Dental Anatomy, Embryology, and Histology Units 1-9 Exam 1, Exams of Dental Anatomy

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Dental Anatomy, Embryology, and

Histology Units 1-9 Exam 1

Anatomical Nomenclature - The system of names for anatomic structures What is anatomical position - Body standing erect, arms at sides with palms and toes directed forward and eyes looking forward Supine - Laying on back Prone - Laying on front Anterior/ventral - Front of an area in relationship to the entire body Posterior/dorsal - Back of an area in relationship to the entire body Superior - Area faces towards the head and away from the feet Inferior/caudal - Area faces away from head and towards the feet Apex - Pointed end of a conical structure Median/midsagittal plane - Imaginary line dividing the body into equal right and left halves Sagittal plane - Imaginary plane parallel to the median plane Horizontal/transverse plane - Imaginary line dividing the body into superior and inferior parts

Frontal/coronal plane - Imaginary line dividing the body at any level into anterior and posterior parts Median - Structure located at the midsagittal/median plane Example: Nose or belly button Medial - Area closer to the median plane of the body or structure; not synonymous with median Example: Eyes are medial to ears Lateral - Area farther from the median plane Ipsilateral - Structures on the same side of the body Contralateral - Structures on the opposite side of the body Superficial - Towards the surface of the body Deep - Structures located inward, away from body surface Dental anatomy definition - The science of describing the form, structure, and parts of the tooth Dentition definition - Used to describe the natural teeth in the jaw bone Primary/deciduous teeth - -20 teeth -8 incisors

-4 canines -8 molars NO PREMOLARS IN PRIMARY DENTITION Permanent/secondary teeth - -32 teeth -8 incisors -4 canines -8 premolars -12 molars Only permanent dentition has premolars Arches - 2 Arches -Maxillary arch -Mandibular arch Quadrants - 4 Quadrants -Max right -Max left -Man left -Man right -8 Teeth in each quadrant in permanent dentition -5 Teeth in each quadrant in primary dentition Anterior teeth - -Incisors -Canines

Posterior teeth - -Premolars -Molars Describe the DAQT system - D-Dentition: Permanent or Primary A-Arch: Maxillary or mandibular Q-Quadrant: Right or Left T-Tooth: What tooth is it? Anatomical crown - -Part of tooth covered by enamel (may change due to attrition or wear)(above CEJ) Clinical crown - -Part of the tooth above the attached periodontal tissues -Part of the tooth where clinical treatment procedures are applied (above gumline) Anatomical root - -Part of tooth covered by cementum (below CEJ) Clinical root - -Part of tooth below the base of the gingival sulcus or periodontal pocket -Part of root where periodontal fibers are attached (anything below gumline) Apex of root - Tip or peak at the end of the root Apical foremen - Opening at the apex through which blood vessels and nerves enter Furcation - -Area of a two or three rooted tooth where root divides -Where root splits

Root trunk - Area from the CEJ to the furcation Root concavities - Broad, shallow, longitudinal depressions on roots Long axis of tooth - -Imaginary line running longitudinally through the center of a tooth from the crown to the root -Equal left and right parts Enamel - -Hard (calcified), white shiny surface of the anatomical crown; most densely mineralized and hardest tissue in the body -96% inorganic (mineralized) -4% organic matter and water (less dense) Cementum - -Hard (calcified), dull yellow external surface of the anatomical root (covering the dentin) -Function: to provide a medium for the attachment of the tooth to the alveolar bone Acellular cementum - -Covers entire anatomical root -Forms at slower rate than cellular cementum -Better calcified than cellular cementum -Doesn't increase during life of a tooth Cellular cementum - -Confined to the apical third of the root -Deposited throughout the life of a tooth Dentin - -Hard (calcified), yellowish tissue surrounding the pulp and underlying the enamel and cementum

-Makes up the bulk of tooth -Capable of adding to itself throughout the life of the tooth What is another name for reparative dentin - Reactive dentin Pulp - -Innermost part of the tooth -Non-calcified soft tissue Components of pulp - -Pulp chamber: portion of pulp cavity in the crown of the tooth -Pulp canals/root canals: portion of the pulp cavity in the root of the tooth -Pulp horns-extensions of pulp tissue into a thin point of the pulp chamber in the tooth crown Functions of pulp - -Formative -Sensory -Nutritive -Defensive/protective Cementoenamel junction (CEJ) - -Also known as cervical line -Separates the enamel of the anatomical crown from the cementum of anatomical root Dentinoenamel junction - -Union of the dentin and enamel -Only visible on a cross section or when preparing a tooth for a restoration Cementodentinal junction - -Union of cementum and dentin -Only visible on a cross section

