The effect of genetic polymorphisms on treatment duration following premolar extraction

Abstract

To elucidate genetic factors affecting orthodontic treatment duration, we employed targeted next-generation sequencing on DNA from the saliva of 117 patients undergoing orthodontic treatment after premolar extraction. The clinical characteristics of patients are summarized, and the association of clinical variables with treatment duration was assessed. Patients whose treatment duration deviated from the average were classified into an extreme long group or an extreme short group. We identified nine single nucleotide polymorphisms (SNPs) of six genes that significantly differed in the two groups via targeted sequencing. The frequency of the CC genotypes of WNT3A, SPP1 (rs4754, rs9138), and TNFSF11, TT genotype of SPP1 (rs1126616), and GG genotype of SFRP2 was significantly higher in the extreme long group than in the short group. In the extreme short group, the TC genotype of SPP1, AA genotype of P2RX7, CT genotype of TNFSF11, and AG genotype of TNFRSF11A tended to exhibit higher frequency than in the long group. Taken together, we identified genetic polymorphisms related to treatment duration in Korean orthodontic patients undergoing premolar extraction. Our findings could lead to further studies predicting the prolongation of the orthodontic treatment duration, and will be of great aid to patients as well as orthodontists.

Genetic polymorphisms linked to extreme postorthodontic external apical root resorption in Koreans

“…This study utilized the genetic information and clinical records collected as part of an orthodontic cohort study [ 19 ]. Of the 117 patients who underwent fixed orthodontic treatment at the Department of Orthodontics, OOO University, from February 2008 to May 2020, 77 individuals with no known biological relationships to each other were finally enrolled in this study.…”

“…Other clinical characteristics of the participants were collected by measuring lateral cephalometric radiographs and screening electronic medical records. Parameters including age, sex, ANB, FMA, U1 to SN, crowding, displacement, overjet, overbite, and peer assessment rating score (PAR, unweighted and weighed) at the pre-treatment time point (T1) were collected, and leveling duration, retraction duration, leveling and retraction duration, total treatment duration, and anterior teeth retraction amount in the horizontal direction were counted and measured according to a previous study [ 19 ]. Displacement was defined as the sum of the absolute values of crowding or spacing to quantify the abnormal tooth positions.…”