Turkish Journal of Orthodontics
Original Article
Skeletal and Dental Effects of Twin-Block Appliances in Patients Treated With or Without Expansion

Skeletal and Dental Effects of Twin-Block Appliances in Patients Treated With or Without Expansion


Department of Orthodontics, Suleyman Demirel University, Faculty of Dentistry, Isparta, Turkey


Department of Orthodontics, Antalya Bilim University, Faculty of Dentistry, Antalya, Turkey

Turk J Orthod 2021; 34: 155-162
DOI: 10.5152/TurkJOrthod.2021.20103
Read: 339 Downloads: 376 Published: 20 September 2021

Objective: To compare the skeletal and dental effects of twin-block appliances with or without expansion.

Methods: From our archives, patients using twin-block appliances were selected. A total of 20 patients with expansion screws were classified as group 1 (10 male, 10 female; mean age 12.48 ± 1.38 years), and 18 patients without screws as group 2 (8 male, 10 female; mean age 12.81 ± 1.16 years). Cephalometric radiographs at pre-and post-treatment were used to evaluate skeletal and dentoalveolar parametric changes; study models and posteroanterior radiographs were used for transverse evaluation. The initial measurements and the treatment-related mean changes within the study groups were analyzed using the Student’s t-test.

Results: Changes in maxillary skeletal measurements were not statistically significantly different between groups except for A-VRL (P > .05). Mandibular measurements showed an increase in SNB (º) and Co-Gn distance in both groups. However, these changes were similar for both groups (P > .05). The maxillary measurements showed that incisors were proclined in the expansion group and retroclined in the non-expansion group. No significant difference was found between the groups in terms of changes in the skeletal transversal measurements (P > .05). On the study models, the changes in maxillary intercanine and intermolar widths, and in arch length differed to a statistically significant degree between groups (P < .05).

Conclusion: The skeletal effects of 2 different types of twin-block appliances in the transversal direction were similar; it was determined that dental expansion was obtained in the maxilla by adding screws to the twin-block appliances.

Cite this article as: Buyukcavus MH, Kale B. Skeletal and dental effects of twin-block appliances in patients treated with or without expansion. Turk J Orthod. 2021; 34(3): 155-162.

EISSN 2148-9505