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Effect of mandibular first molar mesialization on alveolar bone height: a split mouth study
Nicolas Göllner1, Jonas Winkler2, Peter Göllner1
1Private Practice, Spitalgasse 16, CH-3011, Bern, Switzerland.
Progress in Orthodontics
|June 11, 2019
Summary
Extensive tooth movement for space closure can cause minor vertical alveolar bone loss (ABL) in mandibular molars. However, this bone loss is not clinically significant, indicating the treatment is safe.
Area of Science:
- Orthodontics and Dental Research
- Periodontology
- Skeletal Biology
Background:
- Unilateral second premolar agenesis often requires space closure in the mandibular arch.
- Mesialization of mandibular molars is a common strategy for space closure.
- Potential risks of extensive tooth movement, such as alveolar bone loss (ABL), require evaluation.
Purpose of the Study:
- To assess the risk of vertical alveolar bone loss (ABL) in mesialized mandibular permanent molars following space closure.
- To compare ABL on the mesialized molar side with the contralateral control side in patients with unilateral second premolar agenesis.
Main Methods:
- Retrospective analysis of 25 patients undergoing space closure (approx. 10 mm) using skeletal anchorage.
- Measurement of ABL at mesial and distal sites of first molars using panoramic radiographs (pre- and post-treatment).
- Statistical analysis using permutational multivariate analysis of covariance (MANCOVA) to compare ABL and molar angulation.
Main Results:
- No significant difference in ABL was found between the distal sites of mesialized molars and control sites.
- Statistically significant, but not clinically relevant, ABL was observed at the mesial sites of mesialized molars (median 0.19 mm).
- No severe bone level defects or significant changes in molar angulation were detected.
Conclusions:
- Space closure via extensive tooth movement is a risk factor for vertical ABL at the mesial sites of mandibular first molars.
- The observed ABL was minimal and not clinically relevant, suggesting the safety of this orthodontic approach.
- Panoramic radiography is a useful tool for evaluating ABL in such cases, though it has limitations.
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