CT4-LECTURE 1-
JAN 2025
OBJECTIVES
Developmental Anatomy (Embryology):
• Outline the stages of human growth and development, focusing on dental anatomy and root
morphology.
• Correlate developmental processes with hard and soft tissue formation in the oral cavity.
Microscopic Anatomy:
• Classify cells (cytology) and tissues (histology) based on their structure and specialization.
• Evaluate the role of microscopic structures in maintaining oral health.
GROSS Anatomy
• Identify anatomical landmarks of the oral head and neck, including the TMJ, circulatory system,
glands, and nervous system.
• Describe the structures visible to the naked eye and their clinical relevance.
Physiology:
• Explain the functions of body systems and their integration in oral health.
• Analyze the physiological processes affecting the oral cavity.
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Mitosis Meiosis
One cell division Two cell division
Produces two daughter cells Produces
Four daughter cells
Produces diploid cells Produces haploid cells
Daughter cells are
genetically identical
Daughter cells are non-
identical
Produces body cells Produces sex cells
• Mitosis and meiosis are both types of cell division.
• Mitosis is how new body cells are produced, whereas
meiosis is used to produce gametes (i.e. sperm and egg cells).
first week
Spermatozoa + Oocyte =
Zygote (12-24hrs.)
Cell division via mitosis =
Cleavage
1st solid ball called
Morulla
Inside Morulla secretion of
fluids becomes blastocyte
(5days)
Blastocyte has 2 regeions
Trophoblast(peripheral cells)
& Embryoblast layer(inner
mass)
CLINICAL CONSIDERATIONS
FOR PREIMPLANTATION PERIOD
•If any disturbances occur in meiosis during fertilization,
major congenital malformations result from the chromosomal abnormality in
around 10% of cases.
•A syndrome is a group of specific signs and symptoms.
PREIMPLANTATION PERIOD
• After a week of cleavage,
the blastocyst consists of a layer
of peripheral cells, the trophoblast
layer, and a small inner mass of
embryonic cells or embryoblast
layer.
• The trophoblast layer later gives rise
to important prenatal support tissue
while the embryoblast layer
later gives rise to the embryo.
SECOND WEEK
• A bilaminar embryonic disc
• The superior epiblast layer is composed
of high columnar cells.
• The inferior hypoblast layer is composed
of small cuboidal cells.
THIRD WEEK
• Primitive streak (rod shaped
thickening) forms a bilateral symmetry
within the bilaminar embryonic disc.
• Some cells from the epiblast layer
move or migrate toward the hypoblast
layer only in the area of the
primitive streak and become
• Mesoderm, an embryonic
connective tissue,
and embryonic endoderm.
END OF THIRD WEEK
• With three layers present, the bilaminar disc has
thickened into a trilaminar embryonic disc.
• The epiblast layer is now considered ectoderm.
• 3 germ layers
• Ectoderm-becomes skin, nervous system, and
neural crest cells.
• Mesoderm-Becomes muscles, bones, blood, and
connective tissues.
• Endoderm-Forms internal organs like the digestive
and respiratory systems.
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Neural Crest Cells & Mesenchymal Transition(dental tissue)
• Neural crest cells are derived from the ectoderm during neurulation (around weeks 3-4).
• NCC migrate and undergo epithelial-to-mesenchymal transition (EMT), becoming highly
migratory mesenchymal cells.
• They contribute to the formation of facial bones, cartilage, peripheral nerves, and parts of
the heart.
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Embryonic Period: Physiological Process(changes in structure &function)
• INDUCE, PROLIFERATE, DIFFERENTIATE AND MORPH, DON’T WAIT! MATURE AND GROW, IT’S YOUR FATE!"
1. Induction
The process where one group of cells influences another to differentiate into a specific tissue or
organ.
2. Proliferation
Rapid cell division, increasing the number of cells.
3. Differentiation(Cyto, Histo, Morpho)
Cells specialize to perform specific functions.
4. Morphogenesis
The development of the overall shape and structure of tissues and organs.
5. Maturation
The final stage where tissues and organs reach their fully functional form.
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Facial Development
The facial development that starts in the fourth
week of the embryonic period will be
completed later in the twelfth week within the
fetal period.
At the fourth week, the developing brain,
face, and heart are noted.
