Genetic and treatment‐related risk factors associated with external apical root resorption (EARR) concurrent with orthodontia

Abstract

Methods -Utilizing a research data bank containing information from 1450 orthodontically treated patients, pre-and post-treatment radiographs from 460 individuals were evaluated for EARR of the four permanent maxillary incisors. Sixty-seven unrelated Caucasians with moderate to severe EARR were identified and were age-/sex-matched with orthodontically treated Caucasian controls yielding 38 females and 29 males per group. Factors tested for an association with EARR included the following: 1) treatment duration, 2) extraction of maxillary premolars, 3) numerous cephalometric measurements, and 4) DNA polymorphisms within/near candidate genes in a pathway previously implicated in EARR such as the purinergic-receptor-P2X, ligand-gated ion channel 7 (P2RX7; rs208294, rs1718119, and rs2230912), caspase-1 (CASP1; rs530537, rs580253, and rs554344), interleukin-1 beta (IL1B; rs1143634), Results -A long length of treatment and the presence of specific genotypes for P2RX7 SNP rs208294 were significantly associated with EARR.Conclusion -EARR occurrence was associated with both genetic and treatment-related variables, which together explained 25% of the total variation associated with EARR in the sample tested.

Association of genetic polymorphism and external apical root resorption

“…The results of the present review suggest that although some authors have reported that genetic polymorphism may play a role in EARR, [4][5][6][7][8][9][20][21][22][23]24 others have not supported this association. [25][26] Published orthodontic investigations in gene studies have seldom adhered to the STREGA or any genetic guidelines.…”

“…3 Recent investigations have reported an association between polymorphism and EARR in patients undergoing orthodontic treatment. [4][5][6][7][8][9] However, a meta-analysis investigating whether genetic variants of the interleukin-1b (þ,3954 C.T [rs1143634]) (IL-1b þ3954 C.T) gene polymorphisms were associated with orthodontic EARR reported no association. 10 To date, the relationship between genetic polymorphism and EARR in patients undergoing orthodontic treatment remains unknown.…”

Orthodontically induced external apical root resorption in patients treated with fixed appliances vs removable aligners

“…39 Some, however, consider that it is possible to evaluate root resorption with less radiation using lateral or panoramic radiographs. 23,40 The latter may be sufficiently reliable for assessing linear measurements if the head inclination in the anteroposterior plane is controlled with a variation of 108 or less. 41 Also, the accuracy of periapical projections for measuring OIEARR can be influenced by variability in tooth shape.…”

Cellular and Molecular Pathways Leading to External Root Resorption

“…These results partially explain the root resorption process and tooth movement following the mechanostat theory adapted from Frost's (1987) orthopedic theory. Nonetheless, these mathematical models cannot precisely define the fact that root surface resorption represents the cellular action of osteoclasts/odontoclasts nor that the variation seen with different genetic backgrounds challenge a qualitative model that concentrates on the RANKL/OPG ratio (Iglesias-Linares et al 2014;Sharab et al 2015).…”