Assessment of space changes in the lower dental arch after the premature unit loss of a primary molar: A randomized clinical trial

Premature loss of primary teeth presents a significant challenge in oral health, with conflicting views on using space maintainers. To assess mandibular arch space changes associated with premature lower primary molar (PM) loss with or without a space maintainer. A randomized clinical trial with children (6-9 years old) with premature loss of a lower PM divided into two groups: control group (CG), without a space maintainer, and intervention group (IG), with a space maintainer. Dental casts were measured at baseline, 3 months, and 6 months. Linear distance; intercanine width and length; and arch width, length, and perimeter were measured. ANOVA and t-test were applied (p = .05). Twenty-six patients (mean: 7.3 years; standard deviation [SD]: 0.92) were included: 14 in CG and 12 in IG. CG had a greater space loss (-0.9 mm; SD: 0.45) than IG (-0.4 mm; SD: 0.61) at 3 months (p < .05). No difference between the groups was observed after 6 months (p = .610). CG decreases space at 6 months, especially with the first permanent molars without intercuspation (-2 mm; SD: 0.71; p = .007). Premature lower PM loss resulted in reduced arch space loss after 6 months, regardless of a space maintainer use. CG showed more loss of space when the first permanent molars lacked intercuspal relationship.