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• All three embryonic layers are involved in facial
development: the ectoderm, mesoderm, and
endoderm.
• The upper part of the face is derived from the frontonasal
process, the midface from the maxillary processes, and
the lower from the mandibular processes.
Early development of the face is also dominated by the
proliferation and migration of ectomesenchyme, derived
from neural crest cells (NCCs).
Facial Development
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Stomodeum and Oral Cavity Formation
With this disintegration of the membrane, the
primitive mouth is increased in depth and enlarges in
width across the surface of the midface.
Nose and Paranasal Sinus Formation
Apparatus Formation
First branchial/ pharyngeal arch
also known as the mandibular
arch and its associated tissue,
includes Meckel cartilage.
Supplied by Trigeminal nerves
Apparatus Formation
Second branchial/pharyngeal arch,
which is also known as
the hyoid arch, is cartilage like that
of the mandibular arch, Reichert
cartilage.
Apparatus Formation
Third branchial/ pharyngeal arch
Has an unnamed cartilage associa
ted with it. This cartilage will
be responsible for forming parts
of the hyoid bone.
Apparatus Formation
Both the fourth and the sixth branchial
/pharyngeal arch also have unnamed
cartilage associated with them, they fuse
and form most of the laryngeal
cartilages.
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TOOTH DEVELOPMENT: INITIATION STAGE
Stages of Tooth Development:
I Bought Candy Bars After Midnight."
I → Initiation
Bought → Bud
Candy → Cap
Bars → Bell
After → Apposition
Midnight → Maturation
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1. Initiation Stage (Week 6-7):
• Dental placodes form as localized thickenings of oral ectoderm.
• Interaction with neural crest cells induces the formation of the tooth
germ.
2. Bud Stage (Week 8):
• The enamel organ invaginates into the underlying mesenchyme,
creating a tooth bud.
3. Cap Stage (Week 9-10):
• The enamel organ forms a cap-like structure over the dental papilla.
4. Bell Stage (Week 11-12):
• Cells differentiate into ameloblasts (enamel-forming cells) and
odontoblasts (dentin-forming cells).
5. Apposition and Maturation:
• Enamel, dentin, and cementum are laid down and mineralized.
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• Dental Epithelium → Enamel Organ
Enamel organ arises from the dental epithelium and forms ameloblasts, the cells responsible for producing enamel, the
hardest substance in the body.
Dental Mesenchyme → Dental Papilla
Dental papilla forms from the mesenchyme and gives rise to:
• Dentin -Odontoblasts: Cells that produce dentin (the layer beneath enamel).
• Pulp: The soft, living core of the tooth, containing nerves and blood vessels.
• Root Dentin: The dentin in the root of the tooth.
Dental Follicle
• Surrounds the developing tooth and forms:
• Cementum: A calcified tissue covering the root of the tooth, anchoring it to the jaw.
• Periodontal Ligament: Connective tissue fibers that hold the tooth in its socket and absorb chewing forces.
Teeth w e a r c a n b e t r e a t e d
A t t r i t i o n Abrasion Abfraction E r o s i o n
Hunter-Schreger bands (HSB).
• Hunter-Schreger bands (HSB):
• Dark and light bands due to
curvature or bends of the rods.
• increasing the enamel’s strength.
• Near the cusps or incisal ridges,
where the enamel is the thickest
Celiac Disease
˜ Dental enamel problems stemming from celiac
disease involve permanent dentition and include
tooth discoloration—white, yellow, or brown
spots on the teeth—poor enamel formation,
pitting or banding of teeth, and mottled or
translucent-looking teeth.
˜ The imperfections are symmetrical and often
appear on the incisors and molars.
˜ Tooth defects that result from celiac disease may
resemble those caused by too much fluoride or a
maternal or early childhood illness
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ROOT DEVELOPMENT
The process of root development takes place long after the crown
is completely shaped, and the tooth is starting to erupt into the oral
cavity.
The structure responsible for root development is the cervical loop.
The cervical loop is the most cervical part of the enamel organ, a bilayer
rim that consists of only inner enamel epithelium (IEE) and outer enamel
epithelium (OEE).
ROOT DEVELOPMENT
To form the root region, the cervical loop begins to grow
deeper into the surrounding ectomesenchyme of the
dental sac, elongating and moving away from the
newly completed crown area to enclose more of
the dental papilla tissue, forming the Hertwig epithelial
root sheath (HERS).
