Springs in Orthodontics

 Springs are essential components of removable orthodontic appliances, playing a crucial role in facilitating tooth movement. Understanding the mechanics of springs, their classifications, and their applications is vital for effective orthodontic treatment.

•  Springs are active components of removable orthodontic appliances that deliver forces to teeth and/or skeletal structures, inducing changes in their positions.
• Mechanics of Tooth Movement: To achieve effective tooth movement, it is essential to apply light and continuous forces. Heavy forces can lead to damage to the periodontium, root resorption, and other complications.

Components of a Removable Appliance

A removable orthodontic appliance typically consists of three main components:

1. Baseplate: The foundation that holds the appliance together and provides stability.
2. Active Components: These include springs, clasps, and other elements that exert forces on the teeth.
3. Retention Components: These ensure that the appliance remains in place during treatment.

Springs as Active Components

Springs are integral to the active components of removable appliances. They are designed to exert specific forces on the teeth to achieve desired movements.

Components of a Spring

• Wire Material: Springs are typically made from stainless steel or other resilient materials that can withstand repeated deformation.
• Shape and Design: The design of the spring influences its force delivery and stability.

Classification of Springs

Springs can be classified based on various criteria:

1. Based on the Presence or Absence of Helix

• Simple Springs: These springs do not have a helix and are typically used for straightforward tooth movements.
• Compound Springs: These springs incorporate a helix, allowing for more complex movements and force applications.

2. Based on the Presence of Loop or Helix

• Helical Springs: These springs feature a helical design, which provides a continuous force over a range of motion.
• Looped Springs: These springs have a looped design, which can be used for specific tooth movements and adjustments.

3. Based on the Nature of Stability

• Self-Supported Springs: Made from thicker gauge wire, these springs can support themselves and maintain their shape during use.
• Supported Springs: Constructed from thinner gauge wire, these springs lack adequate stability and are often encased in a metallic tube to provide additional support.

Applications of Springs in Orthodontics

• Space Maintenance: Springs can be used to maintain space in the dental arch during the eruption of permanent teeth.
• Tooth Movement: Springs are employed to move teeth into desired positions, such as correcting crowding or aligning teeth.
• Retention: Springs can also be used in retainers to maintain the position of teeth after orthodontic treatment.

Types of Removable Orthodontic Appliances

1. Functional Appliances:

   • Purpose: Designed to modify the growth of the jaw and improve the relationship between the upper and lower teeth.
   • Examples:
     • Bionator: Encourages forward positioning of the mandible.
     • Frankel Appliance: Used to modify the position of the dental arches and improve facial aesthetics.

2. Retainers:

   • Purpose: Used to maintain the position of teeth after orthodontic treatment.
   • Types:
     • Hawley Retainer: A custom-made acrylic plate with a wire framework that holds the teeth in position.
     • Essix Retainer: A clear, plastic retainer that fits over the teeth, providing a more aesthetic option.

3. Space Maintainers:

   • Purpose: Used to hold space for permanent teeth when primary teeth are lost prematurely.
   • Types:
     • Band and Loop: A metal band placed on an adjacent tooth with a loop extending into the space.
     • Distal Shoe: A space maintainer used in the lower arch to maintain space for the first molar.

4. Aligners:

   • Purpose: Clear plastic trays that gradually move teeth into the desired position.
   • Examples:
     • Invisalign: A popular brand of clear aligners that uses a series of custom-made trays to achieve tooth movement.

5. Expansion Appliances:

   • Purpose: Used to widen the dental arch, particularly in cases of crossbite or narrow arches.
   • Examples:
     • Rapid Palatal Expander (RPE): A device that applies pressure to the upper molars to widen the maxilla.

Components of Removable Orthodontic Appliances

• Baseplate: The foundation of the appliance, usually made of acrylic, which holds the other components in place.
• Active Components: Springs, screws, or other mechanisms that exert forces on the teeth to achieve movement.
• Retention Components: Clasps or other features that help keep the appliance securely in place during use.
• Adjustable Parts: Some appliances may have adjustable components to fine-tune the force applied to the teeth.

