Lecture 01
Introduction to Dental Anatomy
Arches & Quadrants · Types of Teeth · Dentitions · Tooth Numbering Systems
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10 محاضرات كاملة + مراجعة ميدتيرم وفاينل
اشترك مرة واحدة بـ 300 جنيه وافتح الترم كامل
اشترك الآن
🦷 Oral Morphology
Definition
Study of the external morphology & internal composition of individual teeth, and their relationship to each other and to the skull
Arches
Teeth are arranged in an upper (maxillary) arch and a lower (mandibular) arch
- Midline: imaginary vertical line dividing each arch into two equal halves
- Quadrant: one half of one arch — 4 total: Maxillary Right/Left and Mandibular Right/Left
🔢 Types of Teeth
| Type | Per Quadrant | Total | Function |
|---|---|---|---|
| Incisors | 2 (central + lateral) | 8 | Biting, cutting, shearing |
| Canines (Cuspids) | 1 | 4 | Tearing, piercing — only single-cusp teeth |
| Premolars (Bicuspids) | 2 | 8 | Tearing + grinding — only in permanent dentition |
| Molars | 3 | 12 | Grinding — largest teeth |
Exam tip: Premolars and the 3rd molars have no deciduous predecessors among permanent molars — remember which teeth are permanent-only.
🍼 Types of Dentitions
1 · Deciduous
Erupt 6 months – 3 years. 20 teeth total. Also called: milk teeth, baby teeth, predecessors
2 · Permanent
Erupt 6 – 21 years. 32 teeth total. Also called: succedaneous / secondary teeth
3 · Mixed
Both deciduous & permanent teeth present together — starts age 6, ends age 12
Succedaneous teeth: permanent teeth that replace deciduous teeth. The 3 permanent molars are NOT succedaneous — they have no deciduous predecessor.
🔠 Tooth Numbering Systems
| System | Description |
|---|---|
| Palmer Notation | Cross (+) grid divided into 4 quadrants; permanent teeth numbered 1–8, deciduous lettered A–E, both counted from the midline |
| FDI System | Two-digit code — 1st digit = quadrant (1–4 permanent, 5–8 deciduous); 2nd digit = position 1–8 from midline. e.g. 11 = upper right permanent central incisor |
| Universal System | American system — permanent teeth 1–32 (starting at upper right 3rd molar); deciduous teeth lettered A–T |
Exam tip: FDI is the international standard system — most likely to appear in MCQs asking you to decode a tooth number.
INTRODUCTION TO DENTAL ANATOMY
🗂️ Arch Organization
Maxillary (upper) arch
Mandibular (lower) arch
Midline → 4 quadrants
🔢 Tooth Types
Incisors — cut — 8 total
Canines — tear — 4 total
Premolars — grind — 8 total
Molars — grind — 12 total
🍼 Dentitions
Deciduous: 20 teeth, 6mo–3yr
Permanent: 32 teeth, 6–21yr
Mixed: ages 6–12
3 permanent molars — no predecessor
🔠 Numbering Systems
Palmer: cross grid, 1–8 / A–E
FDI: 2-digit international standard
Universal: 1–32 / A–T
1
4 Tooth Types
Incisors (cut), Canines (tear), Premolars (tear+grind), Molars (grind) — distributed across 4 quadrants.
2
Tooth Counts
Deciduous = 20 teeth. Permanent = 32 teeth. Mixed dentition spans ages 6–12.
3
No Predecessors
The 3 permanent molars erupt with NO deciduous predecessor — not succedaneous teeth.
4
FDI Decoding
FDI system: 1st digit = quadrant, 2nd digit = position from midline. e.g. tooth 21 = upper left permanent central incisor.
5
Quadrants
The midline divides each arch into halves — giving 4 quadrants total: Max R/L, Mand R/L.
6
CEJ
Cementoenamel junction (CEJ) divides the anatomical crown from the root of a tooth.
7
Canine Uniqueness
Canines are the only single-cusp teeth and have the largest, longest single root in each arch.
8
Premolars
Premolars (bicuspids) appear only in the permanent dentition — there is no deciduous premolar.
9
Numbering Standard
The FDI two-digit system is the international standard used worldwide in dental records.
10
Universal System
American Universal system numbers permanent teeth 1–32, starting from the upper right 3rd molar.
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★ ★ ★ ★ ★
حاجة واحدة بس 🌟
أول لكتشر anatomy بييجي محمّل بأسماء غريبة كتير، وده طبيعي — مش حد بيحفظها من أول مرة.
اللي بيفرق هو إنك تربط كل اسم بصورة أو وظيفة، مش تحفظه لوحده. عشان كده كل محاضرة هنا فيها خريطة ذهنية قبل الحفظ، مش بعده.
جرّب المحاضرة دي وشوف الفرق بنفسك.
🗂️ Arches, Quadrants & Tooth Types
Arches
Maxillary & Mandibular Arches
Teeth are arranged in an upper (maxillary) and lower (mandibular) arch, divided by the midline.
- Midline = imaginary vertical line dividing each arch
- Each half-arch = one quadrant
Quadrants
The 4 Quadrants
Each arch is split by the midline into 2 quadrants — giving 4 quadrants total.
- Q1: Upper Right
- Q2: Upper Left
- Q3: Lower Left
- Q4: Lower Right
Tooth Types
Named Tooth Types in Full Arch
From the midline outward: incisors → canine → premolars → molars.
- Incisors closest to midline (cut)
- Canine = single cusp (tear)
- Premolars (tear + grind)
- Molars farthest back (grind)
🍼 Deciduous vs Permanent Dentition
Dentitions
Deciduous (Left) vs Permanent (Right)
Side-by-side comparison with each tooth labeled — a classic HIGH-YIELD exam image.
- Deciduous: 20 teeth total, no premolars
- Permanent: 32 teeth total, includes premolars
- 3 permanent molars have no deciduous predecessor
🔠 Tooth Numbering Systems
FDI System
FDI Numbering — Permanent Teeth
Two-digit code: 1st digit = quadrant (1–4), 2nd digit = position (1–8) from the midline.
- e.g. 11 = upper right permanent central incisor
- International standard system
Universal System
Universal Lettering — Deciduous Teeth
American Universal system letters deciduous teeth A–T — maxillary A–J, mandibular K–T.
- Permanent teeth instead numbered 1–32
- Counting starts at upper right 3rd molar
⚠️ Exam Trap: The 3 permanent molars are NOT succedaneous teeth — they erupt with no deciduous predecessor. Any MCQ option claiming all permanent teeth replace a deciduous tooth is automatically WRONG.
Answered: 0/30
Correct: 0
Wrong: 0