Thus, HERS will determine if the root will be curved or
straight, short or long as well as single or multiple.
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• Cervical Loop Formation
▪ The cervical loop, located at the junction of the
enamel organ and the crown, elongates to form
Hertwig’s Epithelial Root Sheath (HERS).
▪ HERS determines the shape, length, and number of
roots.
• Root Dentin Formation
▪ Inner cells of HERS induce adjacent dental papilla
cells to differentiate into odontoblasts, which form
root dentin.
▪ Once dentin is deposited, HERS disintegrates.
• Epithelial Rests of Malassez
▪ After HERS disintegrates, remnants form clusters
called epithelial rests of Malassez in the periodontal
ligament.
▪ These remnants can sometimes form cysts later in life.
PRIMARY DENTITION PROPERTIES
The actual dates are not as
important as the eruption sequence,
because there can be a great deal
of variation in the actual dates
of eruption.
However, the sequence tends to be
uniform.
Enamel Histology
• Enamel tufts: Hypomineralized, Located at
the dentino-enamel junction and filled with
organic material. Forms between groups of
enamel rods at the dentino-enamel junction.
• Enamel lamellae are partially
mineralized vertical sheets of enamel matrix
that extend from the DEJ near the tooth’s
cervix to the outer occlusal surface.
Transverse section of
enamel showing enamel
tufts (white arrow) and
enamel lamella (black arrow).
Dentin Matrix Formation
DENTINOGENESIS
LPROCESS o$ CREATING DENTIN
PRIMARY TEETH
_ 14th WEEK of FETAL DEVELOPMENT
PERMANENT TEETH
L 3 MONTHS
AFTER
-PROCESS HAPPENS SLOWLY
PERFORMED by
ODONTOBLASTS
—OUTSIDE INWARDS
- BEGINS with MANTLE DENTIN
ODONTOBLASTS
-PREDENTIN
-SOFT ORGANIC MATRIX
-PROTEINS
FIBROBLASTS
-KORFF'S FIBERS
-THICK COLLAGEN FIBERS
-FRAMEWORK of DENTINOGENESIS
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Principal Fibers Protect, Gingival Fibers Guard."
•Principal → Protection and anchorage of the tooth.
•Gingival → Guard and stabilize gingiva.
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Principle Fibers
"All Hungry Octopuses Appreciate Ice
cream!"
•All → Alveolar Crest
•Hungry → Horizontal
•Octopuses → Oblique
•Appreciate → Apical
•Ice cream → Interradicular
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Gingival Fiber :
"Dentists Always Care
Deeply for Teeth!"
•Dentogingival
•Alveologingival
•Circular
•Dentoperiosteal
•Transseptal
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Primary (Deciduous) Teeth Eruption
"Children Like Fruit Candy More"
•C → Central Incisors
•L → Lateral Incisors
•F → First Molars
•C → Canines
•M → Second Molars
CELL ORGANELLES
SKIN
ANATOMY
COME, LET'S GET SOME BREAD"
C ORNEUM (OUTER), L UCIDUM, G RANULOSUM, S PINOSUM, B ASALE.
• Corneum - tough and protective.
• Lucidum - clear layer (found only in thick skin like palms/soles).
• Granulosum - cells with granules for keratinization.
• Spinosum - "spiny" cells, providing strength and flexibility.
• Basale - base layer where cell division happens.
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Tooth Designation
∙ Commonly used in orthodontics, is
the Palmer Notation Method, also
known as the Military Tooth Numbering
System.
∙ In this system, the teeth are designated
from each other with a right-angle
symbol indicating the quadrants and arch,
with the tooth number placed inside.
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Mixed Dentition Period
∙ The mixed dentition period follows
the primary dentition period.
∙ This period occurs between approximately
6 and 12 years of age.
∙ Both primary and permanent teeth
are present during this transitional stage.
∙ The final dentition period is
the permanent dentition period.
∙ This period begins with shedding of the
last primary tooth.
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General Dental Terms
•Each dental arch can be further divided into
two quadrants, with four quadrants in the entire
oral cavity.
• The correct sequence of words
when describing an individual tooth using a
D-A-Q-T System is based on the tooth
within its quadrant: D for dentition, A for
arch, Q for quadrant, and T for tooth type.
