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.

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.

Paralleling Technique in Dental Radiography

Overview of the Paralleling Technique

The paralleling technique is a method used in dental radiography to obtain accurate and high-quality images of teeth. This technique ensures that the film and the long axis of the tooth are parallel, which is essential for minimizing distortion and maximizing image clarity.

Principles of the Paralleling Technique

1. Parallel Alignment:

   • The fundamental principle of the paralleling technique is to maintain parallelism between the film (or sensor) and the long axis of the tooth in all dimensions. This alignment is crucial for accurate imaging.

2. Film Placement:

   • To achieve parallelism, the film packet is positioned farther away from the object, particularly in the maxillary region. This distance can lead to image magnification, which is an undesirable effect.

3. Use of a Longer Cone:

   • To counteract the magnification caused by increased film distance, a longer cone (position-indicating device or PID) is employed. The longer cone helps:
     • Reduce Magnification: By increasing the distance from the source of radiation to the film, the image size is minimized.
     • Enhance Image Sharpness: A longer cone decreases the penumbra (the blurred edge of the image), resulting in sharper images.

4. True Parallelism:

   • Striving for true parallelism enhances image accuracy, allowing for better diagnostic quality.

Film Holder and Beam-Aligning Devices

• Film Holder:
  • A film holder is necessary when using the paralleling technique, as it helps maintain the correct position of the film relative to the tooth.
  • Some film holders are equipped with beam-aligning devices that assist in ensuring parallelism and reducing partial exposure of the film, thereby eliminating unwanted cone cuts.

Considerations for Pediatric Patients

• Size Adjustment:

  • For smaller children, the film holder may need to be reduced in size to accommodate both the film and the child’s mouth comfortably.

• Operator Error Reduction:

  • Proper use of film holders and beam-aligning devices can help minimize operator error and reduce the patient's exposure to radiation.

• Challenges with Film Placement:

  • Due to the shallowness of a child's palate and floor of the mouth, film placement can be somewhat compromised. However, with careful technique, satisfactory films can still be obtained.

1. Behavior Modification: Aversive Conditioning (HOME)

• Definition: Aversive conditioning is a behavior modification technique used to manage undesirable behaviors in children, particularly in a dental setting.
• Method: Known as the Hand-Over-Mouth Exercise (HOME), this technique was introduced by Evangeline Jordan in 1920.
  • Procedure: The dentist gently places their hand over the child’s mouth to prevent them from speaking or crying, allowing for a calm environment to perform dental procedures. This method is intended to help the child understand that certain behaviors (e.g., crying or moving excessively) are not conducive to receiving care.

2. Dental Materials: Crowns

• Cheng Crowns:

  • Composition: These crowns feature a pure resin facing, which makes them stain-resistant.
  • Design: Pre-crimped for ease of placement and adaptation to the tooth structure.

• Pedo Pearls:

  • Description: Aluminum crown forms coated with tooth-colored epoxy paint.
  • Durability: Relatively soft, which may affect their long-term durability compared to other crown materials.

3. Oral Hygiene for Infants

• Gum Pad Cleaning:
  • Timing: Cleaning of gum pads can begin as early as the first week after birth.
  • Parental Responsibility: Parents should brush or clean their baby’s gums and emerging teeth daily until the child is old enough to manage oral hygiene independently.

4. Indicators of Trauma and Abuse in Children

• Frenum Conditions:

  • Maxillary Labial Frenum: A torn frenum in a young child may indicate trauma from a slap, fist blow, or forced feeding.
  • Lingual Frenum: A torn lingual frenum could suggest sexual abuse or forced feeding.

• Signs of Abuse:

  • Bruising or Petechiae: Presence of bruising or petechiae on the soft and hard palate may indicate sexual abuse, particularly in cases of oral penetration.
  • Infection or Ulceration: If any signs of infection or ulceration are noted, specimens should be cultured for sexually transmitted diseases (STDs) such as gonorrhea, syphilis, or venereal warts.

