Related Experiment Video
Updated: Mar 16, 2026

Author Spotlight: Development of a Novel Finite Element Analysis Model for Improved Orthognathic Surgical Techniques
Published on: October 20, 2023
Slow versus rapid maxillary expansion in bilateral cleft lip and palate: a CBCT randomized clinical trial
Araci Malagodi de Almeida1, Terumi Okada Ozawa1, Arthur César de Medeiros Alves2
1Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Rua Sílvio Marchione, 3-20, Vila Nova Cidade Universitária, São Paulo, Bauru, ZIP CODE 17012-900, Brazil.
Objectives:
The purpose of this "two-arm parallel" trial was to compare the orthopedic, dental, and alveolar bone plate changes of slow (SME) and rapid (RME) maxillary expansions in patients with complete bilateral cleft lip and palate (BCLP).
Material And Methods:
Forty-six patients with BCLP and maxillary arch constriction in the late mixed dentition were randomly and equally allocated into two groups. Computer-generated randomization was used. Allocation was concealed with sequentially, numbered, sealed, opaque envelopes. The SME and RME groups comprised patients treated with quad-helix and Haas/Hyrax-type expanders, respectively. Cone-beam computed tomography (CBCT) exams were performed before expansion and 4 to 6 months post-expansion. Nasal cavity width, maxillary width, alveolar crest width, arch width, palatal cleft width, inclination of posterior teeth, alveolar crest level, and buccal and lingual bone plate thickness were assessed. Blinding was applicable for outcome assessment only. Interphase and intergroup comparisons were performed using paired t tests and t tests, respectively (p < 0.05).
Results:
SME and RME similarly promoted significant increase in all the maxillary transverse dimensions at molar and premolar regions with a decreasing expanding effect from the dental arch to the nasal cavity. Palatal cleft width had a significant increase in both groups. Significant buccal inclination of posterior teeth was only observed for RME. Additionally, both expansion procedures promoted a slight reduction of the alveolar crest level and the buccal bone plate thickness.
Conclusions:
No difference was found between the orthopedic, dental, and alveolar bone plate changes of SME and RME in children with BCLP. Both appliances produced significant skeletal transverse gains with negligible periodontal bone changes. Treatment time for SME, however, was longer than the observed for RME.
Clinical Relevance:
SME and RME can be similarly indicated to correct maxillary arch constriction in patients with BCLP in the mixed dentition.
More Related Videos
07:32Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
05:54Real-Time Dynamic Navigation System for the Precise Quad-Zygomatic Implant Placement in a Patient with a Severely Atrophic Maxilla
Published on: October 18, 2021