[01] Introduction to Oral Anatomy.pdf

DENT 111: ORAL ANATOMY A.Y. ‘24 - ‘25 | SEM 1 | DR. MICHELLE SEGARRA MODULE 1: INTRODUCTION TO ORAL ANATOMY HETERODONT OUTLINE ○ Humans...

DENT 111: ORAL ANATOMY A.Y. ‘24 - ‘25 | SEM 1 | DR. MICHELLE SEGARRA MODULE 1: INTRODUCTION TO ORAL ANATOMY HETERODONT OUTLINE ○ Humans have varying tooth shapes; aligns with the 1.0 Introduction to Oral 3.0 Teeth Landmarks teeth’s individual function Anatomy 3.1 Elevations homo = one 1.1 Dentition Formation 3.2 Depressions hetero = varied 1.2 Dental Formulas 1.3 Types of Teeth 4.0 Nomenclature 1.2 DENTAL FORMULAS 1.4 Parts of a Tooth 4.1 Universal Numbering 1.5 Periodontium System The number-letter system denoting the type and 4.2 Palmer Notation number of each type of teeth in a half-arch dentition 2.0 Terms of Orientation/ System Reference 4.3 FDI Two Digit System Legend: 2.1 Surfaces of the Teeth ○ Letter - the type of tooth 2.2 Divisions of the Teeth I = incisor C = cuspid (or canine) PM = premolar 1.0 INTRODUCTION TO ORAL ANATOMY M = molar ○ Number - number of teeth Oral Anatomy ○ Line - indicates upper and lower teeth ○ Study of stomatognathic system; teeth and its supporting structure Stoma = mouth TABLE 1. DENTAL FORMULAS Gnatha = jaw / temporomandibular joint NOTES IMAGE 1.1 DENTITION FORMATION DECIDUOUS ➔ Calculation The human dentition is characterized as diphyodont ◆(Total no. of teeth in a half-arch) x 2 and heterodont. Figure 1. Deciduous ◆10 x 2 = 20 primary teeth DIPHYODONT ○ Humans have two sets of teeth PERMANENT di = two ➔ Calculation phy = set ◆(Total no. of teeth in odonto = teeth a half-arch) x 2 ◆16 x 2 = 32 PRIMARY DENTITION permanent teeth Figure 2. Permanent ○ First set of teeth ○ also termed as DECIDUOUS DENTITION 6 months: first primary/baby/milk tooth erupts 2 years and 6 months: usual age when all primary 1.3 TYPES OF TEETH teeth erupted All primary teeth can erupt up until 3.5 years Our dentitions are classified as heterodont for having two tooth types: ANTERIOR and POSTERIOR TEETH PERMANENT DENTITION ○ Second set of teeth The anterior teeth are the front teeth 6 years old: first permanent tooth erupts ○ Incisors 17 - 25 years old: all permanent teeth should ○ Cuspids have erupted; except for third molars which may or may not erupt The posterior teeth are the teeth at the corners ○ Premolars MIXED DENTITION ○ Molars ○ When both primary and permanent dentition is apparent at the same time ○ Can occur from ages 6-12 until all primary dentition are shed off SURNAME 1 | SURNAME 2 | SURNAME 3 DDM 2029 | DENT 111 PAGE 1  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY ANTERIOR TEETH 1.3.1 ➔ Help canines form corners of the arch TABLE 2. ANTERIOR TEETH ➔ Erupt at age 8 - 9 NOTES IMAGE ➔ For grinding or crushing food Figure 5. Premolars INCISORS ➔ The front teeth MOLARS ➔ Most posterior of the teeth ➔ 8 in total; 4 upper + 4 lower ➔ Functions in crushing food ➔ Important aesthetically and in maintaining the (central dominance) and vertical dimension of the phonetically too to lower face properly pronounce ◆ Losing molars can sounds result to sunken cheeks and a more aged ➔ Support the upper lip Figure 3. Central and Lateral appearance Incisors ➔ Central Incisors Figure 6. Molars ➔ Maintains arch integrity ◆ Teeth immediately to the right of left of the midian line 1.4 PARTS OF A TOOTH ➔ Lateral Incisors ◆ Tooth next to the There are TWO basic anatomical divisions