Association between root resorption incident to orthodontic treatment and treatment factors

Abstract

The purpose of this study was to clarify the prevalence and degree of root resorption induced by orthodontic treatment in association with treatment factors. The files of 243 patients (72 males and 171 females) aged 9-51 years were randomly selected from subjects treated with multi-bracket appliances. The severity of root resorption was classified into five categories on radiographs taken before and after treatment. The subjects were divided into extraction (n = 113 patients, 2805 teeth) and non-extraction (n = 130 patients, 3616 teeth) groups and surgical (n = 56 patients, 1503 teeth) and non-surgical treatment (n = 187 patients, 4918 teeth) groups. These subjects were also divided into two or three groups based on the duration of multiloop edgewise archwire (MEAW) treatment, elastic use, and total treatment time: 0 month (T1; n = 184 patients, 4831 teeth), range 1-6 months (T2; n = 37 patients, 994 teeth), more than 6 months (T3; n = 22 patients, 596 teeth); range 0-6 months (n = 114 patients, 3016 teeth) more than 6 months (n = 129 patients, 3405 teeth); range 1-30 months (n = 148 patients, 3913 teeth) and more than 30 months (n = 95 patients, 2508 teeth). The prevalence of overall and severe root resorption evaluated by the number of subjects and teeth was compared with a chi-square test. A Student's t-test for unpaired data was used to determine any statistically significant differences. The prevalence of severe root resorption based on the number of teeth was significantly higher in the group with extractions (P < 0.01). Longer use of a MEAW appliance and elastics also produced a significantly higher prevalence of root resorption (P < 0.05). On the other hand, the prevalence of severe root resorption was not significantly different between the subjects treated with or without surgery, but there was a significant increase when treatment time was prolonged (P < 0.05). A significant difference was found in the amount of root movement of the upper central incisors and the distance from their root apices to the cortical bone surface (P < 0.05). These are regarded as essential factors in the onset of root resorption. These results indicate that orthodontic treatment with extractions, long-term use of a MEAW appliance and elastics, treatment time, and distance of tooth movement are risk factors for severe root resorption.

Apical root displacement is a critical risk factor for apical root resorption after orthodontic treatment

“…We superimposed the tracings by means of the ''best fit of anatomical structures'' with a primary emphasis on the concordance of the palatal plane (ANS-PNS) and ANS for the maxilla and mandibular plane (gonion-menton) and menton for the mandible. 11 The horizontal movement (Dx) and vertical movement (Dy) of the maxillary and mandibular central incisal edges were measured using an X-Y coordinate system, defined as the x-axis parallel to the palatal plane or mandibular plane and the y-axis perpendicular to the x-axis passing through the ANS or menton. The þ x value was defined as the direction of protraction and the þ y value as the direction of extrusion.…”

Orthodontic treatment-related risks and complications: part I dental complications

“…The etiology is multifactorial: individual biologic characteristics, genetic predisposition and the effect of orthodontic forces. 6 Studies based on microscopic analysis show a prevalence of 100% after the orthodontic treatment.…”

“…4,5 On the root level, there may appear to be root resorption, early closure of root apex, or ankylosis. [6][7][8] Pulpal complications during orthodontic procedures can be ischemia, pulpitis, or even necrosis.…”

Individual Variations in the Hardness and Elastic Modulus of the Human Cementum

“…Individual Variations in the Hardness and Elastic Modulus of the Human Cementum Masaru Yamaguchi 1) , Eriko Yao-Umezawa 1) , Yasuhiro Tanimoto 2) , Mami Shimizu 1) , Jun Kikuta 1) , Takuji Hikida 1) , Momoko Takahashi-Hikida 1) , Satoshi Horihata 3) Introduction Orthodontically-induced inflammatory root resorption (OIIRR) is an unwanted side effect of orthodontic treatment. Motokawa et al 1) reported that teeth undergoing orthodontic treatment may develop some degree of OIIRR.…”

“…Motokawa et al 1) reported that teeth undergoing orthodontic treatment may develop some degree of OIIRR. It has been reported that 2%-5% of orthodontic patients experience more than 5 mm of resorption during orthodontic treatment with fixed appliances.…”