NEET MDS Lessons
Pedodontics
Classification of Early Childhood Caries (ECC)
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Type 1 ECC (Mild to Moderate)
- Affects molars and incisors
- Typically seen in children aged 2-5 years
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Type 2 ECC (Moderate to Severe)
- Characterized by labiolingual caries affecting maxillary incisors, with or without molar involvement
- Usually observed soon after the first tooth erupts
- Mandibular incisors remain unaffected
- Often caused by inappropriate bottle feeding
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Type 3 ECC (Severe)
- Involves all primary teeth
- Commonly seen in children aged 3-5 years
CARIDEX and CARISOLV
CARIDEX and CARISOLV are both dental products designed for the chemomechanical removal of carious dentin. Here’s a detailed breakdown of their components and mechanisms:
CARIDEX
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Components:
- Solution I: Contains sodium hypochlorite (NaOCl) and is used for its antimicrobial properties and ability to dissolve organic tissue.
- Solution II: Contains glycine and aminobutyric acid (ABA). When mixed with sodium hypochlorite, it produces N-mono chloro DL-2-amino butyric acid, which aids in the removal of demineralized dentin.
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Application:
- CARIDEX is particularly useful for deep cavities, allowing for the selective removal of carious dentin while preserving healthy tooth structure.
CARISOLV
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Components:
- Syringe 1: Contains sodium hypochlorite at a concentration of 0.5% w/v (which is equivalent to 0.51%).
- Syringe 2: Contains a mixture of amino acids (such as lysine, leucine, and glutamic acid) and erythrosine dye, which helps in visualizing the removal of carious dentin.
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pH Level:
- The pH of the CARISOLV solution is approximately 11, which helps in the dissolution of carious dentin.
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Mechanism of Action:
- The sodium hypochlorite in CARISOLV softens and dissolves carious dentin, while the amino acids and dye provide a visual cue for the clinician. The procedure can be stopped when discoloration is no longer observed, indicating that all carious dentin has been removed.
Conditioning and Behavioral Responses
This section outlines key concepts related to conditioning and behavioral responses, particularly in the context of learning and emotional responses in children.
1. Acquisition
- Acquisition refers to the process of learning a new response to a stimulus through conditioning. This is the initial stage where an association is formed between a conditioned stimulus (CS) and an unconditioned stimulus (US).
- Example: A child learns to associate the sound of a bell (CS) with receiving a treat (US), leading to a conditioned response (CR) of excitement when the bell rings.
2. Generalization
- Generalization occurs when the conditioned response is evoked by stimuli that are similar to the original conditioned stimulus. This means that the learned response can be triggered by a range of similar stimuli.
- Example: If a child has a painful experience with a doctor in a white coat, they may generalize this fear to all doctors in white coats, regardless of the specific individual or setting. Thus, any doctor wearing a white coat may elicit a fear response.
3. Extinction
- Extinction is the process by which the conditioned behavior diminishes or disappears when the association between the conditioned stimulus and the unconditioned stimulus is no longer reinforced.
- Example: In the previous example, if the child visits the doctor multiple times without any unpleasant experiences, the fear associated with the doctor in a white coat may gradually extinguish. The lack of reinforcement (pain) leads to a decrease in the conditioned response (fear).
4. Discrimination
- Discrimination is the ability to differentiate between similar stimuli and respond only to the specific conditioned stimulus. It is the opposite of generalization.
- Example: If the child is exposed to clinic settings that are different from those associated with painful experiences, they learn to discriminate between the two environments. For instance, if the child visits a friendly clinic with a different atmosphere, they may no longer associate all clinic visits with fear, leading to the extinction of the generalized fear response.
Anomalies of Number: problems in initiation stage
Hypodontia: 6% incidence; usually autosomal dominant (50% chance of passing to children) with variable expressivity (e.g., parent has mild while child has severe); most common missing permanent tooth (excluding 3rd molars) is Md 2nd premolar, 2nd most common is X lateral; oligodontia (at least 6 missing), and anodontia
1. Clincial implications: can interfere with function, lack of teeth → ↓ alveolar bone formation, esthetics, hard to replace in young children, implants only after growth completed, severe cases should receive genetic and systemic evaluation to see if other problems
2. Syndromes with hypodontia: Rieger syndrome, incontinentia pigmenti, Kabuki syndrome, Ellis-van Creveld syndrome, epidermolysis bullosa junctionalis, and ectodermal dysplasia (usually X-linked; sparse hair, unable to sweat, dysplastic nails)
Supernumerary teeth: aka hyperdontia; mesiodens when located in palatal midline; occur sporadically or as part of syndrome, common in cleft cases; delayed eruption often a sign that supernumeraries are preventing normal eruption
