Dental Anatomy: Tooth Structure and Oral Cavity

Introduction to Dental Anatomy

• Dental Anatomy is a branch of anatomy that specifically studies the structure and morphology of teeth.
• The image displays the different types of teeth in the mouth: incisors, canines, premolars and molars.

Objectives of Studying Teeth

• Acquiring skills related to dental anatomy is essential in dentistry
• Dentistry aims to achieve specific objectives related to dental health and function

Topics Covered

• Overview of the oral cavity and its components
• Discussion of intervals and spaces between teeth
• Examination of teeth at both macroscopic and microscopic levels.
• Understanding the principles of dental formula and notation
• Exploration of point angle, line angle, division of the Intotherds, numbering and naming systems

Components of the Oral Cavity

• Lips: The external soft tissues that surround the mouth opening.
• Gums (Gingiva): The tissue that surrounds and supports the teeth.
• Cheeks: The soft tissues forming the sides of the mouth.
• Tongue: A muscular organ used for taste, speech, and swallowing.
• Floor of the Mouth: The area beneath the tongue.
• Hard and Soft Palates: Forming the roof of the mouth separating the oral and nasal cavities.
• Teeth: The structures used for biting and chewing food.

Lips

• The philtrum is the vertical groove located between the base of the nose and the upper lip.
• Commissures: The corners where the upper and lower lips meet.
• The lips contribute to functions such as speech, facial expression, and eating.

Gums (Gingiva)

• Gums are soft tissues covering the roots of the teeth.

• They are composed of:

  • Free gingiva and attached gingiva, separated by a free gingival groove.
  • Interdental papilla, the gingival tissue between teeth.
  • The alveolar mucosa.

• The attached gingiva is connected to the underlying bone

• Attached gingiva protects the teeth tissues from damage

Cheeks (Buccae)

• The cheeks in Latin form a region located under the eyes and also between the nose.
• The cheek relates to the cheek area
• The cheek is composed of the area between the inner cheek, teeth and gums
• That is also the vestibule, the cheek pouch, or the vestibular cheek area.

Tongue

• The tongue mainly consists of muscle fibers and glands

• Role:

  • Role in speech
  • Taste receptor organ
  • Food blender
  • Food swallowing -Teeth Cleaning

• The tongue contains two anterior parts (right/left)

• These parts have a papillate surface

• One posterior part of the tongue consists of a lymphoid-folliculate surface and connects to the epiglottis

Gross Anatomy of the Tongue

• The foremost two-thirds: This part consists of papillae for taste sensation.
• Back third: is the Lymphatic Area.
• Both parts are separated by a V shaped terminal

Floor of the Mouth and Palate

• The floor of the mouth contains blood vessels and salivary glands
• The palatal root separates the hard and soft palates
• The front palate consists of a pair of bone, that includes gum folds and the alveolar ridge.
• The back palate is typically redder than that of the hard palate.
• The soft palate contains the uvula, which connect to the back palate

Teeth

• Arranged in two arches (upper and lower).

• The upper arch is fixed within the maxillary bone, referred to as maxillary teeth.

• The lower arch is connected to the mandible (the lower jaw), also referred to as mandibular teeth.

• The mandible is connected to the skull through the temporomandibular joint

• The hypothetical dividing line is the dividing median

• The dental arch can be divided into symmetrical halves by the hypothetical dividing line

• Four quadrants are available for both arc's

Teeth Distribution

• Each dental arch is split into halves
• Those halves are also divided into Quarters
• Each quarter can obtain can obtain the next information from tooth, such as,
• The upper right quarter
• The lower right quarter
• The upper left quarter
• The lower left quarter

Function of Teeth

• Chewing:
  • Incisors cut food (biting).
  • Canines tear food (tearing).
  • Premolars and molars grind food (grinding).
• Appearance.
• Speech.
• Jaw development: If a child eats only from one side, only one side of the jaw develops.

Types of Teeth

• Incisors
• Canines
• Premolars
• Molars

Incisors

• Incisors are anterior (front most) teeth in each quarter of the mouth
• The central incisor is closest to the midline

The corner stone: Canines

• Canines are fundamental and are counted as the third tooth starting from the midline
• Canine is present in each quarter

Premolars and Molars Description

• Every quarter contains the presence of two (2) premolars.
• Each quarter contains the presence of three (3) molars
• Both premolars can be counted as the fourth and fifth tooth, as well as, the molars can be counted as the sixth, seventh, and eighth tooth.

Types of Dentition

• Primary (deciduous) teeth: 6 months to 6 years
• Mixed dentition: from 6 to 12 years
• Permanent teeth

Formation of the Teeth

• The Deciduous (milk) teeth can form at a age between The minimum of six (6) months to the highest of six (6) years The primary teeth form between the age range of six (6) years, and upwards of twelve (12) years The permanent teeth occur by the age of twelve (12) and continue for the rest of life

Teething

• The first incisor appears in the sixth (6) month
• The last molar appears in the twenty-fourth (24) month from upwards
• All milk teeth should've had come through by age three (3)
• There contains a value in the amount of twenty (20) milk teeth

Types and Composition of Milk Teeth

• Every row contains two (2) Incisors, one (1) Canines, two (2) Molars
• The teeth are arranged in the occlusal plane
• There occurs twenty (20) teeth: (I2, C1, M2)

Mixed Teeth

• The growth of a first permanent tooth occurs in the sixth year
• The last milk tooh falls out on the 12th year of living
• Missing teeth can sometimes cause space issues with the jaw due to differences from the jaw size
• Sometimes the gum can tear or become red and swollen due to the incoming teeth
• The milkteeth transform into permanent teeth

Development of Permanent Teeth

• The permanent teeth, the secondary teeth, or the successor teeth.
• Occurs from the age of twelve and continues for the rest of life
• There occurs a total of 32 teeth in the permanent configuration.
• Composed: 2 incisors plus a Canine and 2 Premolars including a Molars for each side.
• Molars do not have a predecessor
• The teeth grow continuously until older age

Statistics: Teeth

• Human (permanent) teeth are distinguishable from one another
• One half arc are for humans teeth, as well as, human molars are different from the others as well

Humans can possess a maximum amount of (16) teeth on top arc Human children contain milkteeth count (10)

Dental Formula

• Dental formulas are used to describe the different types and numbers of teeth in the dental arches.

• Dental formula of the Succedaneous Tooth with the count of (20): 2/2 I, 1/1 C, 2/2 M .

• Dental formula of normal teeth: (32) 2/2 I, 1/1 C, 2/2 PM, 3/3 M