Impact of Early Loss of Lower First Permanent Molars on Third Molar Development and Position

Abstract

Objective: To evaluate the effects of unilateral loss of the lower first permanent molar (L6) on the position and development of the lower third molar (L8). Material and Methods: Fifty-four panoramic radiographs of subjects with unilateral loss of L6 were examined. The L8 on the side of the L6 loss was compared with the L8 in the hemiarch without L6 loss (contralateral). The effect of L6 loss on the positioning of L8 was examined in all the samples (n=54), whereas the effect on the development of the third molar was examined in 38 patients with L8 with incomplete root formation. The Signs statistical test was used to evaluate the comparison between loss and contralateral hemiarches. Results: In 20 (37%) of 54 subjects, the L8 was better positioned in the hemiarch with loss of the lower first molar (p<0.001) compared with the control side. In the remaining 34 subjects, no difference was found. When only the L8 considered as impacted on the control side was examined (n=30), the cases with better positioning on the side with L6 loss increased to 66.6% (p<0.001). Conclusion: The loss of lower first molars improves the position of the lower third molar during its active eruption, mainly when the lower third molar is impacted. However, L6 loss does not affect the root development of lower third molars.

Assessment of Dental Caries and Intervention in the First Permanent Molars of Brazilian Children

“…When this element is lost early, there are numerous complications as a consequence, such as the migration of the second molar to the mesial, the extrusion of the antagonist's tooth, the change in the positioning of the anterior teeth, spaces between teeth, changes in the midline, in the Spee curve and in the ATM [8,30]. In order to lessen these implications, orthodontic planning is necessary to establish the patient's normal occlusion and prevent further damage [6,31].…”

“…The first permanent molar is an extremely important dental element in the oral cavity. This teeth eruption impacts on third molar eruption contribute to the development of physiological occlusion and adequate masticatory function [6] and, frequently, parents of children did not attribute the correct relevance for this tooth [7]. Thus, several problems arise when it is lost, such as changing the position of the adjacent tooth and extruding the antagonist [8], and an expensive and multidisciplinary approach is required to avoid these undesirable sequels [9].…”

Stress distribution in lower second molar mesialization using mini-implants: a pilot study using 3D finite element analysis

“…According to data in the literature, the first permanent lower molar is the most affected, as it erupts in the oral cavity in childhood around 6 years of age [1]. Thus, it is often mistaken for a deciduous tooth, and if there is any carelessness in the child's brushing or diet, there may be an accumulation of biofilm, progress to caries, and depending on the state of the disease, could end up causing the loss of element [2].…”