Oral Anatomy Lecture 1 PDF

11/24/24 WELCOME TO 2rd TERM! ORAL ANATOMY BE GOOD AND...

11/24/24 WELCOME TO 2rd TERM! ORAL ANATOMY BE GOOD AND LETS ENJOY THE DR. KATRINA BIANCA B. CRUZ - NATIVIDAD DMD (NU), MDSc (Perio- CSMU) TERM! 1 2 Ehh, DENTAL ANATOMY Shall We Start, Doc? § a field of anatomy dedicated to the study of human tooth structures. § The development, appearance, and classification of teeth fall within its purview. § Dental anatomy is also a taxonomical science: it is concerned with the naming of teeth and the structures of which they are made, this information serving a practical purpose in dental treatment. 3 4 1  11/24/24 NOMENCLATURE DECIDUOUS TEETH § Teeth are named by their set, arch, class, type, and side. § Teeth can belong to one of two sets of teeth: Deciduous teeth ◦ Primary ("baby") teeth ◦ There are 20 primary ("baby") teeth Permanent teeth ◦ Secondary (Adult) teeth ◦ 28 to 32 permanent teeth, the last four being third molars or "wisdom teeth“ 5 6 PERMANENT TEETH PERMANENT TEETH Succedaneous tooth/teeth § refers to those teeth of the permanent dentition that replace primary teeth o incisors, canines, and premolars Non-succedaneous tooth/teeth § pertaining to those permanent teeth that are not preceded by a primary form o molars 7 8 2  11/24/24 Teeth are named by their arch MIDLINE § The imaginary vertical line which divides each arch, as well as the body, into two approximately equal halves. MAXILLARY MANDIBULAR is the term given to is term used for teeth teeth in the upper in the lower jaw; jaw; stationary movable 9 10 QUADRANTS OCCLUSION MASTICATION § The two approximately equal portions of each arch divided by § The manner in which § The term for the the midline. the mandibular teeth process of biting or § Four in the entire mouth. contact the maxillary chewing of food teeth 1. maxillary (upper) right 2. maxillary (upper) left 3. mandibular (lower) left 4. mandibular (lower) right 11 12 3  11/24/24 CLASSIFICATION OF DENTITIONS § Teeth of the first, or primary dentition Heterodont – comprised of different types, or classes, of teeth to perform different functions in the § 6 months to 2 years of age mastication process. Ex: human § 20 teeth Homodont – all of the teeth are the same in form and § milk teeth; baby teeth; temporary teeth type. Ex: lower vertebrates Diphyodont – has two separate sets of teeth, or dentitions. Monophyodont - there is only one set of teeth Polyphyodont - more than two or continuous sets of teeth are developed throughout life 13 14 § Teeth of the second, or adult dentition. § Transitional phase when both deciduous and permanent teeth are present § 32 teeth § 6-21 years of age 15 16 4  11/24/24 Deciduous Dentition: Permanent Dentition: § 5 deciduous teeth per quadrant § 8 permanent teeth per quadrant § 10 per arch § 16 in a complete arch § 20 total teeth § 32 total teeth Incisor Canine Molar When compared to the permanent teeth, the primary dentition 1. Incisors (2) contains an identical number of incisors and canines, but has no 2. Canine (1) premolars and one less molar per quadrant. 3. Premolars (2) or bicuspids Incisor Canine Premolar 4. Molars (3) Molar 1. Incisors (2) – which are named central and lateral incisors 2. Canine (I) or cuspid 3. Molars (2) – which are named first and second molars 17 18 ANTERIOR TEETH POSTERIOR TEETH INCISORS § from Latin incidere, "to cut" § Incisors § Premolars § first kind of tooth in human § Canine § Molars § two teeth of each quadrant which are closest to the midline. § named central and lateral incisors. § functions in mastication: biting, cutting, incising and shearing. § 4 per arch, and a total of 8 in the mouth 19 20 5  11/24/24 CANINE PREMOLARS § Cuspids § Dog teeth, fangs, eye teeth, Bicuspids (in the case of those of the are transitional teeth located bet- upper jaw) ween the canine and molar teeth § Possess the longest roots termed first and second of all teeth and are located at the corners of the dental premolars. arch. masticatory role: tearing, holding, § function in mastication: and grinding. cutting, tearing, piercing, and holding. 4 per arch, and 8 total premolars (permanent dentition) § 2 per arch, and a total of 4 in the mouth. 21 22 MOLAR DENTITION PERIODS § From the Latin name mola, Primary Dentition Period means "millstone” § termed first, second, and third § Only deciduous teeth are present molars. § Approx. 