Normal Eruption Sequence

Primary Teeth (Deciduous Dentition):

• Lower central incisors: 6-8 months (first to erupt)
• Upper central incisors: 8-10 months
• Lateral incisors: 8-12 months
• First molars: 12-18 months
• Canines: 18-24 months
• Second molars: 24-30 months (last to erupt)

Eruption Delays & Variations

Delayed Eruption of Deciduous Teeth: Dentitia Tarda

 Delayed eruption of primary teeth beyond normal chronological limits

Criteria for Diagnosis:

• No teeth by 13 months of age
• Incomplete primary dentition by 3 years
• Delay >6 months beyond expected eruption time

Causes of Dentitia Tarda:

1. Systemic Factors:

   • Hypothyroidism
   • Hypopituitarism
   • Down syndrome
   • Nutritional deficiencies

2. Local Factors:

   • Supernumerary teeth
   • Cysts or tumors
   • Trauma to deciduous teeth
   • Thick gingival tissue

3. Genetic Factors:

   • Familial delayed eruption
   • Cleidocranial dysplasia
   • Regional odontodysplasia

EXAM PEARL: Dentitia tarda diagnosis requires systematic evaluation to rule out underlying systemic conditions.

• Technology: Microprocessor-controlled injection system
• Mechanism:
  • Controls flow rate and pressure of anesthetic delivery
  • Provides consistent, slow injection speed
  • Reduces injection pressure and associated discomfort
• Advantages:
  • Decreased injection pain
  • More precise anesthetic placement
  • Better patient acceptance, especially in children
  • Reduced anxiety through improved comfort
• Clinical Applications:
  • Particularly beneficial for pediatric patients
  • Useful for patients with dental anxiety
  • Effective for palatal injections
• Limitations:
  • Higher cost compared to traditional syringes
  • Requires specific cartridges and needles
  • Learning curve for practitioners

• Arch criminal of caries: Sucrose
• Rampant caries: ≥10 lesions/year
• Fluoride contraindication: Chronic renal failure
• Fluoride in toothpaste (pea size): 250 mg
• Critical pH for demineralization: 5.2 – 5.5
• Plaque pH drop duration: 120 min
• Trace elements increasing caries: Selenium, lead, barium
• Protective trace elements: Molybdenum, vanadium
• Fluorosis etching acid (ortho bonding): Phosphoric acid

Anticonvulsants (Seizure Disorders)

1. Phenytoin (Dilantin)

   • Oral effect: Gingival hyperplasia
   • Management: Excellent oral hygiene, gingivectomy

2. Carbamazepine (Tegretol)

   • Oral effect: Xerostomia, oral ulcers
   • Drug interactions: With some antibiotics

3. Valproic Acid

   • Oral effect: Bleeding tendency
   • Consideration: Pre-surgical evaluation

Antipsychotics

• Oral effects: Xerostomia, tardive dyskinesia
• Dental concerns: Increased caries risk

• Plasma peak of fluoride: 180 min
• Fluoride in breast milk: 5 – 10 mg/L
• Earth’s crust fluoride: ~300 ppm
• Dry tea leaf fluoride: 100 – 400 ppm
• Renal clearance: 30 – 50 mL/min
• Plasma fluoride level: 19 – 38 ng/mL
• Plaque fluoride concentration: 15 – 64 ppm
• Sweat fluoride concentration: 0.067 – 0.05 ppm
• Reliable fluoride analysis method: Microdiffusion (Taves, 1983)
• Fluoride in pea-sized toothpaste: 250 mg
• Non-caloric sweeteners: Saccharin, Aspartame

Sedation Routes & Titratability

Most Titratable Sedation Routes (High-Yield):

1. Inhalation Sedation (Nitrous Oxide)

   • Titratability:  (Excellent)
   • Onset: 2-3 minutes
   • Recovery: 3-5 minutes
   • Advantages:
     • Real-time dose adjustment
     • Rapid onset and recovery
     • Maintains protective reflexes
     • Patient remains conscious

2. Intravenous (IV) Sedation

   • Titratability: (Very Good)
   • Onset: 1-2 minutes
   • Advantages:
     • Precise dose control
     • Immediate effect
     • Can be reversed (benzodiazepines)

Less Titratable Routes:

3. Oral Sedation

   • Titratability:  (Limited)
   • Onset: 30-45 minutes
   • Issues: Fixed dose, variable absorption

4. Rectal Sedation

   • Titratability: (Poor)
   • Onset: 10-30 minutes
   • Issues: Unpredictable absorption

5. Intramuscular Sedation

   • Titratability:  (Poor)
   • Onset: 15-30 minutes
   • Issues: Fixed dose, painful injection

EXAM FOCUS: Inhalation and IV routes allow real-time dose adjustment, making them safest for special needs patients.