Evaluation of the periodontal status of uprighted mandibular second molars using microscrews placed in the retromolar area: A comparison of two surgical techniques

Objective: Permanent mandibular second molar impaction can lead to dental problems including periodontal pockets. In this study, uprighting of impacted mandibular second molars was carried out. Two surgical techniques were compared for time taken to upright the impacted mandibular second molar and if any periodontal pocket was formed on the distal aspect of the uprighted molar due to the surgical removal of bone distal to the impacted second molar after uprighting. Materials and Methods: A total of 20 subjects with impacted mandibular second molars were chosen from our orthodontic practice for this study. All the second molars were mesio-angularly impacted and unerupted. The subjects were divided into two groups. Group I comprised ten subjects with the cementoenamel junction (CEJ) of the unerupted impacted second molar apical to the level of the alveolar ridge. Group II comprised ten subjects with the CEJ of the unerupted impacted second molars at or coronal to the level of the alveolar ridge. 1.8 mm diameter and 10 mm length self-drilling microscrews (3M Unitek temporary anchorage devices) were placed into the retromolar area distal to the impacted second molars. Groups II and I underwent surgical exposure of the impacted second molars and placement of 10 mm length microscrews. In Group I subjects, bone was removed from the entire distal aspect (furrowing) of the impacted second molar. Group II subjects did not undergo any removal of bone on the distal aspect of the impacted second molars. One button each was bonded on the buccal and lingual surfaces of the surgically exposed second molars. Elastomeric chains were attached from the microscrew head to the buccal and lingual buttons so as to bodily upright the molar. After complete uprighting, a single examiner (periodontist) who was blinded to the type of surgical technique evaluated the periodontal status of the second molar by clinical probing of the sulcus depth (SD). The comparison of the significance of the difference of average duration and average SD between the two study groups was tested using Mann–Whitney U-test (a nonparametric test). The value of P< 0.05 is considered to be statistically significant. Results: Average duration of uprighting was significantly longer in Group II compared to Group I (P < 0.001). SD on an average is significantly deeper in Group I (furrowing) as compared to Group II (no furrowing) at distal surfaces (P < 0.001 for all distal sites). Average SD did not differ significantly between Groups II and I at mesial surfaces (P > 0.05 for all mesial sites). Conclusion: In Group I subjects, uprighting was hastened in comparison to Group II subjects where the CEJ was at or coronal to the alveolar bone. The furrowing of the bone does cause a deepening of the SD on the distal surface of the second molar, but this is not clinically significant. This deepening cannot be termed as a periodontal pocket as it is well within normal limits