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Effect of flap design on periodontal healing after impacted third molar extraction: a systematic review and meta-analysis.

Chen YW, Lee CT, Hum L, Chuang SK. . Int J Oral Maxillofac Surg. 2017 Mar;46(3):363-372. doi: 10.1016/j.ijom.2016.08.005. Epub 2016 Sep 3.

The extraction of an impacted third molar violates the surrounding soft and bony tissues. The surgeon's access to the tooth, for which there are various surgical approaches, has an important impact on the periodontium of the adjacent second molar. The aim of this review was to analyze the relationships between the different flap techniques and postoperative periodontal outcomes for the mandibular second molars (LM2) adjacent to the impacted mandibular third molars (LM3). An electronic search of MEDLINE and other databases was conducted to identify randomized controlled trials fulfilling the eligibility criteria. To assess the impact of flap design on the periodontal condition, the weighted mean difference of the probing depth reduction (WDPDR) and the weighted mean difference of the clinical attachment level gain (WDCAG) at the distal surface of LM2 were used as the primary outcomes. The results showed that, overall, the different flap techniques had no significant impact on the probing depth reduction (WDPDR -0.14mm, 95% confidence interval -0.44 to 0.17), or on the clinical attachment level gain (WDCAG 0.05mm, 95% confidence interval -0.84 to 0.94). However, a subgroup analysis revealed that the Szmyd and paramarginal flap designs may be the most effective in reducing the probing depth in impacted LM3 extraction, and the envelope flap may be the least effective.

Different flap designs have no impact on periodontal outcomes on second molars after impacted third-molar extraction

Yong Hur, DDS, DMD, MS Yumi Ogata, DDS, DMD, MS .


Systematic Review Conclusion

The different surgical flap designs for mandibular third-molar extraction did not have a significantly different impact on postoperative periodontal outcomes of the mandibular second molars with a minimum follow-up period of 3 months.

Critical Summary Assessment

This systematic review with limited evidence indicated there is no compelling reason to support the use of a particular flap design for impacted mandibular third-molar extraction.

Evidence Quality Rating

Limited Evidence

This summary is published in the Journal of the American Dental Association and can be accessed at:

Critical Summary Publication Date:


These summaries are not intended to, and do not, express, imply, or summarize standards of care, but rather provide a concise reference for dentists to aid in understanding and applying evidence from the referenced systematic review in making clinically sound decisions as guided by their clinical judgment and by patient needs. American Dental Association © 2019