Review of All Dental Subjects (ROADS) PDF

REVIEW OF ALL DENTAL SUBJECTS (ROADS) Neha Sethi BDS MDS MBA Assistant Professor BRS Dental College and Hospital Panchkula, Haryana, India The Health Sciences Publisher New Delhi | London...

REVIEW OF ALL DENTAL SUBJECTS (ROADS) Neha Sethi BDS MDS MBA Assistant Professor BRS Dental College and Hospital Panchkula, Haryana, India The Health Sciences Publisher New Delhi | London | Panama | Philadelphia  Jaypee Brothers Medical Publishers (P) Ltd Headquarters Jaypee Brothers Medical Publishers (P) Ltd 4838/24, Ansari Road, Daryaganj New Delhi 110 002, India Phone: +91-11-43574357 Fax: +91-11-43574314 Email: [email protected] Overseas Offices J.P. Medical Ltd Jaypee-Highlights Medical Publishers Inc 83, Victoria Street, London City of Knowledge, Bld. 237, Clayton SW1H 0HW (UK) Panama City, Panama Phone: +44-20 3170 8910 Phone: +1 507-301-0496 Fax: +44 (0)20 3008 6180 Fax: +1 507-301-0499 Email: [email protected] Email: [email protected] Jaypee Medical Inc. Jaypee Brothers Medical Publishers (P) Ltd The Bourse 17/1-B, Babar Road, Block-B, Shaymali 111, South Independence Mall East Mohammadpur, Dhaka-1207 Suite 835, Philadelphia, PA 19106, USA Bangladesh Phone: +1 267-519-9789 Mobile: +08801912003485 Email: [email protected] Email: [email protected] Jaypee Brothers Medical Publishers (P) Ltd Bhotahity, Kathmandu, Nepal Phone: +977-9741283608 Email: [email protected] Website: www.jaypeebrothers.com Website: www.jaypeedigital.com © 2015, Jaypee Brothers Medical Publishers The views and opinions expressed in this book are solely those of the original contributor(s)/author(s) and do not necessarily represent those of editor(s) of the book. All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission in writing of the publishers. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. Medical knowledge and practice change constantly. This book is designed to provide accurate, authoritative information about the subject matter in question. However, readers are advised to check the most current information available on procedures included and check information from the manufacturer of each product to be administered, to verify the recommended dose, formula, method and duration of administration, adverse effects and contraindications. It is the responsibility of the practitioner to take all appropriate safety precautions. Neither the publisher nor the author(s)/editor(s) assume any liability for any injury and/or damage to persons or property arising from or related to use of material in this book. This book is sold on the understanding that the publisher is not engaged in providing professional medical services. If such advice or services are required, the services of a competent medical professional should be sought. Every effort has been made where necessary to contact holders of copyright to obtain permission to reproduce copyright material. If any have been inadvertently overlooked, the publisher will be pleased to make the necessary arrangements at the first opportunity. Inquiries for bulk sales may be solicited at: [email protected] Review of All Dental Subjects First Edition: 2015 ISBN 978-93-5152-732-9 Printed at  Dedicated to All My Students and Mentors, Who Sparked My Enthusiasm for Learning  Acknowledgments I gladly utilize this opportunity to express my deep sense of gratitude and indebtedness to my parents and family, without whose everlasting inspiration, incessant encouragement, constructive criticism and valuable suggestions for improvement, the comple- tion of this study would not have been possible. I am immensely indebted to Dr Pankaj Malhotra, MDS Periodontics and Implantoloy, Dr Akash Kasatwar, MDS Oral and Maxillofacial Surgery, Dr Hitesh Chandra, MDS Pedodontics and Public Health Dentistry and all my colleagues for their contribution toward the various chapters in the book. I am also thankful for their constant support and encouragement. My sincere thanks to all my students and MDS aspirants whose continuous queries and suggestions help me make this book better. I am thankful to Ms Chetna Malhotra Vohra, Ms Shagufta Khan and others at Jaypee Group for their cooperation and help whenever I needed. My salutations to ALMIGHTY – A tangent between zero and infinity – for his divine grace bestowed when needed. From the Publisher’s Desk We request all the readers to provide us their valuable suggestions/errors (if any) at: [email protected] so as to help us in further improvement of this book in the subsequent edition  A Few Words to Share Time has gone when the questions were repeated in AIPGDEE from previous year question papers and the repeat questions determined the results. Today almost 35–50 questions are totally new which have not appeared in any preparation books till date. These questions actually determine the result of any exam. All MDS aspirants read the previous papers and are able to solve the repeat. Important aspect here is the correct answers and explanations of these questions. You do not want a repeat question to go wrong! Also to get the edge above others, aspirants need to prepare for the new questions, which have not yet appeared in any question banks. AIPGDEE is well-devised to test the skills in and around various subjects comprehensively but if you are having good un- derstanding of subjects and well updated, you can get through. It is not limited to the last moment preparation or the cramming ability. The trends been changing year by year, with emphasis more on clinically oriented and in-depth specialized topics like or- thodontics, radiology, pharmacology, genetics, molecular biology, etc. The paper been tiresome which tests the tricky nature of common topics. Keeping these in mind, the concept of ROADS was laid. Eight hundred to one thousand pages give you an insight of the topics commonly asked in entrance exams and ‘Good to Know’ points introduce several newer topics and sections to raise your bar above the aspirants. This book will help you crack various pre-PG entrance exams ranging from State entrances to All India level exams. Neha Sethi  Road to MDS AIPGDEE is conducted by AIIMS. The syllabus for AIPGDEE shall be that of the BDS standard. The syllabus shall cover all the subjects taught during the BDS course. Initial Preparation Earlier you start, better it is. As time lost is time gone Start with subjects and topics which interest you more, slowly move on to the less interesting subjects Plan and plan how to start preparation for each subject If preparing with ROADS, read the subject chapter first and then attempt 700–1000 questions of that subject Revise continuously Talk to friends, group study is helpful. Discussing important/difficult topics makes them easier to understand. Do not cut yourself from your life. Four to five hours per day for 8–10 months is usually sufficient. More than the number of hours you put in, important is the amount of concentration you put in those hours of study. So practice meditation exercises regularly to improve your concentration skills Take a break, it is very helpful. Taking a evening off once or twice a month is not a bad idea at all. Last Minute Preparation The last 20–30 days are very crucial and stressful at the same time. These play an important role in how you will do in the exam on D-day. Here are few tips for the last minute preparation. Firstly do not start a new book now Revise all your notes. Use ROADS to consolidate what you have learnt Go through last 2 years papers of NEET, AIIMS (Nov and May) Also go through AIPGMEE papers of at least last 3 years and surely of this year Last but not the least sleep well and eat well before the exams Hope these will be helpful to you and will help to take a step closer to your dreams.  