NEET MDS Lessons
Pedodontics
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.
Erikson's Eight Stages of Psychosocial Development
-
Basic Trust versus Basic Mistrust (Hope):
- Age: Infants (0-1 year)
- Description: In this stage, infants learn to trust their caregivers and the world around them. Consistent and reliable care leads to a sense of security.
- Positive Outcome: If caregivers provide reliable care and affection, the infant develops a sense of trust, leading to feelings of safety and hope.
- Negative Outcome: Inconsistent or neglectful care can result in mistrust, leading to anxiety and insecurity.
-
Autonomy versus Shame and Doubt (Will):
- Age: Toddlers (1-2 years)
- Description: As toddlers begin to explore their environment and assert their independence, they face the challenge of developing autonomy.
- Positive Outcome: Encouragement and support from caregivers foster a sense of autonomy and confidence in their abilities.
- Negative Outcome: Overly critical or controlling caregivers can lead to feelings of shame and doubt about their abilities.
-
Initiative versus Guilt (Purpose):
- Age: Early Childhood (2-6 years)
- Description: Children begin to initiate activities, assert control over their environment, and develop a sense of purpose.
- Positive Outcome: When children are encouraged to take initiative, they develop a sense of purpose and leadership.
- Negative Outcome: If their initiatives are met with criticism or discouragement, they may develop feelings of guilt and inhibition.
-
Industry versus Inferiority (Competence):
- Age: Elementary and Middle School (6-12 years)
- Description: Children learn to work with others and develop skills and competencies. They begin to compare themselves to peers.
- Positive Outcome: Success in school and social interactions fosters a sense of competence and achievement.
- Negative Outcome: Failure to succeed or negative comparisons can lead to feelings of inferiority and a lack of self-worth.
-
Identity versus Role Confusion (Fidelity):
- Age: Adolescence (12-18 years)
- Description: Adolescents explore their personal identity, values, and beliefs, seeking to establish a sense of self.
- Positive Outcome: Successful exploration leads to a strong sense of identity and fidelity to one's beliefs and values.
- Negative Outcome: Failure to establish a clear identity can result in role confusion and uncertainty about one's place in the world.
-
Intimacy versus Isolation (Love):
- Age: Young Adulthood (19-40 years)
- Description: Young adults seek to form intimate relationships and connections with others.
- Positive Outcome: Successful relationships lead to deep connections and a sense of love and belonging.
- Negative Outcome: Fear of intimacy or failure to form meaningful relationships can result in feelings of isolation and loneliness.
-
Generativity versus Stagnation (Care):
- Age: Middle Adulthood (40-65 years)
- Description: Adults strive to contribute to society and support the next generation, often through parenting, work, or community involvement.
- Positive Outcome: A sense of generativity leads to feelings of productivity and fulfillment.
- Negative Outcome: Failure to contribute can result in stagnation and a sense of unfulfillment.
-
Integrity versus Despair (Wisdom):
- Age: Late Adulthood (65 years to death)
- Description: Older adults reflect on their lives and evaluate their experiences.
- Positive Outcome: A sense of integrity arises from a life well-lived, leading to feelings of wisdom and acceptance.
- Negative Outcome: Regret over missed opportunities or unresolved conflicts can lead to despair and dissatisfaction with life.
Pulpectomy
Primary tooth endodontics, commonly referred to as pulpectomy, is a dental procedure aimed at treating the pulp of primary (deciduous) teeth that have become necrotic or infected. The primary goal of this treatment is to maintain the integrity of the primary tooth, thereby preserving space for the permanent dentition and preventing complications associated with tooth loss.
Indications for Primary Tooth Endodontics
-
Space Maintenance:
The foremost indication for performing a pulpectomy on a primary tooth is to maintain space in the dental arch. The natural primary tooth serves as the best space maintainer, preventing adjacent teeth from drifting into the space left by a lost tooth. This is particularly crucial when the second primary molars are lost before the eruption of the first permanent molars, as constructing a space maintainer in such cases can be challenging. -
Restorability:
The tooth must be restorable with a stainless steel crown. If the tooth is structurally sound enough to support a crown after the endodontic treatment, pulpectomy is indicated. -
Absence of Pathological Root Resorption:
There should be no significant pathological root resorption present. The integrity of the roots is essential for the success of the procedure and the longevity of the tooth. -
Healthy Bone Layer:
A layer of healthy bone must exist between the area of pathological bone resorption and the developing permanent tooth bud. Radiographic evaluation should confirm that this healthy bone layer is present, allowing for normal bone healing post-treatment. -
Presence of Suppuration:
The presence of pus or infection indicates that the pulp is necrotic, necessitating endodontic intervention. -
Pathological Periapical Radiolucency:
Radiographic evidence of periapical radiolucency suggests that there is an infection at the root apex, which can be treated effectively with pulpectomy.
