Dental Anatomy, Physiology and Occlusion PDF

Dental anatomy, Physiology and Occlusion Introduction Tooth morphology is the subject which deals with the external and internal structure, morphology, function, eruption and shedding of all teeth in the Mouth. Importance of Dental anatomy study The practitioner has to have knowledge of the morp...

Dental anatomy, Physiology and Occlusion Introduction Tooth morphology is the subject which deals with the external and internal structure, morphology, function, eruption and shedding of all teeth in the Mouth. Importance of Dental anatomy study The practitioner has to have knowledge of the morphology, occlusion, esthetics,Phonetics, and functions of these teeth to be able to differentiate between normal & abnormal cases to reach the correct diagnosis and undertake the appropriate treatment.  THE SURFACE FORM OF THE ORAL CAVITY LIP GINGIVA TEETH ROOF OF THE PALATE MOUTH CHEEK FLOOR OF THE TONGUE MOUTH PALATINE UVULA TONSILS GINGIVA Dental Anatomy Includes 1- The dentition : refers to all the teeth present in upper & lower jaws. 2- The External Morphology And Internal Composition Of Teeth. 3- The Relationship Of The Teeth To Each Other And To The Skull Bone.  TEETH -Teeth Are Arranged In The Oral cavity In Two Arches Called TheDental Arches One Lower And One Upper. -The Upper Arch Is Called The Maxilla The Teeth In This Arch Are CalledUpper Or Maxillary Teeth. -The Lower Arch Is Called The Mandible The Teeth In This Arch Are CalledLower Or Mandibular Teeth. -Each Dental Arch Has AMidline That Divides The Arch Into Two Approximately Equal Right And Left Segments Named As Quadrant. -There AreFour Quadrants In The Entire Oral Cavity.  Classes of teeth Anterior teeth Incisors and Canines Posterior teeth Premolars and Molars (cheek teeth)  In The Oral Cavity There AreFour Classes 2 1 Of Teeth That Includes: 1-Incisors: 3 - There is two incisors Thecentral incisor and Thelateral incisor. 4 2-Canines: -There isone canine in each quadrant. 3-Premolars: -There are two in each quadrant.First and second premolars. 4-Molars: -There are three in each quadrant. They are thefirst molar, thesecond molar and the third molar. -The incisors and canines are considered anterior teeth since they are closer to the midline. - Molars and premolars are considered posterior teeth since they are farther from the midline.  Dental traits - Set traits : distinguish deciduous teeth from permanent. - Arch traits : maxillary and mandibular teeth. (- Class traits :distinguish four classes of teeth according to function (Incisors, canines, premolars and molars differences be Type traits : differentiate teeth within the same class as- central and lateral incisor, 1st & 2nd premolars or between 1st, 2nd (tween & 3rd molars )  Dentition Periods clinically Humans have two dentitions 1-The primary dentition: (deciduous ) (Baby) (Milk) (Lacteal) (Temporary) at the age of ( 6m – 6y) 20 teeth. 10 maxillary and 10 mandibular. 5 teeth are present in each quadrant. 2 incisors. 1 canine. and 2 molars. The mixed dentition ( transitional Period ): at the age (6 y -12 y) and is called (Ugly-Duckling stage) The mixed dentition period is often a difficult time for the young child because of missing teeth, teeth of different colors and sizes, crowding of the teeth, and malposed teeth.  2-The permanent dentition: (secondary, adult or succedaneous ) 32 teeth, 16 maxillary and 16 mandibular. 8 teeth in each quadrant are Present. 2 incisors. 1 canine. 2 premolars. and 3 molars. Thepermanent molars are not preceeded with deciduous teeth so they may be termed asnon-succedaneous teeth.  Deciduous Mixed Primary dentition Mixed dentition 6m-6y Permanent 6 y -12 y Shedding : It is the physiological loss of the deciduous teeth and their subsequent replacement by permanent teeth. Permanent dentition 12 y and up  X – Ray Showing 1- Primary dentition 2- Mixed dentition (6 m - 6 y ) (6 y - 12 y) 3- Permanent dentition (12 y and up)  Functions of teeth 1- Mastication : It is the most important function of the teeth. The teeth are designed to perform this function. Incisors Canine Premolars Molars Chisel like Wedge like At least two Multiple projections Cutting or Cutting and projections (cusps) incising tearing (cusps). Grinding Tearing and grinding 2- Appearance: Aesthetics - Well arranged clean teeth with proper alignment give nice appearance to the face. Teeth give support to the facial expressions. 3- Speech: Phonation Teeth are important for clear pronunciation and for production of sound. 4-Growth of jaws: Teeth play a role in the growth of the jaws in some periods of life. 5- Maintainthe vertical dimension of the face. 6-Protection: in the case of some animals (biting). 7-Para- masticatory functions of teeth: use of teeth as tools.  Human Dental Formula Expresses number and type of teeth per side Primary teeth 2 1 2 I ---- C ---- M --- = 10 2 1 2 Permanent teeth 2 1 2 3 I ---- C ---- P --- M ---- = 16 2 1 2 3  Summary Humans have two dentitions 1-The primary dentition: (deciduous ) 20 teeth. 10 maxillary and 10 mandibular. 5 teeth are present in each quadrant. 