List of Entrance Exams in MDS All India Institute of Medical Science Entrance Exam All India Post Graduate Medical/ Dental Entrance Examination Annamalai University MDS Entrance Exam Avinashilingam Deemed University for Women MDS Entrance Exam Baba Farid University of Health Sciences MDS Entrance Exam Banaras Hindu University (BHU) MDS Entrance Test Bangalore University MDS Entrance Exam Barkatullah University MDS Entrance Exam Bharath University Chennai MDS Entrance Exam Bharati Vidyapeeth Dental College and Hospital (Pune) MDS Entrance Exam Bhavnagar University MDS Entrance Exam Calcutta University MDS Entrance Exam Calicut University MDS Entrance Exam Delhi University MDS Entrance Exam Department of Dental Surgery, All India Institute of Medical Sciences MDS Entrance Exam Dr NTR University of Health Sciences MDS Entrance Exam Dr. Ram Manohar Lohiya, Avadh University MDS Entrance Exam Gitam University MDS Entrance Exam Indira Gandhi National Open University (IGNOU) MDS Entrance Exam Institute of Medical Sciences - Banaras Hindu University MDS Entrance Exam JSS University MDS Entrance Exam Kannur University MDS Entrance Exam Kerala University MDS Entrance Exam KLE University MDS Entrance Exam Maharashtra University MDS Entrance Exam Maharishi Markandeshwar University MDS Entrance Exam Manipal College of Allied Health Sciences MDS Entrance Exam Manipal University MDS Entrance Exam NITTE University Mangalore MDS Entrance Exam Padmashree Dr DY Patil University MDS Entrance Exam Pondicherry University MDS Entrance Exam Pt BD Sharma University of Health Sciences MDS Entrance Exam Punjab University MDS Entrance Exam Rajasthan University of Health Sciences (RUHS) MDS Entrance Exam Rajiv Gandhi University of Health and Sciences MDS Entrance Exam Saveetha University MDS Entrance Exam Sri Ramachandra Medical College and Research Institute MDS Entrance Exam SRM University MDS Entrance Exam  viii  Review of All Dental Subjects Tamil Nadu Dr MGR Medical University MDS Entrance Exam West Bengal University of Health Sciences MDS Entrance Exam Vinayaka Missions University MDS Entrance Exam West Bengal University of Health Sciences All India Post Graduate Entrance Exam Conducted by AIIMS every year Exam date–January Exam center Online application forms are available from November/December of previous year Exam pattern –– There will be only one paper of 3 hours duration. –– The paper shall comprise of 200 MCQs, consisting of Basic Sciences, Para Clinical and Clinical Subjects. –– While each single correct shall be awarded 4 marks, each incorrect response is liable to deduction of one mark. –– Zero mark will be given to those questions which are left unanswered. However the question with one and more response as answers will be treated as incorrect answer and mark shall be deducted. For details–check the website www.aiimsexams.org AIIMS PG Exam Conducted by AIIMS Twice a year Exam date–first week of November and May every year Exam center–Delhi Online application forms are available Exam pattern –– Duration: 90 Minutes –– No. of questions: 90 Objective type questions –– Negative Marking: 1/3rd of the marks allocated for a right response will be deducted if the response is incorrect For details–check the website www.aiimsexams.org PGIMER Entrance Exam Conducted by Post Graduate Institute of Medical Education and Research for admission to postgraduate and postdoctoral programs in MD/MS/MHA/DM/MCh/House Jobs (Oral Health Science). Conducted twice a year, one for the session beginning in January and other in July. Exam pattern –– Duration–1.5 hours –– No. of Questions-100 Multiple Choice Questions –– 0.25 negative marking will be applicable for wrong answer. For details–check the website www.pgimer.edu.in COMEDK PGET Exam date–first week of February Exam center–Bangalore (only) Online application forms are available from November/December of previous year  List of Entrance Exams in MDS ix Exam pattern –– Each test will have 180 Multiple-Choice Questions –– The time allotted for the test would be 180 minutes (3 hours). The test will begin at 10:00 AM and end at 01:00 PM. –– Each correct answer is awarded one mark. –– No Mark/s will be awarded for multiple marking (marking multiple responses) of any question. –– There will be no negative marking For details–check the website www.comedk.org  Reference Books 1. A Concise Textbook of Surgery – S Das 2. A Textbook of Operative Dentistry – Vimal K Sikri 3. BD Chaurasia’s Human Anatomy – BD Chaurasia 4. Boucher’s Complete Denture Prosthodontics – Zarb 5. Burkett’s Oral Medicine – M Glick 6. Carranza’s Clinical Periodontology 7. Clinical Neuroanatomy – Richard S Snell 8. Cohen’s Pathways of the Pulp – Kenneth M Hargreaves 9. Community Dentistry – Soben Peter 10. Concise Medical Physiology – Chaudhari 11. Contemporary Fixed Prosthodontics – Stephen F Rosenstiel 12. Endodontics – Ingle and Backland 13. Essentials of Medical Pharamcology – KD Tripathi 14. Fundamentals of Fixed Prosthodontics – Herbert T Shillingburg 15. Goodman and Gilman’s The Pharmacological Basis of Therapeutics 16. Graber’s Textbook of Orthodontics 17. Human Embryology – IB Singh 18. Handbook of Local Anesthesia – SF Malamed 19. Harper’s Biochemistry 20. Harrison’s Principles of Internal Medicine 21. Killey’s fractures of the mandible – Peter Banks, Homer Charles Killey 22. McCracken’s Removable Partial Prosthodontics 23. McDonald and Avery Dentistry for the Child and Adolescent – Jeffrey A Dean 24. Medicine – Davidson 25. Oral and Maxillofacial Pathology – Neville 26. Oral and Maxillofacial Surgery – Vinod Kapoor 27. Oral and Maxillofacial Surgery – Daniel M Laskin 28. Oral Radiology – SC White and MJ Pharaoh 29. Orban’s Oral Histology and Embryology – GS Kumar 30. Orthodontics – SI Balaji 31. Park’s Textbook of Preventive and Social Medicine 32. Peterson’s Principles of Oral and Maxillofacial Surgery 33. Phillip’s – Science of Dental Materials 34. Robbins Basic Pathology – Vinay Kumar 35. Shafer’s Textbook of Oral Pathology 36. Short Practice of Surgery – Bailley and Love’s 37. Sturdevant’s Art and Science of Operative Dentistry – Swift and Heymann 38. The Essentials of Forensic Medicine and Toxicology – N Reddy 39. Ten Cate’s Oral Histology: Development, Structure, and Function – Antonio Nanci 40. Textbook of Human Histology – Inderbir Singh 41. Textbook of Microbiology – Ananthanarayan and Paniker 42. Textbook of Medical Biochemistry – Chatterjea MN and Shinde Rana 43. Textbook of Pathology – Harsh Mohan 44. Textbook of Pediatric Dentistry – Nikhil Marwah 45. Wheeler’s Dental Anatomy, Physiology and Occlusion – Ash and Fausto  Contents 1. Anatomy...................................................................................................................................1-58 2. Biochemistry........................................................................................................................59-102 3. Physiology..........................................................................................................................103-152 