NEET MDS Lessons
Pedodontics
Leeway Space
Leeway space refers to the size differential between the primary posterior teeth (which include the primary canines, first molars, and second molars) and their permanent successors, specifically the permanent canines and first and second premolars. This space is significant in orthodontics and pediatric dentistry because it plays a crucial role in accommodating the permanent dentition as the primary teeth exfoliate.
Size Differential
Typically, the combined width of the primary posterior teeth is greater than
that of the permanent successors. For instance, the sum of the widths of the
primary canine, first molar, and second molar is larger than the combined widths
of the permanent canine and the first and second premolars. This inherent size
difference creates a natural space when the primary teeth are lost.
Measurement of Leeway Space
On average, the leeway space provides approximately:
- 3.1 mm of space per side in the mandibular arch (lower jaw)
- 1.3 mm of space per side in the maxillary arch (upper jaw)
This space can be crucial for alleviating crowding in the dental arch, particularly in cases where there is insufficient space for the permanent teeth to erupt properly.
Clinical Implications
When primary teeth fall out, the leeway space can be utilized to help relieve
crowding. If this space is not preserved, the permanent first molars tend to
drift forward into the available space, effectively closing the leeway space.
This forward drift can lead to misalignment and crowding of the permanent teeth,
potentially necessitating orthodontic intervention later on.
Management of Leeway Space
To maintain the leeway space, dental professionals may employ various
strategies, including:
- Space maintainers: These are devices used to hold the space open after the loss of primary teeth, preventing adjacent teeth from drifting into the space.
- Monitoring eruption patterns: Regular dental check-ups can help track the eruption of permanent teeth and the status of leeway space, allowing for timely interventions if crowding begins to develop.
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
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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.
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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.
Rubber Dam in Dentistry
The rubber dam is a crucial tool in dentistry, primarily used for isolating teeth during various procedures. Developed by Barnum in 1864, it enhances the efficiency and safety of dental treatments.
Rationale for Using Rubber Dam
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Maintains Clean and Visible Field
- The rubber dam isolates the treatment area from saliva and blood, providing a clear view for the clinician.
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Patient Protection
- Prevents aspiration or swallowing of foreign bodies, such as dental instruments or materials, ensuring patient safety.
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Clinician Protection
- Reduces the risk of exposure to blood and saliva, minimizing the potential for cross-contamination.
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Reduces Risk of Cross-Contamination
- Particularly important in procedures involving the root canal system, where maintaining a sterile environment is critical.
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Retracts and Protects Soft Tissues
- The dam retracts the cheeks, lips, and tongue, protecting soft tissues from injury during dental procedures.
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Increases Efficiency
- Minimizes the need for patient cooperation and frequent rinsing, allowing for a more streamlined workflow.
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Application of Medicaments
- Facilitates the application of medicaments without the fear of dilution from saliva or blood.
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Improved Properties of Restorative Material
- Ensures that restorative materials set properly by keeping the area dry and free from contamination.
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Psychological Benefit to the Patient
- Provides a sense of security and comfort, as patients may feel more at ease knowing that the area is isolated and protected.
Rubber Dam Sheet Specifications
Rubber dam sheets are available in various thicknesses, which can affect their handling and application:
- Thin: 0.15 mm
- Medium: 0.20 mm
- Heavy: 0.25 mm
- Extra-Heavy: 0.30 mm
- Special Heavy: 0.35 mm
Sizes and Availability
- Rubber dam sheets can be purchased in rolls or prefabricated sizes, typically 5” x 5” or 6” x 6”.
- Non-latex rubber dams are available only in the 6” x 6” size.
Color Options
- Rubber dams come in various colors. Darker colors provide better visual contrast, while lighter colors can illuminate the operating field and facilitate the placement of radiographic films beneath the dam.
Surface Characteristics
- Rubber dam sheets have a shiny and a dull surface. The dull surface is typically placed facing occlusally, as it is less reflective and reduces glare, enhancing visibility for the clinician.
