NEET MDS Lessons
Pedodontics
Cherubism
Cherubism is a rare genetic disorder characterized by bilateral or asymmetric enlargement of the jaws, primarily affecting children. It is classified as a benign fibro-osseous condition and is often associated with distinctive radiographic and histological features.
Clinical Presentation
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Jaw Enlargement:
- Patients may present with symmetric or asymmetric enlargement of the mandible and/or maxilla, often noticeable at an early age.
- The enlargement can lead to facial deformities and may affect the child's appearance and dental alignment.
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Tooth Eruption and Loss:
- Teeth in the affected areas may exfoliate prematurely due to loss of support, root resorption, or interference with root development in permanent teeth.
- Spontaneous loss of teeth can occur, or children may extract teeth themselves from the soft tissue.
Radiographic Features
- Bone Destruction:
- Radiographs typically reveal numerous sharp, well-defined multilocular areas of bone destruction.
- There is often thinning of the cortical plate surrounding the affected areas.
- Cystic Involvement:
- The radiographic appearance is often described as "soap bubble" or "honeycomb" due to the multilocular nature of the lesions.
Case Report
- Example: McDonald and Shafer reported a case involving
a 5-year-old girl with symmetric enlargement of both the mandible and
maxilla.
- Radiographic Findings: Multilocular cystic involvement was observed in both the mandible and maxilla.
- Skeletal Survey: A complete skeletal survey did not reveal similar lesions in other bones, indicating the localized nature of cherubism.
Histological Features
- Microscopic Examination:
- A biopsy of the affected bone typically shows a large number of multinucleated giant cells scattered throughout a cellular stroma.
- The giant cells are large, irregularly shaped, and contain 30-40 nuclei, which is characteristic of cherubism.
Pathophysiology
- Genetic Basis: Cherubism is believed to have a genetic component, often inherited in an autosomal dominant pattern. Mutations in the SH3BP2 gene have been implicated in the condition.
- Bone Remodeling: The presence of giant cells suggests an active process of bone remodeling and resorption, contributing to the characteristic bone changes seen in cherubism.
Management
- Monitoring: Regular follow-up and monitoring of the condition are essential, especially during periods of growth.
- Surgical Intervention: In cases where the enlargement causes significant functional or aesthetic concerns, surgical intervention may be considered to remove the affected bone and restore normal contour.
- Dental Care: Management of dental issues, including premature tooth loss and alignment problems, is crucial for maintaining oral health.
Classification of Oral Habits
Oral habits can be classified based on various criteria, including their nature, impact, and the underlying motivations for the behavior. Below is a detailed classification of oral habits:
1. Based on Nature of the Habit
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Obsessive Habits (Deep Rooted):
- International or Meaningful:
- Examples: Nail biting, digit sucking, lip biting.
- Masochistic (Self-Inflicting):
- Examples: Gingival stripping (damaging the gums).
- Unintentional (Empty):
- Examples: Abnormal pillowing, chin propping.
- International or Meaningful:
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Non-Obsessive Habits (Easily Learned and Dropped):
- Functional Habits:
- Examples: Mouth breathing, tongue thrusting, bruxism (teeth grinding).
- Functional Habits:
2. Based on Impact
- Useful Habits:
- Habits that may have a positive or neutral effect on oral health.
- Harmful Habits:
- Habits that can lead to dental issues, such as malocclusion, gingival damage, or tooth wear.
3. Based on Author Classifications
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James (1923):
- a) Useful Habits
- b) Harmful Habits
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Kingsley (1958):
- a) Functional Oral Habits
- b) Muscular Habits
- c) Combined Habits
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Morris and Bohanna (1969):
- a) Pressure Habits
- b) Non-Pressure Habits
- c) Biting Habits
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Klein (1971):
- a) Empty Habits
- b) Meaningful Habits
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Finn (1987):
- I. a) Compulsive Habits
- b) Non-Compulsive Habits
- II. a) Primary Habits
4. Based on Functionality
- Functional Habits:
- Habits that serve a purpose, such as aiding in speech or feeding.
- Dysfunctional Habits:
- Habits that disrupt normal oral function or lead to negative consequences.
Indications for Stainless Steel Crowns in Pediatric Dentistry
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Extensive Tooth Decay:
Stainless steel crowns (SSCs) are primarily indicated for teeth with significant decay that cannot be effectively treated with fillings. They provide full coverage, preventing further decay and preserving the tooth's structure. -
Developmental Defects:
SSCs are beneficial for teeth affected by developmental conditions such as enamel dysplasia or dentinogenesis imperfecta, which make them more susceptible to decay. -
Post-Pulp Therapy:
After procedures like pulpotomy or pulpectomy, SSCs are often used to protect the treated tooth, ensuring its functionality and longevity. -
High Caries Risk:
For patients who are highly susceptible to caries, SSCs serve as preventive restorations, helping to protect at-risk tooth surfaces from future decay. -
Uncooperative Patients:
In cases where children may be uncooperative during dental procedures, SSCs offer a quicker and less invasive solution compared to more complex treatments. -
Fractured Teeth:
SSCs are also indicated for restoring fractured primary molars, which are crucial for a child's chewing ability and overall nutrition. -
Special Needs Patients:
Children with special needs who may struggle with maintaining oral hygiene can benefit significantly from the durability and protection offered by SSCs.
