| id |
6bd55f15-d666-4b2a-9254-caf987d39ddc |
| user_id |
8684964a-bab1-4235-93a8-5fd5e24a1d0a |
| job_id |
baubzcil-4146 |
| base_model_name |
xevyo |
| base_model_path |
/home/sid/tuning/finetune/backend/output/xevyo-bas /home/sid/tuning/finetune/backend/output/xevyo-base-v1/merged_fp16_hf... |
| model_name |
The longevity of space |
| model_desc |
The longevity of space maintainers |
| model_path |
/home/sid/tuning/finetune/backend/output/baubzcil- /home/sid/tuning/finetune/backend/output/baubzcil-4146/merged_fp16_hf... |
| source_model_name |
xevyo |
| source_model_path |
/home/sid/tuning/finetune/backend/output/xevyo-bas /home/sid/tuning/finetune/backend/output/xevyo-base-v1/merged_fp16_hf... |
| source_job_id |
xevyo-base-v1 |
| dataset_desc |
The Longevity of Space Maintainers: A Retrospectiv The Longevity of Space Maintainers: A Retrospective Study is a detailed 1998 investigation published in Pediatric Dentistry examining how long different types of space maintainers last in real clinical settings and which factors contribute to their success or failure. The study analyzed 301 space maintainers fitted in 141 patients (ages 3.4–22.1 years) at the Leeds Dental Institute between 1991 and 1995, making it one of the most extensive retrospective evaluations of space-maintainer performance to date.
Using life-table survival analysis, the researchers found that space maintainers fail frequently and early, with an overall failure rate of 63% and a median survival time of only 7 months. Failure causes varied but were strongly dominated by loss of cement (36%), followed by breakage (24%), and complete loss of the appliance (9%). Only 8% of appliances were deemed fully successful, and 21% were lost to follow-up.
Key Findings
1. Survival Varies Significantly by Appliance Type
Band and Loop (B&L) appliances exhibited the best longevity, with a median survival of 13 months.
Lower Lingual Holding Arches (LLHAs) performed the worst, lasting only 4 months.
Nance appliances: 6-month median survival.
Removable partial dentures: 9-month median survival.
Unilateral appliances survived more than twice as long as bilateral ones.
2. Unexpected Side-Dominance
Left-side B&L maintainers lasted 16 months, while right-side B&Ls survived only 4 months—a statistically significant difference. The authors suggest possible operator-handedness or chewing-side habits as contributing factors.
3. Failure Patterns and Clinical Implications
Cementation failure—often linked to band adaptation, moisture control, or occlusal stress—was the most common cause.
Mechanical failures (e.g., broken solder joints, wire fractures) accounted for nearly a quarter of failures.
Soft-tissue lesions, impingement, and eruption interference also contributed to early removal.
4. Repairs and Replacements Have Different Longevity
The survival time differed dramatically based on what happened after a failure:
Repaired maintainers: 13.5 months (best outcome)
Remade maintainers: 10 months
New maintainers: 7 months
Recemented maintainers: 4.5 months (worst outcome)
This suggests that cement loss often masks deeper design or construction problems.
5. No Effect from Demographic or Operator Variables
Longevity was not influenced by:
Patient age or gender
Dental arch
Operator experience (postgraduate, undergraduate, faculty)
Adequacy of pretreatment assessment
Design and construction quality were far more important than patient or clinician characteristics.
Conclusions
The study provides several evidence-based conclusions:
High failure rate: 63% of appliances failed—substantially higher than reported in earlier research.
Design matters: B&L maintainers outperform all other designs; LLHAs underperform significantly.
Cement issues dominate: Cement loss is the leading cause of failure.
Reassessment is essential: If a space maintainer fails twice from cement loss, its design and suitability must be reevaluated.
Failure risk increases with repeated refitting: Locations where appliances fail multiple times are likely unsuitable for further space maintenance.
Follow-up frequency should be increased:
Bilateral fixed appliances → every 2 months
Unilateral fixed and removable appliances → every 4 months
Overall Summary
This study is a foundational reference on the real-world durability of space maintainers, revealing that survival times are shorter and failure rates higher than often assumed. It emphasizes the importance of proper appliance selection, meticulous design and fabrication, and vigilant follow-up. Its practical recommendations help clinicians improve outcomes and anticipate common complications in pediatric space maintenance.
If you'd like, I can also prepare:
🔸 a one-page clinical summary
🔸 a comparison with the other dental or longevity studies you’ve uploaded
🔸 a visual chart of survival times across appliance types
Just tell me!
Sources
... |
| dataset_meta |
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| dataset_path |
/home/sid/tuning/finetune/backend/output/baubzcil- /home/sid/tuning/finetune/backend/output/baubzcil-4146/data/baubzcil-4146.json... |
| training_output |
null |
| status |
queued |
| created_at |
1765052350 |
| updated_at |
1765053264 |
| source_adapter_path |
NULL |
| adapter_path |
/home/sid/tuning/finetune/backend/output/baubzcil- /home/sid/tuning/finetune/backend/output/baubzcil-4146/adapter... |
| plugged_in |
False |