Retrospective investigation of gingival invaginations : Part I: Clinical findings and presentation of a coding system.

Many orthodontic treatments involve tooth extraction. Gingival invagination is a common side effect after orthodontic extraction space closure leading to compromised oral hygiene and the space closure being hampered. Even the long-term stability of the orthodontic treatment result may be jeopardized. The aim of this study was to identify risk factors for the development of gingival invagination and possible implications on oral health and orthodontic treatment results.A total of 30 patients presenting 101 tooth extractions and subsequent orthodontic space closure were investigated to detect the presence of gingival invagination. The time required until active space closure, the thoroughness of space closure, and probing depths mesial and distal to the extraction site in addition to age, gender and the Periodontal Screening Index were investigated. A new coding system to describe the extent of gingival invagination is introduced for the first time here.Gingival invagination developed more frequently in the lower jaw (50%) than the upper (30%). Complete penetration occurred in the upper jaw in 6% of the patients and in the lower jaw in 25%. All patients without gingival invagination revealed complete space closure, whereas only 70% in the group with gingival invagination did so. The time until initiation of space closure took significantly longer in patients with gingival invagination (7.5 ± 1.4 months) than in patients without (3.3 ± 0.8 months). Probing depths of the adjacent teeth were significantly greater in regions with invaginations.Thus, the time required until space closure was initiated and the extraction site are important risk factors for the development of gingival invagination. The consequences of gingival invagination are instable space closure and deeper probing depths mesial and distal to the extractions. However, no statements concerning the mid- to long-term effects on oral health can be made.