Composition of Stainless Steel Crowns

Stainless steel crowns (SSCs) are primarily made from a specific type of stainless steel alloy, which provides the necessary strength, durability, and resistance to corrosion. Here’s a breakdown of the composition of the commonly used stainless steel crowns:

1. Stainless Steel (18-8) Austenitic Alloy:

• Common Brands: Rocky Mountain, Unitek
• Composition:
  • Iron: 67%
  • Chromium: 17%
  • Nickel: 12%
  • Carbon: 0.08 - 0.15%

This composition provides the crowns with excellent mechanical properties and resistance to corrosion, making them suitable for use in pediatric dentistry.

2. Nickel-Based Crowns:

• Examples: Inconel 600, 3M crowns
• Composition:
  • Iron: 10%
  • Chromium: 16%
  • Nickel: 72%
  • Others: 2%

Nickel-based crowns are also used in some cases, offering different properties and benefits, particularly in terms of strength and biocompatibility.

Babinski Reflex

• Normal Presence: Present at birth
• Normal Disappearance: By 12-18 months of age
• Clinical Test: Stroking sole of foot from heel to toe
• Normal Response:
  • Infants: Big toe extends upward, other toes fan out
  • After 12-18 months: Toes curl downward (plantar response)
• Clinical Significance: Persistence beyond normal timeframe may indicate neurological concerns

Rooting Reflex

• Normal Presence: Present at birth
• Normal Disappearance: By 3-4 months of age
• Clinical Test: Touching cheek or corner of mouth
• Normal Response: Infant turns head toward stimulus and opens mouth
• Function: Facilitates breastfeeding and feeding behaviors
• Dental Relevance: Understanding helps in infant oral examination techniques

Soldered Lingual Holding Arch as a Space Maintainer

Introduction

The soldered lingual holding arch is a classic bilateral mixed-dentition space maintainer used in the mandibular arch. It is designed to preserve the space for the permanent canines and premolars during the mixed dentition phase, particularly when primary molars are lost prematurely.

Design and Construction

• Components:

  • Bands: Fitted to the first permanent molars.
  • Wire: A 0.036- or 0.040-inch stainless steel wire is contoured to the arch.
  • Extension: The wire extends forward to make contact with the cingulum area of the incisors.

• Arch Form: The wire is contoured to provide an anterior arch form, allowing for the alignment of the incisors while ensuring it does not interfere with the normal eruption paths of the teeth.

Functionality

• Stabilization: The design stabilizes the positions of the lower molars, preventing them from moving mesially and maintaining the incisor relationship to avoid retroclination.
• Leeway Space: The arch helps sustain the canine-premolar segment space, utilizing the leeway space available during the mixed dentition phase.

Clinical Considerations

• Eruption Path: The lingual wire must be contoured to avoid interference with the normal eruption paths of the permanent canines and premolars.
• Breakage and Hygiene: The soldered lingual holding arch is designed to present minimal problems with breakage and minimal oral hygiene concerns.
• Eruptive Movements: It should not interfere with the eruptive movements of the permanent teeth, allowing for natural development.

Timing of Placement

• Transitional Dentition Period: The bilateral design and use of permanent teeth as abutments allow for application during the full transitional dentition period of the buccal segments.
• Timing of Insertion: Lower lingual arches should not be placed before the eruption of the permanent incisors due to their frequent lingual eruption path. If placed too early, the lingual wire may interfere with normal incisor positioning, particularly before the lateral incisor erupts.
• Anchorage: Using primary incisors as anterior stops does not provide sufficient anchorage to prevent significant loss of arch length.

Anticonvulsants (Seizure Disorders)

1. Phenytoin (Dilantin)

   • Oral effect: Gingival hyperplasia
   • Management: Excellent oral hygiene, gingivectomy

2. Carbamazepine (Tegretol)

   • Oral effect: Xerostomia, oral ulcers
   • Drug interactions: With some antibiotics

3. Valproic Acid

   • Oral effect: Bleeding tendency
   • Consideration: Pre-surgical evaluation

Antipsychotics

• Oral effects: Xerostomia, tardive dyskinesia
• Dental concerns: Increased caries risk

Nursing Bottle Caries Distribution

Most Susceptible Teeth

• Primary target: Maxillary incisors
• High exposure to pooled liquids during bottle feeding
• Limited saliva flow during sleep increases risk
• Often shows characteristic circular decay pattern

Least Susceptible Teeth

• Protected area: Mandibular incisors
• Tongue position provides natural protection
• Better saliva access for neutralization
• Lower contact with pooled feeding liquids

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.