6 mos to 6 y/o § six vear molar; twelve year; and wisdom tooth § Ends with eruption of the first permanent tooth (mandibular 1st molar) § masticatory function: grinding § primary dentition: 4 per arch; 8 total § permanent dentition: 6 per arch; 12 total 23 24 6  11/24/24 DENTITION PERIODS DENTITION PERIODS Mixed Dentition Period Permanent Dentition Period § Both deciduous and permanent teeth are present § Only permanent teeth are present § Approx. 6y/o to 12y/o § Approx. 12 y/o § Ends with the exfoliation of the last deciduous tooth (maxillary § Continues through the rest of life. 2nd molar) In order for a permanent tooth to erupt into a space where a deciduous tooth is located, the deciduous tooth must first be shed, or exfoliated. The natural process by which deciduous roots are "melted away" to allow for exfoliation is termed resorption 25 26 SUCCEDANEOUS TEETH § Permanent teeth that replace exfoliated deciduous teeth are Deciduous Dentition: Normal Eruption Sequence called succedaneous teeth, which simply means "succeeding" 1. Mandibular central incisor deciduous teeth. 2. Mandibular lateral incisor § 20 deciduous = 20 succedaneous teeth 3. Maxillary central incisor Mandibular deciduous teeth normally precede Incisors 4. Maxillary lateral incisor their maxillary counterparts in eruption. Canines Premolars 5. Mandibular first molar 6. Maxillary first molar Deciduous teeth normally erupt in order from § Molars - only permanent teeth which are not succedaneous the front of the mouth toward the back, even 7. Mandibular canine though the canines in each quadrant normally All succedaneous teeth are permanent teeth, but all permanent teeth are not 8. Maxillary canine erupt after the first molars. succedaneous teeth. 9. Mandibular second molar 10. Maxillary second molar 27 28 7  11/24/24 Deciduous Dentition: Normal Eruption Time Permanent Dentition: Normal Eruption Sequence 1. Mandibular first molar 9. Maxillary first premolar 2. Maxillary first molar 10. Mandibular second premolar 3. Mandibular central incisor 11. Maxillary second premolar 4. Mandibular lateral incisor 12. Maxillary canine 5. Maxillary central incisor 13. Mandibular second molar 6. Maxillary lateral incisor 14. Maxillary second molar 7. Mandibular canine 15. Mandibular third molar 8. Mandibular first premolar 16. Maxillary third molar In the maxillary arch. not only is the first molar out order, but the canine normally follows both premolars. 29 30 NUMBERING SYSTEMS FDI WORLD DENTAL FEDERATION NOTATION § FDI World Dental Federation notation § The FDI (Federation Dentaire Internationale) World Dental Federation developed in 1971 a system to § Universal numbering system identify teeth with a number. § Palmer notation method. § This system is called the FDI Two-Digit Notation, also known as the ISO-3950 notation. § The FDI Two-Digit Notation is widely recognized and used worldwide. 31 32 8  11/24/24 § Each patient’s mouth is divided into quadrants: For deciduous teeth, the system varies § The quadrants are numbered from 1 to 4, in a clock-wise slightly. All child’s quadrants are numbered sense, starting from the upper-right. from 5 to 8, following the same starting point Upper right = 1 and rotation of the permanent numbering. Upper left = 2 Upper right = 5 Lower left = 3 Upper left = 6 Lower right = 4 Lower left = 7 § Teeth are numbered from 1 to 8, going from the central incisor to the third molar. Lower right = 8 § incisors are numbered 1 and 2 (11, 21, 12, 22, 31,41..) § canines are numbered 3 (13, 23, 33, 43) § premolars 4 and 5 (14, 24, 45 …) § molars have a number ranging from 6 to 8 (16, 27, 48…) 33 34 FDI WORLD DENTAL FEDERATION NOTATION Deciduous teeth Permanent teeth 35 36 9  11/24/24 THE UNIVERSAL NUMBERING SYSTEM THE UNIVERSAL NUMBERING SYSTEM § is a simplified method of identifying teeth that is approved and adopted by the American Dental } Tooth number 1 is the patient's maxillary right third Association. molar. Numbering of teeth continues along the upper teeth toward the front and across to the last primary teeth – uppercase letters A through T molar tooth back on left side (number 16). permanent teeth – numbers 1 - 32 } The tooth numbering continues by assigning teeth § Permanent maxillary teeth are numbered from 1- numbers descending to the lower left third molar 16, then permanent mandibular teeth are (number 17) and follows the lower (mandibular) numbered 17-32 jaw up to the tooth farthest back on the bottom right side of the mouth (number 32). § Primary maxillary teeth are lettered from