LAUSR

OBJECTIVE To profile the posts on open orthodontic Facebook groups and identify which communication strategies and media modalities generate the most engagement from users. DESIGN A cross-sectional content analysis. SETTING Facebook Internet-based search. METHODS Post data were collected over a one-month period from the 10 largest public orthodontic Facebook groups. Evaluation of group characteristics included membership levels, number of administrators, time each group had been in existence and growth rate of each group. The number of posts, the numbers and types of engagement (likes, emojis, comments, shares) and engagement rate were calculated. The communication strategies (e.g. case presentation, course promotion, etc.) and media modalities (e.g. plain text, photograph, etc.) were recorded. RESULTS The study identified 190,268 Facebook members from the 10 largest orthodontic Facebook groups (median 17,811; interquartile range [IQR] 11,977). The median time the groups had existed was six years (median 2175 days; IQR 2311 days) and the median number of new group members in the past month was 1257 (IQR 2773). The median number of new group members in the past month was 1257 (IQR 2773). There were 227 postings during the study period with 2546 engagements. The overall median number of engagements was 196 (IQR 445) and the engagement rate of posts was 1.3% overall. Posts relating to course promotion (n = 63, 28%) followed by product promotion (n = 42, 19%) were the most common. Case presentation style posts accounted for 15% (n = 35). The level of engagement was greater for posts that had a clinical component compared to posts that did not (P < 0.001). For media modality, posts that included a photograph had greater engagement (P < 0.001). CONCLUSION There are frequent posts on course and product promotion in orthodontic Facebook groups; however, these are associated with low levels of engagement. Posts that are clinically orientated and include photographs have higher levels of engagement.