HomeCT4-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. 1/16/2025 3 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. 1/16/2025 10 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. 1/16/2025 11 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. 1/16/2025 12 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. 1/16/2025 13 • 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 1/16/2025 14 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. 1/16/2025 20 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 1/16/2025 23 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. 1/16/2025 25 • 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 1/16/2025 29 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. 1/16/2025 33 • 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 1/16/2025 39 Principal Fibers Protect, Gingival Fibers Guard." •Principal → Protection and anchorage of the tooth. •Gingival → Guard and stabilize gingiva. 1/16/2025 40 Principle Fibers "All Hungry Octopuses Appreciate Ice cream!" •All → Alveolar Crest •Hungry → Horizontal •Octopuses → Oblique •Appreciate → Apical •Ice cream → Interradicular 1/16/2025 41 Gingival Fiber : "Dentists Always Care Deeply for Teeth!" •Dentogingival •Alveologingival •Circular •Dentoperiosteal •Transseptal 1/16/2025 42 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. 1/16/2025 45 1/16/2025 46 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. 1/16/2025 47 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. 1/16/2025 48 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. 1/16/2025 49 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. 1/16/2025 50 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. 1/16/2025 51 PRIMARY DENTITION 1/16/2025 52 1/16/2025 53 Eruption 1/16/2025 54 1/16/2025 55 1/16/2025 56 Differences-(Enamel depth/pulp) 1/16/2025 57 Differences: Roots 1/16/2025 58 Importance of Primary teeth - PRIMATE Space 1/16/2025 59 Leeway Space 1/16/2025 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. 1/16/2025 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. 1/16/2025 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). 1/16/2025 66 1/16/2025 67 1/16/2025 68 1/16/2025 69 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. 1/16/2025 72 ➢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). 1/16/2025 73 • 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). 1/16/2025 74 1/16/2025 75 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. 1/16/2025 76 • The muscles of mastication include the • Temporalis, • And Masseter, • Pterygoid muscles, medial and lateral. • These muscles are involved in mastication using these two movements. 1/16/2025 77 1/16/2025 78 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. 1/16/2025 79 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. 1/16/2025 80 • 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. 1/16/2025 81 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. 1/16/2025 83 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 1/16/2025 88 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.