Infraocclusion level and root resorption of the primary molar in second premolar agenesis: A retrospective cross-sectional study in the Portuguese population

Abstract

Background. Mandibular second premolar (M2P) agenesis results in the second primary molar (2pm) retention, infraocclusion, a reduced alveolar height and width, the supraeruption of antagonists, or the movement of the adjacent teeth. Infraocclusion affects the survival of the retained 2pm to a greater extent than root resorption.Objectives. The aim of the study was to evaluate the lifespan of the primary molar as a substitute, with root quality and occlusal adaptation, in cases of M2P agenesis in a low-income population to determine if the attitude of just vigilance could be the best clinical option whenever other clinical problems are absent. Material and methods.A total of 12,949 orthopantomograms were analyzed. Sixty-one patients (25 males and 36 females aged 7-36 years were divided into group 1 (the first permanent molar in occlusion) and group 2 (the second permanent molar also in occlusion). Vertical positioning to the occlusal plane, root condition and the movement of the adjacent teeth were evaluated.Results. Despite the study having a cross-sectional design, root resorption, infraocclusion, the distance between the first permanent molar and the first primary molar or the first permanent premolar, and the width of the 2pm were correlated with age. The primary molar root resorption increased with age, which was more pronounced when the second permanent molar was also in occlusion. The mesial movement of the adjacent teeth was absent in all groups. The 2pm was often occluded, but infraocclusion increased with age. Age periods of 11-15 years and 21-25 years are critical for the primary tooth loss. Conclusions.The second primary molar remains functional in the mandibular arch for up to 25 years. A well-documented no-intervention attitude based on clinical and radiographic data must be weighted in cases without orthodontic issues or with financial constraints.

Factors influencing root resorption in retained mandibular second deciduous molars with congenital absence of second premolars: a cross-sectional study

“…2 : good condition (GC) group (38 teeth in males and 45 teeth in females) with one and two grades of root resorption, which had less root resorption, and the poor condition (PC) group (22 teeth in males and 51 teeth in females) with three and four grades of root resorption, which had more root resorption. The crown height, crown mesiodistal width, adjacent interdental space, and distance from the occlusal plane were measured from panoramic radiographs using callipers [ 12 , 18 , 19 ] (Fig. 3 ).…”

Therapeutic Strategies of Primary Molar Infraocclusion: A Systematic Review

“…The infraoccluded tooth appears depressed with the tipping of the adjacent teeth and the overeruption of opposing teeth [ 33 , 37 , 38 ]. This causes a reduction in arch length and loss of space, especially in cases of severe infraocclusion of deciduous second molars in mixed dentition [ 33 , 39 ]. A significant deviation of the dental inter-incisor midline toward the affected side when the affected tooth has been left in place is another consequence reported in the literature [ 40 ].…”