• Sextants: three parts according to the relationship to
the midline: right posterior sextant, anterior sextant, and
left posterior sextant.
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Root Axis Line (RAL)
∙ Root axis line (RAL), which is an
imaginary line representing the
long axis of a tooth, drawn in a way
to bisect the root (and thus the
crown) in the cervical area into two
halves.
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Restorations: Biologic Width
∙ Biologic width is the distance established
by the junctional epithelium and lamina
propria attachment to the root surface of a
tooth.
∙ This distance is important to consider
when fabricating dental restorations, because
they must respect the natural architecture of
the gingival attachment if harmful
consequences are to be avoided.
∙ Assessment for biologic width can be
made clinically by measuring the distance
between the bone and the restoration margin
using a periodontal probe.
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PRIMARY DENTITION
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Eruption
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Differences-(Enamel depth/pulp)
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Differences: Roots
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Importance of Primary teeth -
PRIMATE Space
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Leeway Space
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Primary Occlusion
60
•Majority of children have Mesial step between distal of Primary 2nd molars. Mandibular 2nd molars are
situated mesially than maxillary.
•A smaller but still large group of children exhibit a flush terminal plane. The distal surfaces of the primary
2nd molars are even with each other.
•A still smaller minority have a distal step. The mandibular 2nd molars are situated more distally than their
maxillary counterparts. Thus, they form a distal step.
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Anatomy of Primary teeth
61
Incisors: resemble the outline of permanent
counterpart except
Primary do not have mamelons on the incisal
ridge and there are no pits on the lingual
surface.
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Primary Canines
62
Canines- resemble the
outline of their permanent
counterparts.
The maxillary canine has a
sharp cusp and appears
especially wide and short.
Maxillary Central and Lateral Incisors
Central Incisors:
• Larger overall; they are the widest teeth mesiodistally in the anterior maxillary
arch.
• Crown is more symmetrical and fan (mesiodistally wider compared to
incisocervical length).
• Lingual fossa is less pronounced.
• Cingulum is well-developed and centered.
• Root is shorter and more conical, with a blunt apex.
• Rarely exhibit significant variation.
Lateral Incisors:
• Smaller and narrower mesiodistally than the central incisors.
• Crown is less symmetrical and more rounded.
• Lingual fossa is deeper, with more pronounced marginal ridges.
• Cingulum is narrower and often slightly off-center to the distal.
• Root is longer and thinner, with a more pointed apex.
• Frequently display developmental variations (e.g., peg-shaped lateral incisors,
congenitally missing).
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CLASSIC TRAITS
➢ From the occlusal view, molar
crowns taper from the buccal to
the lingual EXCEPT for
maxillary 1st molars.
➢ From the occlusal view, molar
crowns taper distally; this allows
more of the occlusal surface to
be visible from the distal aspect
than the mesial.
➢Maxillary molars have 3 roots:
MB, DB, and lingual (palatal).
The lingual root is usually
the longest and the DB is
the shortest.
➢ Mandibular molars have 2 roots:
a long mesial root and a slightly
shorter distal root.
➢ The root furcation on
mandibular molars is close to
the cervical line, making the
root trunk shorter than on
the maxillary molars.
MAJOR AND MINOR CUSPS
➢In general, each cusp is formed from its own lobe.
➢Major cusps are large and well developed.
➢Minor cusps are less developed and have smaller
proportions. They are less functional than the major cusps and
may not always be present.
➢Supplementary cusp is very small and
completely afunctional. They are rarely present.
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➢First molars are the most highly
developed and largest of
the molars and more likely to have
major, minor and
supplementary cusps.
➢Both the 1st and 2nd maxillary
molars have 4 major cusps
but only 2 are visible from
the buccal view.
➢The longest of the 4 major cusps
are the ML, followed by the MB,
DB, and the shortest DL (if
present).
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• Molars (general: crowns larger, squarer, bear more cusps than any other tooth class, have multiple roots, 3rd
molars sometimes mistaken for premolars)
• Generally speaking, the maxilla molars go from largest to smallest (1st molar to 3rd molar) in size and
morphology. The crowns generally have 4 cusps.
• The 1st molar has three roots (two buccal and one lingual, which when seen from the buccal position the
lingual root comes into view in the middle of the two buccal roots). The occlusal surface is described as a
rhomboid in shape with 4 distinctive cusps.
