Treatment duration by morphology and location of impacted maxillary canines: A cone-beam computed tomography investigation

INTRODUCTION

This study aimed to identify whether patients with impacted maxillary canines take longer to treat than orthodontic patients without an impacted canine. We also sought to identify factors that are predictive of increased treatment duration in patients with impacted maxillary canines and treated by surgical exposure.

METHODS

A retrospective investigation of 37 patients with an impacted maxillary canine, treated by surgical exposure and fixed appliance therapy, was undertaken. In addition, an age- and sex-matched control group of 39 patients (without impacted canines) was also collected. Patient age, sex, and total treatment duration were recorded. For patients with an impacted canine, patient records and pretreatment cone-beam computed tomography datasets were assessed. Point coordinates identifying relevant landmarks were recorded, and a geometric method was used to calculate variables describing canine location, orientation, and apical morphology.

RESULTS

Controlling for age and sex, linear regression identified a statistically significant increase in treatment duration of 46.7 and 41.5 weeks for palatal and labial/midalveolar impacted canines, respectively, vs controls (P <0.002). Age and sex of patients with impacted canines collectively affected treatment duration (P = 0.04), with females of increased age being treated faster than younger males. Rotation of the impacted canine crown had a highly significant effect on treatment duration, with every degree of rotation increasing treatment duration by 0.32 weeks (P <0.001). There was a significant degree of multicollinearity between the other radiographic variables. Collectively, radiographic variables describing canine displacement significantly prolonged treatment duration (P <0.001) and explained 29.8% of the variability in total treatment time. The apical morphology of impacted maxillary canines was significantly associated with increased treatment duration (P = 0.01) and explained 11.3% of the overall treatment variability (P = 0.01).

CONCLUSIONS

Increased total treatment duration of surgically exposed impacted maxillary canines is associated with increasing mesiopalatal canine crown rotation, worsening displacement, and hooked apical morphology.

The effectiveness of minimally-invasive corticotomy-assisted orthodontic treatment of palatally impacted canines compared to the traditional traction method in terms of treatment duration, velocity of traction movement and the associated dentoalveolar changes: A randomized controlled trial

Objective: To evaluate the effectiveness of a minimally-invasive corticotomy-assisted treatment of palatally impacted canines (PICs) compared with the traditional method by evaluating treatment time, the velocity of movement, and the associated dentoalveolar changes. Materials and methods: Forty-six patients with palatally or mid-alveolar upper impacted canines were recruited and distributed into two groups: the corticotomy-assisted traction group (CAT group, mean age: 20.39±2.27 years) and the traditional treatment group (TT group, mean age: 20.26±2.17 years). The closed surgical approach was used in both study groups. The velocity of traction movement, traction duration and overall treatment duration were evaluated clinically. In addition, the bone support ratios and the amount of root resorption were assessed on cone-beam computed tomography (CBCT) images. Results: At the end of treatment, significant differences were found between the two groups regarding the velocity of traction movement, traction time, and overall treatment time (P<0.05). The mean velocity of traction movement in the CAT group was greater than the TT group ( x velocity=1.15±0.35 mm/month; 0.70±0.33 mm/month, P=0.027, respectively). The duration of the active traction and the overall orthodontic treatment in the CAT group were significantly shorter than the TT group by 36% and 29%, respectively. The mean bone support ratios of the aligned canines did not differ significantly between the two groups (88% vs. 89% in the CAT and TT groups, respectively). No significant differences were found between the two groups regarding the mean amount of root resorption on the adjacent laterals ( x resorption = 1.30±1.18 mm; 1.22±1.02 mm, P=0.612, in CAT and TT groups, respectively). Conclusions: The traction movement velocity of the palatally impacted canines can be increased using minimally-invasive corticotomy-assisted orthodontic treatment. The side effects of the acceleration procedure were minimal and almost similar to those of the traditional technique.

Success rate, treatment duration, and pain perception in the management of palatally impacted canines using the K9 and Ballista spring: a randomized clinical trial

OBJECTIVES

To evaluate the success rate, treatment duration, and pain perceived during forced eruption of maxillary palatally impacted canines using the K9 and Ballista springs.