4. General Pathology.............................................................................................................153-205 5. Microbiology......................................................................................................................206-247 6. Pharmacology....................................................................................................................248-290 7. General Medicine and Surgery..........................................................................................291-352 8. Dental Materials.................................................................................................................353-389 9. Dental Anatomy and Histology.........................................................................................390-411 10. Oral Pathology and Oral Medicine....................................................................................412-470 11. Complete Dentures.............................................................................................................471-500 12. Removable Partial Dentures..............................................................................................501-518 13. Fixed Partial Dentures........................................................................................................519-533 14. Periodontics........................................................................................................................534-593 15. Radiology............................................................................................................................594-621 16. Pedodontics........................................................................................................................622-649 17. Conservative Dentistry.......................................................................................................650-687 18. Endodontics........................................................................................................................688-709 19. Oral Surgery.......................................................................................................................710-744 20. Orthodontics......................................................................................................................745-783 21. Community Dentistry........................................................................................................784-827 22. Miscellaneous Topics..........................................................................................................828-842 23. AIDS...................................................................................................................................843-850 24. Recent Exams................................................................................................................................... 851-855 CHAPTER 1 Anatomy Objectives Embryology Ear and nose Histology Paranasal sinuses Osteology Tonsil Face Orbit Muscles of mastication Lacrimal apparatus Salivary glands Neck Tongue Brain and spinal cord Palate Thorax Pharynx Abdomen Larynx Miscellaneous EMBRYOLOGY Primitive knot (or primitive node) is the organizer for gastrulation in vertebrates. (AIPG 2008) Merkel’s cartilage –– In birds it is known as “Hensen’s node”. –– Extends from the midline backward and dorsally and (AIPG 2001) terminates as the malleus. –– In amphibians, it is knows as “Spemann’s organizer”. –– Articulates with the incal cartilage. Prechordal plate. –– This primary jaw joint exists for about 4 months until –– Formed by the slight enlargement of the ectodermal the cartilages ossify and become incorporated in the and endodermal cells at the head (or rostral) end of middle ear.  (AIPG 2009, AIIMS MAY 2011) the embryo. –– At the prechordal plate there is firm union between 2 weeks Formation of prechordal plate the ectodermal and endodermal cells. (NEET 2013) 3 months of gestation The secondary jaw joint, the TMJ begins to form Primitive streak 10 weeks First indication of future joint (AIIMS May 2013) –– Develops within along the midline of the floor of the amniotic cavity which is formed by ectoderm.  2  Review of All Dental Subjects –– Narrow groove with slightly bulging areas on each –– This differentiates the embryo into the germ layers- side. (AIPG 1995) endoderm, mesoderm, and ectoderm. –– Rostral end finishes in primitive node. –– This time period (3-4th week of IUL) is sometimes –– Posterior to the node is the primitive pit where the called the trilaminar disk stage and at this time the cells of the epiblast (the upper layer of embryonic cells) initially begin to invaginate. embryo is called Trophoblast. (AIPG 2002) Human cell types/listed derived primarily from ectoderm Surface ectoderm Integumentary system Trichocyte. Keratinocyte Nervous system Anterior pituitary (Gonadotrope, Corticotrope, Thyrotrope, Somatotrope, Lactotrope Neural crest Endocrine system Chromaffin cell (AIPG 2007,2010) Integumentary system Melanoblast → Melanocyte (Nevus cell) Merkel cell Teeth Odontoblast Nervous System Glia: Schwann cell ANATOMY Eyes Corneal Keratocyte Neural tube Nervous system Neuroblast Visual Photoreceptor cells (Cone cell, Rod cell) → (Neural stem cell) (Horizontal cell) Glioblast Bipolar cell → (Amacrine cell) Retinal ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retinal ganglion cells, Photosensitive ganglion cell) Diencephalon: P Cell, M Cell, K-cell, Muller gila Auditory Boettcher cell Other Magnocellular neurosecretory cell. Stellate cell Glioblast Oligodendrocyte precursor cell → Oligodendrocyte. Astrocyte. Ependymal cell. Pinealocyte. Neural crest cells leave neuroectoderm and enter mesoderm. Adrenal medulla Neural crest cells: give rise to heterogeneous array of tissues: Schwann cells  (AIPG 2010) Glial cells Connective tissue and bones of the face and skull. Arachnoid and pia mater (leptomeninges) Cranial nerve ganglia C Cells of the thyroid. Derivatives of Neuroectoderm Odontoblasts All neurons within brain and spinal cord Spinal ganglia Retina Sympathetic chain and preaortic ganglion Neurohypophysis Melanocytes Astrocytes, oligodendrocytes Parasympathetic ganglia of GIT Mesodermal derivatives Paraxial mesoderm is organized into segments called “somitomeres”. They are arranged cephalocaudally from occipital region. Somitomeres arrange into somites. Each somite gives rise to: -- Sclerotome-cartilage and bone of axial and paraxial skeleton (remember neural crest cells give rise to cartilage and bones of skull and face) -- Myotome-segmental muscle component -- Dermatome-segmental skin component (AIPG 2012) Each myotome and dermatome have their own segmental nerve component.  