Evaluation of Periodontal Changes after Miniscrew Assisted Rapid Palatal Expansion in Adults

Introduction: Miniscrew Assisted Rapid Palatal Expanders (MARPE) have been recently utilized in adult patients to correct maxillary transverse deficiency. Clinical research on the effect of different MARPE designs on periodontium of neighbouring teeth has been limited. The aim of this research was to compare the Moon expander and the Dresden appliance in terms of their respective effects on periodontium of neighbouring teeth. Changes in risk factors attributed to gingival recession was also analyzed. Methods: In this retrospective study, Cone Beam Computer Tomography (CBCT) records, intraoral scan records (STL), and intraoral photographs were taken from patients undergoing expansion with either Moon or Dresden appliances. Records were taken at T1 (pre-expansion) and T2 (post-expansion) timepoints. Maxillary first molars (mid-mesiobuccal root), first premolars (mid-buccal root) and second premolars (mid-buccal root) were analyzed. Changes in buccal bone marginal level, buccal bone thickness at 3 and 6 mm from CEJ, buccal gingival level, and gingival thickness at 2mm from CEJ were analyzed using CBCT and superimposed STL data. To assess for changes in risks for further recession, photo-analysis was performed on the photographs taken at T1 and T2. Changes in gingival recession, keratinized tissue thickness, gingival inflammation, and keratinized tissue width were scored. Data were compared between the two groups and analyzed. Results: Data obtained from nine adult patients treated using the Dresden appliance and eleven adult patients treated with the Moon expander were analyzed. The results showed that after maxillary expansion, the buccal bone thickness at 6mm from the CEJ was reduced by 0.31mm around the first maxillary molars (p-value <0.03), regardless of the type of appliance used. Changes in other osseous and gingival dimensional parameters (from T1 to T2) were not statistically different between the two appliance groups. Changes in buccal bone thickness at 3mm from CEJ correlated with gingival thickness changes at 2mm from CEJ around the second premolars in the Dresden appliance group. Nevertheless, changes in other gingival parameters did not correlate with changes in osseous parameters in both groups. Findings also indicated that incidence of gingival inflammation and recession increased in both treatment groups. However, distribution of changes in factors associated with development of gingival recession was not statistically significant between the two groups. Conclusion Within timeframe of this study, while buccal bone thickness at 6mm from CEJ was reduced around maxillary first molars after maxillary expansion, effect of appliance design was not found to be significant for any of the measured parameters. Both appliances equally affect the scored risk factors for further gingival recession.