central incisors ○ CROWN CUSPIDS/CANINES Visible in the oral cavity ➔ The teeth at the corners of Covered with enamel the mouth ○ ROOT ➔ Distinct due to the Embedded in the alveolar bones through the presence of a cusp alveolar sockets Covered with cementum ➔ 4 in total; 2 upper and 2 lower CEMENTO-ENAMEL JUNCTION [CEJ] ➔ Has direct communication ○ Also termed as the CERVICAL LINE with the pulp thru the ○ Cervix → the narrowest part of the crown Figure 4. Cuspids odontoblastic processes ○ Joins the crown and root together ➔ Considered a living tissue: can feel pain or sensitivity POSTERIOR TEETH 1.3.2 Premolars/Bicuspids ○ Mini-molars; found between the canines and the molars Figure 7. Parts of a Tooth ○ Help canines form corners of the arch TABLE 3. POSTERIOR TEETH THE 4 TOOTH TISSUES 1.4.1 NOTES IMAGE can be classified as either hard or soft tissue ○ Refer to Tables 4 and 5 PREMOLARS/BICUSPIDS ➔ Mini-molar; found between canines and molars ➔ 8 in total; 4 upper + 4 lower BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 2  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY TABLE 4. HARD TISSUES TABLE 5. SOFT TISSUE NOTES IMAGE NOTES IMAGE ENAMEL PULP TISSUE ➔ The outermost covering of ➔ The agglomeration of the the crown nerves and the blood vessels of the tooth ➔ Hard substance in the human body ➔ Contained in the pulp cavity ➔ Hard but brittle ◆Pulp chamber: crown portion ➔ 95% - 97% inorganic or ◆Pulp canal: root portion mineralized; more dead (aka root canal) than alive ➔ Provides nutrition and ➔ Grayish in color, highly sensory supply to teeth translucent Figure 8. Enamel Figure 11. Pulp Tissue DENTIN ➔ Makes up the bulk of the CLINICAL VS ANATOMIC CROWN 1.4.2 tooth; the main tissue of the tooth TABLE 6. CLINICAL VS ANATOMIC ➔ Softer than enamel with 70% mineralized or NOTES IMAGE inorganic CLINICAL CROWN ➔ 30% of it is organic, ➔ The portion of the crown making it more organic visible in the oral cavity and ductile ➔ Measured from the gingival ➔ Has direct communication level to the incisal edge with the pulp thru the odontoblastic processes Figure 9. Dentin ➔ Length depends on the level Figure 12. Clinical Crown of the gingiva; in case of: ➔ Considered a living tissue: can feel pain or sensitivity ◆ Gingival recession = longer CEMENTUM ➔ The outermost covering of ◆ Gingival proliferation = the root shorter Figure 13.Gingival Recession ➔ Forms part of the ◆ Tooth erupting = shorter periodontium ➔ Where periodontal fibers are anchored in the tooth ➔ Less mineralized than the Figure 14. Gingival two other hard tissues: Enlargement 55% inorganic & 45% organic ANATOMIC CROWN Figure 10. Cementum ➔ The portion of the tooth covered with enamel ➔ Measured from the CEJ to the incisal edge ➔ Length is constant throughout life Figure 15. Anatomic Crown BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 3  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY DENTAL PULP ANATOMY 1.4.3 TABLE 7. PERIODONTIUM Pulp cavity NOTES IMAGE ○ A hollow cavity at the root CEMENTUM ○ The overall space containing the dental pulp ➔ 50% mineralized tissue ○ Is divided into the pulp chamber and pulp canal ➔ Not too thick covering of Pulp chamber the root of the tooth (in ○ The portion of the cavity at the crown cm) ○ Contains the coronal pulp Corona - Latin word for crown Figure 18. Cementum Pulp canal ALVEOLAR BONE ○ The portion of the cavity at the root ➔ Where the