Cerebral palsy (CP) is a neurological disorder resulting from damage to the brain during its development before, during, or shortly after birth. This condition is non-progressive, meaning that it does not worsen over time, but it manifests as a range of neurological problems that can significantly impact a child's mobility, muscle control, and posture.

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.