Changes over time in canine retraction: An implant study

doi:10.1016/j.ajodo.2007.10.044

American Journal of Orthodontics and Dentofacial Orthopedics

Volume 136, Issue 1, July 2009, Pages 87-93

https://doi.org/10.1016/j.ajodo.2007.10.044 Get rights and content

Introduction

The objective of this study was to analyze rates of canine movement over the first 2 months of continuous retraction, when rate changes are expected.

Methods

Ten patients with bone markers placed in the maxilla and the mandible had their canines retracted over a 2-month period. Retraction was accomplished with beta-titanium alloy T-loop springs. Standardized 45° oblique cephalograms where taken initially and every 28 days thereafter. The radiographs were scanned and digitized twice (the average was used for the analyses). The radiographs were superimposed by using the bone markers and oriented on the functional occlusal plane. Paired t tests were used to compare side and jaw effects.

Results

There were no significant differences between sides. The maxillary cusp was retracted 3.2 mm, with less movement during the first (1.1 mm) than during the second 4 weeks (2.1 mm). The maxillary apices did not move horizontally. There were no significant vertical movements in the cusps and apices of the maxillary canines. The mandibular cusp was retracted 3.8 mm—1.1 mm during the first and 2.7 mm during the second 4 weeks. The mandibular apices were protracted 1.1 mm. The cusps and apices were intruded 0.6 and 0.7 mm, respectively. The only difference between jaws was the greater protraction of the mandibular apices during the second 4 weeks and in overall movement.

Conclusions

The rate of canine cusp retraction was greater during the second than the first 4 weeks. The mandibular canines were retracted by uncontrolled tipping whereas the maxillary canines were retracted by controlled tipping.

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.

References (39)

J.J. Pilon et al.
Magnitude of orthodontic forces and rate of bodily tooth movement. An experimental study
Am J Orthod Dentofacial Orthop
(1996)
E.H. Hixon et al.
Optimal force, differential force
anchorage. Am J Orthod
(1969)
G.F. Andreasen et al.
A clinical evaluation of the differential force concept as applied to the edgewise bracket
Am J Orthod
(1980)
D.J. Huffman et al.
A clinical evaluation of tooth movement along arch wires of two different sizes
Am J Orthod
(1983)
K. Yamasaki et al.
Clinical application of prostaglandin E1 (PGE1) upon orthodontic tooth movement
Am J Orthod
(1984)
P. Ziegler et al.
A clinical study of maxillary canine retraction with a retraction spring and with sliding mechanics
Am J Orthod Dentofacial Orthop
(1989)
J. Daskalogiannakis et al.
Canine retraction with rare earth magnets: an investigation into the validity of the constant force hypothesis
Am J Orthod Dentofacial Orthop
(1996)
L.P. Lotzof et al.
Canine retraction: a comparison of two preadjusted bracket systems
Am J Orthod Dentofacial Orthop
(1996)
L.R. Iwasaki et al.
Human tooth movement in response to continuous stress of low magnitude
Am J Orthod Dentofacial Orthop
(2000)
R.J. Herman et al.
Mini-implant anchorage for maxillary canine retraction: a pilot study
Am J Orthod Dentofacial Orthop
(2006)

M.T. Sakima et al.

The validity of superimposing oblique cephalometric radiographs to assess tooth movement: an implant study

Am J Orthod Dentofacial Orthop

(2004)

R.S. Quinn et al.

A reassessment of force magnitude in orthodontics

Am J Orthod

(1985)

A. Hart et al.

The effectiveness of differential moments in establishing and maintaining anchorage

Am J Orthod Dentofacial Orthop

(1992)

M.M. Rajcich et al.

Efficacy of intra-arch mechanics using differential moments for achieving anchorage control in extraction cases

Am J Orthod Dentofacial Orthop

(1997)

C.J. Burstone

The segmented arch approach to space closure

Am J Orthod

(1982)

L.R. Iwasaki et al.

Speed of tooth movement is related to stress and IL-1 gene polymorphisms

Am J Orthod Dentofacial Orthop

(2006)

R.P. Martins et al.

T-loop for differential moment mechanics: An implant study

Am J Orthod Dentofacial Orthop

(2009)

C.J. Burstone et al.

