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Pedodontics

Dens in Dente (Tooth Within a Tooth)

Dens in dente, also known as "tooth within a tooth," is a developmental dental anomaly characterized by an invagination of the enamel and dentin, resulting in a tooth structure that resembles a tooth inside another tooth. This condition can affect both primary and permanent teeth.

Diagnosis

  • Radiographic Verification:
    • The diagnosis of dens in dente is confirmed through radiographic examination. Radiographs will typically show the characteristic invagination, which may appear as a radiolucent area within the tooth structure.

Characteristics

  • Developmental Anomaly:
    • Dens in dente is described as a lingual invagination of the enamel, which can lead to various complications, including pulp exposure, caries, and periapical pathology.
  • Occurrence:
    • This condition can occur in both primary and permanent teeth, although it is most commonly observed in the permanent dentition.

Commonly Affected Teeth

  • Permanent Maxillary Lateral Incisors:
    • Dens in dente is most frequently seen in the permanent maxillary lateral incisors. The presence of deep lingual pits in these teeth should raise suspicion for this condition.
  • Unusual Cases:
    • There have been reports of dens invaginatus occurring in unusual locations, including:
      • Mandibular primary canine
      • Maxillary primary central incisor
      • Mandibular second primary molar

Genetic Considerations

  • Inheritance Pattern:
    • The condition may exhibit an autosomal dominant inheritance pattern, as evidenced by the occurrence of dens in dente within the same family, where some members have the condition while others present with deep lingual pits.
  • Variable Expressivity and Incomplete Penetrance:
    • The variability in expression of the condition among family members suggests that it may have incomplete penetrance, meaning not all individuals with the genetic predisposition will express the phenotype.

Clinical Implications

  • Management:
    • Early diagnosis and management are crucial to prevent complications associated with dens in dente, such as pulpitis or abscess formation. Treatment may involve restorative procedures or endodontic therapy, depending on the severity of the invagination and the health of the pulp.

Cerebral palsy (CP) is a neurological disorder resulting from damage to the brain during its development before, during, or shortly after birth. This condition is non-progressive, meaning that it does not worsen over time, but it manifests as a range of neurological problems that can significantly impact a child's mobility, muscle control, and posture.

Causes:
The primary cause of CP is any factor that leads to decreased oxygen supply (hypoxia) to the developing brain. This can occur due to various reasons, including complications during pregnancy, childbirth, or immediately after birth.

Classification of Cerebral Palsy:

  1. Based on Anatomical Involvement:

    • Monoplegia: One limb is affected.
    • Hemiplegia: One side of the body is affected.
    • Paraplegia: Both legs are affected.
    • Quadriplegia: All four limbs are affected.
  2. Based on Neuromuscular Involvement:

    • Spasticity: Characterized by stiff and tight muscles; this is the most common type, seen in 70% of cases. Affected individuals may have limited head movement and a limp gait.
    • Athetosis: Involves involuntary, writhing movements, seen in 15% of cases. Symptoms include excessive head movement and drooling.
    • Ataxia: Affects balance and coordination, seen in 5% of cases. Individuals may exhibit a staggering gait and slow tremor-like movements.
    • Mixed: A combination of more than one type of cerebral palsy, seen in about 10% of cases.

 

1. Spastic Cerebral Palsy (70% of cases)

Characteristics:

  • Limited Head Movement: Individuals have restrictions in moving their head due to increased muscle tone.
  • Involvement of Cerebral Cortex: Indicates that the motor control areas of the brain (especially those concerning voluntary movement) are affected.
  • Limping Gait with Circumduction of the Affected Leg: When walking, the patient often swings the affected leg around instead of lifting it normally, due to spasticity.
  • Hypertonicity of Facial Muscles: Increased muscle tension in the facial region, contributing to a fixed or tense facial expression.
  • Unilateral or Bilateral Manifestations: Symptoms can occur on one side of the body (hemiplegia) or affect both sides (diplegia or quadriplegia).
  • Slow Jaw Movement: Reduced speed in moving the jaw, potentially leading to functional difficulties.
  • Hypertonic Orbicularis Oris Muscles: Increased muscle tone around the mouth, affecting lip closure and movement.
  • Mouth Breathing (75%): The individual may breathe through their mouth due to poor control of oral musculature.
  • Spastic Tongue Thrust: The tongue pushes forward excessively, which can disrupt swallowing and speech.
  • Class II Division II Malocclusion (75%): Dental alignment issue often characterized by a deep overbite and anterior teeth that are retroclined, sometimes accompanied by a unilateral crossbite.
  • Speech Involvement: Difficulties with speech articulation due to muscle coordination problems.
  • Constricted Mandibular Arch: The lower jaw may have a narrower configuration, complicating dental alignment and oral function.