Indications for Use

• Correction of Malocclusions: Removable appliances can be used to address various types of malocclusions, including crowding, spacing, and crossbites.
• Space Maintenance: To hold space for permanent teeth when primary teeth are lost prematurely.
• Tooth Movement: To move teeth into desired positions, particularly in growing patients.
• Retention: To maintain the position of teeth after orthodontic treatment.
• Jaw Relationship Modification: To influence the growth of the jaw and improve the relationship between the dental arches.

Advantages of Removable Orthodontic Appliances

• Patient Compliance: Patients can remove the appliance for eating, brushing, and social situations, which can improve compliance.
• Hygiene: Easier to clean compared to fixed appliances, reducing the risk of plaque accumulation and dental caries.
• Flexibility: Can be adjusted or modified as treatment progresses.
• Less Discomfort: Generally, removable appliances are less uncomfortable than fixed appliances, especially during initial use.
• Aesthetic Options: Clear aligners and other aesthetic appliances can be more visually appealing to patients.

Disadvantages of Removable Orthodontic Appliances

• Compliance Dependent: The effectiveness of removable appliances relies heavily on patient compliance; if not worn as prescribed, treatment may be delayed or ineffective.
• Limited Force Application: They may not be suitable for complex tooth movements or significant skeletal changes.
• Adjustment Period: Some patients may experience discomfort or difficulty speaking initially.

Nail Biting Habits

Nail biting, also known as onychophagia, is one of the most common habits observed in children and can persist into adulthood. It is often associated with internal tension, anxiety, or stress. Understanding the etiology, clinical features, and management strategies for nail biting is essential for addressing this habit effectively.

Etiology

1. Emotional Problems:

   • Persistent nail biting may indicate underlying emotional issues, such as anxiety, stress, or tension. It can serve as a coping mechanism for dealing with these feelings.

2. Psychosomatic Factors:

   • Nail biting can be a psychosomatic response to stress or emotional discomfort, manifesting physically as a way to relieve tension.

3. Successor of Thumb Sucking:

   • For some children, nail biting may develop as a successor to thumb sucking, particularly as they transition from one habit to another.

Clinical Features

• Dental Effects:

  • Crowding: Nail biting can contribute to dental crowding, particularly if the habit leads to changes in the position of the teeth.
  • Rotation: Teeth may become rotated or misaligned due to the pressure exerted during nail biting.
  • Alteration of Incisal Edges: The incisal edges of the anterior teeth may become worn down or altered due to repeated contact with the nails.

• Soft Tissue Changes:

  • Inflammation of Nail Bed: Chronic nail biting can lead to inflammation and infection of the nail bed, resulting in redness, swelling, and discomfort.

Management

1. Awareness:

   • The first step in management is to make the patient aware of their nail biting habit. Understanding the habit's impact on their health and appearance can motivate change.

2. Addressing Emotional Factors:

   • It is important to identify and treat any underlying emotional issues contributing to the habit. This may involve counseling or therapy to help the individual cope with stress and anxiety.

3. Encouraging Outdoor Activities:

   • Engaging in outdoor activities and physical exercise can help reduce tension and provide a positive outlet for stress, potentially decreasing the urge to bite nails.

4. Behavioral Modifications:

   • Nail Polish: Applying a bitter-tasting nail polish can deter nail biting by making the nails unpalatable.
   • Light Cotton Mittens: Wearing mittens or gloves can serve as a physical reminder to avoid nail biting and can help break the habit.

5. Positive Reinforcement:

   • Encouraging and rewarding the individual for not biting their nails can help reinforce positive behavior and motivate them to stop.

