Anatomy of Dentistry

Related Subjects: |Macroglossia |Microstomia |Glossitis |Medical Teeth |Gum hypertrophy |Angular Stomatitis - Cheilitis |Oral Aphthous Ulcers |Oral Leukoplakia

🦷 Dental Anatomy is the study of the structure and development of teeth. Understanding it is essential for diagnosing and treating dental issues, as well as for carrying out dental procedures effectively. It covers morphology, function, and the relationships of teeth within the oral cavity.

🪥 Types of Teeth

• 🦷 Incisors :
  • Located at the front of the mouth.
  • Sharp, chisel-shaped edges ➝ designed for cutting food.
  • 4 in each arch: 2 central + 2 lateral.
• 🐺 Canines :
  • Corner teeth (“eye teeth”).
  • Pointed cusp for tearing food and guiding occlusion.
  • 2 in each arch.
• 🍪 Premolars (Bicuspids) :
  • Located behind canines.
  • Have 2 cusps ➝ crushing & grinding food.
  • 4 in each arch (2 per side).
• 🍖 Molars :
  • At the back of the mouth.
  • Multiple cusps ➝ efficient grinding/chewing of fibrous food.
  • 6 in each arch (including wisdom teeth).

🔬 Tooth Structure

• 👑 Crown : Visible part above gum, covered by enamel.
• 🌱 Root : Anchored in jawbone, covered with cementum.
• 💎 Enamel : Hardest substance in the body, protects tooth.
• 🟡 Dentin : Beneath enamel/cementum, transmits sensation.
• ❤️ Pulp : Nerves, blood supply, connective tissue.
• 🪨 Cementum : Calcified covering of root, anchors tooth.
• 🪢 Periodontal Ligament : Fibers connecting root to alveolar bone, absorbs chewing forces.

🦴 Dental Arches

• Maxillary Arch (Upper Jaw) – part of maxilla.
• Mandibular Arch (Lower Jaw) – part of mandible.

👶 vs. 🧑 Primary vs Permanent Dentition

• Primary (Deciduous) Teeth :
  • “Baby teeth” – total of 20.
  • Erupt from ~6 months ➝ replaced later by permanent teeth.
• Permanent (Adult) Teeth :
  • Total of 32 (including wisdom teeth).
  • Eruption begins ~6 years ➝ continues through adolescence.

🧠 Nerve Supply of the Jaw & Teeth

• Trigeminal nerve (CN V): Primary sensory nerve of face, jaws & teeth.
• Maxillary division (V2):
  • Supplies 🦷 upper teeth & gingivae.
  • Branches: posterior, middle & anterior superior alveolar nerves.
  • Also supplies palate (via greater/lesser palatine nerves) and nasopalatine nerve (incisors).
• Mandibular division (V3):
  • Supplies 🦷 lower teeth & gingivae.
  • Main branch: inferior alveolar nerve → mandibular teeth, chin & lower lip.
  • Lingual nerve → anterior 2/3 tongue sensation + lingual gingiva.
  • Buccal nerve → buccal gingiva of molars.

💉 Anaesthesia of Upper Teeth (V2)

• Infiltration:
  • Inject above apex of tooth; anaesthetic diffuses through thin maxillary bone.
  • Effective for most upper teeth.
• Nerve blocks:
  • Posterior superior alveolar block → molars.
  • Infraorbital block → premolars, canines, incisors.
  • Greater palatine / nasopalatine blocks → palatal gingiva.

💉 Anaesthesia of Lower Teeth (V3)

• Inferior alveolar nerve block:
  • Main technique for mandibular molars/premolars (bone too dense for infiltration).
  • Landmark: inject near mandibular foramen (medial ramus).
  • Anaesthetises lower teeth, lower lip & chin.
• Supplementary blocks:
  • Lingual block → lingual gingiva & tongue.
  • Long buccal block → buccal gingiva of molars.
  • Mental block → premolars, canines, incisors, lower lip.

📝 Exam Pearls

• Upper jaw → infiltrations usually sufficient ✅
• Lower jaw → requires inferior alveolar nerve block ❌ infiltration rarely works.
• Always aspirate before injecting to avoid intravascular administration 💉

⚖️ Occlusion & Alignment

• Occlusion : Relationship of upper & lower teeth when jaws close. Essential for chewing, speech, and jaw health.
• Malocclusion : Misalignment ➝ problems with chewing, speech, ↑ risk of decay & gum disease.

🩺 Common Dental Conditions

• 🕳️ Dental Caries – bacterial breakdown of enamel/dentin.
• 🪥 Gingivitis – gum inflammation due to plaque; reversible.
• 🦠 Periodontitis – advanced gum disease ➝ ligament/bone loss, tooth loss.
• 💥 Dental Abscess – pus collection from infection, painful, urgent treatment needed.
• 🦷 Malocclusion – improper alignment ➝ functional & cosmetic issues.

💊 Dental Treatments

• 🛠️ Restorative – fillings, crowns, implants.
• 📏 Orthodontic – braces, aligners.
• 🌿 Periodontal – deep cleaning, gum grafts, surgery.
• 🧪 Endodontic – root canal therapy.
• 🦾 Prosthodontic – dentures, bridges, implant-supported replacements.
• 🛡️ Preventive – fluoride, sealants, regular hygiene visits.

📚 Summary

Dental anatomy explains tooth types, structure, and relationships within the oral cavity. Understanding these is vital for diagnosing conditions (caries, gum disease, malocclusion) and planning treatments. ✨ Preventive care (brushing, flossing, fluoride, dental visits) is key to lifelong oral health.