1. Multiple supernumerary teeth: cleidocranial dysplasia/dysostosis, Down’s, Apert, and Crouzon syndromes, etc.
Anomalies of Size: problems in morphodifferentiation stage
Microdontia: most commonly peg laterals; also in Down’s syndrome, hemifacial microsomia
Macrodontia: may be associated with hemifacial hypertrophy
Fusion: more common in primary dentition; union of two developing teeth
Gemination: more common in primary; incomplete division of single tooth bud → bifid crown, one pulp chamber; clinically distinguish from fusion by counting geminated tooth as one and have normal # teeth present (not in fusion)
Anomalies of Shape: errors during morphodifferentiation stage
Dens evaginatus: extra cusp in central groove/cingulum; fracture can → pulp exposure; most common in Orientals
Dens in dente: invagination of inner enamel epithelium → appearance of tooth within a tooth
Taurodontism: failure of Hertwig’s epithelial root sheath to invaginate to proper level → elongated (deep) pulp chamber, stunted roots; sporadic or associated with syndrome (e.g., amelogenesis imperfecta, Trichodento-osseous syndrome, ectodermal dysplasia)
Conical teeth: often associated with ectodermal dysplasia
Anomalies of Structure: problems during histodifferentiation, apposition, and mineralization stages
Dentinogenesis imperfecta: problem during histodifferentiation where defective dentin matrix → disorganized and atubular circumpulpal dentin; autosomal dominant inheritance; three types, one occurs with osteogenesis imperfecta (brittle bone syndrome); not sensitive despite exposed dentin; primary dentition has bulbous crowns, obliterated pulp chambers, bluish-grey or brownish-yellow teeth that are easily worn; permanent teeth often stained but can be sound
Amelogenesis imperfecta: heritable defect, independent from metabolic, syndromes, or systemic conditions (though similar defects seen with syndromes or environmental insults); four main types (hypoplastic, hypocalcified, hypomaturation, hypoplastic/hypomaturation with taurodontism); proper treatment addresses sensitivity, esthetics, VDO, caries and gingivitis prevention
Enamel hypoplasia: quantitative defect of enamel from problems in apposition stage; localized (caused by trauma) or generalized (caused by infection, metabolic disease, malnutrition, or hereditary disorders) effects; more common in malnourished children; least commonly Md incisors affected, often 1st molars; more susceptible to caries, excessive wearing → lost VDO, esthetic problems, and sensitivity to hot/cold
Enamel hypocalcification: during calcification stage
Fluorosis: excess F ingestion during calcification stage → intrinsic stain, mottled appearance, or brown staining and pitting; mild, moderate, or severe; porous enamel soaks up external stain
Classifications of Intellectual Disability
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Intellectual Disability (General Definition)
- Description: Intellectual disability is characterized by significant limitations in both intellectual functioning and adaptive behavior, which covers many everyday social and practical skills. It originates before the age of 18.
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Classifications Based on IQ Scores:
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Idiot
- IQ Range: Less than 25
- Description: This classification indicates profound intellectual disability. Individuals in this category may have very limited ability to communicate and perform basic self-care tasks.
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Imbecile
- IQ Range: 25 to 50
- Description: This classification indicates severe intellectual disability. Individuals may have some ability to communicate and perform simple tasks but require significant support in daily living.
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Moron
- IQ Range: 50 to 70
- Description: This classification indicates mild intellectual disability. Individuals may have the ability to learn basic academic skills and can often live independently with some support. They may struggle with complex tasks and social interactions.
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Social Learning Theory
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Antecedent Determinants:
- Definition: Antecedent determinants refer to the factors that precede a behavior and influence its occurrence. This includes the awareness of the child regarding the context and the events happening around them.
- Application in Pedodontics: In a dental setting, if a child is aware of what to expect during a dental visit (e.g., through explanations from the dentist or caregiver), they are more likely to feel prepared and less anxious. Providing clear information about procedures can help reduce fear and promote cooperation.
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Consequent Determinants:
- Definition: Consequent determinants involve the outcomes that follow a behavior, which can influence future behavior. This includes the child’s perceptions and expectations about the consequences of their actions.