2 incisors, 1 canine and 2 molars. The dental formula is: 2 1 2 I --- C ---- M ---- = 10 2 1 2 2-The permanent dentition: (secondary, adult orsuccedaneous ) 32 teeth, 16 maxillary and 16 mandibular, 8 teeth in each quadrant are present, 2 incisors, 1 canine, 2 premolars and 3 molars. The dental formula is : 2 1 2 3 I ---- C ---- P --- M ---- = 16 2 1 2 3 Thepermanent molars are not preceeded with deciduous teeth so they may be termed asnon-succedaneous teeth. Tooth numbering systems 1) Palmer Notation System: (1861) It is the most widely used system it represents the four quadrants of the dentition as if you facing patient. In upper right In upper left In lower right In lower left Thepermanent teeth are numbered from 1-8 on each side from the midline. Upper right Upper left 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 Lower right Lower left Thedeciduous teeth are lettered from A-E on each side from the midline. Upper right Upper left E D C B A A B C D E E D C B A A B C D E Lower right Lower left 2) The two digit system (F.D.I) (1971) The teeth are designed by using two-digit system: a. Thefirst digit of the code is located at the left side of the number and indicates the quadrant. In the permanent dentition. In the deciduous dentition. U.R. 1 2 U.L. U.R. 5 6 U.L L.R. 4 3 L. L. L.R. 8 7 L.L. b- Thesecond digit is located at the right side of the number and indicates the number of the tooth in the quadrant. The two digits should be pronounced separately. The permanent teeth are numbered from 1-8 from the midline. The deciduous teeth are numbered from 1-5 from the midline. Permanent teeth 18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28 48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38 Deciduous teeth 55 54 53 52 51 61 62 63 64 65 85 84 83 82 81 71 72 73 74 75  3)The universal numbering system (American numbering system)(A.D.A) system:. The number is always preceded by the sign # to designate that the system is used for universal system. Permanent teeth (1 – 32) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Deciduous teeth (A - T) A B C D E F G H I J T S R Q P O N M L K 4- Dane (Hederup system): symbols as (+) & (-) are used 8  7  6  5  4  3  2 1  1  2  3  4  5  6  7  8 Permanent dentition: R 8  7  6  5  4  3  2 1  ‫׀‬ 1  2  3  4  5  6  7  8 L - Deciduous dentition: R 05  04  03  02  01  05  04  03  02  01  ‫׀‬  01  02  03  04  05  01  02  03  04  05 L  Parts of tooth 1- Macro-anatomy of the tooth Each tooth has Four anatomical parts : Enamel I.Crown Cementum II.The Neck: cervical line or cemento-enamel junction (CEJ). II.Root (s) IV. Pulp cavity Anatomical And Clinical Crown And Root Clinical Anatomical Crown Crown Clinical Root Anatomical Root Anatomical And Clinical Crown And Root Gingival Recession Gingival Recession Anatomical crown Clinical Crown Part of the Anatomical root  Anatomical And Clinical Crown And Root C.C. CROWN A.C. C.R. ROOT A.R. Newly Erupted Teeth CROWN A.C. C.C A.R. ROOT C.R. Gingival Recession Dental tissues 2- Micro-anatomy of the tooth - Three calcified tissues: Enamel (hardest tissue) Dentin Cementum + One soft specialized connective tissue: Pulp. Cementum Periodontal Ligament  Junctions Of Tooth Tissues There Are Three Sites Of Junction Enamel DEJ 1- Cemento-enamel junction (CEJ): CEJ Dentin 2- Dentino-enamel junction (DEJ): Pulp 3- Dentino-cemental junction (DCJ): DCJ Cementum  The Teeth and Investing Structures Enamel PDL Dentin alveolar bone Cementum oral mucosa Pulp gingiva saliva TMJ Enamel: Covers, Most Mineralized, Yellowish White. Cementum: Covers, Medium For The Attachment, Dull Yellow, Thickness. Dentin: Surrounds The Pulp Cavities, Underlying The Enamel And The Cementum, Yellow. Pulp: Housed In The Pulp Cavity, Soft Tissue, Supply.  The Pulp Consists Of Two Parts 1 –Coronal pulp : Pulp Pulp chamber + pulp horns Horn 2 – Radicular pulp : Root canal + apical foramen+ accessory canals Note: Many roots m ay be formed with more than one canal, which may end in a common foramen.  The Periodontium Is The Investing And Supporting Attachment System Of Teeth. It consists of: Two Soft Tissues Two Hard Tissues 1- Gingiva 1- Cementum The Oral Mucous Membrane, Covers The Anatomical Root Which Covers Of The Tooth The Neck Of The Tooth And Part Of The Alveolar Bone. 2- Periodontal Ligament 2- Alveolar Bone The Strong Ligament that Attaches Bone Of The Jaw That The Tooth To The Alveolar Bone Surrounds The Root Of The Tooth  Tooth Surfaces Each Tooth Has Five Surfaces Like A Box With 4 Sides And A Roof. MASTICATORY DISTAL LINGUAL MESIAL FACIAL F FACIAL ACIAL LABIAL OR BUCCAL TOWARDS TOWARDS THE LIP THE CHEEK FOR FOR ANTERIOR POSTERIOR TEETH TEETH FACIAL  LINGUAL PALATAL OR LINGUAL TOWARDS THE TOWARDS THE PALATE TONGUE FOR MAXILLARY LINGUAL FOR MANDIBULAR TEETH TEETH PROXIMAL MESIAL & DISTAL TOWARDS THE MIDLINE AWAY FROM THE MIDLINE DISTAL MESIAL FOR ALL THE TEETH  MIDLINE M M D D M = MESIAL SURFACES D = DISTAL SURFACES  MASTICATORY INCISAL OR OCCLUSAL MASTICATORY FOR ANTERIOR TEETH FOR POSTERIOR TEETH The Surfaces Are Identified By The Relationship To Other Orofacial Structures M M Proximal MIDLINE D D Anterior surfaces teeth for all the Distal surface teeth Mandibular Maxillary teeth PALATE teeth Posterior TONGUE teeth CHEEK (buccal) Posterior teeth LIP Anterior teeth  :So The Tooth Surfaces Are A- Facial. B- Lingual. C- proximal. Distal surface D- Masticatory. E- Apical