Holographic determination of centers of rotation produced by orthodontic forces

Am J Orthod

(1980)

K. Tanne et al.

Moment to force ratios and the center of rotation

Am J Orthod Dentofacial Orthop

(1988)

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T-loop spring vs ricketts maxillary canine retractor in canine retraction efficacy and anchorage loss control: A cone-beam computed tomography study
2022, AJO-DO Clinical Companion
This study aimed to compare the Burstone technique using the T-loop spring (TLS) and Ricketts maxillary canine retractor (RMCR) in canine retraction efficacy and anchorage loss control using cone-beam computed tomography. Data was taken from 31 patients with maxillary canine retraction using either the Burstone technique, in which an off-centered TLS was applied (TLS group, n = 14), or Ricketts technique, in which the RMCR was applied (RMCR group, n = 17). Cone-beam computed tomography images were obtained before and after retraction. The evaluated outcomes were the vertical and sagittal movement amounts of the centers of resistance, the tipping, the rotation, and the buccolingual inclination of both canine and molar, in addition to the amount of root resorption of the canine. Using the TLS demonstrated a significantly greater amount of canine retraction and intrusion (P = 0.003; P = 0.002) and fewer degrees of mesial-out rotation (P = 0.004) than the RMCR. No significant differences in canine tipping and inclination were found. The difference in root resorption was also insignificant. No significant differences were found in molar linear and angular movement changes, except for the anteroposterior tipping direction (P <0.001). The molar protracted bodily with the TLS and tipped mesially with the RMCR. The TLS can control the sagittal canine movement more effectively than the RMCR, whereas the RMCR can better control the canine movement vertically. Both springs can cause a similar and significant amount of canine root resorption. The molar tends to tip distally when the TLS is used, and it tips mesially when the RMCR is used, with a significant difference between the methods.
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 Research
Citation 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.
Three-dimensional analysis of the moment, force and M/F ratio generated at the anterior and posterior region of the T-loop in five different groups of pre-activation curvatures using the finite element method.
In this study, the geometric model of maxilla was constructed using a CBCT scan. The bracket system simulated was of the STb lingual bracket system from Ormco (0.18slot) with specified tip and torque values of all maxillary teeth and the arch wire used was 0.016″x 0.016″ TMA (Ormco) for fabrication of T-loop with dimensions of 6 × 2 × 7 mm. There were five different models generated with pre-activation of: 20°,30°,40°,50° and 60° in T-loop. The software used for the post-processing of the model was ANSYS Workbench 19.2.
When the amount of pre-activation of T-loop increased there was an increase in the moment, force and M/F ratio in all the five groups in lingual biomechanics.
Although, the M/F ratio depicts the type of movement that will take place is uncontrolled tipping in all the five pre-activation groups, clinically we should give pre-activation ranging from 30° to 60° in T-loop in lingual orthodontics.
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 Orthopedics
Citation 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.
The objective of this study was to evaluate the distalization rate and changes in inclination of the maxillary canines in alveoli preserved with leukocyte-platelet–rich fibrin (L-PRF) membranes in adult patients. The null hypothesis was that there are no differences in the canine distalization movement rate between the treated and the control sides.
A total of 21 healthy adult patients with a minimum age of 20 years (mean age, 33 ± 5.9 years) and Angle Class I or Class II Division 1 malocclusion, who had an indication of extraction of the maxillary first premolars and orthodontic distalization of the maxillary canines were included in this study. A randomized controlled clinical split-mouth trial was conducted; the experimental maxillary side was treated with L-PRF membranes, and the other side served as the control. A randomization sequence of the experimental sides among patients was generated using the random number generation function of Microsoft Excel. Neither the patients nor the operators were blinded. Fifteen days after the extractions, distalization was initiated using an elastic chain applying 150 g of force to the canines on a 0.020-in stainless steel archwire. The distalization rate was the main outcome of the study, and it was assessed monthly for 5 months through the intraoral use of a flexible ruler. The degree of inclination of the canines was the secondary outcome, and it was evaluated through cone-beam computed tomography. A Shapiro-Wilk test was performed, and a Wilcoxon signed rank test was subsequently used to compare the experimental and the control group. Spearman rank correlation coefficient was calculated to evaluate the correlation between distalization and inclination for each side.
Four of the subjects dropped out of the study, leaving a total of 17 patients (n = 17). The distalization rate and inclination of the canines were greater on the control side than on the side treated with L-PRF (P <0.05). A weak correlation was found between the distalization rate and inclination of the canines for both sides (control side, ρ = 0.17; experimental, ρ = 0.11). No harm was observed during the study.