• Oblique ridge max molars only and transverse ridge one on max 2 on mandibular.
• The 2nd molar has three roots but the two buccal roots are nearly parallel with each other and is described as
heart shape in the occlusal view.
• The 3rd molar has three roots present but the two buccal roots are often fused, and the outline of the occlusal
surface is also described as a heart shape. The 3rd molar also shows greater developmental variation than
either the 1st or
• 3rd molars are often the tooth that is congenitally missing. All roots of the molars angle distally with respect
to the major crown axes (White & Folkens 2005: 152).
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Joint Movement
˜ Two basic types
of movement of
the mandible
are performed by the
TMJ and its
associated muscles
of mastication:
˜ a gliding movement and
˜ a rotational movement.
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• The muscles of mastication
include the
• Temporalis,
• And Masseter,
• Pterygoid muscles, medial
and lateral.
• These muscles are involved
in mastication using these
two movements.
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TMD: Acute Episode
• Trismus or the inability to
normally open the mouth.
• When the patient tries to close
and elevate the mandible, the
condylar heads cannot move
posteriorly because both the bony
relationships prevent this, and
the muscles have become spastic.
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Overjet
• Overjet is measured in millimeters with the tip of
a periodontal probe, once a patient is in CO.
• The probe is placed at 90°or at a right angle to the
labial surface of a mandibular incisor at the base of
the incisal ridge of a maxillary incisor.
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• Overbite is measured in millimeters with
the tip of a periodontal probe after a
patient is placed in CO.
• The probe is placed on the incisal edge
of the maxillary incisor at 90º or at a
right angle to the mandibular incisor.
• When the reverse is the case and the
mandibular arch and its incisors extends
beyond the maxillary arch and its
incisors, it is causes an underbite.
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Lymph Nodes
• The lymph flows (arrows) into the lymph node through
many afferent vessels. (A is first comes in)
• On one side of the node is a depression, or hilus,
where the lymph through fewer vessels, or even a
single efferent vessel. (E is Exit)
• Primary or Secondary.
• Region drains into primary nodes.
• Primary nodes, in turn, drain into secondary nodes (or
central nodes).
Lymphatics: General Drainage pattern of body
Right
jugular
trunk
Left
jugular
trunk
Enters venous system
near junction of left
subclavian vein and
left internal jugular
Thoracic
duct
Left side of
head, neck,
thorax, entire
abdomen,
pelvis, lower
extremities
Enters venous system
near junction of right
subclavian vein and
right internal jugular
Right side of
head, neck,
thorax
*Lymphatic vessels are small and directly drain tissues and connect lymph nodes.
*Lymphatic ducts are much larger, receive lymph from many lymphatic vessels, and drain
into the venous system.
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Superficial Lymph Nodes of the Head
(five categories)
1. Facial; lie along
facial vein.
2 Superficial Parotid;
superficial to parotid
gland.
3. Anterior Auricular;
anterior to external
auditory meatus.
4. Posterior Auricular;
posterior to external
auditory meatus.
5. Occipital; lie in the
occipital region.
*Tissue drainage: buccal mucosa, skin of zygomatic and infraorbital regions, scalp, external ear, lacrimal gland
Deep Lymph Nodes of Head
(two categories)
1. Deep Parotid; lie deep in
the parotid gland, superficial
to the masseter muscle
2. Retropharyngeal; posterior to
the pharynx at the level of the
atlas (first cervical vertebrae).
*Tissue drainage: parotid gland, paranasal sinuses, hard and soft palate, middle ear
Superficial Cervical Lymph Nodes
(4 categories)
1. Submental; inferior to the chin in the submental space.
2. Submandibular; along the inferior border of the mandible, superficial to the submandibular salivary gland
3. External Jugular; along the external jugular vein, superficial to the sternocleidomastoid muscle.
4. Anterior Jugular; along the anterior jugular vein, anterior to the sternocleidomastoid muscle.
Tissue drainage:
1.Submental and submandibular; teeth and
related tissues, apex and body of tongue, anterior
hard palate, floor of mouth, lips, chin, sub-
mandibular and sublingual glands, cheeks.
2. External and anterior jugular;
superficial tissues in the anterior and
posterior triangles.
