Long-term evaluation of lower incisors gingival recessions after orthodontic treatment

Summary Aim The development of gingival recessions has been associated with orthodontic treatment; however, a clear etiology is still unknown. The aim of the present study was to further clarify potential association between the development of labial and lingual recessions and inclination of the lower incisors during orthodontic treatment, vertical facial morphology, width of the alveolar bone process, height and width of their symphysis after orthodontic treatment and at long-term retention. Methods On dental casts and good quality lateral cephalograms of 126 orthodontically treated patients, relevant measurements were performed and gingival recessions were assessed and recorded before, immediately after treatment and at long-term retention. Results Taking into account the whole sample at three different occasions, on the buccal side, the lateral incisors have significantly less recessions than the central incisor. On the lingual side, tooth 32 presented with lower risk of recession compared to all other three incisors. No association was found between the width of the alveolar bone process at the apex (Wapex), at the level of the crest (Wcrest) and at mid of the root (Wmid), the width (D), the vertical skeletal pattern (AnsPns-Go’Me) and the onset of buccal or lingual recessions. Development of new recessions was clearly associated with males and with increasing age. The symphysis height (Me-Wcrest) was statistically related with the onset of lingual recessions on 32 and 42. The ratio between the symphysis height and the width at the crest level demonstrated a statistically significant association with the presence of buccal and lingual recessions. Excessive proclination (≥10°) of the lower incisors demonstrated an association with the onset of recessions in 25 per cent of the cases. Conclusion Based on the sample of this study, there is some evidence that increased symphysis height (Me-Wcrest), and ratio between the symphysis height and the width at the crest level as well as big change of lower incisor inclination during treatment are associated with the development of recessions.