The null hypothesis was rejected. The use of L-PRF in young adult patients decreased the rate of distalization and changes in inclination of the maxillary canines compared with the control group.
This trial was not registered.
The protocol was not published before trial commencement.
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 Orthodontists
Citation 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.
Assess the changes in the force system of T-loop springs (TLSs) preactivated by bends and curvature, when secured in place with a constant strain over time.
A total of 120 TLSs with dimensions 6 x 10 mm, produced out of 0.017 × 0.025-inch TMA, were randomly divided into two groups of 60 TLSs, each according to what preactivation was going to be used, concentrated bends or gradual curvature. Subgroup 1 was tested immediately and the remaining subgroups were tested after they were secured at 5-mm activation for different periods of time in an interbracket distance of 23 mm. Subgroups 2, 3, 4, 5, and 6 were kept activated for 24, 48, and 72 hours, 1 and 2 weeks, respectively. Using a moment transducer coupled to a digital extensometer indicator adapted to a universal testing machine, the amount of horizontal force, moment, and moment-to-force (MF) ratios were recorded.
Both groups showed a decrease in force levels over time (P < 0.001 and 0.005 for bend and curvature preactivation, respectively), but with different behaviors. The group preactivated by bends showed a reduction in moments over time (P < 0.001), whereas the group preactivated by curvature did not (P = 0.410). The MF ratio has not changed over time in either group.
The stress-relaxation effect is more evident on group preactivated by bends.
Comparison of direct and indirect skeletal anchorage systems combined with 2 canine retraction techniques
2016, American Journal of Orthodontics and Dentofacial Orthopedics
Citation 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.
We compared the effectiveness of 2 canine retraction springs and anchorage systems (direct and indirect skeletal anchorage) in patients requiring first premolar extractions and maximum anchorage in the maxilla.
Thirty-six patients were included (17 male, 19 female; mean age, 16.8 ± 2.4 years). A mini-implant–supported Nance appliance with indirect skeletal anchorage system was used in 18 patients and a mini-implant–supported direct skeletal anchorage system in the remaining patients. In each patient, a segmental retraction arch with a reverse closing loop was applied to a maxillary canine, and a Ladanyi spring (Dentaurum, Ispringen, Germany) was applied to the other canine randomly after extraction of the maxillary first premolars. The retraction process was continued until a Class I canine relationship was obtained. Lateral cephalometric films and orthodontic casts taken before and after retraction in the distalization process were used to evaluate changes during canine distalization. The measurements were statistically evaluated using paired and independent t tests with 95% confidence intervals.
The reverse closing loop and the Ladanyi spring were found to be effective in canine distalization (P ≤0.001). There were no statistically significant differences between the reverse closing loop and the Ladanyi spring with regard to canine distalization rates (P ≥0.05). Both systems were effective in providing maximum anchorage (P ≥0.05); no statistically significant differences were detected in molar anchorage loss rates between the 2 methods (P ≥0.05).
These 2 systems can be used during segmental distalization of canines requiring maximum anchorage with no significant anchorage loss.
Evaluation of canine retraction following periodontal distraction using NiTi coil spring and implants - A clinical study
2014, Journal of Oral Biology and Craniofacial Research
Citation 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.
To evaluate the amount of canine retraction with periodontal distraction using miniscrew implants and NiTi coil spring.
Sample comprised of 25 patients who were scheduled for all 1st premolar extraction (13 males and 12 females), in the age range of 16–22 years with mean age 18.8 ± 2.7 years. For each patient left side served as control side (Group I) and right side as experimental side (Group II). At the time of first premolar extraction, periodontal distraction was performed only on the experimental side, followed by retraction of canine from mini-implant by closed NiTi coil spring on both the sides. “Nemotech” software was used to evaluate the amount of canine retraction for a period of 3 months.
Significantly higher amount of tooth movement was seen from T0–T1 and from T1–T2 in Group II for the maxillary parameters 3C-5C, 6CF-3C, 3C-I/3C-J and for the mandibular parameter 6CF″-3C″. Whereas no significant amount of tooth movement was observed for maxillary and mandibular parameters between T2-T3 except for 6CF″-3C″ (p ≤ 0.01) which was significantly higher for the Group II.
There was accelerated canine retraction on the periodontal distraction side as compared to the control side, with negligible anchorage loss.

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: The authors report no commercial, proprietary, or financial interest in the products or companies described in this article.

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Special articleChanges over time in canine retraction: An implant study

Introduction

Methods

Results

Conclusions

Section snippets

Material and methods

Results

Discussion

Conclusions

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Special article
Changes over time in canine retraction: An implant study