Association between arch perimeter management and the occurrence of mandibular second molar eruption disturbances:

Abstract

Objectives To investigate the association between the management of mandibular arch perimeter during development of the dentition and its effects on second permanent molar (M2) eruption. Materials and Methods Seven electronic databases were searched without restrictions up to June 2020. Assessment was performed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool for non-randomized clinical trials (non-RCT). Odds ratio (OR) with 95% confidence intervals was calculated from random-effects meta-analyses. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the certainty of the evidence. Results Five non-RCTs, with serious to moderate risk of bias, were included. A low certainty of evidence indicated that individuals undergoing mandibular arch perimeter management by controlling the position of the first molar had a high prevalence of M2 eruption difficulties. The odds of eruption disorders was 7.5 times higher (OR: 7.57, [3.72, 15.41], P < .001) in treated individuals. Subgroup analysis revealed that appliances that increased the arch perimeter lead to a greater chance of eruption disorders compared to appliances that only maintained the perimeter. The predictive factors for the M2 eruption difficulty were its previous mesioangulation in relation to the first molar (>24°) and the treatment time (>2 years). Conclusions Mandibular arch perimeter management during development of the dentition leads to an increase in the occurrence of M2 eruption difficulties. The identification of possible risk factors as well as the choice of the appropriate appliance type and the monitoring of these individuals seems to be essential to avoid undesirable effects with this therapy.

WITHDRAWN: Clinical Oral Investigations Comparison of localized mandible morphology between patients with impacted and non-impacted mandibular second molars in three dimensions

“…Cassetta [19] found that there was a positive correlation between impaction of MM2 and a smaller distance rst molar from mandibular ramus, smaller mandibular jaw angle, vertically condylar growth and crowding. Santana [20] showed that the relationship between MM1 and MM2, the space available in the posterior region played an important role in the eruption of MM2. Similarly, L7-MR was the most relevant factor according to the equation, as the ratio was 2.244: 1 in the study.…”

Estimativa do espaço disponível para erupção de caninos, pré-molares e segundos molares permanentes inferiores a partir do índice de Little

“…Assim, apesar do seu uso extensivo na prática clínica e dos desfechos favoráveis veiculados por meio de relatos de caso De maneira geral, a frequência de casos em que há impacção dos MM2 é baixa, variando entre 0,06% e 2,3% (Johnsen, 1977;Farman et al, 1978;Grover & Lorton;1985;Bondemark & Tsiopa, 2007;Magnusson & Kjellberg, 2009;Varpio & Wellfelt, 1988) lingual ou uma combinação dos dois, observaram uma taxa de impacção de 7,8%, 4,7% e 14,7%, respectivamente, em relação a uma taxa de 1% encontrada no grupo controle. Entretanto, o risco de problemas durante a erupção do MM2 com o uso de dispositivos mantenedores de Leeway space tem sido descrito com baixa evidência cientifica Jacob et al, 2014;Arunachalam et al, 2021;Santana et al, 2021).…”