A-J, then primary mandibular teeth are lettered K-T 37 38 THE UNIVERSAL NUMBERING SYSTEM THE UNIVERSAL NUMBERING SYSTEM § All teeth that should be there are numbered, including those teeth that have been removed for any reason or have not erupted yet (e.g. wisdom teeth). Deciduous teeth Permanent teeth 39 40 10  11/24/24 PALMER NOTATION PALMER NOTATION § Although supposedly superseded by the FDI § The Palmer notation consists of a symbol (┘└ ┐┌) World Dental Federation notation, it designating in which quadrant the tooth is found and a number indicating the position from the midline. overwhelmingly continues to be the preferred method used by orthodontists, dental students and § Adult teeth are numbered 1 to 8, with deciduous (baby) practitioners in the United Kingdom teeth indicated by a letter A to E. § It was originally termed the Zsigmondy § Hence the left and right maxillary central incisor would have the same number, "1", but the right one would have the system after the Hungarian dentist Adolf symbol, "┘", underneath it, while the left one would have, Zsigmondy who developed the idea in 1861, using "└". a Zsigmondy cross to record quadrants of tooth positions. 41 42 PERMANENT TEETH DECIDUOUS TEETH RIGHT LEFT RIGHT LEFT 43 44 11  11/24/24 RECAP § Dental Anatomy § Nomenclature of tooth: § Primary and permanent § Succeedaneous and non-suceedaneous § Maxillary and mandibular § Anterior and posterior § Classes of teeth § Numbering system § FDI system § Universal System § Palmer’s notation 45 46 TOOTH SURFACES SURFACES AND RIDGES § Apical Apical Apical § Labial/Buccal § Lingual/Palatal Mesial Distal § Distal Labial § Mesial Lingual § Incisal/Occlusal Incisal Incisal 47 48 12  11/24/24 LABIAL SURFACE BUCCAL SURFACE LINGUAL / PALATAL SURFACE § Surface of the § Surface of posterior anterior tooth facing tooth facing toward toward the lip the cheek § This is the surface of a tooth that is closest or next to your tongue. On your upper teeth, this is called the palatal surface. On your lower teeth, it's called the lingual surface. 49 50 PROXIMAL INCISAL SURFACE SURFACE Surface of the teeth facing toward the surface of the adjacent teeth § Surface of the anterior tooth which is use for cutting or MESIAL SURFACE tearing food Surface of the tooth which is toward the median line DISTAL SURFACE Surface of the tooth which is away the median line 51 52 13  11/24/24 OCCLUSAL SURFACE § Surface of the posterior tooth which is used for grinding food and the surface of a tooth which occludes with the opposing tooth. 53 54 § 1. occlusal surface 4. distal surface § 2. mesial surface 5. buccal surface § 3. lingual surface 6. incisal surface 55 56 14  11/24/24 } A linear, rounded border of enamel that forms the mesial and distal margins § It is any linear elevation on the surface of the crown of the tooth of anterior teeth as viewed and is named according to its location. from the lingual, and the mesial and distal borders of occlusal surfaces on posterior teeth. 57 58 § It is a linear elevation which } The only tooth on which an descends from the tip of the oblique ridge is found is the cusp to the central part of maxillary molar. the occlusal. } Consists of an § The slope of each side of the elevated prominence on the o ridge resemble 2 sides of a cclusal surface and extends triangle. obliquely from the tips of the mesiolingual cusp to the distobuccal cusp 59 60 15  11/24/24 § The ridge of enamel that } Each cusp has four cusp extends from the cingulum ridges radiating from its to the cusp tip on the lingual tip. surface of most cuspids. } They are named according to the direction they take away from the cusp tip (for example, mesial, distal, buccal, or lingual) 61 62 } The union of a buccal and lingual triangular ridge that crosses the surface of a posterior tooth transversely (roughly 90° to both the buccal and lingual tooth surfaces) 63 64 16  11/24/24 LANDMARKS 65 66 § A pointed or rounded § Found on the lingual aspect elevation of enamel found on of an anterior tooth. cuspids and on the chewing § It is a convex mount of surfaces of bicuspids and enamel localized to the molars cervical one-third of the crown 67 68 17  11/24/24 § It is a small pinpoint depression found at the junction or terminals of the developmental grooves and named according to its location § A rounded or angular depression of varying size found on the surface of a tooth 69 70 § Centrally located depression § Irregular, shallow found onthe occlusal surface depression found on the of molars and mandibular lingual surfaces of an incisor second bicuspids. or cuspid. 