• Neglect Indicators:

  • A child presenting with extensive untreated dental issues, untreated infections, or dental pain may be considered a victim of physical neglect, indicating that parents are not attending to the child’s basic medical needs.

5. Classical Conditioning

• Pavlov’s Contribution: Ivan Petrovich Pavlov was the first to study classical conditioning, a learning process that occurs through associations between an environmental stimulus and a naturally occurring stimulus.
  • Relevance in Dentistry: Understanding classical conditioning can help dental professionals develop strategies to create positive associations with dental visits, thereby reducing anxiety and fear in children.

The American Academy of Pediatric Dentistry (AAPD) Caries Risk Assessment Tool is designed to evaluate a child's risk of developing dental caries (cavities). The tool considers various factors to categorize a child's risk level as low, moderate, or high.

Low Risk:
- No carious (cavitated) teeth in the past 24 months
- No enamel white spot lesions (initial stages of tooth decay)
- No visible dental plaque
- Low incidence of gingivitis (mild gum inflammation)
- Optimal exposure to fluoride (both systemic and topical)
- Limited consumption of simple sugars (at meal times only)

Moderate Risk:
- Carious teeth in the past 12 to 24 months
- One area of white spot lesion
- Gingivitis present
- Suboptimal systemic fluoride exposure (e.g., not receiving fluoride supplements or living in a non-fluoridated water area)
- One or two between-meal exposures to simple sugars

High Risk:
- Carious teeth in the past 12 months
- More than one area of white spot lesion
- Visible dental plaque
- Suboptimal topical fluoride exposure (not using fluoridated toothpaste or receiving professional fluoride applications)
- Presence of enamel hypoplasia (developmental defect of enamel)
- Wearing orthodontic or dental appliances that may increase caries risk
- Active caries in the mother, which can increase the child's risk due to oral bacteria transmission
- Three or more between-meal exposures to simple sugars

Eruption Gingivitis

• Eruption gingivitis is a transitory form of gingivitis observed in young children during the eruption of primary teeth. It is characterized by localized inflammation of the gingiva that typically subsides once the teeth have fully emerged into the oral cavity.

Characteristics

• Age Group:

  • Eruption gingivitis is most commonly seen in young children, particularly during the eruption of primary teeth. However, a significant increase in the incidence of gingivitis is often noted in the 6-7 year age group when permanent teeth begin to erupt.

• Mechanism:

  • The increase in gingivitis during this period is attributed to several factors:
    • Lack of Protection: During the early stages of active eruption, the gingival margin does not receive protection from the coronal contour of the tooth, making it more susceptible to irritation and inflammation.
    • Food Impingement: The continual impingement of food on the gingiva can exacerbate the inflammatory process, leading to gingival irritation.

Contributing Factors

• Accumulation of Debris:
  • Food debris, material alba, and bacterial plaque often accumulate around and beneath the free gingival tissue. This accumulation can partially cover the crown of the erupting tooth, contributing to inflammation.
• Common Associations:
  • Eruption gingivitis is most frequently associated with the eruption of the first and second permanent molars. The inflammation can be painful and may lead to complications such as:
    • Pericoronitis: Inflammation of the soft tissue surrounding the crown of a partially erupted tooth.
    • Pericoronal Abscess: A localized collection of pus in the pericoronal area, which can result from the inflammatory process.

Clinical Management

• Oral Hygiene:

  • Emphasizing the importance of good oral hygiene practices is crucial during this period. Parents should be encouraged to assist their children in maintaining proper brushing and flossing techniques to minimize plaque accumulation.

• Professional Care:

  • Regular dental check-ups are important to monitor the eruption process and manage any signs of gingivitis or associated complications. Professional cleanings may be necessary to remove plaque and debris.

• Symptomatic Relief:

  • If the child experiences pain or discomfort, topical analgesics or anti-inflammatory medications may be recommended to alleviate symptoms.