Contraindications for Stainless Steel Crowns
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Allergy to Nickel:
- Some patients may have an allergy or sensitivity to nickel, which is a component of stainless steel. In such cases, alternative materials should be considered.
-
Severe Tooth Mobility:
- If the tooth is severely mobile due to periodontal disease or other factors, placing a stainless steel crown may not be appropriate, as it may not provide adequate retention.
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Inadequate Tooth Structure:
- If there is insufficient tooth structure remaining to support the crown, it may not be feasible to place an SSC. This is particularly relevant in cases of extensive decay or fracture.
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Active Dental Infection:
- If there is an active infection or abscess associated with the tooth, it is generally advisable to treat the infection before placing a crown.
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Patient Non-Compliance:
- In cases where the patient is unlikely to cooperate with the treatment or follow-up care, the use of SSCs may not be ideal.
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Aesthetic Concerns:
- In anterior teeth, where aesthetics are a primary concern, parents or patients may prefer more esthetic options (e.g., composite crowns or porcelain crowns) over stainless steel crowns.
-
Severe Malocclusion:
- In cases of significant malocclusion, the placement of SSCs may not be appropriate if they could interfere with the occlusion or lead to further dental issues.
-
Presence of Extensive Caries in Adjacent Teeth:
- If adjacent teeth are also severely decayed, it may be more beneficial to address those issues first rather than placing a crown on a single tooth.
Xylitol and Its Role in Dental Health
Xylitol is a naturally occurring sugar alcohol that is widely recognized for its potential benefits in dental health, particularly in the prevention of dental caries.
Properties of Xylitol
- Low-Calorie Sweetener: Xylitol is a low-calorie sugar substitute that provides sweetness without the high caloric content of traditional sugars.
- Natural Occurrence: It is found in small amounts in various fruits and vegetables and can also be produced from birch wood and corn.
Mechanism of Action
- Inhibition of Streptococcus mutans:
- Xylitol has been shown to inhibit the growth of Streptococcus mutans, the primary bacterium responsible for dental caries.
- It disrupts the metabolism of these bacteria, reducing their ability to produce acids that demineralize tooth enamel.
Research and Evidence
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Studies by Makinen:
- Dr. R. Makinen has conducted extensive research on xylitol, collaborating with various researchers worldwide.
- In 2000, he published a summary titled “The Rocky Road of Xylitol to its Clinical Application,” which highlighted the challenges and successes in the clinical application of xylitol.
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Caries Activity Reduction:
- Numerous studies indicate that xylitol chewing gum significantly reduces caries activity in both children and adults.
- The evidence suggests that regular use of xylitol can lead to a decrease in the incidence of cavities.
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Transmission of S. mutans:
- Research has shown that xylitol chewing gum can decrease the transmission of S. mutans from mothers to their children, potentially reducing the risk of early childhood caries.
Applications of Xylitol
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Incorporation into Foods and Dentifrices:
- Xylitol has been tested as an additive in various food products and dental care items, including toothpaste and mouth rinses.
- Its sweetening properties make it an appealing option for children, promoting compliance with oral health recommendations.
-
Popularity as a Caries Prevention Strategy:
- The use of xylitol chewing gum is gaining traction as an effective caries prevention strategy, particularly among children.
- Its palatable taste and low-calorie nature make it an attractive alternative to traditional sugary snacks.
Soldered Lingual Holding Arch
The soldered lingual holding arch is a classic bilateral mixed dentition space maintainer used in the mandibular arch. It is designed to maintain the space for the canines and premolars during the transitional dentition period, preventing unwanted movement of the molars and retroclination of the incisors.
Design and Construction
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Components:
- Bands: Fitted to the first permanent molars, which serve as the primary anchorage points for the appliance.
- Wire: A 0.036- or 0.040-inch stainless steel wire is used, which is contoured to the arch form.
-
Arch Contouring:
- The wire is extended forward to make contact with the cingulum area of the incisors, providing stability and maintaining the position of the lower molars.
- The design must ensure that the wire does not interfere with the normal eruption paths of the incisors and provides an anterior arch form to facilitate alignment.
Functionality
-
Space Maintenance:
- The soldered lingual holding arch stabilizes the position of the lower molars, preventing mesial movement, and maintains the incisor relationships, thereby preserving the leeway space for the eruption of canines and premolars.
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Eruption Considerations:
- The appliance should not interfere with the eruptive movements of the permanent canines and premolars, allowing for normal dental development.
Clinical Considerations
-
Placement Timing:
- The lingual arch should not be placed before the eruption of the permanent incisors due to their frequent lingual eruption path.
