NEET MDS Lessons
Pedodontics
Primary Maxillary Second Molar Resembles: Permanent Maxillary First Molar
Morphological Similarities:
- Crown outline: Rhomboidal shape
- Cusp pattern: 4 cusps (MB, DB, ML, DL)
- Groove pattern: Similar H-pattern
- Root configuration: 3 roots (MB, DB, P)
- Occlusal table: Similar proportions
Key Differences:
- Size: Primary is smaller
- Cervical convergence: More pronounced in primary
- Root divergence: Greater in primary
- Enamel thickness: Thinner in primary
Primary Mandibular First Molar Resembles: Permanent Mandibular First Molar
Morphological Similarities:
- Cusp number: 5 cusps (MB, ML, DB, DL, D)
- Groove pattern: Y-groove pattern
- Root configuration: 2 roots (mesial, distal)
- Developmental grooves: Similar arrangement
- Distal cusp: Present in both (cusp 5)
Unique Primary Features:
- Cervical ridge: Very prominent buccally
- Crown convergence: More pronounced occlusally
- ML cusp: Often largest cusp
- Roots: More flared and curved
CLINICAL SIGNIFICANCE: These resemblances help in:
- Space analysis: Predicting permanent molar size
- Treatment planning: Understanding occlusal relationships
- Morphology studies: Evolutionary dental patterns
Caries Detection Method Comparison
| Method | Sensitivity | Specificity | Cost | Time | Best Use |
|---|---|---|---|---|---|
| Visual-Tactile | Low-Moderate | High | Low | Fast | Cavitated lesions |
| Bitewing XR | High | High | Moderate | Moderate | Interproximal caries |
| DIAGNOdent | High | Moderate | High | Fast | Occlusal surfaces |
| FOTI/DIFOTI | Moderate | High | Moderate | Fast | Smooth surfaces |
| Quantitative LF | Very High | Moderate | High | Slow | Research |
EXAM NOTES:
- Bitewing radiographs - Most accepted overall
- Visual-tactile - Most commonly used
- DIAGNOdent - Best for occlusal surfaces
- FOTI - Good for anterior approximal
- At birth: Alveolar process = Gum pad
- Gum pad segmentation: Transverse groove
- Division into labio-buccal & lingual: Dental groove
- Groove between canine & 1st molar: Lateral sulcus
- Gingival groove (upper arch): Separates gum pad from palate
- Gum pad shape: Upper = horseshoe; Lower = U-shaped, rectangular
- Natal teeth: Present at birth
- Neonatal teeth: Erupt within 30 days
- Associated syndromes: Ellis-van Creveld, Craniofacial Dysostosis
- Riga-Fede disease: Ulceration from natal/neonatal teeth
- Primary dentition period: 6 months to 6 years
- Primate spaces:
- Maxilla: Between lateral incisor & canine
- Mandible: Between canine & 1st molar
- Most common molar relation: Flush terminal plane
- Incisal liability: 7 mm (upper), 5 mm (lower)
- Leeway space:
- Maxilla: 1.8 mm (0.9 mm each side)
- Mandible: 3.4 mm (1.7 mm each side)
Trace Elements
| Type | Elements |
|---|---|
| Cariogenic | Selenium, Lead, Barium |
| Protective | Molybdenum, Vanadium |
Vitamin K
- Exhibits anti-cariogenic properties by inhibiting bacterial growth.
Veillonella
- Considered anti-cariogenic due to lack of glycolytic enzymes; utilizes lactate produced by other bacteria.
- 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
Types of Crying
-
Obstinate Cry:
- Characteristics: This cry is loud, high-pitched, and resembles a siren. It often accompanies temper tantrums, which may include kicking and biting.
- Emotional Response: It reflects the child's external response to anxiety and frustration.
- Physical Manifestation: Typically involves a lot of tears and convulsive sobbing, indicating a high level of distress.
-
Frightened Cry:
- Characteristics: This cry is not about getting what the child wants; instead, it arises from fear that overwhelms the child's ability to reason.
- Physical Manifestation: Usually involves small whimpers, indicating a more subdued response compared to the obstinate cry.
-
Hurt Cry:
- Characteristics: This cry is a reaction to physical discomfort or pain.
- Physical Manifestation: It may start with a single tear that runs down the child's cheek without any accompanying sound or resistance, indicating a more internalized response to pain.
-
Compensatory Cry
-
Characteristics:
- This type of cry is not a traditional cry; rather, it is a sound that the child makes in response to a specific stimulus, such as the sound of a dental drill.
- It is characterized by a constant whining noise rather than the typical crying sounds associated with distress.
-
Physical Manifestation:
- There are no tears or sobs associated with this cry. The child does not exhibit the typical signs of emotional distress that accompany other types of crying.
- The sound is directly linked to the presence of the stimulus (e.g., the drill). When the stimulus stops, the whining also ceases.
-
Emotional Response:
- The compensatory cry may indicate a child's attempt to cope with discomfort or fear in a situation where they feel powerless or anxious. It serves as a way for the child to express their discomfort without engaging in more overt forms of crying.
-
Methods of Age Determination:
1. Demirjian Method (Most commonly used)
- 8 stages (A-H) for each tooth
- Maturity scores assigned
- Dental age calculated from tables
2. Nolla Method
- 10 stages (0-10) of development
- Crown and root development stages
- Age estimation from developmental stage
3. Moorrees, Fanning & Hunt (MFH)
- 14 stages of development
- Separate standards for boys and girls
- More detailed root development stages
CLINICAL APPLICATIONS:
- Forensic identification
- Treatment timing in orthodontics
- Legal age determination
- Growth and development assessment