Dental Anatomy: Deciduous Teeth Overview

Dental Anatomy Study Notes

• Sheet number: 10
• Year: 2024
• Written by: Lajneh Teejan
• Edited by: Lajneh wisdom
• Doctor: Aseel Sharaireh

Introduction: Deciduous Teeth

• Deciduous teeth, also known as baby or milk teeth, are temporary teeth that are shed and replaced by permanent teeth.
• The deciduous teeth develop during early childhood and last until approximately 12 years of age.
• These teeth are important for oral development, speech, and the proper growth of the oral cavity.
• Premature loss of deciduous teeth can affect the growth and development of the jaw and the eruption of permanent teeth.

Function of Primary Teeth

• Masticatory: These teeth are critical for cutting, tearing, and grinding food into smaller pieces, enabling proper digestion.
• Craniofacial Development: Primary teeth maintain space for permanent teeth, preventing the displacement of developing teeth.

General Differences Between Deciduous and Permanent Teeth

• Size: Primary teeth are smaller than their permanent counterparts.
• Crown Shape: Primary teeth have flatter chewing surfaces and are often fatter (wider)
• Root Shape & Structure: Primary tooth roots are slender and divergent compared to the thicker, more bulbous permanent roots.
• Pulp Chamber: Primary tooth pulp chambers are larger than permanent teeth.
• Cusps: The cusps in primary canines are more slender and conical while permanent ones are more rounded.

Specific Tooth Anatomical Features

• Central Incisors (Maxillary): The only incisors with a mesio-distal width larger than the crown height, overarching mesial and distal profiles over the root, and no labial grooves on their surfaces.
• Central Incisors (Mandibular): Bilaterally symmetrical with 90-degree mesio-incisal and disto-incisal angles; the incisal margin is horizontal.
• Lateral Incisors (Maxillary): Very similar to the maxillary central incisor. Its mesio-distal width is smaller than the crown length. Distal incisal angle is rounded.
• Lateral Incisors (Mandibular): Very similar to the mandibular central incisor but the crown height/mesio-distal ratio is greater.
• Canines (Maxillary): Mesio-distal width is larger than the crown height and has no labial ridge or depression; well-developed sharp cusp.
• Canines (Mandibular): Crown height is more extensive than the mesio-distal width, and less cervically converging mesial and distal profiles. The cervix (neck) area is often more constricted.
• First Molars (Maxillary): Morphologically atypical, intermediate between a premolar and molar; smallest molar in all aspects (except bucco-palatal).
• First Molars (Mandibular): Also unique in shape, more molar-like with 4-cusps. Mesial side is usually larger than the distal side. The crown shows a bulging and overhanging appearance over the root.
• Second Molars (Maxillary): Morphologically similar to the first maxillary molar.
• Second Molars (Mandibular): Morphologically similar to the first mandibular molar. Small root trunk with three thin roots and has well-developed cusps. Oblique ridge and cusp is present

Chronology of Eruption and Shedding

• Shows the timing of eruption (when teeth first appear) and shedding (when teeth fall out) for different teeth in both the upper and lower arches.

Clinical Implications

• Primary teeth are more susceptible to pulp exposures during cavity preparation due to their thinner structure and larger pulp horn.
• Root canal treatment in primary teeth is unique and requires particular technique to accommodate physiological resorption.

Other Important Information

• Behavioral Management: Important for patients and parents to address anxiety and fear around dental procedures.