MATERIALS AND METHODS

Thirty unilateral palatal canine impactions of moderate and difficult category as determined by KPG index (score between 10 and 19) were enrolled. Group 1 comprised canine impactions managed with K9 springs, and Group 2 comprised Ballista springs. Block randomization and opaque sealed envelopes were used for allocation. The success rate and treatment duration (application of force to ligation of the impacted canine into the initial alignment archwire) were recorded. Pain perception was evaluated on a 10-point visual analogue scale (VAS) and modified McGill Pain Questionnaire. Chi-square test and Mann-Whitney U-test were used to compare the groups.

RESULTS

The success rate for eruption of palatally impacted canines was 100%. The average treatment duration was 296.13 ± 96.45 days and 311.93 ± 94.34 days, respectively for Group 1 and Group 2. VAS scale scores for pain were greater for Group 2 compared to Group1, and the differences were statistically significant at all time intervals except at T1. The frequency of none and mild pain was significantly greater at all time intervals in both groups.

CONCLUSIONS

The impacted canines of moderate and difficult category were erupted with a 100% success rate and similar treatment duration with both interventions. The pain scores of Ballista springs were greater after 24 hours of force application.

A Scoping Review of the Efficacy of Diode Lasers Used for Minimally Invasive Exposure of Impacted Teeth or Teeth with Delayed Eruption

Background: The use of diode lasers for oral surgery soft tissue procedures is associated with less pain and bleeding, quick recovery, and better surgical site visibility. Objectives: This scoping review identifies and analyses the evidence evaluating the efficacy of the diode laser surgical exposure of impacted teeth or teeth with delayed eruption (both with no overlaying bone) vs. conventional scalpel surgical exposure. Materials and Methods: The PubMed/Medline, SCOPUS, and Google Scholar databases were searched up to January 2022 for randomized clinical trials and case-control studies comparing diode laser impacted-tooth surgical exposure vs. conventional surgical methods. Furthermore, the surgical exposure of an impacted mandibular canine or premolars with a 940 nm (InGaAsP) diode laser was presented. Results: The literature search revealed no high-quality evidence. However, four prospective studies were identified. Diode laser application was associated with less pain or analgesic need, minimal/no bleeding, and no need for suturing after surgery. The laser wavelengths used were 808, 810, 935, and 980 nm. A comparison of the study outcomes was not possible; all the studies had methodological issues and their funding sources were not mentioned. Conclusions: Adequately powered clinical trials are needed for comparing outcomes from diode laser surgical exposure vs. conventional methods, identifying the ideal laser characteristics, and assessing the long-term periodontal health of laser-exposed teeth and any potential risks.

Canine exposure: open or closed?

Evidence for open or closed exposure of palatally displaced canines is equivocal, but this study sheds light on new facets which may influence the method of choice. The aim of this article is to give a short perspective on this field, highlight the merits of a study published in this issue of the European Journal of Orthodontics by Björksved et al. the study, place the findings into context and show how it may influence clinical practice.

Open and closed surgical exposure of palatally displaced canines: a cost-minimization analysis of a multicentre, randomized controlled trial

OBJECTIVE

To evaluate the costs of open and closed surgical exposure and subsequent orthodontic treatment for the correction of palatally displaced canines (PDCs).

TRIAL DESIGN

A multicentre, two-arm parallel group randomized controlled trial.

METHODS

One hundred twenty adolescents between 9 and 16 years of age, from three orthodontic specialist centres, were randomized to one of the two surgical exposure interventions. The randomization was conducted according to a two-arm parallel group 1:1 allocation ratio, using computerized lists with block randomization. In both the surgical techniques, whole mucoperiosteal flaps were raised, and bone covering the PDCs was removed. In the open technique, glass ionomer was built up on the PDC crown - reaching above the mucosa through a hole punched in the flap - to allow the canine to erupt autonomously. After eruption, the canine was orthodontically moved above the mucosa. In the closed technique, an eyelet was bonded onto the PDC, the flap was repositioned and the canine was orthodontically moved beyond the mucosa. The trial ended when the PDC was successfully aligned in the dental arch.Cost analysis was performed including costs for surgery, orthodontic treatment, emergency visits, and material, as well as costs for transports and time spent in connection with every appointment.

BLINDING

Patients and caregivers could not be blinded due to obvious limitations of the clinical setting, while outcome assessors and data analysts were blinded.

RESULTS

A cost-minimization analysis was performed since both exposure groups succeeded equally well in terms of treatment effects. The two different surgical exposures and following orthodontic treatments did not differ significantly in terms of costs.

