Efficacy of lower arch leveling, lower incisors’ root resorption, and pain associated with the correction of curve of Spee using different orthodontic archwires: a randomized clinical trial

Abstract

Objectives To compare between 3 archwires (AWs) for leveling curve of Spee (COS) in terms of efficacy of reduction, external apical root resorption (EARR), pain experienced, and the lower arch dimensional changes during COS leveling. Trial design Randomized clinical trial. Setting Jordan University of Science and Technology Postgraduate dental clinics. Material and methods Fifty-three subjects with COS > 5 mm were included in this study. The subjects were randomly divided into three groups based on the AW used: group 1, 0.017 × 0.025-inch stainless-steel (SS) AW; group 2, 0.019 × 0.025-inch SS AW; and group 3, 0.021 × 0.025-inch β-titanium (TMA) AW. The intervention was randomly allocated using the permuted random block size of 3 with a 1:1:1 allocation ratio. In the three groups, a 5-mm depth reverse COS was placed in the AWs. The following time points were defined for COS assessment: T1, before interventional leveling AW placement; and T2–T7, 1–6 months after interventional leveling AW placement. Records consisted of dental study models and periapical (PA) radiographs. Pain scores were recorded using visual analogue scale. Patients were followed up on a monthly basis until COS < 1.5 mm. Main outcome measures COS depth reduction, lower incisors’ EARR, pain scores, and arch dimensional changes. Results An overall reduction of 3.82 mm, 4.47 mm, and 3.85 mm of the depth of COS was achieved in groups 1, 2, and 3, respectively. The mean differences of 0.65 mm between groups 1 and 2 and 0.62 mm between groups 2 and 3 were significant at P < 0.05. Lower incisors’ EARR during leveling COS ranged from 0.68 to 0.72 mm, from 0.63 to 0.82 mm, and from 0.53 to 0.88 mm in groups 1, 2, and 3, respectively (P > 0.05). Higher pain scores were reported by group 2 subjects during the first 24 h. Arch length and width increased significantly in groups 2 and 3 (P < 0.05). In all groups, COS leveling was achieved by lower incisor intrusion and proclination and lower molar extrusion. Conclusions All investigated AWs were effective in leveling COS with minimal lower incisors’ EARR (< 1 mm). COS was leveled by lower incisors’ intrusion and proclination and lower molar extrusion. Pain scores were the highest in group 2 during the first 24 h. Clinical relevance The 3 investigated leveling AWs were effective for the leveling COS and at the same time safe on the roots of the lower anterior teeth.

Leveling the curve of Spee using different sized archwires: a randomized clinical trial of blood flow changes

“…Although BF changes during extrusion and intrusion orthodontic forces have been previously reported [10,15,19,[22][23][24][25], these studies were done on individual teeth (incisors or upper molars) with forces applied in a different way to that during conventional fixed orthodontic treatment. Since it has been shown that during orthodontic treatment, COS is leveled by molars and premolars extrusion, and lower incisors intrusion [2][3][4][5], the current study was conducted to investigate and compare BF in the lower teeth during lower arch COS leveling using different AWs. The null hypothesis of this study was partly rejected as there were significant differences in the BF changes between the intrusion and extrusion forces using different AW size and material.…”

“…Although intrusion is associated with more crushing of cells and vessels in the apical tissues than luxation injuries, and more detrimental effect on the vasculature of the pulp [18], this effect might have been superseded by higher trauma to the apical vasculature by virtue of larger vertical movements during extrusion. Nasrawi et al [5] assessed the amount of lower intrusion and molar extrusion during COS leveling using 3 different AWs. They reported that COS was leveled by 0.41 mm, 0.06 mm, and 0.16 mm of lower molar extrusion and by 0.04 mm, 0.24 mm, and 0.58 mm of lower incisor intrusion when 0.017 × 0.025 SS AW, 0.019 × 0.025 SS AW, and 0.021 × 0.025 TMA AW were used, respectively [18].…”

“…The COS correction is usually achieved by posterior teeth extrusion and lower incisor intrusion [2][3][4]. A randomized clinical trial conducted by Nasrawi et al [5] to measure the vertical movement for the lower incisors and lower molars associated with leveling excessive COS using 3 different archwire (AW) sizes concluded that leveling the COS was achieved in all groups by incisor intrusion, molar extrusion, and incisor proclination on different levels.…”

“…In the current orthodontic practice, 0.17 × 0.025-inch stainless steel (SS), 0.019 × 0.025-inch (SS), and 0.021 × 0.025-inch β-titanium (TMA) AWs are used for COS leveling during orthodontic treatment [ 5 ]. The smaller AW/bracket-slot play when 0.021 × 0.025-inch TMA AW is used has the advantage of more torque control and a less low incisor proclination during leveling.…”

Variability in depth of curve of Spee and its associated skeletal and dental implications in population of Pakistan

“…The evaluation of the connection of the COS with odonto-skeletal morphology is critical for understanding the effect of many variables that contribute to variation in its depth [25,26]. Despite the fact that Spee curve levelling is a common occurrence, little research has been conducted on this occurrence in orthodontic practices done to investigate the relationship between the Spee curve and a variety of factors influencing its depth, which may be good for determining the viability of levelling the Spee curve as a result of orthodontic treatment.…”