Anatomy 3 Intermediate mesoderm Differentiates into excretory units of urinary system and the gonads (urogenital system) Lateral plate mesoderm Splits into parietal and visceral layers. Parietal mesoderm + overlying ectoderm gives rise to lateral and ventral body wall viscera. Mesoderm + embryonic endoderm give rise to wall of the gut. Cortical portion of suprarenal gland and spleen also develop from mesoderm. Human cell types derived primarily from mesoderm Paraxial Mesenchymal stem cell Osteochondro Bone: Osteoblast, Osteocyte cartilage: Chondroblast, (MSC) Cartilage/ bone/ progenitor cell (OCP) Chondrocyte muscle Myofibroblast Fibroblast Fibrocyte Muscle: Myoblast Myocyte. Satellite cell. Tendon cell. Myocardiocyte Digestive system Adipose: Lipoblast, Adipocyte Interstitial cell of kajal Intermediate Renal Stem Cell (RSC) Angioblast, Endothelial cell. Mesangial cell Intraglomerular, Extraglomerular. ANATOMY Urinary system Juxtaglomerular cell. Macula densa cell Stromal cell, Interstitial cell Simple epithelial cell, Podocyte. Kidney proximal tubule brush border cell Reproductive system Sertoli cell. Leydig cell. Peg cell (spermatozoon and ovum are germ cells) Lateral plate Hematopoietic stem cell Lymphoid B Cell. T cell (Cytotoxic T cell, Natural Killar T cell, hemangioblast (HSC) Blood/immune (CFU-L) Regulatory T cell, T helper cell). Natural Killer cell Myeloid (CFU- Granulocytes (Basophil granulocyte, Eosinophil GEMM) granulocyte, Neutrophil granulocyte/Hypersegmented neutrophil). Monocyte/Macrophage. Red blood cell (reticulocyte). Thrombocyte/Megakaryocyte. Mast cell. Dendritic cell Circulatory system Endothelial progenitor cell. Endothelial stem cell. Angioblast/Mesoangioblast Pericyte. Mural cell Derivatives of Endoderm Germ Layer Category System Products Endoderm General Gastrointestinal tract The entire alimentary canal except part of the mouth, pharynx and the terminal part of the rectum (ectoderm), the lining cells of all the glands. Buccopharyngeal membrane is both ectodermal (towards future oral cavity) and endoderm membrance (towards future GIT). This breaks open at 4th week to communicate between foregut and amniotic cavity. Endoderm General Respiratory tract Epithelial lining of respiratory tract, the trachea, bronchi, and alveoli of the lungs Endoderm General Endocrine glands and Parenchyma of thyroid, parathyroid, liver and pancreas. Reticular stoma of the organs tonsils and thymus (the lining of the follicles of the thyroid gland and thymus) Endoderm Auditory system The epithelial lining of the auditory tube and tympanic cavity Endoderm Urinary system The epithelial lining of urinary bladder and part of the urethra Arch Skeletal element Nerve Muscle I (Mandibular) Meckel’s cartilage (AIPG 2000) Mandibular-third Medial and lateral pterygoid Incus, malleus division of the V Masseter (KAR 1997, NEET 2013) cranial nerve Anterior mandible Temporalis Zygomatic bone Mylohyoid Palatine bone Ant.belly of digastric Part of temporal bone Tensor tympani Ligament of the malleus Tensor palati Sphenomandibular ligament (KAR 2001) (KAR 1997, AIIMS Nov 2012) Also responsible for formation of maxilla  4  Review of All Dental Subjects II Hyoid Stapes Facial Muscles of face Styloid process (COMEDK 2007) (COMEDK 2006) Smaller cornu of hyoid bone Occipitofrontalis Superior part of body hyoid bone Platysma, stylohyoid Post belly of digastric (PGI 2002) Stapedius (AIPG 2001) Auricular muscles III Greater cornu of hyoid bone Glosso-pharyngeal Stylopharyngeus Lower part of the body of hyoid bone (PGI 1998) IV Cartilages of larynx are derived from both Superior All The muscles of pharynx except IV and VI Laryngeal stylopharyngeus All the muscles of palate except tensor veli palate Cricothyroid muscle Brachial arches and pouches ANATOMY Pouches Derivatives 1st Pouch Pharyngotympanic tube Middle ear cavity (KAR 1999) Tympanic antrum 2nd Pouch Tonsil (KCET 2009) Tubotympanic recess 3rd Pouch Inferior parathyroid glands (APPSC 1999) Thymus 4th Pouch Superior parathyroid glands 5th Pouch (ultimobranchial pouch) Parafollicular cells of thyroid (KAR 2003) HISTOLOGY Squamous epithelium Mesothelium Lungs and free surface of pericardium, pleura and peritoneum. Endocardium Inside lining of heart Endothelium Inside lining of blood vessels and lymphatics Stratified squamous Lining of skin and mucosa subjected to friction such as oral cavity, oesophagus Columnar epithelium Simple columnar Lining of stomach and large intestine. Ciliated columnar Respiratory tract, uterus, uterine tubes, auditory tube Striated columnar Small intestine (regular microvilli) Brush border columnar Gall bladder (regular microvilli) Secretary columnar Stomach and intestine Cuboidal Simple cuboidal Thyroid gland follicles, ducts of glands, surface of ovary (germinal epithelium) Brush border cuboidal Proximal convoluted tubule. Pseudostratified epithelium Simple pseudostratified Auditory tube, olfactory area of nose, male urethra (COMEDK 2008) Ciliated pseudostratified Trachea and large bronchi. Transitional epithelium (AIPG 2008) Ureter, urinary bladder, parts of urethra  Anatomy 5 Cartilage Modified connective tissue. It consists of intercellular material called matrix. Mesenchymal in original. Cartilage-forming cells are called chondroblasts. Cartilage grows by both interstitial and appositional growth. Some mesenchymal cells that surround the developing cartilage form the perichondrium. Types of Cartilage Hyaline cartilage Matrix consists of lacunar capsule containing individual Costal cartilage chondrocytes. Articular cartilages of most synovial joints Widely distributed in the body. Thyroid, cricoid and arytenoid cartilages, pharyngeal Surface covered by perichondrium. cartilages, parts of nasal septum, epiphyseal plate Type II collagen is found (AIPG 2008) essential for bone growth Fibrous cartilage Also called white cartilage. It is found in symphysis. Type I collagen is found. Intervertebral discs, public symphysis, articular disc of ANATOMY Perichondrium is absent. most of the joints and menisci of knee joint. Highest tensile force. Calcification may occur with age. Elastic cartilage Yellow cartilage. It is found in auricle. (AIPG 2002) This is similar to hyaline cartilage except that elastic fibres Wall of the medial part of the auditory tube. are present instead of type II collagen fibres. Epiglottis, corniculate, cuneiform and apical part of the calcification does not occur. arytenoids cartilages of larynx. Types of Glands Aprocrine Glands Apical part of cell is shed off to discharge secretion (decapitation secretion) E.g. sweat glands in axilla, groin, mammary glands Holocrine glands Entire cell disintegrates discharges secretion E.g. sebaceous glands Eccrine glands Cell is intact, secretions are thrown out by exocytosis. (merocrine) E.g. sweat gland on palm Modified sweat glands are ceruminous glands, ciliary glands Meibomian glands, glands of Zeis are modified sebaceous glands OSTEOLOGY Bone Epiphysis Ends and tips of bone which ossify from secondary centres Following types: -- Pressure epiphysis is articular and takes part in transmission of the weight. Example: head of femur; lower and of radius, etc. -- Traction epiphysis is nonarticular and does not take part in the transmission of the weight. It always provides attachment to one or more tendons which exert a traction on the epiphysis. The traction epiphyses ossify later than the pressure epiphyses. Examples: trochanters of femur and tubercles of humerus. -- Atavistic epiphysis is phylogenetically and independent bone which in man becomes fused to another bone. Examples: coracoid process of scapula and os trigonum. -- Aberrant epiphysis is not always present. Examples: epiphysis at the head of the first metacarpal and at the base of other metacarpal bones Diaphysis It is the elongated shaft of a long bone which ossifies from a primary centre Metaphysis The epiphysis ends of a diaphysis and called metaphysis. Each metaphysis is the zone of active growth Most common site for osteomyelitis (AIPG 2003)  6  Review of All Dental Subjects Stages during growth of epiphyseal plate (AIPG 2005) Growth (proliferation of cells/interstitial and appositional growth) ↓ Transformation (Hypertrophy/calcification of matrix) ↓ Ossification (Chondrolysis/ Vascularization/ osteogenesis) ↓ Remodelling Stages during growth of epiphyseal plate (AIPG 2005) Skull ANATOMY Skull is composed of 22 bones. (AP 2003, 1999) It is composed of: Neurocranium Viscerocranium Surrounds the brain, eyes, middle and inner ears. The face and viscerocranium are formed from the neural crest Contains 8 bones derived membrane bones. -- 2 – bilateral (parietal and temporal bone) Facial skeleton includes from forehead to chin -- 4 single bones -- Frontal bones * Frontal -- Orbital bones * Occipital -- Nasal bones * Sphenoid -- Vomer * Ethmoid -- Maxilla -- Mandible The maxilla and mandible are included since they form from the first brachial arch Also included are medial pterygoid plates of sphenoid bone -- Palatine bones -- Tympanic bones Ethmoid Bone (AIIMS Nov 2013) The ethmoid bone consists of four parts –– Horizontal or cribriform part-forming part of base of cranium –– A perpendicular part-constituting part of nasal septum –– 2 lateral labryrinths Each ethmoidal labryinth consists of thin walled highly variable air cells arranged in three groups: anterior, middle and posterior. These are referred to as anterior air cells (middle and anterior–2-8 in number) Inferior turbinates: Largest among the three. Responsible for the airflow direction, humidification, heating and filtering of the inhaled air. Lambda Junction of sagittal and lambdoid sutures Junction of sagittal and coronal sutures Bregma (AIPG 97, Man 94) Highest point on skull head in anatomic position Most prominent point on external occipital protruberance Vertex (PGI 2003) Junction of frontal, parietal, sphenoid and temporal bones Inion Pterion (AIPG 2006, Man 2000)  Anatomy 7 Cervical Vertebra Identified by the presence of foramen transversarium (transmits vertebral artery, vertebral veins and inferior cervical ganglion) (AIIMS May 2009, AIPG 1996) There are 7 cervical vertebrae –– 3 to 6 are typical –– 1st, 2nd and 7th are atypical. –– 1st–Atlas-ring shaped without body and spine. –– 2nd-axis” (Epistropheus)- identified by the presence of dens (odontoid process), which is a strong tooth-like structure; Its tip is bifid, terminating in two rough tubercles. –– 7th-“vertebra prominens” because of its long, most prominent spinous process. The anterior tubercle of 6th cervical vertebra is large and is called the “carotid tubercle” because the common carotid artery can be compressed against it. ANATOMY Types of Bones Sesamoid Pneumatic bones (having air filled spaces) Membranous bone Patella Ethmoid Skull vault bone Pisiform Maxilla Facial bones Fabella Sphenoid Frontal Mastoid Classification of Joints Fibrous joints Sutures – Skull Syndesmosis- Inferior tibiofibular joint (AIIMS 2007, AP 2008) Gomphosis - Tooth in sockets Cartilaginous joints Primary cartilaginous joints -- Synchondrosis or hyaline cartilaginous joints (MCET 2010) -- Bones are united by a plate of hyaline cartilage so that joint is immovable -- Examples * Joint between epiphysis and diaphysis * Spheno-occipital joint * First chondrosternal joint * Costochondral joint (AIPG 2004) Secondary cartilaginous joint -- Symphysis or fibrocartilaginous joints -- Articular surfaces are covered by a thin layer of hyaline cartilage and united by a disc of fibrocartilage -- Typical these joints occur in median plane and allow limited movements -- Examples * Symphysis pubis * Manubriosternal joint * Intervertebral joint between bodies  8  Review of All Dental Subjects Synovial joint- freely Hinge joint (only flexion and extension possible) Elbow, ankle, interphalangeal joints movable joints (AIPG 2010) Ellipsoidal joint Wrist, altanto – occipital Pivot (trachoid) joint Altanto – axial, superior and inferior radioulnar joint Condylar/bicondylar joint Knee, TMJ Saddle joint (Sellar) Thumb, sternoclavicular calcaneocuboidal, incudo- malleus joint Ball and socket Shoulder, hip, incus- stapedial joint Atlanto-axial joint Joints move as one unit and permit rotation (right and left) of the atlas along with the entire skull. The atlas carrying the globe of the head rotates around the dens of the axis. (AIPG 2004, KCET 2010) The atlanto-axial joints are called the joints of ‘no’ or “negative” expression Atlanto- occipital joints The movements permitted at these joints are flexion, extension (nodding), and lateral flexion. ANATOMY They are called joints of ‘yes’ or “positive” expression A functional classification of joints is based on the degree of movement permitted within the joint. Using this type of classification, the three kids of articulations are as follows: Synarthroses: Immovable joints. Amphiarthyroses: Slightly movable joints. (AIPG 2007) Diarthroses: Freely movable joints. You should know Father of modern anatomy is Andreas Vesalius. Father of anatomy-Herophileus Total bones in human body are 206. Total vertebrae in human body are 33: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal. Formina of Skull and Structures Passing Through Them Norma verticals Parietal foramen Transmits and emissary vein from superior sagittal sinus Norma occipitalis Mastoid foramen Transmits an emissary vein and meningeal branch of occipital artery. (MAN 1999) Norma frontalis Supraorbital foramen Transmits supraobital nerves and vessels Infraorbital foramen Transmits infraobital nerve and vessels Zygomaticofacial foramen Transmits the nerve of same name Mental foramen on mandible (AIPG 2004) Transmits mental nerve and vessels. Norma lateralis Tympanomastoid fissue Transmits auricular branch of vagus nerve Mastoid foramen Transmits an emissary vein connecting the sigmoid sinus with posterior auricular vein, meningeal branch of occipital artery Zyogomaticotemporal Transmits the nerve of same name and a minute artery. foramen Norma basalis Incisive foramen transmits Terminal parts of greater palatine vessels from palate to nose. Terminal part of nasopalatine nerve from nose to palate.  Anatomy 9 Greater palatine foramen Greater palatine vessels, anterior palatine nerve Lesser palatine foramen Transmits middle and posterior palatine nerves. Palatovaginal canal transmits Pharynegeal branch from pterygopalatine ganglion. Small pharynegeal branch of maxillary artery. Vomerovaginal canal Branches of pharyngeal nerves and vessels. Foramen ovale Mandibular nerve and accessory artery (COMEDK 2006, MAN 1999) Foramen spinosum Middle meningeal artery (Br of internal maxillary Artery) (AIPG 2006, AIIMS 2002, KAR 1994) Emissary sphenoidal Transmits and emissary vein connecting cavernous sinus with pterygoid plexus of veins. foramen Canalis innominatus Tansmits lesser petrosal nerve. Carotid canal Transmits internal carotid artery, venous and sympathetic plexus around the artery. ANATOMY Foramen lacerum Meningeal branch of ascending pharyngeal artery and an emissary vein from cavernous sinus, internal carotid artery with venous and sympathetic plexus around it. In the upper part of foramen the greater petrosal nerve unites with the deep petrosal nerve to form nerve of pterygoid canal. Petro tympanic fissure Transmits the chorda tympani nerve and anterior tympanic artery Foramen magnum Through wider posterior part -- Lower part of medulla -- Tonsils of cerebellum max -- Meninges Through subarachnoid space -- Spinal accessory nerve -- Vertebral arteries -- Sympathetic plexus around the vertebral arteries -- Anterior and posterior spinal arteries Through narrow anterior part -- Apical ligament of dens -- Membrana tectoria. Hypoglossal canal (HAEM) Anterior condylar canal transmits the hypoglossal nerve, meningeal branch of ascending pharyngeal artery, emissary vein connecting sigmoid sinus with the internal jugular, meningeal branch of hypoglossal nerve. Posterior condylar canal Transmits an emissary vein connecting the sigmoid sinus with suboccipital venous plexus. Jugular foramen (AIPG 2003) Through anterior part; Inferior petrosal sinus Meningeal branch of ascending pharyngeal artery. Through Middle part 9th, 10th, 11th cranial nerves. Through posterior part: Internal jugular vein. Meningeal branch of occipital artery. Mastoid canailculus Transmits auricular branch of vagus nerve Typmpanic canailculus Transmits tympanic branch of glossopharyngeal nerve to middle ear. Stylomastoid foramen Facial nerve Anterior and posterior Anterior and posterior ethmoidal canals ethmoidal canals Foramen caecum Blind in nature Optic canal transmits Optic nerve and ophthalmic artery  10  Review of All Dental Subjects Superior orbital fissure Lateral part -- Lacrimal nerve -- Frontal nerve -- Trochlear nerve, -- Lacrimal and middle meningeal artery Middle part -- Occulomotor nerve (AIIMS May 2009) -- Nasocilliary nerve -- Abducent nerve Inferior Orbital Fisssure -- Maxillary nerve -- Zygomatic nerve -- Orbital branches of pterygopalatine ganglion -- Infraorbital nerve and vessel -- Communication between inferior ophthalmic vein and pterygoid plexus of veins ANATOMY Foramen rotundum Maxillary nerve (AIPG 2001) Internal acoustic meatus Transmits the 7th and 8th cranial nerves and labyrinthine vessels. Good to know points Maxilla articulates with nasal, lacrimal, frontal, palatine and zygomatic bones. Mental foramen is present on outer surface of body of mandible between the roots of two premolars   (AIIMS 1998, MAN 1995) Lingua is a sharp tongue shaped projection at the anterior margin of mandibular foramen. It gives attachment to sphenomandibular ligament. (TNPSC 1999) The orbital plate of ethmoid is the thinnest and weakest part of the orbit and is k/a lamina papyracea The frontal process of maxilla, lacrimal bone, orbital plate of ethmoid and sphenoid make the medial wall of orbit. Mandibular fossa is a part of temporal bone. It along with articular tubercle forms the upper articular surface of temporomandibular joint. Suprameatal triangle externally represents mastoid antrum.  (KAR 2003) Foramen transversium is typically exclusive to the transverse process of cervical vertebra. It is not present in thoracic and lumbar vertebra. (AIIMS 2009) Face Facial Muscles Origin Insertion Action Corrugator supercilli Medial end of supercilliary Skin of eye brow Vertical wrinkling of forehead: arch frowning Orbicularis oris: Medial part of medial Concentric rings return to Closes lid tightly, wrinkling, protects -- Orbital part, on and palpebral ligament and the point of origin eye from bright light around the orbital adjoining bone margin -- Palpebral part, in Lateral part of medial Lateral palpabral raphae Closes lid gently the lids palpebral ligament -- Lacrimal part, Lacrimal fascia and Upper and lower tarsi Dilates lacrimal sac, directs lac. lateral and deep to lacrimal bone Puncta into lacus lacrimalis; the lacrimal sac supports the lower lid. Orbiularis oris Superior incisivus, from Angle of mouth Closes and purses the mouth, -- Intrinsic part, maxilla, inferior incisivus, numerous extrinsic muscles make deepest stratum, from mandible it more versatile for various types of very thin sheet grimaces  Anatomy 11 -- Extrinsic part, two Thickest middle stratum, Lips and the angle of the strata, formed by derived from buccinators, mouth converging muscles thick superficial stratum, derived from elevators and depressors of lips and their angles Buccinators, the Upper fibres, from maxilla, Upper fibres, straight to the Flattens cheek against gums and muscle of cheek opposite molar teeth upper lip teeth, prevents accumulation of food in the vestibule Lower fibres, from Lower fibres, straight to the mandible opposite molar lower lip teeth Middle fibres, from Middle fibres decussate pterygomandibular raphae before passing to the lips (AIPG 2002) Platysma Upper parts of pectoral and Anterior fibres, to the base Releases pressure of skin on ANATOMY deltoid fasciae of the mandible, posterior the subjacent veins, depresses fibres, to the skin of the mandible, pulls the angle of the lower face and lip, and mouth downwards as in horror or may be continuous with the surprise. (AIPG 1994, MAN 1994) risorius Facial expressions Muscles involved Smiling and laughing Zygomaticus major Sadness Levator labli superioris and levator anguli oris Grief Depressor anguli oris Anger Dilator naris and depressor septi Frowning (KAR 2000) Corrugator supercilii and procerus Functional groups of facial muscles Opening Sphincter Dilators Palpebral fissure Orbicularis oculi Levator palpebrae superioris Occipitofrontalis part. Oral fissure Orbicularis oris All the muscles around the mouth, except the orbicularis oris the sphincter, and the mentalis which does not mingle with orbicularis oris. Nostrils Compressor naris Dilator naris. Depressor septi. Medial slip of levator labli superoris alaequae nasi. Nerve Supply of Face Facial nerve (VII) the motor nerve of the face for all muscles, except levator palpebrae superious, which is supplied by occulomotor nerve (III) Trigeminal nerve is the main sensory nerve of the face (V) The skin over angle of the jaw is supplied through great auricular nerve (PGI 2005) Arch of Aorta Brachiocephalic artery –– Right common carotid artery  12  Review of All Dental Subjects €€ External carotid artery €€ Internal carotid artery –– Right subclavian artery Left common carotid Left subclavian artery Arteries of the Face External carotid Facial artery The anterior branches on the face are large and named. Artery (ECA) They are (1) Inferior labial, (2) superior labial, and (3) (AIPG 2001) Interal nasal to the ala and dorsum of the nose. The posterior branches are small and unnamed. Maxillary artery Inferior alveolar is The Buccal and mental (MAN 2002, AIIMS 1991) Formed From the second artery from inferior ANATOMY part of maxillary artery alveolar. (AIPG 1994, MAN 1994) Superficial temporal artery Transverse facial is a small branch of superficial temporal. It supplies the parotid gland and its duct, Masseter and the overlying skin. and ends by anastomosing with neighbouring arteries. Internal carotid Ophthalmic artery arises from cerebral Supraobital, supratrochlear, dorsal nasal branches. artery (ICA) part of ICA (AIPG 1998) Lingual Artery Arises from the anterior surface of external carotid artery Supplies the tongue and floor of the mouth Branches –– Dorsal lingual artery –– Sublingual artery –– Supplies the hyoglossus, genioglossus Deep lingual artery Right Subclavian Artery Principal artery of upper limb Branches – Vertebral artery (first and largest branch) – Internal thoracic – Thyrocervical trunk – Inferior thyroid artery – Supra scapular – Superficial cervical artery – Costo cervical trunk – Dorsal scapular artery Maxillary Artery Terminal