Introduction: This study aimed to systematically review the current evidence on the occurrence of pulp changes as side effects from orthopaedic rapid maxillary expansion (ORME) or surgically assisted rapid maxillary expansion (SARME).
Methods: An electronic search was performed in eleven databases. The eligibility criteria included clinical studies assessing vitality, sensibility or dimensions of the pulp chamber of permanent teeth before and after ORME or SARME, without restrictions on publication year or language. The risk of bias was analysed with the NIH 'Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group' and the 'JBI for quasi-experimental studies' tool. The GRADE tool was used to assess the certainty of evidence.
Results: The initial search resulted in 1,197 records, from which only seven before-after studies were included. There was a change in the pulpal blood flow (PBF) of maxillary incisors and canines up to 5 days after SARME, which gradually returned after 7 days to 3 months. After ORME, one study observed an increased PBF and one study observed a reduced PBF, which gradually returned after the end of expansion. Two studies observed that both ORME and SARME caused temporary changes in pulp sensibility. Three studies observed a significant reduction in the pulp chamber after ORME or SARME. The outcomes presented a very low certainty of evidence.
Conclusions: Although limited, the evidence shows that ORME and SARME caused temporary changes in pulp vitality and sensibility, with the possibility of inducing a reduction in pulp chamber dimensions.
Keywords: palatal expansion technique; pulp chamber dimensions; pulp sensibility; pulpal blood flow; systematic review.
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