Space Maintainers in Dentistry: A Comprehensive Guide
Space Maintainers in Dentistry
Contraindications of Space Maintainers
- No alveolar bone over erupting tooth
- Space closure desired for congenitally missing tooth
- Gross discrepancy requiring corrective orthodontics
- Excessive space
- High caries activity and poor oral hygiene
- Poor patient and parent cooperation
Requirements of Space Maintainers
- Passively maintain the space and prevent rotation or tipping of the abutment tooth
- Not cause damage to teeth or injury to soft tissue
- Not interfere with growth and development, eruption of permanent teeth, or functional movement
- Simple to construct and maintain
- Durable, strong, and stable
- Easily cleanable and not enhance dental caries or soft tissue pathology
Crown-Loop Space Maintainer
Indication
The abutment tooth requires full coverage stainless steel crown (SSC) due to multi-surface caries, hypoplasia, and pulp treatment.
Advantages
- Protects the tooth from enamel decalcification
- Better retention
- No need to be removed
Disadvantages
If the solder joint fails or the wire breaks, there is no way to repair the appliance.
Band and Loop Space Maintainer
Indications
- Premature loss of one tooth
- Unilateral early loss of the first primary molar before or after the eruption of the first permanent molar
- Unilateral loss of the second primary molar after the eruption of the first permanent molar
- Bilateral loss of the first primary molar before eruption of the permanent incisors and first permanent molar
Contraindications
- Marked space loss
- Severe malocclusion
- Mobile abutment tooth
Advantages
- Easy to construct
- Inexpensive
- Easily adjusted
- Gives room for eruption of permanent tooth
- Non-invasive
- Painless
Disadvantages
- Does not restore function
- Does not prevent extrusion of opposing tooth
- Has to be replaced by other space maintainers
Fixed Space Maintainers
Advantages
- Usually no breaking problems
- More hygienic
- Can be used in uncooperative patients
Disadvantages
- Does not restore function
- Does not restore esthetics
- Needs a good patient recall system for frequent check-ups
Unilateral Space Maintainers
- Band and loop
- Crown and loop
- Distal shoe
Bilateral Space Maintainers
- Nance appliance & transpalatal bar
- Lingual arch space maintainers
Removable Space Maintainers
Advantages
- Restores function
- Restores esthetics
- Easy to clean
- May restore vertical dimension
- Dental checkups for caries are easy
- No need for band construction
Disadvantages
- May be lost or broken by the patient
- Needs a highly cooperative child and parent
- Less hygienic
- Retention problems
- Requires laboratory time and multiple appointments
Functional Space Maintainers
- Restore masticatory function
- Resist force of occlusion
- Prevent overeruption of the opposing tooth
Passive Space Maintainers
Do not exert force.
Active Space Maintainers
Exert active force on the teeth adjacent to the space to open it.
Distal Shoe
Description
Intra-alveolar space maintenance, guides the first permanent molar into place, has an extension going subgingivally.
Indications
Premature loss or extraction of the second primary molar prior to the eruption of the first permanent molar.
Contraindications
- Inadequate abutment due to multiple loss of teeth
- Poor patient or parental cooperation
- Poor oral hygiene
- Systemic diseases (blood dyscrasias)
Disadvantages
- Difficult in accurate construction
- Improper placement will deflect the first permanent molar
- Foreign body
- Infection through mucosal communication
- Cooperation needed
Lingual Arch
Indication
Bilateral single or multiple tooth loss in the mandibular arch after eruption of the permanent incisors and permanent first molar.
Advantages
- Prevents mesial movement of molars and lingual movement of incisors
- Maintains the space throughout the mixed dentition period
Nance Appliance
Indication
Bilateral single or multiple tooth loss in the maxillary arch.
Advantages
- Resists maxillary molar rotation in the mesial direction around palatal roots
- Incorporates an acrylic button in contact with the palate
- Acrylic button rests in the rugae area
Transpalatal Arch
Indication
When one side of the arch is intact but several primary teeth are missing (rarely used).
Care of Fixed Space Maintainers
- Do not bite on hard or sticky objects
- Clean and maintain good oral hygiene
- Eating and swallowing may be difficult until the patient gets used to it
- Checkups must be done regularly
Factors to be Considered Before Planning for Space Maintainers
- Space available in the arch (arch length deficiency of fewer than 1-2 mm per quadrant – if arch length deficiency is more, we can do space regaining, serial extraction, comprehensive orthodontics)
- Sequence of teeth eruption (more space loss if the adjacent tooth is erupting)
- Amount of space closure (loss of the maxillary second primary molar before age 6 results in the greatest amount of closure)
- Direction of closure (maxillary posterior space closes by mesial bodily movement and mesiolingual rotation around the palatal root)
- Eruption timing of permanent successors (depends on dental age, teeth erupt when three-fourths of the root is developed)
- Amount of bone covering the unerupted tooth (premolars usually require 4-6 months to move through 1 mm of bone)
- Time elapsed since the loss of the first tooth
- Abnormal oral musculature
- Congenital absence of permanent teeth