Dental Anatomy PDF

1 Nadeen Khataybeh Tasneem Jarwan Heba Al-zer  Introduction to Dental Anatomy Introduction: Human dentition is diphyodont ( this expression means that it has 2 sets) 2 sets of dentitions: ( every set has more than one naming ) 1- Primary / deciduous / baby / milk : 20...

1 Nadeen Khataybeh Tasneem Jarwan Heba Al-zer  Introduction to Dental Anatomy Introduction: Human dentition is diphyodont ( this expression means that it has 2 sets) 2 sets of dentitions: ( every set has more than one naming ) 1- Primary / deciduous / baby / milk : 20 teeth in total as: Incisors/canines/molars Smaller size begins to form prenatally at about 14 weeks in utero and is completed postnatally at about 3years of age begin to appear in the oral cavity at the mean age of 6 months, and the last emerge at a mean age of 28 4 months 2- Secondary / permanent / succedanous(comes after): 32 teeth in total Incisors/canines/premolars (present only here)/molars Bigger size begin to appear in the oral cavity at the mean age of 6 years completed (including the roots) at about 14 to 15 years of age (avg 12+ years ), except for the third molars, which are completed at 18 to 25 years of age WHY DO WE HAVE TO HAVE 2 SETS OF TEETH? Baby teeth are found in small skull and technically jaws. When we grow up our skull shape and size and function changes , the function becomes heavier and the skull shape and size also becomes bigger, so that’s why we need a different set of teeth that are larger and can cut the heavy food the adult eat. Adult teeth are found in bigger jaws,  the transition or mixed dentition period in which there is a mixture of deciduous and succedaneous teeth present. ‫(يعني لما يكون الطفل بكبر و األسنان بتتبدل بكون موجود بالفك اسنان لبنية و‬ ‫)اسنان دائمة بنفس الوقت‬ The transition period lasts from about 6 to 12 years of age and ends when all the deciduous teeth have been shed (‫)يعني لما األسنان اللبنية يتبدلو كاملين باسنان دائمة‬ ) ‫ النه غير طبيعي‬، ‫ سنة‬١٢ ‫(طبيب االسنان الزم يتخذ اجراءات اذا شاف اسنان لبنية عند طفل اكبر من‬ the transition from the primary dentition to the permanent dentition begins with the emergence of the first permanent molars(upper or lower jaw), shedding of the deciduous incisors, and emergence of the permanent incisors (first permanent molars and incisors merge together most of the time) The jaws have to accommodate the increased number of permanent teeth and their bigger size. STAGES OF HUMAN DENTITION:(summary) Edentulous stage: 0-6months Eruption of primary dentition: 6 months-2.5 years Functioning primary dentition: 2.5 - 6 years(stage when baby can grind food) Mixed dentition: 6 -12 years Permanent dentition: 12+ years (If deciduous teeth are present in the mouth of a child over 12 years old, they are considered retained and not normal. This may require certain procedures) Full permanent dentition: (18-25)+ years(stage when 3rd molar is completely developed) DENTAL FORMULA (A way to write the number and types of teeth found in our jaws) I: incisors (First four teeth that we use to cut food with a knife cutting edge) C :Canines(corner stones, sharp edge) PM: premolars(round hexagonal shape,used to grind food) M:molars ( big teeth with large surface,grind food too) Deciduous are preceded by the letter D. The numbers refer to the number of teeth of eachtype in the upper then the lower jaw for one side only.  o Deciduous teeth: DI2/2 DC1/1 DM2/2=10 )‫ كيناين فوق و واحد تحت وهكذا على األسنان الدائمة‬١، ‫ تحت‬٢ ‫ انسايزرز فوق و‬٢ ‫(يعني على حسب الرسمة‬ o Permanent teeth: I2/2 C 1/1 PM2/2 M 3/3 =16 ‫ قسمنا الفك قسمين و بنعد األسنان بعد القسم فوق و تحت لكل سن بحيث لما نجمعهم يعطونا نص العدد‬:‫اختصارا‬ ً ‫األصلي‬. ‫ في نصف الفك السفلي و هكذا‬٢ ‫ في نصف الفك العلوي و‬٢‫) بتعبر عن وجود االنسايزرز‬٢/٢( ‫مالحظة‬ NOMENCLATURE: system of names, used to describe or classify the material included in the subject, here teeth could be classified according to:(important) Set trait:( a specific criteria applies for the whole set) Deciduous or permenant Arch trait:( a specific criteria applies for one arch ) Maxillary or mandibular Class trait:(a specific component) Incisor/canine/premolar /molar Type trait (order within a class) Central or lateral First/second/third Side: Right or left Quadrant )‫(ارباع‬: o UR(upper right) o UL(upper left) o LR(lower right) o LL(lower left) Crown: the white layer that appears when you see your teeth Root: the part that is embedded in the jawbone (invisible) CEJ (Cementoenamel junction): the cervical line. Separates the anatomic crown from the anatomic root at cervix. junction between two tissues-the enamel and cementum. The cervical line is important in your laboratory drawings and clinical work.  