Contraindications for Primary Tooth Endodontics
-
Floor of the Pulp Opening into the Bifurcation:
If the floor of the pulp chamber opens into the bifurcation of the roots, it complicates the procedure and may lead to treatment failure. -
Extensive Internal Resorption:
Radiographic evidence of significant internal resorption indicates that the tooth structure has been compromised to the extent that it cannot support a stainless steel crown, making pulpectomy inappropriate. -
Severe Root Resorption:
If more than two-thirds of the roots have been resorbed, the tooth may not be viable for endodontic treatment. -
Inaccessible Canals:
Teeth that lack accessible canals, such as first primary molars, may not be suitable for pulpectomy due to the inability to adequately clean and fill the canals.
The Pulpectomy Procedure
-
Accessing the Pulp Chamber:
The procedure begins with the use of a high-speed bur to create an access opening into the pulp chamber of the affected tooth. -
Canal Preparation:
Hedstrom files are employed to clean and shape the root canals. This step is crucial for removing necrotic tissue and debris from the canals. -
Irrigation:
The canals are irrigated with sodium hypochlorite (hypochlorite solution) to wash out any remaining tissue and loose dentin, ensuring a clean environment for filling. -
Filling the Canals:
After thorough cleaning and shaping, the canals and pulp chamber are filled with zinc oxide eugenol, which serves as a biocompatible filling material. -
Post-Operative Evaluation:
A post-operative radiograph is taken to evaluate the condensation of the filling material and ensure that the procedure was successful. -
Restoration:
Finally, the tooth is restored with a stainless steel crown to provide protection and restore function.
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:
-
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.
-
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.
Apexogenesis
Apexogenesis is a vital pulp therapy procedure aimed at promoting the continued physiological development and formation of the root end of an immature tooth. This procedure is particularly relevant in pediatric dentistry, where the goal is to preserve the vitality of the dental pulp in young patients, allowing for normal root development and maturation of the tooth.
Indications for Apexogenesis
Apexogenesis is typically indicated in cases where the pulp is still vital but has been exposed due to caries, trauma, or other factors. The procedure is designed to maintain the health of the pulp tissue, thereby facilitating the ongoing development of the root structure. It is most commonly performed on immature permanent teeth, where the root has not yet fully formed.
Materials Used
Mineral Trioxide Aggregate (MTA) is frequently used in apexogenesis
procedures. MTA is a biocompatible material known for its excellent
sealing properties and ability to promote healing. It serves as a
barrier to protect the pulp and encourages the formation of a calcified barrier
at the root apex, facilitating continued root development.
Signs of Success
The most important indicator of successful apexogenesis is the
continuous completion of the root apex. This means that as the pulp
remains vital and healthy, the root continues to grow and mature, ultimately
achieving the appropriate length and thickness necessary for functional dental
health.
Contraindications
While apexogenesis can be a highly effective treatment for preserving the
vitality of the pulp in young patients, it is generally contraindicated in
children with serious systemic illnesses, such as leukemia or cancer. In these
cases, the risks associated with the procedure may outweigh the potential
benefits, and alternative treatment options may be considered.
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.
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.
- Major Target/Function:
-
Lactoferrin
- Major Target/Function:
- Targets bacteria, yeasts, and viruses.
- Functions by binding iron, which inhibits bacterial growth (iron sequestration) and has direct antimicrobial activity.
- Major Target/Function:
-
Salivary Peroxidase and Myeloperoxidase
- Major Target/Function:
- Targets bacteria.
- Functions in the decomposition of hydrogen peroxide (H2O2) to produce antimicrobial compounds.
- Major Target/Function:
-
Histatin
- Major Target/Function:
- Targets fungi (especially Candida) and bacteria.
- Functions as an antifungal and antibacterial agent, promoting wound healing and inhibiting microbial growth.
- Major Target/Function:
-
Cystatins
- Major Target/Function:
- Targets various proteases.
- Functions as protease inhibitors, helping to protect tissues from proteolytic damage and modulating inflammation.
- Major Target/Function:
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.
- Major Target/Function:
-
Glycoproteins
- Major Target/Function:
- Functions similarly to agglutinins, promoting the aggregation of bacteria and other microorganisms.
- Major Target/Function:
-
Mucins
- Major Target/Function:
- Functions in the inhibition of adhesion of pathogens to oral surfaces, enhancing clearance and protecting epithelial cells.
- Major Target/Function:
-
β2-Microglobulin
- Major Target/Function:
- Functions in the enhancement of phagocytosis, aiding immune cells in recognizing and eliminating pathogens.
- Major Target/Function:
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.
- Major Target/Function:
-
IgG
- Major Target/Function:
- Functions similarly to IgA, providing additional protection against a wide range of pathogens.
- Major Target/Function:
-
IgM
- Major Target/Function:
- Functions in the agglutination of pathogens and enhancement of phagocytosis.
- Major Target/Function: