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.

Stainless Steel Crowns

Stainless steel crowns (SSCs) are a common restorative option for primary teeth, particularly in pediatric dentistry. They are especially useful for teeth with extensive carious lesions or structural damage, providing durability and protection for the underlying tooth structure.

Indications for Stainless Steel Crowns

• Primary Incisors or Canines:
  • SSCs are indicated for primary incisors or canines that have extensive proximal lesions, especially when the incisal portion of the tooth is involved.
  • They are particularly beneficial in cases where traditional restorative materials (like amalgam or composite) may not provide adequate strength or longevity.

Crown Selection and Preparation

1. Crown Selection:

   • An appropriate size of stainless steel crown is selected based on the dimensions of the tooth being restored.

2. Contouring:

   • The crown is contoured at the cervical margin to ensure a proper fit and to minimize the risk of gingival irritation.

3. Polishing:

   • The crown is polished to enhance its surface finish, which can help reduce plaque accumulation and improve esthetics.

4. Cementation:

   • The crown is cemented into place using a suitable dental cement, ensuring a secure fit even on teeth that have undergone significant carious structure removal.

Advantages of Stainless Steel Crowns

• Retention:
  • SSCs provide excellent retention and can remain in place even when extensive portions of carious tooth structure have been removed.
• Durability:
  • They are highly durable and can withstand the forces of mastication, making them ideal for primary teeth that are subject to wear and tear.

Esthetic Considerations

• Esthetic Limitations:

  • One of the drawbacks of stainless steel crowns is their metallic appearance, which may not meet the esthetic requirements of some children and their parents.

• Open-Face Stainless Steel Crowns:

  • To address esthetic concerns, a technique known as the open-face stainless steel crown can be employed.
  • In this technique, most of the labial metal of the crown is cut away, creating a labial "window."
  • This window is then restored with composite resin, allowing for a more natural appearance while still providing the strength and durability of the stainless steel crown.

Mental Age Assessment

Mental age can be assessed using the following formula:

• Mental Age = (Chronological Age × 100) / 10

Mental Age Descriptions

• Below 69: Mentally retarded (intellectual disability).
• Below 90: Low average intelligence.
• 90-110: Average intelligence. Most children fall within this range.
• Above 110: High average or superior intelligence.

 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

Hypophosphatasia in Children

Hypophosphatasia is a rare genetic disorder characterized by defective mineralization of bones and teeth due to a deficiency in alkaline phosphatase, an enzyme crucial for bone mineralization. This condition can lead to various dental and skeletal abnormalities, particularly in children.

Clinical Findings

1. Premature Exfoliation of Primary Teeth:

   • One of the hallmark clinical findings in children with hypophosphatasia is the premature loss of anterior primary teeth.
   • This loss is associated with deficient cementum, which is the tissue that helps anchor teeth to the alveolar bone.
   • Teeth may be lost spontaneously or as a result of minor trauma, highlighting the fragility of the dental structures in affected children.

2. Absence of Severe Gingival Inflammation:

   • Unlike other dental conditions that may cause tooth mobility or loss, severe gingival inflammation is typically absent in hypophosphatasia.
   • This absence can help differentiate hypophosphatasia from other periodontal diseases that may present with similar symptoms.

3. Limited Alveolar Bone Loss:

   • The loss of alveolar bone associated with hypophosphatasia may be localized, often limited to the anterior region where the primary teeth are affected.

Pathophysiology

• Deficient Alkaline Phosphatase Activity:

  • The disease is characterized by improper mineralization of bone and teeth due to deficient alkaline phosphatase activity in various tissues, including serum, liver, bone, and kidney (tissue nonspecific).
  • This deficiency leads to inadequate mineralization, resulting in the clinical manifestations observed in affected individuals.

• Increased Urinary Phosphoethanolamine:

  • Patients with hypophosphatasia often exhibit elevated levels of urinary phosphoethanolamine, which can serve as a biochemical marker for the condition.

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.