GENERALIZABILITY AND LIMITATIONS

Costs are estimated in the Swedish setting, which needs to be considered if applying the results in other settings. Calculations of total cost do not include finishing, debonding, retention, and follow-up.

CONCLUSION

There is no significant difference in costs between closed and open surgical exposure with following orthodontic treatments in PDCs.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02186548.

Palatally displaced and impacted canines – What is taught during postgraduate orthodontics training in Europe?

Objectives:

One of the most challenging orthodontic treatments is displaced and impacted canines palatally displaced canines (PDC/PIC). The aim of this study was, therefore, to assess what postgraduate students are taught about PDC and PIC during their postgraduate orthodontic training (POT) in Europe.

Materials and Methods:

A digital survey containing 22 questions was sent to 164 POT programs in 28 European countries. Questions were asked about which interceptive and surgical treatments are taught, the advantages of different surgical procedures, and what dressing materials and X-rays are used for PIC therapy planning. Reminders were sent 4 times.

Results:

About 43% (71 POT programs) responded. Extraction of deciduous canines (76%) was the most favored interceptive treatment. A closed technique with a gingival margin flap and a gold plated chain was the most commonly taught surgical technique (69%), even though both open and closed exposure of PICs were performed in 54 postgraduate programs. Coe-Pak™ with sutures was one of the preferred dressing materials in open exposure. Active treatment was started before the canine erupted, that is, spontaneous eruption of the tooth following open exposure was not awaited by 1/3 of the respondents and 1/3 left the question unanswered. Closed exposure was more often preferred than open exposure for post-surgical, periodontal, and esthetic reasons. The most common radiographs before surgery were panoramic and intraoral radiographs. Cone-beam computed tomography was taken by half of the respondents when resorption of adjacent teeth was suspected.

Conclusion:

Extraction of deciduous canines as an interceptive approach to PDC and closed exposure of PIC were taught in most of the POT programs.

Management of maxillary impacted canines: A prospective study of orthodontists' preferences

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Children should be examined by the age of eight or nine years to assess for maxillary canine displacement and possible impaction.

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Maxillary impacted canines are best approached and managed through interdisciplinary approach involving a pediatric dentist, orthodontist, oral surgeon, and periodontist.

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The pediatric dentist can be the first specialist for early diagnosis and management of maxillary impacted canines, which can be achieved by facilitating the maxillary canine’s eruption and guiding it to its proposed location in the dental arch.

Background

Maxillary canines are considered the most commonly impacted teeth, after the third molars. Orthodontists have different preferences on how to approach maxillary impacted canines (MIC). The objective of this article was to investigate orthodontists’ approach to managing MIC.

Material and methods

A cross-sectional study comprising a comprehensive survey with 22 questions was sent to practicing orthodontists. This study explored the preferred diagnostic measures, surgical techniques, materials, and mechanics utilized to manage MIC;104 responses were returned.

Results

Palatal impaction was reported to be encountered more often than labial impaction by 60% of the respondents. In 62% of the respondents, an oral and maxillofacial surgeon was the specialist preferred to perform the surgical exposure. In 66%, the choice of required surgical techniques was reported as a joint decision between orthodontists and other specialists who perform the surgery. Cone-beam computed tomography (CBCT) was reported to be the diagnostic x-ray of choice. The gold button with a chain was the preferred bonded attachment in 86% of cases. Less than half of the respondents bonded the attachments themselves during surgical exposure. A clear plastic retainer was the preferred retainer in 61% of the respondents, and 43% of the respondents tended to use a closed exposure technique. Coe-pak^TM was the preferred surgical pack for orthodontists who prefer an open exposure technique. Piggyback (double wire) was the preferable mechanic to move a palatally impacted canine.

Conclusion

Our findings indicate that there are variations among orthodontists on how to manage MICs in terms of diagnostic methods, surgical management, materials, and mechanics.

Surgical exposure and orthodontic alignment of palatally displaced canines: can we shorten treatment time?

This review will discuss the influence of various factors on the time taken to orthodontically align a palatally displaced maxillary permanent canine following surgical exposure. Previously unpublished data from a clinical trial, involving participants with unilateral PDC randomly allocated to either a closed or open surgical exposure, will be included to strengthen the debate.