Deep Cervical Lymph Nodes
(2 categories)
1. Superior Deep Cervical; lie along internal jugular vein, superior to the omohyoid muscle.
*Jugulo-digastric- becomes enlarged when a palatine tonsil or the pharynx is involved in infection.
2. Inferior Deep Cervical; lie along internal jugular vein, inferior to the omohyoid muscle.
*Jugulo-omohyoid-drains the submental region and base of the tongue.
Additional Deep
Cervical Nodes
1. Accessory; lie
along accessory
nerve
2. Subclavicular; lie
along clavicle.
*Tissue drainage: mostly secondary nodes
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Sequence of lymph nodes draining various tissues
Most of face, scalp,
ear, orbit, sinuses,
nasal cavities
Most maxillary and mandibular
teeth and associated tissues,
apex and body of tongue,
floor of mouth, sublingual
and submandibular glands,
lips
Maxillary third molars and
associated tissues, base of
tongue, pharynx, tonsils
Tissue Primary nodes Secondary
nodes
Submental and
submandibular
nodes
Facial, anterior auricular,
retroauricular, occipital
superficial and deep parotid,
and retropharyngeal nodes
Submandibular,
deep cervical
nodes
Retropharyngeal, deep
cervical nodes
Neck and cervical
viscera
Superficial and deep
cervical nodes
Right
jugular
trunk
Right
subclavian
vein
Left
jugular
trunk
Left
subclavian
vein
Thoracic
duct
Endocrine-secrete
substance into blood,
examples-adrenal gland
pituitary gland, thyroid
gland
Exocrine-secretes
substance through a
duct leading outside
the body (digestive
tract, skin). Examples-
sweat glands, salivary
glands, mucous
glands, pancreas
Where are the salivary ducts located
intraorally?
Parotid (Stensen) duct opening
> Parotid Papilla.
Submandibular (Wharton) duct opening
Sublingual Caruncle.
Plica Sublingualis Sublingual Caruncle
Parotid Papilla
Sublingual duct opening - Via Duct of
Bartholin
→ Sublingual Caruncle.
OR
Via smaller Ducts of Rivinus > Plica
Sublingualis.
Thyroid and Parathyroid
glands (endocrine)
Thyroid: 1.Located inferior to the larynx along the sides
of the trachea. 2. Has 2 lobes, connected by an isthmus.
3. Secrets thyroxin which influences metabolic rate
Parathyroid: 1. Four small glands located on the posterior
aspect of the thyroid gland. 2. Secrete parathyroid hormone,
which regulates calcium and phosphate levels.
Thymus
1. Located in the thorax and
anterior region of the base of
the neck, deep to the sternum
and sternohyoid and sternothyroid
muscles.
2. Involved in the maturation of
T-cell lymphocytes
3. Shrinks in size with age
Teeth and Periodontium Commonly Involved in Clinical
Presentations of Abscesses and Fistulae
1. Abscess in maxillary vestibule or palate,
2. Penetration of nasal floor
3. Abscess in nasolabial skin region
4. Penetration into maxillary sinus
5. Abscess in buccal skin region
6. Abscess in mandibular vestibule
7. Abscess in submental skin region
8. Abscess in sublingual region
→ Any maxillary tooth (except
maxillary canines for palate)
• Maxillary central incisors
→ Maxillary canine
→ Maxillary molars
• Maxillary or mandibular
molars
→ Any mandibular tooth
• Mandibular incisors
→ Mandibular molars with short
roots superior to mylohyoid
Teeth/Periodontium and Spaces Possibly Involved With
Various Clinical Presentations of Cellulitus
Location Space Involved Teeth/Periodontium Involved
Infraorbital region
Zygomatic region
Buccal region
Buccal space
Maxillary premolars, and
maxillary and mandibular
molars
Submental region Submental space Anterior mandibular teeth
Submandibular
region (unilateral)
Submandibular space Posterior mandibular teeth
Submandibular
region (bilateral)
Submental, sublingual
Submandibular spaces
Spread of mandibular
dental infection
Lateral cervical
region
Parapharyngeal space Spread of mandibular
dental infection
4 major routes
1. Spread to the paranasal sinuses
2. Spread by the vascular system
3. Spread by the Lymphatic system
4. Spread by spaces
Bacteria can spread through the blood from infected dental tissues to other areas.
(1) An infected thrombus (blood clot) can travel as an embolus and spread infection.
