In maxillofacial surgery, intrasulcular incisions are often used. This prospective case series was established to evaluate the detrimental effects of intrasulcular incisions on periodontal structures. In 35 patients, measurements of probing depth and crown length before and 10 months postoperatively were performed to calculate changes of attachment level and gingival recession. In a subgroup, surgically treated sites were compared with untreated control sites. A nonparametric test was applied for longitudinal and split-mouth comparisons. Overall, intrasulcular incisions did not induce significant attachment loss. The frequency of sites losing > or = 2 mm of attachment was 5.0%, 2.6%, and 4.7% at mesial, buccal, and distal sites, respectively. Intrasulcular incisions caused only a slight increase in gingival recession by 0.4 +/- 0.5, 0.2 +/- 0.3, and 0.3 +/- 0.4 mm at mesial, buccal, and distal sites, respectively. Within the limitations of the study design, it can be concluded that intrasulcular incisions without additional vertical incisions do not impose a serious risk for attachment loss and/or gingival recession.