Objective This study aimed to evaluate and compare the levels of pain, discomfort, and functional impairments between slow and rapid maxillary expansion (RME) in treating skeletal maxillary constriction in the adolescence period (i.e., between 12 and 16 years). Materials and methods The study sample consisted of 52 patients (21 males and 31 females) with maxillary skeletal constriction in the posterior region. The patients were randomly distributed into either RME (26 patients, with a mean age of 13.87 (± 1.31) years) or slow maxillary expansion group (SME, 26 patients, with a mean age of 14.31 (± 1.19) years). The levels of pain, discomfort, and functional difficulties were assessed after 24 hours (T1), 7 days (T2), 15 days (T3), one month (T4), and four months (T5) following the onset of the expansion procedure. Results Patients in the RME group encountered significantly greater levels of pain and discomfort than those in the SME group at T1, T2, and T3 (p>0.001). Chewing and swallowing difficulties were significantly greater in the RME group at T1, T2, T3, and T4 (P≤0.001). The pressure on soft tissue was greater in the RME group at T2 and T3 (p>0.001). After four months (T5), the levels of pain and discomfort decreased to their lowest levels, as well as the difficulties of chewing and swallowing, and the pressure on soft tissue were almost non-existent in both groups. Conclusion Patients treated with the removable slow maxillary expander reported lower levels of pain and discomfort, fewer chewing and swallowing difficulties, and less pressure on soft tissues than those treated with the bonded rapid maxillary expander. These difficulties gradually decreased over time in both groups. The lower levels of pain and discomfort may make the SME an effective and comfortable treatment alternative for adolescents with skeletal maxillary constriction.

Background. Maxillary expansion is one of the treatment options for the correction of the skeletal constriction of the upper jaw. However, evidence regarding the best treatment effects with the use of rapid vs. slow maxillary expansion in the early adolescence period (i.e., between the age of 12 and 16 years) is still lacking in the available literature.Objectives. The aim of the present study was to investigate the effectiveness of rapid and slow maxillary expansion in treating posterior skeletal constriction, and to compare the 2 techniques in terms of skeletal and dentoalveolar changes by using cone-beam computed tomography (CBCT). Material and methods.The sample consisted of 34 patients (15 males and 19 females) suffering from posterior skeletal constriction. They were randomly allocated either to the rapid maxillary expansion (RME) group (17 patients aged 13.76 ±0.32 years) or to the slow maxillary expansion (SME) group (17 patients aged 14.02 ±0.28 years). The skeletal and dental landmarks, and changes in the posterior dimensions were examined using CBCT radiographs at the beginning of treatment (T1) and at the end of the observation period (T2).Results. There were no significant differences between the 2 groups in terms of skeletal and dental changes except the amount of change in the inter-premolar width at the root apex, which was greater in the SME group (p = 0.007), as well as the amount of change in the skeletal palatal width in the molar region, which was also greater in the SME group (p = 0.008). Conclusions.Both maxillary expansion protocols were effective in treating posterior skeletal constriction. The average changes in the skeletal and dental widths were generally similar in both groups. Therefore, SME can be considered as an alternative to RME in patients with skeletal maxillary constriction in the early adolescence period.