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Pedodontics

Phenytoin-Induced Gingival Overgrowth

  • Phenytoin (Dilantin):
    • An anticonvulsant medication primarily used in the treatment of epilepsy.
    • First introduced in 1938 by Merrit and Putnam.

Gingival Hyperplasia

  • Gingival hyperplasia refers to the overgrowth of gum tissue, which can lead to aesthetic concerns and functional issues, such as difficulty in maintaining oral hygiene.
  • Historical Context:
    • The association between phenytoin therapy and gingival hyperplasia was first reported by Kimball in 1939.
    • In his study, 57% of 119 patients taking phenytoin for seizure control experienced some degree of gingival overgrowth.

Mechanism of Gingival Overgrowth

  • Fibroblast Activity:

    • Early research indicated an increase in the number of fibroblasts in the gingival tissues of patients receiving phenytoin.
    • This led to the initial terminology of "Dilantin hyperplasia."
  • Current Understanding:

    • Subsequent studies, including those by Hassell and colleagues, have shown that true hyperplasia does not exist in this condition.
    • Findings indicate:
      • There is no excessive collagen accumulation per unit of tissue.
      • Fibroblasts do not appear abnormal in number or size.
    • As a result, the term phenytoin-induced gingival overgrowth is now preferred, as it more accurately reflects the condition.

Clinical Implications

  • Management:

    • Patients on phenytoin should be monitored for signs of gingival overgrowth, especially if they have poor oral hygiene or other risk factors.
    • Dental professionals should educate patients about maintaining good oral hygiene practices to minimize the risk of gingival overgrowth.
    • In cases of significant overgrowth, treatment options may include:
      • Improved oral hygiene measures.
      • Professional dental cleanings.
      • Surgical intervention (gingivectomy) if necessary.
  • Patient Education:

    • It is important to inform patients about the potential side effects of phenytoin, including gingival overgrowth, and the importance of regular dental check-ups.

Self-Mutilation in Children: Causes and Management

Overview of Self-Mutilation

Self-mutilation through biting and other forms of self-injury can be a significant concern in children, particularly those with severe emotional disturbances or specific syndromes. Understanding the underlying causes and appropriate management strategies is essential for healthcare providers.

Associated Conditions

  1. Lesch-Nyhan Syndrome (LNS):

    • A genetic disorder characterized by hyperuricemia, neurological impairment, and self-mutilating behaviors, including biting and head banging.
    • Children with LNS often exhibit severe emotional disturbances and may engage in self-injurious behaviors.
  2. Congenital Insensitivity to Pain:

    • A rare condition where individuals cannot feel physical pain, leading to a higher risk of self-injury due to the inability to recognize harmful stimuli.
    • Children with this condition may bite or injure themselves without understanding the consequences.
  3. Autism:

    • Children with autism may engage in self-injurious behaviors, including biting, as a response to sensory overload, frustration, or communication difficulties.
    • Friedlander and colleagues noted that facial bruising, abrasions, and intraoral traumatic ulcerations in autistic children are often the result of self-injurious behaviors rather than abuse.

Management Strategies

Management of self-mutilation in children requires careful consideration of the underlying condition and the child's developmental stage. Two primary approaches are often discussed:

  1. Protective Appliances:

    • Mouthguards:
      • Littlewood and Mitchell reported that mouthguards can be beneficial for children with congenital insensitivity to pain. These devices help protect the oral cavity from self-inflicted injuries.
      • Mouthguards can serve as a temporary measure until the child matures enough to understand and avoid self-mutilating behaviors, which is typically learned through painful experiences.
  2. Surgical Procedures:

    • In some cases, surgical intervention may be necessary to address severe self-injurious behaviors or to repair damage caused by biting.
    • The decision to pursue surgical options should be made on a case-by-case basis, considering the child's overall health, the severity of the behaviors, and the potential for improvement.
  3. Pharmacological Interventions:

    • Carbamazepine:
      • Cusumano and colleagues reported that carbamazepine may be beneficial for children with Lesch-Nyhan syndrome. This medication can help manage behavioral symptoms and reduce self-injurious behaviors.

Agents Used for Sedation in Children

  1. Nitrous Oxide (N₂O)

    • Type: Gaseous agent
    • Description: Commonly used for conscious sedation in pediatric dentistry. It provides anxiolytic and analgesic effects, making dental procedures more tolerable for children.
  2. Benzodiazepines

    • Examples:
      • Diazepam: Used for its anxiolytic and sedative properties.
      • Midazolam: Frequently utilized for its rapid onset and short duration of action.
  3. Barbiturates

    • Description: Sedative-hypnotics that can be used for sedation, though less commonly in modern practice due to the availability of safer alternatives.
  4. Chloral Hydrate

    • Description: A sedative-hypnotic agent used for its calming effects in children.
  5. Narcotics

    • Examples:
      • Meperidine: Provides analgesia and sedation.
      • Fentanyl: A potent opioid used for sedation and pain management.
  6. Antihistamines

    • Examples:
      • Hydroxyzine: An anxiolytic and sedative.
      • Promethazine (Phenergan): Used for sedation and antiemetic effects.
      • Chlorpromazine: An antipsychotic that can also provide sedation.
      • Diphenhydramine: An antihistamine with sedative properties.
  7. Dissociative Agents

    • Example:
      • Ketamine: Provides dissociative anesthesia, analgesia, and sedation. It is particularly useful in emergency settings and for procedures that may cause significant discomfort.

Laminate Veneer Technique

The laminate veneer technique is a popular cosmetic dental procedure that enhances the esthetic appearance of teeth. This technique involves the application of thin shells of porcelain or composite resin to the facial surfaces of teeth, simulating the natural hue and appearance of healthy tooth structure.

Advantages of Laminate Veneers

  • Esthetic Improvement:

    • Laminate veneers provide significant esthetic enhancement, allowing for the restoration of teeth to a natural appearance.
    • When properly finished, these restorations closely mimic the color and translucency of natural teeth.
  • Gingival Tolerance:

    • Laminate restorations are generally well tolerated by gingival tissues, even if the contour of the veneers is slightly excessive.
    • Maintaining good oral hygiene is crucial, but studies have shown that gingival health can be preserved around these restorations in cooperative patients.

Preparation Technique

  1. Intraenamel Preparation:

    • The preparation for laminate veneers involves the removal of 0.5 to 1 mm of facial enamel.
    • The preparation tapers to about 0.25 to 0.5 mm at the cervical margin, ensuring a smooth transition and adequate bonding surface.
  2. Cervical Margin:

    • The cervical margin should be finished in a well-defined chamfer that is level with the crest of the gingival margin or positioned no more than 0.5 mm subgingivally.
    • This careful placement helps to minimize the risk of gingival irritation and enhances the esthetic outcome.
  3. Incisal Margin:

    • The incisal margin may end just short of the incisal edge or may include the entire incisal edge, terminating on the lingual surface.
    • It is advisable to avoid placing incisal margins where direct incising forces occur, as this can compromise the integrity of the veneer.

Bonded Porcelain Techniques

  • Significance:
    • Bonded porcelain techniques are highly valuable in cosmetic dentistry, providing a strong and durable restoration that can withstand the forces of mastication while enhancing the appearance of the teeth.
  • Application:
    • These techniques involve the use of adhesive bonding agents to secure the veneers to the prepared tooth surface, ensuring a strong bond and longevity of the restoration.

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.

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.

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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