SEQUENCE OF ERUPTION OF DECIDUOUS TEETH

Upper/Lower   A B D C E 

SEQUENCE OF ERUPTION OF PERMAMENT TEETH 

Upper:   6 1 2 4 3 5 7           Lower:    6 1 2 3 4 5 7   
      
or       6 1 2 4 5 3 7              or  6 1 2 4 3 5 7 
 

ANTHROPOID SPACE / PRIMATE SPACE / SIMIEN’S SPACE  

The space mesial to upper deciduous canine and distal to lower deciduous  canine is characteristically found in primates and hence it is called primate space.  

INCISOR LIABILITY 

When the permanent central incisor erupt, these teeth use up specially all the spaces found in the normal dentition. With the eruption of permanent lateral incisor the space situation becomes tight. In the maxillary arch it is just enough to accommodate but in mandibular arch there is an average 1.6 mm less space available. This difference between the space present and space required is known as incisor liability. 
These conditions overcome by;  

      1. This is a transient condition and extra space comes from slight increase in arch width.   
      2. Slight labial positioning of central and lateral incisor. 
      3. Distal shift of permanent canine.        

      
LEE WAY SPACE (OF NANCE)  

The combined mesiodistal width of the permanent canines and pre molars is usually less that of the deciduous canines and molars. This space is 
called leeway space of Nance.     

Measurement of lee way space: 
 
Is greater in the mandibular arch than in the maxillary arch  It is about 1.8mm [0.9mm on each side of the arch] in the maxillary arch. 
And about 3.4mm [1.7 mm on side of the arch] in the mandibular arch. 
 
Importance:  

 This lee way space allows the mesial movement of lower molar there by correcting flush terminal plane.     
 LWS can be measure with the help of cephalometry.    

FLUSH TERMINAL PLANE (TERMINAL PLANE RELATIONSHIP) 

Mandibular 2nd deciduous molar is usually wider mesio-distally then the maxillary 2nd deciduous molar. This leads to the development of flush terminal plane which falls along the distal surface of upper and lower 2nd deciduous molar. This develops into class I molar relationship. 

Distal step relationship leads to class 2 relationship.
Mesial step relationship mostly leads to class 3 relationship.  

FEATURE OF IDEAL OCCLUSION IN PRIMARY DENTITION 

1. Spacing of anterior teeth. 
2. Primate space is present. 
3. Flush terminal plane is found. 
4. Almost vertical inclination of anterior teeth. 
5. Overbite and overjet varies.  

UGLY DUCKLING STAGE  

Definition:  
Stage of a transient or self correcting malocclusion is seen sometimes is called ugly duck ling stage. 
 
Occurring site: Maxillary incisor region 

Occuring age: 8-9 years of age.  

This situation is seen during the eruption of the permanent canines. As the developing p.c. they displace the roots of lateral incisor mesially this results is transmitting of the force on to the roots of the central incisors which also gets displaced mesially. A resultant distal divergence of the crowns of the two central incisors causes midline spacing.  

This portion of teeth at this stage is compared to that of ugly walk of the duckling and hence it is called Ugly Duckling Stage. 

Described by Broad bent. In this stage children tend to look ugly. Parents are often apprehensive during this stage and consult the dentist.  

Corrects by itself, when canines erupt and the pressure is transferred from the roots to the coronal area of the incisor.  
IMPORTANCE OF 1ST MOLAR
 
1. It is the key tooth to occlusion. 
2.  Angle’s classification is based on this tooth. 
3.  It is the tooth of choice for anchorage. 
4.  Supports occlusion in a vertical direction. 
5.  Loss of this tooth leads to migration of other tooth. 
6.  Helps in opening the bite.   

Anterior bite plate is an orthodontic appliance used primarily to manage various dental issues, particularly those related to occlusion and alignment of the anterior teeth. It is a removable appliance that is placed in the mouth to help correct bite discrepancies, improve dental function, and protect the teeth from wear.

Indications for Use

1. Anterior Crossbite:

   • An anterior bite plate can help correct an anterior crossbite by repositioning the maxillary incisors in relation to the mandibular incisors.

2. Open Bite:

   • It can be used to help close an anterior open bite by providing a surface for the anterior teeth to occlude against, encouraging proper alignment.

