RESUMO
The aims of this study were to evaluate the effectiveness of a lower lingual holding arch (LLHA) in maintaining arch length, and to compare the effectiveness of two LLHAs made of two different gauges (0.9 and 1.25 mm) of stainless steel (SS) wire. The sample comprised 44 subjects (24 males and 20 females) who for various reasons attended orthodontic clinics at Jordan University of Science and Technology Dental Teaching Center. The subjects were randomly divided into two treatment groups. The first group contained 20 subjects (12 males/8 females, average age 10.76 ± 0.75 years). The LLHA used in this group was made of 0.9 mm SS wire. The second group comprised 24 subjects (12 males/12 females, average age 10.57 ± 0.54 years). The LLHA used in this group was made of 1.25 mm SS wire. The third group consisted of 23 subjects (15 males/8 females, average age 10.63 ± 0.66 years) who served as the control. The records consisted of lateral cephalograms, dental pantomograms, and study casts. Paired t-test, analysis of variance, and chi-square tests were used to determine whether significant differences existed between the groups. In both treatment groups, the lower incisors proclined and moved forward, and space loss of the lower primary second molar occurred. The LLHA made of 0.9 mm SS was superior to that made of 1.25 mm SS in terms of arch length preservation.