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Impaction of permanent mandibular second molar: a retrospective study
Michele Cassetta1, Federica Altieri, Alfonso Di Mambro
1Department of Oral and Maxillofacial Sciences, Sapienza University of Rome , Italy . michele.cassetta@uniroma1.it
Medicina Oral, Patologia Oral Y Cirugia Bucal
|March 26, 2013
Summary
Impacted mandibular second molars (MM2) are rare in orthodontic patients. MM2 impaction is associated with dental crowding, increased MM2 inclination, and reduced space between the first molar and mandibular ramus.
Area of Science:
- Dentistry
- Orthodontics
- Oral Surgery
Background:
- Mandibular second molar (MM2) impaction is a clinical concern in orthodontics.
- Understanding its prevalence and associated factors is crucial for treatment planning.
Purpose of the Study:
- To determine the prevalence of impacted MM2 in a Caucasian orthodontic population.
- To investigate the association between MM2 impaction and dental crowding.
- To evaluate the clinical significance of specific angular and spatial measurements in MM2 impaction.
Main Methods:
- Retrospective study of 2,945 Caucasian orthodontic patient records.
- 40 subjects with MM2 impaction (study group) compared to 200 controls.
- Measurements included crowding, MM2 inclination angle, and distance between the first molar and mandibular ramus.
Main Results:
- Prevalence of impacted MM2 was 1.36%.
- Significant associations found between MM2 impaction and crowding (P ≤ 0.001).
- Higher MM2 inclination angles (P ≤ 0.001) and reduced MM1-ramus distance (P ≤ 0.001) were observed in the impacted group.
Conclusions:
- MM2 impaction is uncommon in Caucasian orthodontic patients.
- Dental crowding, increased MM2 inclination, and reduced MM1-ramus distance are characteristic of MM2 impaction.
- These factors are significant at the time of one-third MM2 root formation.