Stages of Freud's Model
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Oral Stage (1-2 years):
- Focus: The mouth is the primary source of interaction and pleasure. Infants derive satisfaction from oral activities such as sucking, biting, and chewing.
- Developmental Task: The primary task during this stage is to develop trust and comfort through oral stimulation. Successful experiences lead to a sense of security.
- Example: Sucking on a pacifier or breastfeeding helps infants develop trust in their caregivers.
- Potential Outcomes: Fixation at this stage can lead to issues with dependency or aggression in adulthood. Individuals may develop oral-related habits, such as smoking or overeating.
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Anal Stage (2-3 years):
- Focus: The anal zone becomes the primary source of pleasure. Children derive gratification from controlling bowel movements.
- Developmental Task: Toilet training is a significant aspect of this stage. The way parents handle toilet training can influence personality development.
- Outcomes:
- Overemphasis on Toilet Training: If parents are too strict or demanding, the child may develop an anal-retentive personality, characterized by compulsiveness, orderliness, and stubbornness.
- Lax Toilet Training: If parents are too lenient, the child may develop an anal-expulsive personality, leading to impulsiveness and a lack of organization.
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Phallic Stage (3-5 years):
- Focus: The child becomes aware of their own genitals and develops sexual feelings. This stage is marked by the Oedipus complex in boys and the Electra complex in girls.
- Oedipus Complex: Boys develop an attraction to their mother and view their father as a rival for her affection. This leads to feelings of jealousy and fear of punishment (castration anxiety).
- Electra Complex: Girls experience a similar attraction to their father and may feel competition with their mother, leading to "penis envy."
- Developmental Task: Resolution of these complexes is crucial for developing a mature sexual identity and healthy relationships.
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Latency Stage (6 years to puberty):
- Focus: Sexual feelings are repressed, and children focus on developing skills, friendships, and social interactions. This stage corresponds with the development of mixed dentition (the transition from primary to permanent teeth).
- Developmental Task: The maturation of the ego occurs, and children develop their character and social skills. They engage in activities that foster learning and peer relationships.
- Potential Outcomes: Successful navigation of this stage leads to the development of self-confidence and competence in social settings.
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Genital Stage (puberty onward):
- Focus: The individual develops a mature sexual identity and seeks to establish meaningful relationships. The focus is on the genitals and the ability to engage in sexual activity.
- Developmental Task: The individual learns to balance the needs of the self with the needs of others, leading to the ability to form healthy, intimate relationships.
- Potential Outcomes: Successful resolution of earlier stages leads to a well-adjusted adult who can satisfy their sexual and emotional needs while also pursuing goals related to reproduction and personal identity.
Oedipus Complex: Young boys have a natural tendency to be attached to
the mother and they consider their father as their enemy.
Indications for Stainless Steel Crowns in Pediatric Dentistry
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Extensive Tooth Decay:
Stainless steel crowns (SSCs) are primarily indicated for teeth with significant decay that cannot be effectively treated with fillings. They provide full coverage, preventing further decay and preserving the tooth's structure. -
Developmental Defects:
SSCs are beneficial for teeth affected by developmental conditions such as enamel dysplasia or dentinogenesis imperfecta, which make them more susceptible to decay. -
Post-Pulp Therapy:
After procedures like pulpotomy or pulpectomy, SSCs are often used to protect the treated tooth, ensuring its functionality and longevity. -
High Caries Risk:
For patients who are highly susceptible to caries, SSCs serve as preventive restorations, helping to protect at-risk tooth surfaces from future decay. -
Uncooperative Patients:
In cases where children may be uncooperative during dental procedures, SSCs offer a quicker and less invasive solution compared to more complex treatments. -
Fractured Teeth:
SSCs are also indicated for restoring fractured primary molars, which are crucial for a child's chewing ability and overall nutrition. -
Special Needs Patients:
Children with special needs who may struggle with maintaining oral hygiene can benefit significantly from the durability and protection offered by SSCs.
