To assess and compare the effects produced in the maxillary dental arch by means of Connecticut intrusion arch (CIA) with or without a cinch back on the distal end of the tube of the first molars.

Materials and Methods

This study included 44 patients with a mean age of 13.1 ± 1.8 years treated for deep bite with a CIA randomly divided into two groups: group 1 (G1), 22 patients with initial mean age of 12.72 ± 1.74 years treated with the CIA in the upper arch without a cinch back on the distal surface of the tube of the first molars, and group 2 (G2), 22 patients with an initial mean age of 13.67 ± 2.03 years treated with the CIA with a cinch back. Lateral cephalograms were available before treatment (T1) and after intrusion of maxillary incisors (T2). The mean treatment period was 5.5 ± 1.45 months. Intragroup and intergroup changes in the maxillary incisor and molar positions were analyzed by paired and independent t-tests associated with the Holm-Bonferroni correction method for multiple comparisons (P < .05).


There were significant differences between groups in terms of maxillary incisor displacement. The maxillary incisors flared labially (2.17°) and proclined (1.68 mm) in group 1, whereas a palatal inclination (−1.99°) and retroclination (−1.13 mm) was observed in group 2. No significant differences were found for the molar positions between the groups.


The presence or absence of a distal bend in CIA affects incisor tipping and proclination during intrusion mechanics.

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Author notes


Postgraduate Doctorate Student, Department of Orthodontics, University of North Paraná, Londrina-Paraná, Brazil.


Senior Professor, Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru-São Paulo, Brazil.


Full Professor, Department of Orthodontics, University of North Parana, Londrina Paraná, Brazil.