Background: The aim of this study was to investigate the relationship between missing maxillary lateral incisors and the mesio-distal (MD) diameters of the teeth. Occlusal and skeletal characteristics of the patients have been analyzed.
Methods: Seventy-nine patients were included in the study (permanent dentition, mean age: 13.7): 30 subjects with uni- or bilateral maxillary lateral incisors agenesis (study group, SG) and 49 patients with no maxillary lateral incisors agenesis (control group, CG). Orthopanoramics, plaster models and cephalometric analysis were used to perform the evaluations.
Results: Compared to the CG, in the SG, most of the teeth had smaller MD diameter. In the bilateral agenesis subgroup, the average differences between teeth diameters were lower than those found by comparing them to the unilateral agenesis subgroup and to the SG. Overjet was reduced on average in the SG. In the SG were found less cases of cross-bite and scissor-bite, less frequency of impaction of at least one tooth and agenesis of other teeth, crowding only in the lower arch, square or ovoid arch shape in the upper arch and square in the lower arch, increased interincisal angle and decreased SN^GoMe.
Conclusions: Upper lateral incisors agenesis, especially in cases of unilateral agenesis, is associated with MD teeth reduction. The agenesis of the upper lateral incisors is associated with a greater probability of agenesis affecting other teeth, molar and canine class II, reduced overjet and overbite, square or ovoid upper arch shapes, increased interincisal angle and reduced total divergence.