Contraindications for Stainless Steel Crowns
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Allergy to Nickel:
- Some patients may have an allergy or sensitivity to nickel, which is a component of stainless steel. In such cases, alternative materials should be considered.
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Severe Tooth Mobility:
- If the tooth is severely mobile due to periodontal disease or other factors, placing a stainless steel crown may not be appropriate, as it may not provide adequate retention.
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Inadequate Tooth Structure:
- If there is insufficient tooth structure remaining to support the crown, it may not be feasible to place an SSC. This is particularly relevant in cases of extensive decay or fracture.
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Active Dental Infection:
- If there is an active infection or abscess associated with the tooth, it is generally advisable to treat the infection before placing a crown.
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Patient Non-Compliance:
- In cases where the patient is unlikely to cooperate with the treatment or follow-up care, the use of SSCs may not be ideal.
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Aesthetic Concerns:
- In anterior teeth, where aesthetics are a primary concern, parents or patients may prefer more esthetic options (e.g., composite crowns or porcelain crowns) over stainless steel crowns.
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Severe Malocclusion:
- In cases of significant malocclusion, the placement of SSCs may not be appropriate if they could interfere with the occlusion or lead to further dental issues.
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Presence of Extensive Caries in Adjacent Teeth:
- If adjacent teeth are also severely decayed, it may be more beneficial to address those issues first rather than placing a crown on a single tooth.
Distal Shoe Space Maintainer
The distal shoe space maintainer is a fixed appliance used in pediatric dentistry to maintain space in the dental arch following the early loss or removal of a primary molar, particularly the second primary molar, before the eruption of the first permanent molar. This appliance helps to guide the eruption of the permanent molar into the correct position.
Indications
- Early Loss of Second Primary Molar:
- The primary indication for a distal shoe space maintainer is the early loss or removal of the second primary molar prior to the eruption of the first permanent molar.
- It is particularly useful in the maxillary arch, where bilateral space loss may necessitate the use of two appliances to maintain proper arch form and space.
Contraindications
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Inadequate Abutments:
- The presence of multiple tooth losses may result in inadequate abutments for the appliance, compromising its effectiveness.
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Poor Patient/Parent Cooperation:
- Lack of cooperation from the patient or parent can hinder the successful use and maintenance of the appliance.
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Congenitally Missing First Molar:
- If the first permanent molar is congenitally missing, the distal shoe may not be effective in maintaining space.
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Medical Conditions:
- Certain medical conditions, such as blood dyscrasias, congenital heart disease (CHD), rheumatic fever, diabetes, or generalized debilitation, may contraindicate the use of a distal shoe due to increased risk of complications.
Limitations/Disadvantages
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Overextension Risks:
- If the distal shoe is overextended, it can cause injury to the permanent tooth bud of the second premolar, potentially leading to developmental issues.
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Underextension Risks:
- If the appliance is underextended, it may allow the molar to tip into the space or over the band, compromising the intended space maintenance.
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Epithelialization Prevention:
- The presence of the distal shoe may prevent complete epithelialization of the extraction socket, which can affect healing.
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Eruption Path Considerations:
- Ronnermann and Thilander (1979) discussed the path of eruption, noting that drifting of teeth occurs only after eruption through the bone covering. The lower first molar typically erupts occlusally to contact the distal crown surface of the primary molar, using that contact for uprighting. Isolated cases of ectopic eruption should be considered when evaluating the eruption path.
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:
- Superficial Position of Tooth Germs: The positioning of tooth germs can lead to early eruption.
- Infection: Infections during pregnancy may influence tooth development.
- Malnutrition: Nutritional deficiencies can affect dental health.
- Eruption Acceleration: Febrile incidents or hormonal stimulation can hasten the eruption process.
- Genetic Factors: Hereditary transmission of a dominant autosomal gene may play a role.
- Osteoblastic Activities: Bone remodeling phenomena can impact tooth germ development.
- 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).