What should be included in an orthodontic summary table for space maintenance?

Orthodontic Space Maintenance Summary Table

Space maintainers are indicated following premature loss of primary teeth to prevent space loss and reduce future malocclusion severity, though evidence supporting their use remains limited and clinical decisions must be guided by individual patient factors rather than robust scientific data. 1

Indications for Space Maintenance

• Premature loss of primary molars in the mixed dentition is the primary indication, as these teeth are critical determinants of occlusion development 2
• Space maintenance should be considered when first permanent molars have not yet erupted, as this represents the most challenging clinical scenario 2
• Fixed orthodontic appliances and space maintainers should not be worn during neutropenia until mucositis resolves, to prevent mechanical trauma and infection of oral mucosa 3

Types of Space Maintainers and Clinical Applications

Fixed Appliances

Clinical Scenario	Appliance of Choice	Key Considerations
Premature loss of maxillary/mandibular first primary molar	Band and loop	Most commonly recommended fixed appliance [4]
Premature loss of second primary molar (maxillary)	Nance appliance or Transpalatal Arch (TPA)	NB shows less space loss (0.695mm) vs TPA (1.336mm) overall [5]
Premature loss of second primary molar (mandibular)	Lower Lingual Holding Arch (LLHA)	Maintains bilateral space in mandibular arch [4]
Unilateral second primary molar loss	Nance Button preferred over TPA	Significantly less space loss with NB in unilateral cases (p<0.05) [5]

Removable Appliances

• Free-end (distal shoe) space maintainers can be used when the first permanent molar has not erupted, serving to guide eruption while maintaining mucosal integrity 2
• Removable appliances function as both space maintainers and prosthetic replacements, avoiding complications of subgingival maintainers 2

Expected Outcomes and Space Loss

Comparative Effectiveness

• Nance Button demonstrates superior space maintenance compared to Transpalatal Arch, particularly for unilateral second primary molar loss 5
• Mean space loss with TPA: 1.336mm 5
• Mean space loss with Nance Button: 0.695mm 5
• No statistically significant differences in total space loss based on type of dental loss within either appliance group 5

Potential Benefits

• Reduced prevalence or severity of: crowding, ectopic eruption, tooth impaction, crossbite, excessive overbite/overjet, and poor molar relationship 1
• Potential for considerable cost savings by reducing need for future orthodontic treatment 1

Complications and Disadvantages

Common Adverse Events

• Soft tissue impingement 1
• Interference with eruption of adjacent teeth 1
• Pain and discomfort 1
• Plaque accumulation and increased caries risk 1
• Broken, dislodged, or lost appliances 1

Special Populations

• Neutropenic patients: All fixed orthodontic appliances must be removed during neutropenia to prevent mechanical trauma and infection until mucositis resolves 3

Clinical Decision-Making Algorithm

Step 1: Assess tooth loss location

• First primary molar → Band and loop 4
• Second primary molar → Proceed to Step 2

Step 2: Determine arch and laterality

• Maxillary + unilateral loss → Nance Button (preferred) 5
• Maxillary + bilateral loss → Nance or TPA 4
• Mandibular → LLHA 4

Step 3: Evaluate first permanent molar eruption status

• Not erupted → Consider removable free-end maintainer 2
• Erupted → Use fixed appliance per Steps 1-2

Step 4: Screen for contraindications

• Active neutropenia or mucositis → Delay placement 3
• Poor oral hygiene → Address before placement 1

Evidence Quality and Strength of Recommendation

The evidence supporting space maintainer use is categorized as Grade C (poor evidence), meaning recommendations cannot be made definitively for or against their use based on scientific evidence alone 1. Clinical decisions must therefore incorporate:

• Individual patient factors including age, dental development stage, and oral hygiene capacity 1
• Risk-benefit analysis weighing potential malocclusion prevention against appliance-related complications 1
• Economic considerations regarding future orthodontic treatment needs 1

Critical Caveats

• Space loss in primary dentition is considered a main cause of permanent dentition malocclusion, yet robust evidence for space maintainer efficacy remains limited 4, 1
• The leeway space loss is greater with TPA than Nance Button, particularly in unilateral cases—this should guide appliance selection 5
• Prosthetic replacement options (conventional or resin-bonded bridges) and orthodontic solutions should be considered as alternatives to implant-based space maintenance in appropriate cases 3