - ANS -Inner layer
Forms:
(1) *D*igestive system (stomach, intestines, etc.)
Frontal Process - ANS = 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 - ANS -@ *3 weeks*
-primitive oral cavity via *invagination*
Invagination - ANS pushing in of the ectoderm
Evagination - ANS pushing out of the ectoderm
Rathke's Pouch - ANS -forms via *evagination* of the ectoderm
-*primitive pituitary gland*
Buccopharyngeal Membrane - ANS 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
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
WITH VERIFIED ANSWERS. A+ GRADE
2025/2026.
IMPORTANT DATES - ANS +*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 - ANS -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
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,Embryonic Development of the Face - ANS 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 - ANS =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) - ANS -Outer layer
-Forms:
(1) *c*avities (nasal + oral)
(2) *to*oth (enamel organ)
(3) *nervous system*
Mesoderm (Primary Embryonic Layer) - ANS -Middle layer
-Forms:
(1) *s*keleton
(2) muscles
(3) blood
(4) *so*ft organs
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, Endoderm (Primary Embryonic Layer) - ANS -Inner layer
Forms:
(1) *D*igestive system (stomach, intestines, etc.)
Frontal Process - ANS = 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 - ANS -@ *3 weeks*
-primitive oral cavity via *invagination*
Invagination - ANS pushing in of the ectoderm
Evagination - ANS pushing out of the ectoderm
Rathke's Pouch - ANS -forms via *evagination* of the ectoderm
-*primitive pituitary gland*
Buccopharyngeal Membrane - ANS 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
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
