Ch 4- Dentition

ARRANGEMENT OF TEETH

• General Arrangement of Teeth: This is referred to as dentition.

  • Primary Dentition: Composed of 20 deciduous teeth, commonly known as baby teeth.

  • Secondary Dentition: Comprises 32 permanent teeth.

• Comparison of Dentition:

  • Permanent dentition (32 teeth):

  • Each arch (maxillary and mandibular) consists of 16 teeth.

  • Primary dentition (20 teeth):

  • Each arch has 10 teeth.

ARCHES OF DENTITION

• Upper and Lower Arches:

  • Maxillary Arch: Refers to the teeth anchored in the upper jaw.

  • Mandibular Arch: Refers to the teeth supported by the mandible (lower jaw).

• Division of each Arch:

  • Each arch is divided into a right half and a left half, creating four quadrants (two in each arch).

  • Midline:

  • The dividing line between the right and left sides is known as the midsagittal plane in technical terms and the midline or median line in dentistry.

• Quadrants Representation:

  • Palmer Notation System: Utilizes vertical and horizontal lines to determine quadrants.

  • Maxillary Quadrants: Represented by numbers or letters above the horizontal line.

  • Mandibular Quadrants: Indicated below the horizontal line.

STRUCTURE OF QUADRANTS

• Permanent Dentition Quadrant: Contains 8 teeth:

  • Structures: Central and lateral incisor; canine; first and second premolar; first, second, and third molar.

• Deciduous (Primary) Quadrant: Contains 5 teeth:

  • Structures: Two incisors, one canine, and first and second molars (no premolars are present).

• Succedaneous and Nonsuccedaneous Teeth:

  • Succedaneous Teeth: Permanent teeth that replace deciduous teeth.

  • Nonsuccedaneous Teeth: Permanent molars that do not replace any preceding teeth.

  • Deciduous Molars: Replaced by permanent premolars.

TYPES OF DENTITION

• Mixed Dentition: A dentition that combines permanent and deciduous teeth.

  • Occurs during the transition from primary to secondary teeth.

  • Some adults may retain primary teeth, leading to the presence of mixed dentition in adulthood.

NAMING AND CODING TEETH

• Identification Method: List the appropriate characteristics for a specific tooth in the following order:

  1. Dentition

  2. Arch

  3. Quadrant

  4. Tooth Name

  • Example: Permanent [dentition], Mandibular [arch], Right [quadrant], Central Incisor [tooth].

• Universal System:

  • Uses Arabic numerals 1-32 for permanent teeth and letters A-T for primary teeth.

  • Tooth Assignment:

  • The number 1 corresponds to the maxillary right third molar.

  • The highest number (32) denotes the permanent mandibular right third molar.

  • The letter A represents the primary maxillary right second molar, and letter T for the primary mandibular right second molar.

• Examples of Tooth Representation: Universal System:

  1. Secondary mandibular left first molar: 19

  2. Secondary maxillary right first premolar: 5

  3. Primary maxillary right first molar: B

  4. Primary mandibular left central incisor: O

  5. Permanent maxillary left first premolar: 31

  6. Deciduous mandibular right canine: A.

PALMER NOTATION SYSTEM

• Quadrant Representation: Each quadrant has its symbol or bracket:

  • Maxillary teeth: Number/letter above the line.

  • Mandibular teeth: Number/letter below the line.

• Tooth Number Assignment:

  • Central incisors: Number 1 (permanent), Letter A (deciduous).

  • Lateral incisors: Number 2.

  • Canines: Number 3.

  • First molars: Number 6.

  • Third molars: Number 8.

• Midline Visualization:

  • Tooth identifiers are positioned relative to the midline based on the practitioner’s perspective.

FEDERATION DENTAIRE INTERNATIONALE (FDI) SYSTEM

• Two-Digit Numbering: Each tooth is assigned a unique two-digit number that indicates its quadrant and position relative to the midline.

  • Permanent Teeth Assignment:

  • Maxillary right: 11-18

  • Maxillary left: 21-28

  • Mandibular left: 31-38

  • Mandibular right: 41-48.

  • Deciduous Teeth Assignment: Assigned first digit identifying the quadrant, with the second digit showing the position.

• Examples of FDI Tooth Number:

  • The respective symbols for permanent teeth vary according to their location in the mouth and whether they are deciduous or permanent.

REVIEW QUESTIONS

1. Types of Dentition:

   • Primary Dentition: 20 teeth.

   • Secondary Dentition: 32 teeth.

2. Different Arches:

   • Maxillary and Mandibular.

   • Primary arch: 10 teeth; Secondary mandibular arch: 16 teeth.

3. Different Quadrants: Total of 4 quadrants - upper right, upper left, lower right, lower left.

4. Succedaneous Primary Teeth: None, since primary teeth are not succeeded by other primary teeth.

5. Nonsuccedaneous Teeth: All permanent molars.

6. Are Secondary Molars Nonsuccedaneous?: No, they are the successors of deciduous molars.

7. Dentition with Both: This is called mixed dentition.

8. Number of Dentitions: Two types (primary and secondary).

9. Identification through Universal System:
   a. Numbers: 3, 5, 19, 28, 32
   b. Letters: A, E, J, M, S

10. Universal Symbols for Teeth:

    • a. Primary maxillary left central: E

    • b. Primary mandibular right first molar: C

    • c. Primary maxillary right canine: B

    • d. Permanent maxillary right second premolar: 4

    • e. Permanent mandibular right central incisor: 25

11. Identify by Dentition, Arch, and Quadrant:

    • a. 8: Permanent maxillary right first molar

    • b. E: Primary maxillary left central

    • c. 1: Permanent maxillary right central incisor

    • d. 6: Permanent maxillary right first premolar

12. Translate Symbols from Palmer to Universal System: Based on their quadrant assignments.

13. Palmer, Universal, and FDI Symbols for Permanent Mandibular Right First Molar: Codified according to mentioned systems.

14. Identification of Symbols: Documentation of systems from which they are derived and their corresponding teeth representations.