(2) Transient bacteremia (presence of bacteria in the blood) can occur during dental treatment. For example,
a needle advanced too far during an attempt at PSA block can penetrate the pterygoid venous plexus
after being inserted through infected tissue (needle track contamination).
(3) The pterygoid venous plexus drains the dental tissues and communicates with the cavernous sinus via
the inferior ophthalmic vein.
(4) Infections in dental tissues can initiate an inflammatory response, which can result in thrombus
formation, blood stasis, and increased extravascular pressure.
(5) Veins in the head do not have valves, so backflow of blood carrying pathogens into the cavernous sinus
can occur.
Cranial Nerve Names & Function
Names: "Only One Of The Two Athletes Felt Very Good, Victorious, And Healthy"
Function: "Some Say Marry Money, But My Brother Says Big Brains Matter Most"
1. Only (Some) = Olfactory (S)
2. One (Say) = Optic (S)
3. Of (Marry) = Oculomotor (M)
4. The (Money) = Trochlear (M)
5. Two (But) = Trigeminal (B)
6. Athletes (My) = Abducens (M)
7. Felt (Brother) = Facial (B)
8. Very (Says) = Vestibulocochlear (S)
9. Good (Big) = Glossopharyngeal (B)
10. Victorious (Brains) = Vagus (B)
11. And (Matter) = Accessory (M)
12. Healthy (Most) = Hypoglossal (M)
Blood
Branching of Carotid Arteries from Aorta
Common
Carotid
Arteries To upper limb
Subclavian
artery
Subclavian
artery
Brachiocephalic
trunk
Aortic arch
From heart To thorax, abdomen, legs
Blood Flow
LAB RAT
LEFT ATRIUM=BICUSPID
RIGHT ATRIUM= TRICUSPID
Right ABC'S
THE AORTIC ARCH GIVES RISE TO
-BRACIOCHEPHALIC TRUNK
COMMON COROTID ARTERY
SUBCLAVIAN ARTERY
Left: carotid & subclavian
LUNG
BAGHT PULMONARY
ARTERY
PILNONARY
WEIN
TRICUSPID
VALVE
L E F T
LUNG
S U P.
VENA CAVA
AORTIC
ARCH
LEFT PULMONARY ARTERY
RIGHT
ATRIUM PALMONART
PULMONARY
ARTERY
LEFT ATRIUM
PULMONARY
VINN
PELNONARY
WEIN
LEFT
VENTRICLE
RIGHT
VENTRICLE
B L O O D
FLOW
THROUGH
THE HEART
MITRAL
VALVE I N
2 MINUTES
INF. VENA
CAVA
Foramina, Canals, etc. Traversed by Various Blood Vessels
Vertebral artery- transverse foramina in cervical vertebrae, foramen magnum
Internal carotid artery-carotid canal, foramen lacerum, groove for the internal carotid artery
Maxillary artery-terminates in pterygoid fossa
Posterior superior alveolar artery-posterior superior alveolar foramina
Infraorbital artery-inferior orbital fissure, infraorbital groove, infraorbital canal, infraorbital foramen
Sphenopalatine artery-sphenopalatine foramen, incisive canal, incisive foramen
Descending palatine artery-divides into greater and lesser palatine arteries which traverse same named foramina
Inferior alveolar artery-mandibular foramen, mandibular canal
Mental artery-mental foramen
Mylohyoid artery-mylohyoid groove
Ophthalmic artery-optic canal
Anterior and posterior ethmoid arteries-anterior and posterior ethmoid foramina
Middle menningeal artery-foramen spinosum
Internal jugular-jugular foramen
EXTERNAL
CAROTID
ARTERY
LINGUAL-
→ SUPRAHYOID
→ DORSAL LINGUAL
→ SUBLINGUAL
→ DEEP LINGUAL
- TONGUE
- SOFT PALATE
- SUBLINGUAL
SALIVARY GLAND
- MUSCLES
ATTACHED
to HYOID
ARTERIAL SUPPLY:
FACIAL- - MAXILLARY (3 PARTS)
→ ASCENDING MANDIBULAR PART:
PALATINE
→ INFERIOR ALVEOLAR
→ TONSILAR
- LOWER TEETH - CHEEK
→ SUBMENTAL - MYLOHYOID
→ GLANDULAR
BRANCHES MUSCULAR PART:
→ SUPERIOR LABIAL → MASSETERIC → - MASSETER
→ INFERIOR LABIAL → DEEP
TEMPORAL →
- TEMPORALIS
PTERYGOPALATINE PART:
- SOFT PALATE
- PALATINE TONSIL
- ROOT of TONGUE
- SUBMANDIBULAR &
SUBLINGUAL
SALIVARY GLANDS
- LIPS
→ DESCENDING
- HARD PALATE
PALATINE
- SOFT PALATE
→ POSTERIOR
SUPERIOR ALVEOLAR
- PALATINE TONSIL
- UPPER PREMOLAR
& M O L A R S
→ INFRAORBITAL → - UPPER TEETH
It gives off six branches before it divides into two terminating
branches. They are in ascending order:
• superior thyroid,
• ascending pharyngeal,
• lingual,
• facial,
• occipital, and
• posterior auricular.