Functions of teeth - -Incisors: Biting, incising -Canines: Pierce or tear -Premolars: Assist canines in tearing, assists molars in grinding -Molars: Grind food Dividing the tooth into thirds - -You can only use horizontal lines when dividing the ROOT -You can use horizontal and vertical lines when dividing the CROWN -Study images Line angles of teeth - -Angle formed by junction or meeting of two surfaces -Anterior teeth have 6 line angles -Posterior teeth have 8 line angles Point angles of teeth - -Angle formed by junction or meeting of three surfaces -Anterior teeth have 4 point angles -Posterior teeth have 4 point angles Interproximal space - -Triangular space between adjacent teeth cervical to their contact -Occupied by interdental papilla in healthy individuals Embrasures - -V-shaped spillway space or triangular shaped space adjacent to the contact area on adjacent teeth -Lingual embrasure is larger -Incisal embrasure is smallest -No contact no embrasure

Function of embrasures - -Spillways to direct food away from gingiva -Make the teeth more self-cleansing -Protect the gingival tissue from undue frictional trauma and provide provide proper degree of stimulation to the tissue Height of contour/Crest of Curvature - Most convex bulge of tooth/widest part of the crown of the tooth Eruption - Moving of the tooth occlusally Exfoliation - To shed a tooth Resorption - Physiological removal of a hard tissue such as enamel, dentin, cementum, or bone Active eruption - The emergence of a tooth from its position in the jaw to its position in occlusion Passive eruption - The increased exposure of a tooth Succedaneous - -Tooth that replaces another tooth -Incisors, canines, and premolars Nonsuccedaneous - -Permanent teeth without primary predecessors -Molars Universal Numbering System (UNS) - -Most widely accepted method to record teeth -Primary teeth: A-T

-Permanent teeth: 1- Palmer Notation System - -Primary teeth: A-E for quadrant -Permanent teeth: 1-8 for quadrant -Used in some ortho offices Federation Dentaire Internationale (FDI) - -AKA International Standards Organization Designation System (ISO System) (International Numbering System) -Each quadrant is assigned a number -Primary: 5,6,7,8 Distally count 1- -Permanent: 1,2,3,4 Distally count 1- Where are marginal ridges found of anterior teeth? - On the lingual aspect Mesial and distal incisal angles on maxillary central incisors - -Mesial is acute (90 degrees) -Distal is rounded Root characteristics of maxillary central incisors - Rarely have root concavities Which incisor is most likely to have variation in form and more developmental disturbances? - Maxillary lateral incisors What is the smallest tooth in the oral cavity? - Mandibular central incisors Which tooth is bilaterally symmetrical having a fan shape? - Mandibular central incisors

Are mandibular lateral incisors crowns twisted mesially or distally? - Distally What is a developmental disturbance that can happen with a mandibular lateral incisor? - Can have an accessory root or bifurcated root Labial aspect of maxillary canines - Mesial cusp slope is shorter at eruption than distal cusp slope Do canines have labial and lingual ridges? - Yes -The lingual ridges separate the mesiolingual and distolingual fossae Most likely anterior tooth to have a bifurcated root - Mandibular canine Which cingulum is more pronounced, Max or Mand Canine? - Maxillary canine Height of contour for posterior teeth - -Facial: Cervical third -Lingual: Middle third Maxillary first premolar buccal aspect - Mesial cusp slope is longer than the distal cusp slope Is the maxillary first premolar bifurcated? - Yes How many types of mandibular second premolars are there? - -Two types -2 Cusp type -3Cusp type Lingual aspect of mandibular first premolars - Small lingual cusp-afunctional

3 cusp type mandibular second premolar - -Mesiolingual cusp is wider and longer than the distolingual cusp -Lingual groove is present 2 cusp type mandibular second premolar - Lingual groove is not present but it may have a distolingual developmental depression where the lingual cusp ridge joins the distal marginal ridge Occlusal aspect of mandibular second premolar - -3 cusp type: no transverse ride and can have a Y shaped groove pattern -On the 2 cusp type occlusal outline is more rounded and there is no lingual groove or central pit. Can have a U or H groove pattern How many cusps does a maxillary first molar have - -4 or 5 -Mesiobuccal, distobuccal, mesiolingual, distolingual, and cusp of carabelli (if present) Which cusp is the cusp of carabelli on? - Mesiolingual cusp Root characteristics of maxillary first molars - -3 roots: mesiobuccal, distobuccal, lingual(palatal) -Lingual root is largest and longest -Longitudinal grooves(root convavities) may be found ob the lingual surface of the lingual root, mesial surface of the mesial buccal root and all furcation surfaces Occlusal aspect of maxillary second molars - -Rhomboidal type: 4 cusps -Heart shaped: 3 cusps Characteristics of third molars - -Most likely to be missing

-More anomalies -Most likely to be deviated in form How many cusps does a mandibular first molar have? - 5: mesiolingual, distolingual, mesiobuccal, distobuccal, and distal Do mandibular molars tilt lingually? - Yes Do mandibular molars have oblique ridges? - No How many roots do mandibular molars have? - 2 roots: mesial and distal On the mandibular second molar, what shape is on the occlusal table? - Cross shaped groove