- Application in Pedodontics: If a child experiences positive outcomes (e.g., praise, rewards) after cooperating during a dental procedure, they are more likely to repeat that behavior in the future. Conversely, if they perceive negative outcomes (e.g., pain or discomfort), they may develop anxiety or avoidance behaviors.
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Modeling:
- Definition: Modeling is the process of learning behaviors through observation of others. Children often imitate the actions of adults, peers, or even media figures.
- Application in Pedodontics: Dental professionals can use modeling to demonstrate positive behaviors. For example, showing a child how to sit still in the dental chair or how to brush their teeth properly can encourage them to imitate those behaviors. Additionally, having older children or siblings model positive dental experiences can help younger children feel more comfortable.
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Self-Regulation:
- Definition: Self-regulation involves the ability to control one’s own behavior through self-monitoring, judgment, and evaluation. It includes setting personal goals and assessing one’s own performance.
- Application in Pedodontics: Encouraging children to set goals for their dental visits (e.g., staying calm during the appointment) and reflecting on their behavior afterward can foster self-regulation. Dental professionals can guide children in evaluating their experiences and recognizing their progress, which can enhance their sense of agency and responsibility regarding their oral health.
Salivary Factors and Their Mechanisms
1. Buffering Factors
Buffering factors in saliva help maintain a neutral pH in the oral cavity, which is vital for preventing demineralization of tooth enamel.
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HCO3 (Bicarbonate)
- Effects on Mineralization: Acts as a primary buffer in saliva, helping to neutralize acids produced by bacteria.
- Role in Raising Saliva or Plaque pH: Increases pH by neutralizing acids, thus promoting a more favorable environment for remineralization.
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Urea
- Effects on Mineralization: Releases ammonia (NH3) when metabolized, which can help raise pH and promote mineralization.
- Role in Raising Saliva or Plaque pH: Contributes to pH elevation through ammonia production.
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Arginine-rich Proteins
- Effects on Mineralization: Releases ammonia, which can help neutralize acids and promote remineralization.
- Role in Raising Saliva or Plaque pH: Increases pH through ammonia release, creating a less acidic environment.
2. Antibacterial Factors
Saliva contains several antibacterial components that help control the growth of pathogenic bacteria associated with dental caries.
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Lactoferrin
- Effects on Bacteria: Binds to iron, which is essential for bacterial growth, thereby inhibiting bacterial proliferation.
- Effects on Bacterial Aggregation or Adherence: May promote clearance of bacteria through aggregation.
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Lysozyme
- Effects on Bacteria: Hydrolyzes cell wall polysaccharides of bacteria, leading to cell lysis and death.
- Effects on Bacterial Aggregation or Adherence: Can indirectly promote clearance by breaking down bacterial cell walls.
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Peroxidase
- Effects on Bacteria: Produces hypothiocyanate (OSCN), which inhibits glycolysis in bacteria, reducing their energy supply.
- Effects on Bacterial Aggregation or Adherence: May help in the aggregation of bacteria, facilitating their clearance.
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Secretory IgA
- Effects on Bacteria: Neutralizes bacterial toxins and enzymes, reducing their pathogenicity.
- Effects on Bacterial Aggregation or Adherence: Binds to bacterial surfaces, preventing adherence to oral tissues.
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Alpha Amylase
- Effects on Bacteria: Produces glucose and maltose, which can serve as energy sources for some bacteria.
- Effects on Bacterial Aggregation or Adherence: Indirectly promotes bacterial aggregation through the production of glucans.
3. Factors Affecting Mineralization
Certain salivary proteins play a role in the mineralization process and the maintenance of tooth enamel.
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Histatins
- Effects on Mineralization: Bind to hydroxyapatite, aiding in the supersaturation of saliva, which is essential for remineralization.
- Effects on Bacteria: Some inhibition of mutans streptococci, which are key contributors to caries.
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Proline-rich Proteins
- Effects on Mineralization: Bind to hydroxyapatite, aiding in saliva supersaturation.
- Effects on Bacteria: Promote adherence of some oral bacteria.
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Cystatins
- Effects on Mineralization: Bind to hydroxyapatite, aiding in saliva supersaturation.
- Effects on Bacteria: Promote adherence of some oral bacteria.
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Statherin
- Effects on Mineralization: Bind to hydroxyapatite, aiding in saliva supersaturation.
- Effects on Bacteria: Promote adherence of some oral bacteria.
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Mucins
- Effects on Mineralization: Provide a physical and chemical barrier in the enamel pellicle, protecting against demineralization.
- Effects on Bacteria: Facilitate aggregation and clearance of oral bacteria.