Related Experiment Video
Updated: Jul 14, 2026
Finite Element Analysis Model for Assessing Expansion Patterns from Surgically Assisted Rapid Palatal Expansion
Published on: October 20, 2023
Mandibular behavior with slow and rapid maxillary expansion in skeletal Class II patients: a long-term study
Roberto M A Lima Filho1, Antonio Carlos de Oliveira Ruellas
1robertomario@terra.com.br
Objective:
To evaluate anteroposterior and vertical mandibular changes in skeletal Class II patients treated with slow or rapid maxillary expansions at 10-year follow-up.
Materials And Methods:
The sample consisted of 70 patients divided into two groups, treated with (1) a cervical headgear (CHG) with expansion of the inner bow or (2) a Haas-type rapid maxillary expansion (RME) appliance in conjunction with CHG (RME-CHG). The CHG group consisted of 40 patients (18 males and 22 females, with an average age of 10.6 years at pretreatment [T(1)], 13.6 years at posttreatment [T(2)], and 23.6 years at postretention [T(3)]), and the RME-CHG group consisted of 30 patients (14 males and 16 females with an average age of 10.4 years at T(1), 14.0 years at T(2), and 24.6 years at T(3)).
Results:
The profiles of SNB, B-Hor, and Pog-Hor showed significant increases for all treatment phases in both groups. The SN-Go-Gn angle showed no significant decrease from T(1) to T(2) and a significant decrease from T(2) to T(3).
Conclusions:
For the entire sample (CHG + RME-CHG) the profile analysis between the phases showed mean increases in B-Ver and Pog-Ver for both phases.