2. Athetoid Cerebral Palsy (15% of cases)

Characteristics:

  • Excessive Head Movement: Involuntary, uncontrolled movements lead to difficulties maintaining a stable head position.
  • Involvement of Basal Ganglia: Damage to this area affects muscle tone and coordination, leading to issues like chorea (involuntary movements).
  • Bull Neck Appearance: The neck may appear thicker and less defined, owing to abnormal muscle development or tone.
  • Lack of Head Balance, Drawn Back: The head may be held in a retracted position, affecting posture and balance.
  • Quick Jaw Movement: Involuntary rapid movements can lead to difficulty with oral control.
  • Hypotonic Orbicularis Oris Muscles: Reduced muscle tone around the mouth can lead to drooling and lack of control of oral secretions.
  • Grimacing and Drooling: Facial expressions may be exaggerated or inappropriate due to muscle tone issues, and there may be problems with managing saliva.
  • Continuous Mouth Breathing: Patients may consistently breathe through their mouths rather than their noses.
  • Tissue Biting: Increased risk of self-biting due to lack of muscle control.
  • Tongue Protruding: The tongue may frequently stick out, complicating speech and intake of food.
  • High and Narrow Palatal Vault: Changes in the oral cavity structures can lead to functional difficulties.
  • Class II Division I Malocclusion (90%): Characterized by a deep bite and anterior open bite.
  • Speech Involvement: Affected due to uncontrolled muscle movements.
  • Muscle of Deglutition Involvement: Difficulties with swallowing due to affected muscles.
  • Bruxism: Involuntary grinding or clenching of teeth.
  • Auditory Organs May be Involved: Hearing impairments can coexist.

3. Ataxic Cerebral Palsy (5% of cases)

Characteristics:

  • Slow Tremor-like Head Movement: Unsteady, gradual movements of the head, indicative of coordination issues.
  • Involvement of Cerebellum: The cerebellum, which regulates balance and motor control, is impacted.
  • Lack of Balance Leading to Staggering Gait: Individuals may have difficulty maintaining equilibrium, leading to a wide-based and unsteady gait.
  • Hypotonic Orbicularis Oris Muscles: Reduced muscle tone leading to difficulties with oral closure and control.
  • Slow Jaw Movement: The jaw may move slower, affecting chewing and speech.
  • Speech Involvement: Communication may be affected due to poor coordination of the speech muscles.
  • Visual Organ May be Involved (Nystagmus): Involuntary eye movements may occur, affecting visual stability.
  • Varied Type of Malocclusion: Dental alignment issues can vary widely in this population.

4. Mixed:
Mixed cerebral palsy involves a combination of the above types, where the individual may exhibit spasticity, athetosis, and ataxia to varying degrees.

Dental Considerations for Mixed CP:
- Dental care for patients with mixed CP is highly individualized and depends on the specific combination and severity of symptoms.
- The dentist must consider the unique challenges that arise from the combination of muscle tone issues, coordination problems, and potential for involvement of facial muscles.
- A multidisciplinary approach, including occupational therapy and speech therapy, may be necessary to address oral function and hygiene.
- The use of sedation or general anesthesia might be considered for extensive dental treatments due to the difficulty in managing the patient's movements and ensuring safety during procedures.

Associated Symptoms:
Children with CP may exhibit persistent reflexes such as the asymmetric tonic neck reflex, which can influence their dental treatment. Other symptoms may include mental retardation, seizure disorders, speech difficulties, and joint contractures.

Dental Problems:
Children with cerebral palsy often experience specific dental challenges:

  • They may have a higher incidence of dental caries (tooth decay) due to difficulty in maintaining oral hygiene and dietary preferences.
  • There is a greater likelihood of periodontal disease, often exacerbated by medications like phenytoin, which can lead to gum overgrowth and dental issues.

Dental Treatment Considerations:
When managing dental care for children with cerebral palsy, dentists need to consider:

  • Patient Stability: The child’s head should be stabilized, and their back should be elevated to minimize swallowing difficulties.
  • Physical Restraints: These can help manage uncontrolled movements during treatment.
  • Use of Mouth Props and Finger Splints: These tools can assist in controlling involuntary jaw movements.
  • Gentle Handling: Avoid abrupt movements to prevent triggering the startle reflex.
  • Local Anesthesia (LA): Administered with caution, ensuring stabilization to prevent sudden movements.
  • Premedication: Medications may be given to alleviate muscle hypertonicity, manage anxiety, and reduce involuntary movements.
  • General Anesthesia (GA): Reserved for cases that are too challenging to manage with other methods.