root is ○ Contains the radicular pulp embedded in a body Radicula - Latin word for root socket called the ALVEOLUS Figure 19. Alveolar Bone PERIODONTAL LIGAMENT ➔ Made up of periodontal fibers ➔ Fill the periodontal space Figure 16. Pulp Cavity ➔ Connects cementum to the alveolar bone (tooth to Pulp horns bone connection) ○ The projection of coronal pulp toward the incisal edge of the cusp tips ➔ ANKYLOSIS: the condition Figure 20. Periodontal wherein no periodontal Ligament Apical Foramen space is present; tooth ○ The small hole that aids in the communication of being directly attached to the pulp to the outside systems the bone, makes extraction ○ Found at the apex or tip of the root extra difficult GINGIVA ➔ Soft tissue overlapping the alveolar bone ➔ Color: ◆Pink = healthy ◆Red, puffy = periodontal disease Figure 21. Gingiva ➔ GUMS in layman’s term Figure 17. Pulp Horns & Apical Foramen Periodontium = attachment apparatus of the teeth 1.5 PERIODONTIUM → Periodontitis: a disease of the periodontium; when teeth became loose, can lead to tooth loss Periodontium ○ The supporting structures of the teeth ○ Focused by periodontics 2.0 TERMS OF ORIENTATION/REFERENCE Consists of cementum, alveolar bone, periodontal The teeth is divided into two arches: the Maxillary ligaments, and the gingiva and the Mandibular arch BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 4  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY Each arch has 16 teeth consisting of: TABLE 8. SURFACES OF THE TEETH ○ 4 incisors ○ 2 cuspids NOTES IMAGE ○ 4 premolars ○ 6 molars PROXIMAL ➔ Surfaces facing toward Median line/Midline adjoining teeth in the same ○ An imaginary line (between the central incisors) dental arch dividing the arches into bilaterally symmetrical right ➔ Each tooth has two: and left halves mesial and distal surface ◆Mesial - surfaces facing There are 4 quadrants in the oral cavity (each toward the midline quadrant having the same content and quantity) ◆Distal - surfaces facing ○ 8 teeth away from the midline Figure 24. Mesial Surfaces 2 incisors 1 cuspid 2 premolars 3 molars Figure 25. Distal Surfaces FACIAL ➔ Can be labial or buccal surface ➔ Labial: surfaces facing the lips; from Latin “Labial” = lips Figure 26. Labial and Buccal ➔ Buccal: surfaces facing Surfaces the cheeks; from Latin Figure 22. Four Quadrants “Bucco” = cheeks 2.1 SURFACES OF THE TEETH LINGUAL ➔ Surfaces facing toward the The FIVE surfaces of the teeth tongue; Latin “Lingua” = ○ Mesial tongue ○ Distal ○ Facial ➔ In case of maxillary teeth, the term used is palatal ○ Lingual surface ○ Occlusal/Incisal Figure 27. Lingual Surfaces INCISAL/OCCLUSAL ➔ The working surfaces of the teeth ➔ Differentiation: ◆Incisal - for anterior teeth; they incise food ◆Occlusal - for posterior teeth; occlude or come into contact with the opposite arch Figure 28. Incisal (red) / Figure 23. Surfaces of the Teeth Occlusal (blue) surfaces BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 5  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY OTHER TERMS OF REFERENCE 2.1.1 Apical TABLE 9. DIVISION OF A TOOTH INTO THIRDS ○ Toward the apex NOTES IMAGE Cervical ○ At the cervical portion INCISO- / OCCLUSO- ○ More toward the CEJ CERVICALLY Incisal/Occlusal 1) Incisal / Occlusal third ○ Toward the incisal or occlusal surfaces ◆Incisal → anterior teeth ◆Occlusal → posterior teeth 2 ) Middle third 3 ) Cervical third Figure 