Root apex: tip/end of the root Bifurcation, trifurcation: branches of the roots, bi (2) tri (3). Enamel ( white tissue covers The Crown.) Cementum ( Yellow tissue covers The Root.) TOOTH STRUCTURE: (if you cut a molar in half ) Enamel: The protective outer surface of the anatomic crown. It is 96% mineral and is the hardest tissue in the body. Dentin: Located in both the crown and root, it makes up the bulk of the tooth beneath the enamel and cementum. It lines the pulp cavity. Pulp: The central, innermost portion of the tooth. It has formative, sensory, nutritive( feels pain), and functions during the life of the tooth. (coronal, radicular) Cementum: This substance covers the surface of the anatomic root. Crown: pulp chamber Root(s) : root canal(s). ANTERIOR VS POSTERIOR Incisors teeth: incisal edges(cutting edge of incisor teeth) Canines: single cusps. Premolars/molars: two or more cusps. Cusp Incisal edge The root is fixed in the bony process of the jaw called the alveolar process. The bone of the tooth socket is called the alveolus (alveoli) Septa: thin walls that that divide 2 structures The fully erupted crown is partly covered at the cervical third in young adults by the (Gingiva/Gums). ).‫( إحنا فعليا ما بنشوف طول الكراون الحقيقي النه في جزء منه مغطى باللثة‬ Crown: the term can be decided in 2 ways: o The anatomical crown is covered with enamel ‫الطول‬.‫الحقيقي للسن من الخط لعند الحافة النهائية‬. o The clinical crown is the portion of the anatomical crown that is visible clinically. It is what you see when you look in the mouth.  Root: the term can be defined in 2 ways: o The anatomical root is the portion of the tooth that is covered with cementum, a bone-like substance that facilitates anchorage of the tooth in its bony socket (the alveolus). o The clinical root is that part of the anatomical root that is actually embedded in the jaw (not visible clinically). In a patient with advanced bone loss, the clinical root may be reduced in size. Surfaces and ridges Incisors and canines have four surfaces and a ridge (labial, lingual,distal,mesial, incisal) Premolars and molars have five surfaces (buccal, palatal, mesial, distal, occlusal) Surfaces are named according to their positions and uses. Contact area: The area of the mesial or distal surface of a tooth that touches its neighbor. 1- Facial surfaces (faces outside the oral cavity) a-Labial: facial surface of anterior teeth that faces the lips. b-Buccal: facial surface of posterior teeth that faces the cheek 2- Lingual and palatal surfaces a- Lingual: teeth that faces the tongue (lower part) b- Palatal: teeth that faces the palate (upper part) 3- Incisal and occlusal edges a- Incisal: anterior teeth used for biting b- Occlusal: posterior teeth used for chewing 4- Mesial surface (proximal surface): the surface of the tooth that is closer to the midline 5-Distal surface (proximal surface): the surface of the tooth that is farthest from the midline DIVISION INTO THIRDS: to describe the location in a tooth precisely cutting the crown into thirds: Horizontally: a-Cervical: near the cervix of the tooth (neck of the tooth) b-Middle c-Incisal: near the incisal edge Vertically : a-Distal: further from the midline b- Middle Cervical c-Mesial: closer to the midline From the side: Apical a-lingual b-middle c-labial NOMENCLATURE : -Notation systems are then invented to ease classification by simple letters and/or symbols ).‫(عشان لما أطباء األسنان يتواصلوا مع بعض ما يضطروا يكتبوا اسم السن كامل فيستخدموا الرموز‬ Most common systems: 1- Palmer/Zigmondy notation system 2- Universal numbering system 3- FDI numbering system 1-Palmer/Zigmondy notation system (used in Jordan and uni): Tooth is represented by a number 1 – 8 (permanent) or a letter A – E (deciduous) Two lines; indicates which quadrant the tooth belongs to Maxillary: upper jaw – a horizontal representing the occlusal plane Mandibular: lower jaw – a vertical representing the midline  :‫شرح بطريقة بسيطة‬ ‫إذا بين السطر األفقي و العامودي رقم يعني السن دائم أما إذا كان حرف يعني السن لبني‬.1 ‫إذا الخط العامودي متجه ألعلى يعني سن علوي و إذا السفل يعني سن سفلي‬.2 ‫إذا الخط األفقي متجه لليمين يعني السن في الجهة اليسار اما ً إذا كان متجه لليسار يعني السن في الجهة اليمين‬.3 ‫ اتأكد أنها يسار‬L ‫لو طلع حرف‬.4 ‫ ممكن تكمل الرسمة و تربطها مع الجدول لتتأكد و يطلع الجواب اسرع‬:‫مالحظة لتسريع الطريقة‬.5 Mandibular left second deciduous molar Maxillary right central incisor 2-UNIVERSAL NUMBERING SYSTEM Palmer - difficulty in keyboard typing Uppercase letters for deciduous teeth o Consecutive from A to T o Following a clockwise order from maxillary right second molar to mandibular right second molar Numbers for permanent teeth o Consecutive from 1 to 32 o Following a clockwise order from maxillary right third molar to mandibular right third molar 3-FDI NUMBERING SYSTEM Each tooth is allocated a two-digit number; the left designates the quadrant (permanent dentition have the numbers 1- 4 and in deciduous have the numbers 5 - 8, both clockwise) and the right designates the tooth order 1-8 (central incisor till third molar) Examples Mandibular right permanent canine 43 Maxillary left deciduous lateral incisor 62 ‫ ارباع ببلش العد من اليمين (يمين الفك) باتجاه عقارب الساعة‬٤ ‫يعني ببساطة األسنان الدائمة الها‬ ‫كل ربع بعبر عنه الرقم األيسر و الزم نحفظ مكانه‬ 1x 2x 3x 4x ‫ يمين تحت‬٤ ‫ يسار تحت‬٣ ‫ يسار فوق‬٢ ‫ يمين فوق‬١.‫ بتعبر عن رقم السن و تعداده من خط الوسط زي ما مبين بالجدول‬x.‫ دعواتكم لها بالرحمة والمغفرة‬،‫ت ّمت كتابة هذا الشيت صدقة جارية عن روح والدة زميلنا عمرو رائد من دفعة تيجان‬