Dental Anatomy PDF

1  Introduction To Dental Anatomy -Human dentition is diphyodont (2 sets of dentitions): Primary/deciduous secondary/permanent - 20 teeth in total – 32 teeth in total - Incisors/canines/molars -incisors/canines/mol...

1  Introduction To Dental Anatomy -Human dentition is diphyodont (2 sets of dentitions): Primary/deciduous secondary/permanent - 20 teeth in total – 32 teeth in total - Incisors/canines/molars -incisors/canines/molars/premolars - Smaller size – Bigger size They are smaller and have They accommodate to the bigger spaces between them. size of skull and jaws of adults. Why 2 sets of dentitions? The jaws have to accommodate the increased number of permanent teeth and their bigger size. Dental formula: We use it to describe the number and the class of teeth that’s found in the oral cavity of different species, for this formula we use number and letters. for example: - "I" for Incisors - "C" for Canines - "PM" for Pre-Molars - "M" for Molars –Deciduous teeth are indicated by the letter D before the initial For Example, Human Dental formula: 1-Deciduous teeth: DI 2/2 DC 1/1 DM 2/2 =10 in each side (so 20 in total) Let’s explain this, as we mentioned before, if we are talking about deciduous, we must put the letter (D) before all letters, and each letter after (D) describes the class of the teeth, so what about number? The numbers following the letter refer to the number of teeth of each type in the upper then the lower dentition for one side only. You must memorize names of teeth Example: respectively. As we see, there are two incisors in the upper and the lower jaw (ONLY ONE SIDE), so we write it like this: molars incisors 2 upper DI 2/2 2 lower Canine This line cuts the oral cavity two sides, we need only one side. 2- Permanent teeth: I 2/2 C 1/1 PM 2/2 M 3/3 = 16 in each side (so 32 in total) We don’t put a letter (D) because we are talking about permanent teeth, as the previous formula, we put the letters that describe the class of teeth then we put the numbers that refer to the number of teeth of each type in the upper then the lower dentition for one side only. You must memorize names of teeth respectively. Example: There are 3 molars in the upper and the lower jaw (ONLY ONE SIDE), so we write it like this: 3 upper M 3/3 3 lower Quadrants: We can divide the jaws to quadrants, we have four quadrants: 1 2 Horizontal line =occlusal plane 5 6 4 3 8 7 Vertical line=midline As We see: – Right maxillary (1 or 5) – Left maxillary (2 or 6) Maxillary: upper jaw – Left mandibular (3 or 7) – Right mandibular (4 or 8) Mandibular: lower jaw Quadrants in permanent dentition have the numbers 1 – 4 and in deciduous have the numbers 5 – 8. 1 or 5 2 or 6 4 or 8 3 or 7 Dental Nomenclature: Is the way that we can name the tooth either words or numbers, letters and/or symbols. -By words: 1- Set of teeth: deciduous or permanent. 2- Jaw: maxillary or mandibular. 3- Class: Incisor / Canine / Premolar / Molar. 4- Order within a class: Central or lateral First / Second / Third 5-Side: right or left. -By number, letters and/or symbols: 1-Palmer/zsigmondy notation system (Teeth order that is used in Jordan): Used by American association in 1947. It uses letters to represent the deciduous teeth, and numbers to represent permanent teeth. In this system, we use two lines: - a horizontal line representing the occlusal plane (the line that divides maxillary from mandibular and upper or lower) - a vertical representing the midline (divides right from left) Examples: – Maxillary right central incisor 1 – Mandibular left second deciduous molar E  2-Universal numbering system - Palmer – difficulty in keyboard typing. - ADA adopted the universal system in 1968. Uppercase letters for deciduous teeth – Consecutive from A to T – Following a clockwise order from maxillary right second molar to mandibular right second molar Numbers for permanent teeth – Consecutive from 1 to 32 – Following a clockwise order from maxillary right third molar to mandibular right third molar Examples: - Maxillary left permanent lateral incisor = 10 - Mandibular right permanent second premolar = 29 -Maxillary left deciduous first molar = I 3- FDI numbering system: - Proposed by FDI & adopted by WHO - we use a specific number for each quadrant of the jaw then we use another number that represents the tooth order, so each tooth is allocated a two-digit number. -Secondary/Permanent:- takes numbers (1-4) for quadrants. -Primary/Deciduous:- takes numbers (5-8) for quadrants. Examples: – Mandibular right permanent canine 43 – Maxillary left deciduous lateral incisor 62 Types of dentition: A- According to number of sets: 1.Monophyodont: Some mammals--such as the manatee, seals, and walruses have only a single generation of teeth. 2.Diphyodont We are referring to most mammals -humans included- that actually have two generations of teeth. 3.Polyphyodont: Most reptiles and fishes develop a lifetime of generations of successional teeth-- Such teeth have a brief functional life and are anatomically simple in design. B- According to the shape of the teeth: 1.homodont: In many vertebrates, all the teeth in the jaw are alike. They differ from each other only in size. The alligator is an example of homodontism. 2.heterodont: Most mammals, humans included(such as incisor, canine, premolars and molars) develop distinctive classes of teeth that are regionally specialized. C- According to presence or absence of teeth: 1.Normal Anodontia: Is the developmental absence of teeth. Among mammals, the whalebone whale and the anteater are toothless; their ancestors had teeth. 2.Pathological Anodontia: In humans, anodontia is a pathological condition, Partial anodontia is one or a few teeth missing. SUMMARY IN THE NEXT PAGE ‫"إلهي أنا ُكلّي رجا ٌء وأ َمل بأن تلك المساعي لن تخيب“‬ ‫‪THE END OF SHEET #1‬‬ ‫‪ ‬بداية موفقة تيجان‬