branch of external carotid artery Divided into 3 by lateral pterygoid into 3 parts  Anatomy 13 First or mandibular Deep auricular artery part -- Supplies TMJ, external acoustic meatus and tympanic membrane Anterior tympanic branch -- Supplies the middle ear Middle meningeal artery -- Supplies duramater, periosteum of bone and red bone marrow -- The frontal or anterior branch is the commonest source of extradural hemorrhage (AIIMS MAY 2013) Accessory meningeal artery -- Supplies meninges and infratemporal fossa Inferior alveolar artery -- Lingual branch to tongue -- Br to mylohyoid muscle -- Mental br to supply the chin Second or Branches to muscles of mastication pterygoid part Branches to buccinators ANATOMY Third or pterygoid These are closely involved in Le Fort I, II, III fractures. palatine part Posterior superior alveolar -- Supplies molars and premolars -- Supplies maxillary sinus Infraorbital -- Supplies incisors and canines -- Lacrimal sac, nose, upper lip Greater palatine -- Supplies palate and gums -- Gives lesser palatine branch that supplies soft palate and tonsil Pharyngeal branch -- Supplies the nasopharynx, auditory tube, sphenoidal air sinus Artery of pterygoid canal -- Supplies the pharynx, auditory tube and tympanic cavity Sphenopalatine artery -- Postero lateral nasal branches to lateral wall of nose and paranasal sinuses -- Posterior septal branches to nasal septum Venous Drainage of Head, Neck and Face Retromandibular vein Formed by the junction of superficial temporal vein and maxillary vein. It lies in the substance of parotid gland Divides into 2 divisions: Anterior and posterior division Anterior branch joins facial vein to form common facial vein (drain into internal jugular vein) Posterior branch joins posterior auricular vein to form external jugular vein. External Jugular Vein Site of origin: –– Union of posterior division of retromandibular vein and posterior auricular vein – just below the angle of the mandible (KAR 2000) –– It is provided by two valves one at the termination and other at 4 cm above clavicle. Between these two valves the vein is dilated to form a sinus.  14  Review of All Dental Subjects Tributaries: –– Posterior auricular –– Posterior division of retromandibular –– Transverse cervical –– Suprascapular –– Anterior jugular –– Occipital –– Oblique jugular –– Posterior external jugular vein Anterior jugular vein: Site of origin: –– Just below the chin by the union of small tributaries from the submandibular region and runs down the anterior median line. Terminates by going laterally deep to sternocleidomastoid and draining into external jugular vein. –– Sometimes vein of kocher replaces the external jugular vein and accompanies the anterior jugular vein. ANATOMY Dangerous area of Face Facial veins are devoid of valves and rests directly on muscles Infection from the upper lip and the lower part of nose may travel in retrograde direction to cavernous sinus, due to communication between deep facial vein and angular vein. Deep facial vein drains into cavernous sinus. (AIPG 2002) Cutaneous Nerves of the Face Main nerve Branch Area of distribution Ophthalmic division of Supratrochlear nerve Scalp up to vertex, forehead; trigeminal nerve Supraorbital nerve Upper eyelid; conjunctiva, small part of lower eyelid. Lacrimal nerve and root, dorsum and tip of nose. External nasal nerve Maxillary division of Infraorbital nerve Upper lip; side and ala of nose; most of the lower eyelid; trigeminal nerve Zygomaticofacial nerve (AIPG 1998) upper part of cheek.Upper part of the cheek. Zygomatico temporal nerve anterior part of temple. Mandubular division of Auriculo temporal nerve Upper 2/3 of lateral surface of auricle; and side of head. trigeminal nerve Buccal nerve Lower and major part of the cheek. Mental nerve Lowe lip; chin; lower part of cheek; lower jaw except over the angle. Cervical plexus Anterior division of great auricular nerve Skin over the angle of the jaw and over the parotid gland. Cutaneous nerve (C2,C3). Lower margin of the lower jaw. lower 1/3rd of both lateral Upper division of transverse (anterior) and medial surface of pinna. cutaneous nerve of neck (C 2, C3) MUSCLES OF MASTICATION Mainly four muscles: (AIPG 2003, AIIMS 1989) Masseter Temporalis Lateral pterygoid Medial pterygoid Origin Insertion Nerve supply Actions Masseter Masseteric nerve, Elevation of mandible It is quadrilateral; in shape and has 3 branch of the anterior layers: trunk of mandibular nerve  Anatomy 15 Origin Insertion Nerve supply Actions -- Superficial layer: Its fibres originate Downwards and backwards into from the angle and lower half of the * Zygomatic process of maxilla in lateral surface of mandible the form of a thick aponeurosis * Anterior 2/3rd of the lower border of zygomatic arch (AIIMS 1992) -- Middle layer: From the following Into the middle part of ramus. two places of zygomatic arch: * Deep surface of anterior 2/3rd of the arch * Lower border of posterior 1/3rd of the arch -- Deep layer: Into the upper part of the ramus From the deep surface of zygomatic and coronoid process ANATOMY arch Temporalis: The fibres converge By deep temporal Elevates mandible * From whole length of temporal downwards. The anterior branches of the posterior fibres retract the fossa fibres descend vertically, anterior trunk of the mandible after protraction intermediate obliquely and mandibular nerve (MAN 2002) * From deep surface of temporalis posterior fibres horizontally to (AP 2001) fascia (AP 2000) Helps in lareral sliding of get inserted into the coronoid mandible during grinding process and anterior margin of ramus of mandible (PGI 2005) Some fibres also join masseter and pass on to the mandible Lateral pterygoid: It is short thick Fibres pass backwards and By a branch of It helps in opening the mouth by muscle with origin by two heads laterally to get inserted into: mandibular nerve pulling the condylar process of mandible forward (AIPG 2014, 2012, AIIMS May 2010) * Upper head: Arises from Depression in front of the Protrusion of mandible along infra temporal surface and neck of mandible with medial pterygoid infratemporal crest of greater wing of sphenoid * Lower head: Arises from the Articular disc of lateral surface of lateral pterygoid temporomandibular joint plate of sphenoid (COMEDK 2006) Medial pterygoid: It is a thick Raises the mandible quadrilateral muscle * Superficial part: Into the lower and back part of By a branch of Assists in protrusion of From the medial surface of lateral the medial surface of angle and mandibular nerve mandible pterygoid plate. ramus of mandible as high as Acting with lateral pterygoid mandibular foramen above and alternatively, it produces a From the grooved surface of the nearly as forwards as mylohyoid movement pyramidal surface of palatine bone groove * Deep part: small slip originates from the lateral surface of palatine bone and tuberosity of maxilla Movement Muscles Elevation Masseter, temporalis, medial pterygoid (MAN 1994, AIIMS 1993)  16  Review of All Dental Subjects Movement Muscles Depression Lateral pterygoid (AIPG 2012, AIIMS MAY 2013) Depression of mandible Digastric, genohyoid, mylohyoid against resistance (Mouth is opened wide or against resistance) Protrusion (PGI 2001) Lateral and medial pterygoid Retraction Posterior fibers of temporalis Resistance of retraction Middle and deep fibres of masseter, digastric