The two terminating branches are the
• maxillary and
• superficial temporal arteries.
Lingual artery supplies the tongue, Floor of the mouth and
suprahyoid muscles.
FACIAL ARTERY
1) The facial artery runs anteriorly and
superiorly near the labial commissure and
along the lateral side of the naris of the
nose.
2) The facial artery terminates at the medial
canthus of the eye.
3) Supplies the face in the oral, buccal,
zygomatic, nasal, infraorbital, and orbital
regions.
o Cervical – Ascending Palatine,
submental and tonsillar
o Facial branches – Glandular
(submandibular), Angular,
Superior Labial & Inferior labial
*Face, palate, tonsils,
submandibular, stylohyoid, digastric
muscles
Maxillary artery
Acessory middle
meningeal artery
Masseteric artery
Middle meningeal artery
Deep temporal arteries
Pharyngeal artery
- Artery of pterygoid canal
Sphenopalatine artery
Infraorbital artery
Anterior superior alveolar artery
Deep auricular artery
Anterior tympanic artery
Inferior alveolar artery
Mylohyoid artery
Posterior superior alveolar artery
Greater palatine artery
Lesser palatine arteries
Buccal artery
Lingual branch
Incisive branches
Mental artery
• 1st Mandibular part
• 5 branches
→ Retromandibular foramen
• 2nd Pterygoid part
• 5 branches
→ Infratemporal foramen
• 3rd Pterygopalatine part
• 6 branches
→ Pterygopalatine foramen
Epicranial Surprise
Orbicularis oculi Closing eyelid and squinting
Corrugator supercilii Frowning
Orbicularis oris Closing and pursing lips as well
as pouting and grimacing
Buccinator Compresses the cheeks
during chewing
Risorius Stretching lips
Levator labii superiori
s
Raising upper lip
Levator labii superiori
s alaeque nasi
Raising upper lip and dilating
nares with sneer
Zygomaticus major Smiling
Zygomaticus minor Raising upper lip to assist
in smiling
Levator anguli oris Smiling
Depressor anguli oris Frowning
Depressor labii inferi
oris
Lowering lower lip
Mentalis Raising chin protruding lower lip
Platysma Raising neck skin and grimacing
Class I
Malocclusion
•The MB cusp of the maxillary first
molar occludes with the MB groove of
the mandibular first molar.
Facial profile as described by
many clinicians with the
older term mesognathic.
Class II
Malocclusion
Class II malocclusion (distoclusion)
MB cusp of the maxillary first molar occluding
(by more than the width of a premolar) mesial
to the MB groove of the mandibular first molar.
• The older term for describing the
facial profile in Class II, division I,
is retrognathic.
Class II Malocclusion
Division I Division II
• Based on the
• Position of the anterior teeth.
• Shape of the palate
• Resulting facial profile.
Class II Malocclusion
Division I
maxillary incisors protrude facially from the
mandibular incisors causing a severe over
bite (or deep bite).
Upper incisors are tilted outwards, creating
significant overjet.
Division II
Protrusive maxillary incisors, the maxillary
central incisors are either upright or
retruded.
Upper incisors are labially inclined.
Class III
Malocclusion
The MB cusp of the maxillary first molar occludes (by
more than the width of a premolar) distal to the MB
groove of the mandibular first molar.
• The older term that describes the facial profile
with a Class III malocclusion is prognathic.
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