American Journal of Orthodontics and Dentofacial Orthopedics
Special articleChanges over time in canine retraction: An implant study
Section snippets
Material and methods
This prospective study included 10 patients (6 adolescent girls, 4 adolescent boys) aged 17.4 ± 2.6 years of age at the start of treatment, selected according to the following criteria: Class I molar relationship, treatment requiring 4 premolar extractions, maxillary and mandibular dental protrusion, and good hygiene and healthy dentition.
Four tantalum bone markers were placed in the maxilla (2 apical to the first molars and 1 on each side of the midpalatal suture, apical to the central
Results
The movements of the right and left canines were averaged because there were no significant (P >0.05) differences between sides.
The maxillary canine cusp tip was moved distally 3.2 mm over the 8-week retraction period (Table III). The changes during the first 4 weeks (1.1 mm) were significantly (P = 0.03) less than changes during the second 4 weeks (2.1 mm). There was no significant vertical movement of the cusp tip. The maxillary apices were maintained in place, both vertically and
Discussion
The rates of canine cusp tip movements were greater during the second than the first 4 weeks of retraction (Fig 2). This provides indirect evidence of a lag phase during the first month of movement. Of the 9 articles pertaining to human canine retraction with frictionless mechanics (Table II), only 1 reported a clear lag phase during the first month of movement.16 The remaining studied did not provide sufficient information (eg, only initial and final records were taken, large force variations,
Conclusions
- 1.
Rates of canine cusp tip retraction were greater during the second than the first 4 weeks of retraction.
- 2.
The only significant difference in tooth movements between jaws pertained to the canine apices, which moved anteriorly 1 mm in the mandible and did not move in the maxilla.
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Cited by (19)
Comparative evaluation of T-Loop with different amount of pre-activation curvatures in lingual orthodontics- A finite element study
2021, Journal of Oral Biology and Craniofacial ResearchCitation Excerpt :However, they do not give different amount of pre-activation bends in their study. Martins et al.18 did a study using implant markers to study the rate of canine movement over a period 8 weeks using 45° pre-activated T-loop in labial orthodontics. They found that the rate of canine retraction was greater in the last four weeks.
Distalization rate of maxillary canines in an alveolus filled with leukocyte-platelet–rich fibrin in adults: A randomized controlled clinical split-mouth trial
2020, American Journal of Orthodontics and Dentofacial OrthopedicsCitation Excerpt :The force of 150 g was effective in causing distalization of the canines by sliding in both groups, in line with previous studies.9,28,40 Other studies on canine distalization used frictionless mechanics with the use of segmented mechanics or power arms,41,42 which caused higher rates of movement owing to the absence of friction. When evaluating the distal inclination of the canines, the values of the angles decreased on both the experimental and control sides.
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature
2017, Journal of the World Federation of OrthodontistsCitation Excerpt :Nowadays, the TLSs are preferred to be produced from β-Ti wires, which greatly improves the physical properties of these springs [4,5]. A TLS with normally used sizes (6–7 × 10 mm) cannot produce moment-to-force (MF) ratios that are high enough to produce translation out of their activation moment [1,3]; thus, more moment is required, which could be produced by gable bends [6–14] or curvature (residual moment) [6,9,14–18]. These adjustments made before engaging the TLS to the brackets to increase the MF ratio are called preactivation.
Comparison of direct and indirect skeletal anchorage systems combined with 2 canine retraction techniques
2016, American Journal of Orthodontics and Dentofacial OrthopedicsCitation Excerpt :Most previous studies also used 4-week intervals as the unit of time.12,19,20 Our results were similar to those of Martins et al,21 who used the same time interval. We can summarize the results as follows.
Evaluation of canine retraction following periodontal distraction using NiTi coil spring and implants - A clinical study
2014, Journal of Oral Biology and Craniofacial ResearchCitation Excerpt :In the present study the amount of canine retraction on the side without periodontal distraction was 5.31 mm in 3 months, but in other studies amount of canine retraction without the support of mini-implant was, 1.91 mm/month with PG retraction spring and 1.41 mm/month with the sliding mechanics,17 5.69 mm (over 10.7 weeks) with tip-edge bracket and 5.58 mm (11.8 weeks) in straight wire brackets.21 In studies where implant supported canine retraction was done, mean value were 4.29 mm in maxilla in 4–6 months7 and 3.2 mm over 8 week.22 The result of the present study was higher compared to the above mentioned studies; the reason for above finding can be explained by the fact that the force level was maintained in our study by monthly activation.
The authors report no commercial, proprietary, or financial interest in the products or companies described in this article.