Predisposing factors for external apical root resorption associated with orthodontic treatment

Abstract

ObjectiveThis study aimed to identify possible risk factors for external apical root resorption (EARR) in the maxillary incisors after orthodontic treatment.MethodsThe root length of 2,173 maxillary incisors was measured on periapical radiographs of 564 patients who received orthodontic treatment. The Kappa test was performed to evaluate intraexaminer and interexaminer reproducibility. Multiple binary logistic regression was used to determine the association between EARR and various factors. Odds ratios and 95% confidence intervals were reported.ResultsThe risk of developing EARR was 70% higher in orthodontic treatment with maxillary premolar extraction (p = 0.004), 58% higher in patients with increased overjet (p = 0.012), 41% lower in two-phase orthodontic treatment (p = 0.037), and 33% lower in patients with deep bite (p = 0.039). The lateral incisors were 54% more likely to develop EARR (p < 0.001), dilacerated roots were 2.26 times more likely to develop EARR (p < 0.001), and for each additional millimeter of root length, the risk of EARR increased by 29% (p < 0.001).ConclusionsThe potential risk factors for EARR after orthodontic treatment included treatment with maxillary premolar extraction, increased overjet at the beginning of treatment, and dilacerated roots.

GWAS of Post-Orthodontic Aggressive External Apical Root Resorption Identified Multiple Putative Loci at X-Y Chromosomes

“…Regression analysis performed in the present study suggests that both cohorts are unlikely to be marginally influenced ( p > 0.05) by some of the collected covariables. In this regard, the treatment time has been described as a risk factor influencing EARR severity within a degree-time dependent effect [ 44 ]; however, this suggestion is not supported for the case of aEARR based on the present research data. A robust risk association was not directly imputed to treatment length by itself according to comparisons between both cohorts in the current study [ 44 , 45 , 46 ].…”

“…In this regard, the treatment time has been described as a risk factor influencing EARR severity within a degree-time dependent effect [ 44 ]; however, this suggestion is not supported for the case of aEARR based on the present research data. A robust risk association was not directly imputed to treatment length by itself according to comparisons between both cohorts in the current study [ 44 , 45 , 46 ]. It is thus plausible that some confounding factors associated with treatment length and not treatment time itself, might explain some of the differences in some cases [ 38 , 47 ].…”

“…In line with this, several diagnostic and clinical factors have been previously associated with moderate degrees of EARR secondary to orthodontic forces [ 2 , 40 ]. Demographic factors such as age and gender, morphological factors such as root shape type or clinical factors such as treatment duration, magnitude of orthodontic forces, previous dental trauma, maxillary expansion degree, direction of tooth movement, extraction treatment, use of intermaxillary elastics, or even appliance type have been suggested [ 9 , 41 , 42 , 43 , 44 ]. Nevertheless, a significant number of controversial related results are also found in literature.…”

Reabsorción radicular externa asociada al tratamiento ortodóncico: revisión de la literatura

“…La mayoría de los estudios coinciden que los incisivos laterales superiores son los dientes más propensos a sufrir de RRE debido a la extensión del movimiento durante el tratamiento y presentan mayor probabilidad de tener raíces con dilaceración hacia distal 26 . Respecto a la morfología radicular, raíces cortas, dilaceradas, puntiagudas o con forma de pipeta son más propensas a reabsorberse porque distribuyen de manera diferente las fuerzas 1,3,15,25 , al aplicar una fuerza a nivel del ápice, la distribución de la carga es diferente a la que se genera en una raíz con una anatomía radicular normal, , causando un trauma al ligamento periodontal 3 .…”

“…Las exodoncias dentales por razones ortodóncicas son un factor de riesgo para reabsorción radicular externa 3,22,26 porque implica mayor extensión de movimiento dental, y de mayor fuerza para lograr la retrusión de las raíces para cerrar los espacios 9,16,20,31 .…”