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

Use of Nitrous Oxide (N₂O) in Pedodontics

Nitrous oxide, commonly known as "laughing gas," is frequently used in pediatric dentistry for its sedative and analgesic properties. Here’s a detailed overview of its use, effects, dosages, and contraindications:

Dosage and Effects of Nitrous Oxide

1. Common Dosage:

   • 40% N₂O + 60% O₂: This combination is commonly used for conscious sedation in pediatric patients.

2. Effects Based on Concentration:

   • 5-25% N₂O:
     • Effects:
       • Moderate sedation
       • Diminution of fear and anxiety
       • Marked relaxation
       • Dissociative sedation and analgesia
   • 25-45% N₂O:
     • Effects:
       • Floating sensation
       • Reduced blink rate
   • 45-65% N₂O:
     • Effects:
       • Euphoric state (often referred to as "laughing gas")
       • Total anesthesia
       • Complete analgesia
       • Marked amnesia

Benefits of Nitrous Oxide in Pediatric Dentistry

• Anxiolytic Effects: Helps reduce anxiety and fear, making dental procedures more tolerable for children.
• Analgesic Properties: Provides pain relief, allowing for more comfortable treatment.
• Rapid Onset and Recovery: Nitrous oxide has a quick onset of action and is rapidly eliminated from the body, allowing for a quick recovery after the procedure.
• Control: The level of sedation can be easily adjusted during the procedure, providing flexibility based on the child's response.

Contraindications for Nitrous Oxide Sedation

While nitrous oxide is generally safe, there are specific contraindications where its use should be avoided:

1. Chronic Obstructive Pulmonary Disease (COPD): Patients with COPD may have difficulty breathing with nitrous oxide.
2. Asthma: Asthmatic patients may experience exacerbation of symptoms.
3. Respiratory Infections: Conditions that affect breathing can be worsened by nitrous oxide.
4. Sickle Cell Anemia: For general anesthesia, all forms of anemia, including sickle cell anemia, are contraindicated due to the risk of hypoxia.
5. Otitis Media: The use of nitrous oxide can increase middle ear pressure, which may be problematic.
6. Epilepsy: Patients with a history of seizures may be at risk for seizure activity when using nitrous oxide.

Natal and neonatal teeth, also known by various synonyms such as congenital teeth, prediciduous teeth, dentition praecox, and foetal teeth. This topic is significant in pediatric dentistry and has implications for both diagnosis and treatment.

Etiology

The etiology of natal and neonatal teeth is multifactorial. Key factors include:

1. Superficial Position of Tooth Germs: The positioning of tooth germs can lead to early eruption.
2. Infection: Infections during pregnancy may influence tooth development.
3. Malnutrition: Nutritional deficiencies can affect dental health.
4. Eruption Acceleration: Febrile incidents or hormonal stimulation can hasten the eruption process.
5. Genetic Factors: Hereditary transmission of a dominant autosomal gene may play a role.
6. Osteoblastic Activities: Bone remodeling phenomena can impact tooth germ development.
7. Hypovitaminosis: Deficiencies in vitamins can lead to developmental anomalies.

Associated Genetic Syndromes

Natal and neonatal teeth are often associated with several genetic syndromes, including:

• Ellis-Van Creveld Syndrome
• Riga-Fede Disease
• Pachyonychia Congenital
• Hallemann-Steriff Syndrome
• Sotos Syndrome
• Cleft Palate

Understanding these associations is crucial for comprehensive patient evaluation.

Incidence

The incidence of natal and neonatal teeth varies significantly, ranging from 1 in 6000 to 1 in 800 births. Notably:

• Approximately 90% of these teeth are normal primary teeth.
• In 85% of cases, the teeth are mandibular primary incisors.
• 5% are maxillary incisors and molars.
• The remaining 10% consist of supernumerary calcified structures.

Clinical Features

Clinically, natal and neonatal teeth may present with the following features:

• Morphologically, they can be conical or normal in size and shape.
• The color is typically opaque yellow-brownish.
• Associated symptoms may include dystrophic fingernails and hyperpigmentation.

Radiographic Evaluation

Radiographs are essential for assessing:

• The amount of root development.
• The relationship of prematurely erupted teeth to adjacent teeth.

Most prematurely erupted teeth are hypermobile due to limited root development.

Histological Characteristics

Histological examination reveals:

• Hypoplastic enamel with varying degrees of severity.
• Absence of root formation.
• Ample vascularized pulp.
• Irregular dentin formation.
• Lack of cementum formation.

These characteristics are critical for understanding the structural integrity of natal and neonatal teeth.

Harmful Effects

Natal and neonatal teeth can lead to several complications, including:

• Laceration of the lingual surface of the tongue.
• Difficulties for mothers wishing to breast-feed their infants.

Treatment Options

When considering treatment, extraction may be necessary. However, precautions must be taken:

• Avoid extractions until the 10th day of life to allow for the establishment of commensal flora in the intestine, which is essential for vitamin K production.
• If extractions are planned and the newborn has not been medicated with vitamin K immediately after birth, vitamin K supplements should be administered before the procedure to prevent hemorrhagic disease of the newborn (hypoprothrombinemia).

Photostimulable Phosphors (PSPs) in Digital Imaging

• Photostimulable phosphors (PSPs), also known as storage phosphors, are materials used in digital imaging for the acquisition of radiographic images. They serve as an alternative to traditional film-based radiography.

Characteristics of PSPs

• Storage Mechanism: Unlike conventional screen materials used in panoramic or cephalometric imaging, PSPs do not fluoresce immediately upon exposure to x-ray photons. Instead, they capture and store the incoming x-ray photon information as a latent image.

• Latent Image: The latent image is similar to that found in traditional film radiography, where the image is not visible until processed.

Image Acquisition Process

1. Exposure:

   • The PSP plate is exposed to x-rays, which causes the phosphor material to absorb and store the energy from the x-ray photons.

2. Scanning:

   • After exposure, the PSP plate is scanned by a laser beam in a drum scanner. This process is crucial for retrieving the stored image information.

3. Energy Release:

   • The laser scanning excites the phosphor, causing it to release the stored energy as an electronic signal. This signal represents the latent image captured during the x-ray exposure.

4. Digitalization:

   • The electronic signal is then digitized, with various gray levels assigned to different points on the curve. This process creates the final image information that can be viewed and analyzed.

Advantages of PSP Systems

• Image Quality: PSPs can produce high-quality images with a wide dynamic range, allowing for better visualization of anatomical structures.

• Reusability: PSP plates can be reused multiple times, making them a cost-effective option for dental practices.

• Compatibility: PSP systems can be integrated into existing digital imaging workflows, providing flexibility for dental professionals.

Available PSP Imaging Systems

• Soredex: OpTime
• AirTechniques: Scan X
• Gendex: Denoptix

These systems offer various features and capabilities, allowing dental practices to choose the best option for their imaging needs.

Infants (0 - 6 months): No fluoride supplementation is recommended regardless of water fluoridation levels. Toddlers (0.5 - 3 years): Supplementation is recommended only if the water fluoridation level is less than 0.3 ppm. Preschoolers (3 - 6 years): Dosages vary based on water fluoridation levels, with higher dosages for lower fluoride levels. Children over 6 years: Higher dosages are recommended for lower fluoride levels, but no supplementation is needed if the water fluoridation level exceeds 0.6 ppm.

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.