71 72 18  11/24/24 § Located adjacent to the ma rginal ridges on the occlusal surfaces of posterior teeth. § Two types of triangular fossae are mesial and distal § A small linear depression on the surface of a tooth 73 74 — Fissure between the cusps on the crown of — A minor, auxiliary groove the tooth. that — Cusp tips are the initial site where enamel branches off from a mu develops. ch more prominent developmental groove. — As the enamel develops and spreads laterally, it touches enamel developing from other — They do not represent the cusps. junction of primary tooth parts and gives the occlusal — This junction forms a developmental surface a wrinkled appea groove. rance — Such grooves appear on the labial, buccal, and lingual surfaces, and are least apparent on the labial aspect of anteriors 75 76 19  11/24/24 § Is one of the primary divisions of § Are small, rounded a crown; all teeth develop from projections of enamel from four or five lobes. the incisal edges of newly erupted anterior teeth. § Lobes are usually separated by readily identifia § The projections wear away ble developmental grooves soon after eruption 77 78 BLUE LINES RIDGES GREEN ARROWS GROOVES RED DOTS PITS 79 80 20  11/24/24 81 82 83 84 21  11/24/24 MBCR, Mesiobuccal cusp ridge; CF, central fossa (shaded area); MTF, mesial triangular fossa MMR, mesial marginal ridge; MLCR, mesiolingual cusp ridge; OR, oblique ridge; DLCR, distolingual cusp ridge; DF, distal fossa; DTF, distal triangular fossa (shaded area); DMR, distal marginal ridge; DBCR, distobuccal cusp ridge. 85 86 1. MesioBuccalCusp DIVISION INTO THIRDS, LINE 2. DistoBuccal Cusp 3. MesioLingual Cusp 10. Distal Marginal ANGLES AND POINT ANGLES 4. DistoLingual Cusp Ridge 5. Buccal 11. Mesial Developmental Triangular Fossa Groove 12. Distal 6. Lingual Triangular Fossa Developmental 13. Central Fossa Groove 14. Disto Buccal 7. Central Sulcus Triangular Ridge (Developmental (Crest) Groove) 15. Oblique Ridge 8. Supplemental Groove 9. Mesial Marginal Ridge 87 88 22  11/24/24 LONG AXIS AND AXIAL SURFACE DIVISION INTO THIRDS — The long axis of a tooth is § ROOT an imaginary line that goes § Divided into cervical third, middle third, and apical third through the crown and root around which the substance of a tooth is most § CROWN symmetrically distributed. § Divided into thirds in three directions: inciso-occlusocervically, mesiodistally, or labio- or buccolingually. — — Any surface of a tooth that is parallel to the long axis is called an axial surface Figure 2-8. Long Axis (for example, mesial, distal, facial, or lingual surfaces). 89 90 DIVISION OF A CROWN INTO THIRDS § The facial/lingual, mesial/distal surfaces of a crown can be divided into thirds, both horizontally and longitudinally: MESIAL/DISTAL SURFACE – divided longitudinally § HORIZONTALLY: cervical 3rd, middle 3rd, occlusal/incisal 3rd § LONGITUDINALLY: § Facial/lingual surface: Labial/Buccal 3rd, middle 3rd,lingual 3rd § Mesial/Distal surface: Mesial 3rd, middle 3rd, Distal 3rd FACIAL/LINGUAL SURFACE – divided horizontally and longitudinally 91 92 23  11/24/24 § An angle formed by the junction of two crown surfaces. It derives its name from those surfaces. § There are eight line angles per tooth 93 94 LINE ANGLE — Anterior Tooth Line Angles — Posterior Tooth Line Angles — 1. Mesiolabial — 1. Mesiobuccal § formed by the junction of three crown surfaces — 2. Mesiolingual — 2. Mesiolingual — 3. Distolabial — 3. Distobuccal § the name of the point angle is derived by combining the names — 4. Distolingual — 4. Distolingual of the three surfaces. — 5. Labioincisal — 5. Bucco occlusal — 6. Linguoincisal — 6. Linguo occlusal — 7. Mesioincisal — 7. Disto occlusal — 8. Distoincisal — 8. Mesio occlusal 95 96 24  11/24/24 § Anterior Tooth Point Angles § Posterior Tooth Point Angles § 1. Mesiolabioincisal § 1. Mesiobucco-occlusal § 2. Mesiolinguoincisal § 2. Mesiolinguo-occlusal § 3. Distolabioincisal § 3. Distobucco-occlusal § 4. Distolinguoincisal § 4. Distolinguo-occlusal 97 98 D A.Mesiolinguo-occlusal A D point angle A B E B.Mesiobucco-occusal B E point angle C F C F C.Mesiolingual line angle D.Distolinguo-occlusal point angle E.Distobucco-occlusal point angle F.Distobuccal line angle 99 100 25  11/24/24 ü Ruler ü Pencil ü Coloring pencils/crayons ü Activity sheet 101 102 QUIZ NEXT MEETING! 103 26