3. Bruxism:

   • The appliance can protect the anterior teeth from wear caused by grinding or clenching, acting as a barrier between the upper and lower teeth.

4. Space Maintenance:

   • In cases where anterior teeth have been lost or extracted, an anterior bite plate can help maintain space for future dental work or the eruption of permanent teeth.

5. Facilitation of Orthodontic Treatment:

   • It can be used as part of a comprehensive orthodontic treatment plan to help achieve desired tooth movements and improve overall occlusion.

Design and Features

• Material: Anterior bite plates are typically made from acrylic or thermoplastic materials, which are durable and can be easily adjusted.
• Shape: The appliance is designed to cover the anterior teeth, providing a flat occlusal surface for the upper and lower teeth to meet.
• Retention: The bite plate is custom-fitted to the patient’s dental arch to ensure comfort and stability during use.

Mechanism of Action

• Repositioning Teeth: The anterior bite plate can help reposition the anterior teeth by providing a surface that encourages proper occlusion and alignment.
• Distributing Forces: It helps distribute occlusal forces evenly across the anterior teeth, reducing the risk of localized wear or damage.
• Encouraging Proper Function: By providing a stable occlusal surface, the bite plate encourages proper chewing and speaking functions.

Management and Care

• Patient Compliance: For the anterior bite plate to be effective, patients must wear it as prescribed by their orthodontist. This may involve wearing it during the day, at night, or both, depending on the specific treatment goals.
• Hygiene: Patients should maintain good oral hygiene and clean the bite plate regularly to prevent plaque buildup and maintain oral health.
• Regular Check-Ups: Follow-up appointments with the orthodontist are essential to monitor progress and make any necessary adjustments to the appliance.

Types of Springs

In orthodontics, various types of springs are utilized to achieve specific tooth movements. Each type of spring has unique characteristics and applications. Below are a few examples of commonly used springs in orthodontic appliances:

1. Finger Spring

• Construction: Made from 0.5 mm stainless steel wire.
• Components:
  • Helix: 2 mm in diameter.
  • Active Arm: The part that exerts force on the tooth.
  • Retentive Arm: Helps retain the appliance in place.
• Placement: The helix is positioned opposite to the direction of the intended tooth movement and should be aligned along the long axis of the tooth, perpendicular to the direction of movement.
• Indication: Primarily used for mesio-distal movement of teeth, such as closing anterior diastemas.
• Activation: Achieved by opening the coil or moving the active arm towards the tooth to be moved by 2-3 mm.

2. Z-Spring (Double Cantilever)

• Construction: Comprises two helices of small diameter, suitable for one or more incisors.
• Positioning: The spring is positioned perpendicular to the palatal surface of the tooth, with a long retentive arm.
• Preparation: The Z-spring needs to be boxed in wax prior to acrylization.
• Indication: Used to move one or more teeth in the same direction, such as proclining two or more upper incisors to correct anterior tooth crossbites. It can also correct mild rotation if only one helix is activated.
• Activation: Achieved by opening both helices up to 2 mm at a time.

3. Cranked Single Cantilever Spring

• Construction: Made from 0.5 mm wire.
• Design: The spring consists of a coil located close to its emergence from the base plate. It is cranked to keep it clear of adjacent teeth.
• Indication: Primarily used to move teeth labially.

4. T Spring

• Construction: Made from 0.5 mm wire.
• Design: The spring consists of a T-shaped arm, with the arms embedded in acrylic.
• Indication: Used for buccal movement of premolars and some canines.
• Activation: Achieved by pulling the free end of the spring toward the intended direction of tooth movement.

5. Coffin Spring

• Construction: Made from 1.2 mm wire.
• Design: Consists of a U or omega-shaped wire placed in the midpalatal region, with a retentive arm incorporated into the base plates.
• Retention: Retained by Adams clasps on molars.
• Indication: Used for slow dentoalveolar arch expansion in patients with upper arch constriction or in cases of unilateral crossbite.