and genohyoid Lateral movement (example Alternate contraction and relaxation of pterygoid muscles. towards right) Ex. contraction of left lateral pterygoid and right medial pterygoid followed by relaxation of right lateral (AIIMS Nov 2013) pterygoid Chewing movements/side- Medial and lateral pterygoid of each side acting alternately. ANATOMY side movements Structure present superficial to hyoglossus are: Structures present deep to hyoglossus are: (AIIMS 1998, AIPG 1999) Lingual nerve Glossopharyngeal nerve Hypoglossal nerve Lingual artery Submandibular ganglion Stylohyoid ligament Submandibular gland Genioglossus -- Submandibular duct Intrinsic muscles of tongue -- Styloglossus SALIVARY GLANDS The daily secretion of saliva: 500 and 1500 milliliters. Normal stimulated secretion rate in adults is 1 – 2 ml per minute. Circadian variation: Unstimulated flow peaks at approx 5pm in most individuals, with a minimum flow at night (0.05ml/ min) during sleep allowing populations of bacteria to build up in mouth - result is a dragon breath in morning Saliva is a merocrine secretion The viscosity of saliva is non-Newtonian. The ability to draw out a thread of saliva is known as ‘Spinnbarkelt’. Saliva has a pH between 6.0 and 7.4 (with the higher pH exhibited upon increased secretion). Salivary Gland Gland Situation Duct opening Secretion Innervation Parotid Below the external Stensons duct Purely serous Parasympathetic Nerves: secretomotor. They reach acoustic meatus ----after piercing the the gland through the auriculotemporal nerve. The between the ramus buccinators opens preganglionic fibres begin in the inferior salivatory of mandible and into the vestibule of nucleus, pass through the 9th nerve, its tympanic sternocleidomastoid. mouth opposite the branch, tympanic plexus and lesser petrosal nerve Largest of all crown of maxillary and relay in the otic ganglion. The post ganglionic salivary glands 2nd molar fibres pass through the auriculotemporal nerve and reach the gland. (PGI 2001, KCET 2007) Sympathetic Nerves: Sympathetic nerves are vasomotor. They are derived from the plexus around the external carotid artery. Sensory Nerves: Auriculotemporal nerve.  Anatomy 17 Gland Situation Duct opening Secretion Innervation Submandibular Roughly J shaped Wharton’s duct--- Mixed and Supplied by submandibular ganglia. salivary gland, opens on the floor predominantly Parasympathetic Fibres: Are secretomotor situated in the of mouth, on the serous from chorda tympani. They begin in the superior anterior part of the summit of the sub salivatory nucleus and pass through sensory root digastrics triangle. lingual papilla, at of facial nerve, geniculate ganglion, facial nerve, The gland is divided the side of frenulum chorda tympani, lingual nerve and submandibular into larger superficial of tongue. ganglion where the preganglionic fibres relay. and small deep The post ganglionic fibres emerge from the parts by mylohyoid ganglion and soon enter the submandibular muscle gland. (AIIMS 1999) Sympathetic Fibres: Are vasomotor. They are Sublingual Smallest of the three Bartholin’s Mixed and from the plexus around the facial artery. salivary gland. It is duct—10 – 15 predominantly Sensory Fibers: From lingual nerve ANATOMY situated above the ducts emerge mucous mylohyoid, below from the gland. the mucosa of the Most of them open floor of the mouth. directly into the (AIPG 2007, AIIMS floor of the mouth Nov 2012) on the summit of sublingual fold. A few of them join the submandibular duct. Parotid Duct (AIIMS May 2008) Labial and Glands of lips and cheeks are mixed buccal glands consisting of mucous tubules with serous Thick walled and is about 5 cm long demilunes. Intercalated ducts are variable It emerges from the middle of the anterior border of the in length. gland Glossopalatine Pure mucous glands. They are principally glands localized to the region of the isthmus in At the anterior border of masseter it turns medially and glossopalatine fold. pierces (AIIMS 1989, AIPG 2007) Palatal glands Pure mucous in nature lying in the lamina –– Buccal pad of fat propria of the posterior lateral region of the –– The buccopharyngeal fascia hard palate –– Buccinators (obliquely) Lingual glands The glands of tongue in the anterior region called glands of Blandin and Nuhn are Orifice is located on the buccal surface near maxillary purely mucous in nature where as glands in surface of 2nd molar (AIPG 2003) the posterior tongue are mixed. The posterior lingual serous glands called Von Ebner’s glands are located between Structures within the parotid gland: (COMEDK 2006, the muscle fibres of the tongue below the PGI 1999, KAR 1998) circumvallate papilla –– Arteries: €€ External carotid artery TONGUE €€ Maxillary artery Development of Tongue: €€ Superficial temporal vessel €€ Posterior auricular artery  (PGI 2000, AIIMS 1998, KAR 2000, 1999) –– Veins: Retromandibular vein Epithelium –– Anterior 2/3rd: First branchial arch: two lingual –– Nerve: Facial nerve swellings and one tuberculum impar Minor salivary glands: small groups of secretory units –– Posterior 1/3rd: Third branchial arch: cranial half of opening via short ducts directly into the mouth. hypobranchial eminence  (AIPG 2002)  18  Review of All Dental Subjects –– Posterior most: Fourth arch Muscle: occipital myotomes   (AIPG 2008, COMEDK 2006) Connective tissues: Local mesenchyme Pre sulcal mucosa: Tuberculum impar Post sulcal part: Hypobranchial eminence Development of Genioglossus Motor nerves:  (AIPG 1999, AIIMS 1994) –– All muscles except palatoglossus are supplied by hypoglossal nerve  (AIPG 2009) –– Palatoglossus is supplied by cranial part of accessory nerve  (AIPG 2012) Sensory: (AIIMS may 2013) –– Anterior 2/3rd €€ Lingual nerve: General sensory ANATOMY €€ Chorda tympani: Special sensory –– Posterior 1/3rd: Glossopharyngeal nerve – general and special sensory (AIIMS MAY 2013, AIPG 2002, 2007, KCET 2009) –– Posterior most part: Vagus (internal laryngeal) Genioglossus is the only tongue muscle which protrudes it. It is used for testing the integrity of hypoglossal nerve. If the right hypolglossal is paralysed, the tongue will deviate towards the right as the normal left hypoglossal will pull the base of tongue to left and resultant deviation of the apex towards the right.  (AIIMS Nov 2013) Lymphatics: (AIPG 2014, AIIMS Nov 2013) Drain chiefly into the deep cervical lymph nodes. Lymph nodes situated at the bifurcation of common carotid artery is intimately associated with the lymph vessels from tongue so also known as principal gland/node of the tongue. Lymph vessels from the tongue may be divided into: Apical: From the tip of the tongue. Drains bilaterally into the submental lymph nodes   (MAR 1998, MAN 2000) Lateral: From lateral margins of the tongue, these pierce the mylohyoid to drain in the submaxillary lymph nodes or directly into the deep cervical nodes. Basal: From vallate papillae region. Drain into the upper deep cervical lymph nodes. Median Ultimately the whole lymph drains into the jugulo-omohyoid nodes. Arterial supply: Lingual artery  (AIPG 1996) The base of the tongue is attached to the hyoid bone and mandible.  (PGI 2006) Muscles of Tongue Extrinsic muscles (paired with a central raphae) Intrinsic muscles Genioglossus Superior longitudinal Hyoglossus Inferior longitudinal Chondroglossus Transverse Styloglossus Vertical Palatoglossus  Anatomy 19 Origin