- If placed too early, the wire may interfere with the normal positioning of the incisors, particularly before the eruption of the lateral incisors.
-
Anchorage:
- Using primary incisors as anterior stops does not provide sufficient anchorage to prevent significant loss of arch length. Therefore, the appliance should rely on the permanent molars for stability.
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Durability and Maintenance:
- The soldered lingual holding arch is designed to present minimal problems with breakage and oral hygiene concerns.
- It should not interfere with the child’s ability to wear the appliance, ensuring compliance and effectiveness.
Major Antimicrobial Proteins of Human Whole Saliva
Human saliva contains a variety of antimicrobial proteins that play crucial roles in oral health by protecting against pathogens, aiding in digestion, and maintaining the balance of the oral microbiome. Below is a summary of the major antimicrobial proteins found in human whole saliva, their functions, and their targets.
1. Non-Immunoglobulin (Innate) Proteins
These proteins are part of the innate immune system and provide immediate defense against pathogens.
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Lysozyme
- Major Target/Function:
- Targets gram-positive bacteria and Candida.
- Functions by hydrolyzing the peptidoglycan layer of bacterial cell walls, leading to cell lysis.
- Major Target/Function:
-
Lactoferrin
- Major Target/Function:
- Targets bacteria, yeasts, and viruses.
- Functions by binding iron, which inhibits bacterial growth (iron sequestration) and has direct antimicrobial activity.
- Major Target/Function:
-
Salivary Peroxidase and Myeloperoxidase
- Major Target/Function:
- Targets bacteria.
- Functions in the decomposition of hydrogen peroxide (H2O2) to produce antimicrobial compounds.
- Major Target/Function:
-
Histatin
- Major Target/Function:
- Targets fungi (especially Candida) and bacteria.
- Functions as an antifungal and antibacterial agent, promoting wound healing and inhibiting microbial growth.
- Major Target/Function:
-
Cystatins
- Major Target/Function:
- Targets various proteases.
- Functions as protease inhibitors, helping to protect tissues from proteolytic damage and modulating inflammation.
- Major Target/Function:
2. Agglutinins
Agglutinins are glycoproteins that promote the aggregation of microorganisms, enhancing their clearance from the oral cavity.
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Parotid Saliva
- Major Target/Function:
- Functions in the agglutination/aggregation of a number of microorganisms, facilitating their removal from the oral cavity.
- Major Target/Function:
-
Glycoproteins
- Major Target/Function:
- Functions similarly to agglutinins, promoting the aggregation of bacteria and other microorganisms.
- Major Target/Function:
-
Mucins
- Major Target/Function:
- Functions in the inhibition of adhesion of pathogens to oral surfaces, enhancing clearance and protecting epithelial cells.
- Major Target/Function:
-
β2-Microglobulin
- Major Target/Function:
- Functions in the enhancement of phagocytosis, aiding immune cells in recognizing and eliminating pathogens.
- Major Target/Function:
3. Immunoglobulins
Immunoglobulins are part of the adaptive immune system and provide specific immune responses.
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Secretory IgA
- Major Target/Function:
- Targets bacteria, viruses, and fungi.
- Functions in the inhibition of adhesion of pathogens to mucosal surfaces, preventing infection.
- Major Target/Function:
-
IgG
- Major Target/Function:
- Functions similarly to IgA, providing additional protection against a wide range of pathogens.
- Major Target/Function:
-
IgM
- Major Target/Function:
- Functions in the agglutination of pathogens and enhancement of phagocytosis.
- Major Target/Function:
Moro Reflex and Startle Reflex
Moro Reflex
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The Moro reflex, also known as the startle reflex, is an involuntary response observed in infants, typically elicited by sudden movements or changes in position of the head and neck.
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Elicitation:
- A common method to elicit the Moro reflex is to pull the baby halfway to a sitting position from a supine position and then suddenly let the head fall back a short distance.
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Response:
- The reflex consists of a rapid abduction and extension of the arms, accompanied by the opening of the hands.
- Following this initial response, the arms then come together as if in an embrace.
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Clinical Importance:
- The Moro reflex provides valuable information about the infant's muscle tone and neurological function.
- An asymmetrical response may indicate:
- Unequal muscle tone on either side.
- Weakness in one arm.
- Possible injury to the humerus or clavicle.
- The Moro reflex typically disappears by 2 to 3 months of age, which is a normal part of development.
Startle Reflex
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The startle reflex is similar to the Moro reflex but is specifically triggered by sudden noises or other unexpected stimuli.
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Response:
- In the startle reflex, the elbows are flexed, and the hands remain closed, showing less of an embracing motion compared to the Moro reflex.
- The movement of the arms may involve both outward and inward motions, but it is less pronounced than in the Moro reflex.
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Clinical Importance:
- The startle reflex is an important indicator of an infant's sensory processing and neurological integrity.
- It can also be used to assess the infant's response to environmental stimuli and overall alertness.