To explore the effect of RW splints on the position and occlusal relationship of class Ⅱ malocclusion patients with temporomandibular disorder (TMD) to provide a basis for the diagnosis and design of this kind of patient.

Fifteen patients with class Ⅱ malocclusions with TMD were enrolled in this study. After 8 months of RW-splint treatment, the changes in jaw position (∠ANB, SN-MP, ∠S-G0/N-Me) and occlusal relationship (molar, cuspid teeth displacement and anterior overbite/overjet value) were recorded by a condylar displacement measuring instrument at the CR position and CO position.

After RW-splint treatment, the mean values of ∠ANB (t = 4.971, P = 0.001) and ∠SN-MP (t = 9.895, P < 0.01) were increased in all 15 patients, and the mean value of S-G0/N-Me (t = 5.342, P = 0.005) was decreased. The mean values of the distal movement of the first molars on the left and right sides of the mandible were (1.57 ± 0.79) mm and (1.69 ± 1.29) mm, respectively; the mean values of the distal movement of the canines on the left and right sides of the mandible were (1.54 ± 0.50) mm and (1.51 ± 1.08) mm, respectively; and the mean values of the overbite were (1.16 ± 0.60) mm and (1.99 ± 0.85) mm, respectively.

After RW-splint treatment, the jaw rotates clockwise, and the relationship between the molars and canines changes obviously in class Ⅱ patients with TMD, which provides a reference for the diagnosis and treatment plan of this kind of patient.

To investigate the manufacturing procedures of personalized miniscrew-assisted rapid palatal expanders (pMARPE) using digital technologies and to evaluate the effect of the expanders when expanding the midpalatal suture of an adult.

Digital technologies were used to make pMARPE, which was used to treat a 21-year-old woman with maxillary transverse deficiency (MTD). The relevant literature on MARPE was reviewed.

PMARPE could be manufactured using intraoral digital scanning, computer-aided design and computer-aided manufacturing(CAD/CAM), and 3D printing technologies. After expansion, the width of the anterior midpalatal suture, posterior midpalatal suture and maxillary skeletal width increased by 3.9 mm, 3.2 mm and 4.7 mm, respectively. There was no significant change in the inclination of maxillary first molars, and the height of alveolar ridge decreased slightly. It could be seen that using digital technologies to manufacture personalized expanders was possible for MARPE, and the initial stability of miniscrews played an important role in the expansion success rate, the increase of molar inclination is composed of many parts, and the decrease of alveolar ridge height may be overestimated due to the measurement method, as shown by a literature review.

The midpalatal suture of an adult patient with MTD could be expanded by pMARPE. However, the effect of this expander on the inclination of the first molar and alveolar bone height needs to be further studied with a larger sample size.