30. Occluservical Division MESIODISTALLY 1) Mesial third Figure 29. Apical, Cervical, Incisal/Occlusal Reference 2 ) Middle third 3 ) Distal third 2.2 DIVISIONS OF THE TEETH Divisions into THIRDS of the crowns and roots for purposes of description of specific surfaces; naming Figure 31. Mesiodistal Division according to location LABIO- / BUCCOLINGUALLY Descriptive terms for the junctions of the crown surfaces 1) Labio / Buccal third ○ LINE ANGLES ◆Labio → anterior teeth ○ POINT ANGLES ◆Buccal → posterior teeth Crown 2 ) Middle third ○ Is divided into 3 ) Lingual third incisal/occlusal third Figure 32. Buccolingual Middle third Division Cervical third ○ In three directions Inciso- / occluso-cervically Mesiodistally: mesial, middle, distal thirds Labio- or bucco-lingually: labial/buccal, middle, lingual thirds ○ General Format 1 middle third 2 other thirds (based on location) Root ○ may be divided into Cervical third Middle third Apical third BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 6  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY Line Angle Point Angle ○ Imaginary lines formed by the junction of two ○ Formed by the junction of three surfaces surfaces ○ Name is derived from the combination of the three ○ Name is derived from the combination of the two surfaces surfaces Ex: junction of the mesial + buccal + occlusal Ex: mesial + labial surfaces = mesiolabial line surfaces of a molar = mesiobucco-occlusal point angle angle TABLE 10. ANTERIOR LINE ANGLES TABLE 12. ANTERIOR POINT ANGLES ➔ Mesiolabial ➔ Mesiolabioincisal ➔ Mesiolingual ➔ Mesiolinguoincisal ANTERIOR ➔ Distolabial ➔ Distolabioincisal ANTERIOR ➔ Distolingual ➔ Distolinguoincisal ➔ Labioincisal ➔ Linguoincisal Figure 35. Anterior Point Angles TABLE 13. ANTERIOR POINT ANGLES Figure 33. Anterior Line Angles ➔ Mesiobucco-occlusal TABLE 11. POSTERIOR LINE ANGLES ➔ Distobucco-occlusal FOR POSTERIOR ➔ Mesiolinguo-occlusal ➔ Mesiobuccal ➔ distolinguo-occlusal ➔ Distobuccal ➔ Mesiolingual ➔ Distolingual POSTERIOR ➔ Mesio-occlusal ➔ Disto-occlusal ➔ Bucco-occlusal ➔ linguo-occlusal Figure 36. Anterior Point Angles Figure 34. Posterior Line Angles BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 7  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY 3.0 LANDMARKS RIDGES 3.1.3 TABLE 16. RIDGES 3.1 ELEVATIONS NOTES IMAGE Refers to convex/raised areas on a tooth surface TRIANGULAR RIDGE ➔ Descend from the tips of the cusps of molars and CUSPS 3.1.1 premolars toward the central part of the occlusal surfaces TABLE 14. CUSPS ➔ Named as it is because NOTES IMAGE the slopes of each side of the ridge are inclined to CUSPS resemble two sides of a Figure 40. Triangular ridge ➔ Triangular elevations triangle found on the occlusal surface of posterior teeth TRANSVERSE RIDGE and incisal edge of the ➔ Ridge formed by the union cuspids Figure 37. Mesiobuccal cusp of of a buccal and lingual mandibular 2nd molar (red dot) ridge ➔ Named depending on their location ➔ Formed by the union of 2 Figure 41. Transverse ridge on triangular ridges crossing posterior tooth transversely the surface of a posterior tooth Figure 38. Distolingual cusp of OBLIQUE RIDGE mandibular 2nd molar (red ➔ Ridge crossing obliquely outline) the occlusal surfaces of maxillary molars ➔ Found only on maxillary Figure 42. Oblique ridge on molars maxillary molar (top left = CINGULUM 3.1.2 ➔ Formed by the union of the distobuccal cusp; low right = triangular ridge of the mesiolingual cusp) TABLE 15. CINGULUM distobuccal cusp and the distal ridge of the mesiolingual cusp NOTES IMAGE CINGULUM MARGINAL RIDGE ➔ Round elevation found on ➔ Rounded borders of the the cervical third on the enamel that form the lingual surfaces of anterior mesial and distal margins teeth of the occlusal surfaces of posterior teeth and the Figure 43. Marginal ridge ➔ Can be only found on mesial and distal margins anterior teeth Figure 39. Cingulum on of the lingual surfaces of anterior tooth anterior teeth ➔ Called marginal ridge because they delineate the boundaries/proximal margins of the teeth BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 8  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY LABIAL RIDGE FOSSAE 3.2.2 ➔ Linear elevation running cervico-incisally on the Irregular depression or cancavities. labial surface of a cuspid Fossae: plural; Fossa: singular ➔ The well-developed middle lobe of the tooth Figure 44. Labial ridge named according to their location BUCCAL RIDGE TABLE 18. FOSSAE ➔ Linear elevation running cervico-occlusally on the buccal surface of a NOTES IMAGE maxillary first premolar MAJOR FOSSA ➔ Central fossa for anterior tooth Figure 45. Buccal ridge ➔ Maxillary of lateral incisor CERVICAL RIDGE ➔ Ridge running mesiodistally across the cervical third of the labial surface of permanent maxillary molars and all deciduous teeth Figure 46. Cervical ridge 3.2 DEPRESSIONS Refers to the concave (curves inward) areas on a tooth surface Figure 49. Central fossa MINOR FOSSAE GROOVES 3.2.1 ➔ Mesial triangular fossa ➔ Distal triangular fossa Any linear depression on the surface of a tooth ➔ Very important to Figure 50. Minor fossae TABLE 17. GROOVES stimulate during restorations NOTES IMAGE MAJOR GROOVES ➔ Buccal groove PITS 3.2.3 ➔ Lingual groove Pinpoint depressions located at the junction of Figure 47. Major grooves developmental grooves or at end of grooves ➔ Central groove MINOR GROOVES TABLE 19. PITS ➔ Mesiobuccal groove NOTES IMAGE ➔ Mesiolingual groove Figure 48. Minor grooves PITS ➔ Distobuccal groove ➔ Prone to tooth decay if a person has poor oral ➔ Distolingual groove hygiene or fond of fermented carbohydrates or sweets Figure 51. Pits BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 9  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY LOBES 3.2.4 4.0 NOMENCLATURE One of the primary sections of formation in the In clinical practice, some “shorthand” system of tooth development of the crown notation is necessary for recording data All anterior teeth show traces of 4 lobes: three Types of nomenclature labially, and one represented by the cingulum ○ Universal Numbering System / ADA ○ Zsigmondy/Palmer’s Notation System Mamelons ○ FDI Two Digit System ○ In the incisor, each labial lobe terminates incisally in rounded eminences 4.1 UNIVERSAL NUMBERING SYSTEM Labial grooves ○ Fusion between each lobes on the labial surface is Also called as American Dental Association (ADA) marked system ○ Aesthetically, these are important as they give character and optical illusions on the teeth in In 1968, ADA recommended the “universal” restoration numbering system In posterior teeth, the tip of each cusp represents the PERMANENT DENTITION 4.1.1 primary center of formation of each lobe 1-32 for each permanent tooth TABLE 20. LOBES ○ Maxillary: 1 - 16 ○ Mandibular: 17 - 32 NOTES IMAGE For ex.: LOBES ○ “15” = permanent maxillary left 2nd premolar ➔ anterior tooth, 4th lobe is the cingulum on the lingual surface ➔ Maxillary premolar ➔ Mandibular first molar ➔ Maxillary molar Figure 52. Lobes Note: ELEVATION VS DEPRESSION Figure 54. ADA Permanent Dentition Figure 55. ADA Permanent Dentition Figure 53. Elevation vs Depression PRIMARY DENTITION 4.1.2 → Elevation = like a mountain Uppercase letters for each primary tooth → Depression = sort of sunken ○ Maxillary: A - J ○ Mandibular: K - T For ex.: ○ “N” = primary mandibular left lateral incisor BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 10  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY Figure 56. ADA Primary Dentition Figure 58. Palmer Notation System - Permanent Dentition Figure 57. ADA Primary Dentition Figure 59. Palmer Notation System - Permanent Dentition 4.2 PALMER NOTATION SYSTEM PRIMARY DENTITION 4.2.2 Often referred as Palmer notation system, less frequently as Zsigmondy/Palmer notation system Each tooth is denoted as A-E from the central incisor to the 2nd molar Published in 1870 ○ Oldest and most widely used For example ○ ⎾B = primary mandibular left lateral incisor Arches are divided into quadrants ○ ⎿D = primary mandibular left 1st molar PERMANENT DENTITION 4.2.1 Each tooth is denoted as 1-8 from the central incisor to the third molar in each quadrant Each quadrant is depicted as ○ ⏌→ First quadrant ○ ⎿ → Second quadrant ○ ⏋→ Third quadrant ○ ⎾ → Fourth quadrant For example: Figure 60. Palmer Notation System - Primary Dentition ○ 7⏋= permanent mandibular 2nd molar ○ 4⏌ = permanent maxillary right 1st premolar ○ ⎿3 = permanent maxillary left cuspid Figure 61. Palmer Notation System - Primary Dentition BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 11  ORAL ANATOMY | DR. MICHELLE SEGARRA | MODULE 1: INTRODUCTION TO ORAL ANATOMY 4.3 FDI TWO DIGIT SYSTEM PRIMARY DENTITION 4.3.2 Referred as two digit system 1st digit indicates the quadrant (5 to 8) ○ Q5 = maxillary right Proposed by Fédération Dentaire Internationale (FDI) ○ Q6 = maxillary left which has been adopted by WHO ○ Q7 = mandibular left ○ Q8 = mandibular right 1st digit indicates the quadrant; 2nd digit indicates the tooth 2nd digit indicates the tooth within the quadrant(1 to 5) ○ Start with number 1 (central incisor) at the midline PERMANENT DENTITION 4.3.1 to number 5 (2nd molar) 1st digit indicates the quadrant (1 to 4) For example ○ Q1 = maxillary right ○ “64” is the primary maxillary right 1st molar ○ Q2 = maxillary left ○ Q3 = mandibular left ○ Q4 = mandibular right 2nd digit indicates the tooth within the quadrant(1 to 8) ○ Start with number 1 (central incisor) at the midline to number 8 (3rd molar) For example ○ “11” is the permanent maxillary right central incisor ○ Pronounced as “one one”, not “eleven” Figure 64. FDI - Primary Dentition Figure 65. FDI - Primary Dentition REFERENCES VLE Edpuzzle | Introduction to Oral Anatomy Figure 62. FDI - Permanent Dentition VLE Edpuzzle | Surfaces and Landmarks, Terms of Orientation S. J., Ash, M. M., & Ash, M. M. (2015). Wheeler’s Dental Anatomy, physiology, and Occlusion. Saunders/Elsevier. AbuDaif, M. (2017, March 24). Introduction to dental anatomy [Slide show]. SlideShare. https://www.slideshare.net/slideshow/introduction-to-de ntal-anatomy-73618792/73618792 8/21/24 Lecture by Dr. Michelle Segarra Figure 63. FDI - Permanent Dentition BIEN | GAJISAN DDM 2029 | DENT 111 PAGE 12