Erythroblastosis fetalis
Blue-green colour of primary teeth only. It is due to excessive haemolysis of RBC. The Staining occurs due to diffusion of bilirubin and biliverdin into the dentin


Porphyria
Purplish brown pigmentation. to light and blisters on The other features hands and face e Hypersensitivity are are red red coloured urine, urine,


Cystic fibrosis
(Yellowish gray to dark brown. It is due to tetracycline, which is the drug of choice in this disease


Tetracycline

Yellow or yellow-brown pigmentation in dentin and to a lesser extent in enamel that are calcifying during the time the drug is administered. The teeth fluoresce yellow under UV light 

Transpalatal Arch

The transpalatal arch (TPA) is a fixed orthodontic appliance used primarily in the maxillary arch to maintain or regain space, particularly after the loss of a primary molar or in cases of unilateral space loss. It is designed to provide stability to the molars and prevent unwanted movement.

Indications

  • Unilateral Loss of Space:
    • The transpalatal arch is particularly effective in cases where there is unilateral loss of space. It helps maintain the position of the remaining molar and prevents mesial movement of the adjacent teeth.
    • It can also be used to maintain the arch form and provide anchorage during orthodontic treatment.

Contraindications

  • Bilateral Loss of Space:
    • The use of a transpalatal arch is contraindicated in cases of bilateral loss of space. In such situations, the appliance may not provide adequate support or stability, and other treatment options may be more appropriate.

Limitations/Disadvantages

  • Tipping of Molars:
    • One of the primary limitations of the transpalatal arch is the potential for both molars to tip together. This tipping can occur if the arch is not properly designed or if there is insufficient anchorage.
    • Tipping can lead to changes in occlusion and may require additional orthodontic intervention to correct.

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.

  • Lysozyme

    • Major Target/Function:
      • Targets gram-positive bacteria and Candida.
      • Functions by hydrolyzing the peptidoglycan layer of bacterial cell walls, leading to cell lysis.
  • Lactoferrin

    • Major Target/Function:
      • Targets bacteria, yeasts, and viruses.
      • Functions by binding iron, which inhibits bacterial growth (iron sequestration) and has direct antimicrobial activity.
  • Salivary Peroxidase and Myeloperoxidase

    • Major Target/Function:
      • Targets bacteria.
      • Functions in the decomposition of hydrogen peroxide (H2O2) to produce antimicrobial compounds.
  • Histatin

    • Major Target/Function:
      • Targets fungi (especially Candida) and bacteria.
      • Functions as an antifungal and antibacterial agent, promoting wound healing and inhibiting microbial growth.
  • Cystatins

    • Major Target/Function:
      • Targets various proteases.
      • Functions as protease inhibitors, helping to protect tissues from proteolytic damage and modulating inflammation.

2. Agglutinins

Agglutinins are glycoproteins that promote the aggregation of microorganisms, enhancing their clearance from the oral cavity.

  • Parotid Saliva

    • Major Target/Function:
      • Functions in the agglutination/aggregation of a number of microorganisms, facilitating their removal from the oral cavity.
  • Glycoproteins

    • Major Target/Function:
      • Functions similarly to agglutinins, promoting the aggregation of bacteria and other microorganisms.
  • Mucins

    • Major Target/Function:
      • Functions in the inhibition of adhesion of pathogens to oral surfaces, enhancing clearance and protecting epithelial cells.
  • β2-Microglobulin

    • Major Target/Function:
      • Functions in the enhancement of phagocytosis, aiding immune cells in recognizing and eliminating pathogens.

3. Immunoglobulins

Immunoglobulins are part of the adaptive immune system and provide specific immune responses.

  • Secretory IgA

    • Major Target/Function:
      • Targets bacteria, viruses, and fungi.
      • Functions in the inhibition of adhesion of pathogens to mucosal surfaces, preventing infection.
  • IgG

    • Major Target/Function:
      • Functions similarly to IgA, providing additional protection against a wide range of pathogens.
  • IgM

    • Major Target/Function:
      • Functions in the agglutination of pathogens and enhancement of phagocytosis.

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.

  • 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.
  • 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.
  • 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.

  • 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.
  • 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.
  • 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.
  • 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.
  • 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.

  • 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.
  • Proline-rich Proteins

    • Effects on Mineralization: Bind to hydroxyapatite, aiding in saliva supersaturation.
    • Effects on Bacteria: Promote adherence of some oral bacteria.
  • Cystatins

    • Effects on Mineralization: Bind to hydroxyapatite, aiding in saliva supersaturation.
    • Effects on Bacteria: Promote adherence of some oral bacteria.
  • Statherin

    • Effects on Mineralization: Bind to hydroxyapatite, aiding in saliva supersaturation.
    • Effects on Bacteria: Promote adherence of some oral bacteria.
  • 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.

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

  • 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.
  • 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.

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