An interventional study of Closed surgical technique and Open surgical technique in Tooth, Impacted, sponsored by Örebro County Council. Completed at 3 sites in Sweden. Open to participants aged 8 Years to 16 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2021-09-10.
Sponsored by Örebro County Council · Not applicable, Interventional, and Treatment
Permanent canines in the maxilla usually erupt into the mouth at 11-12 years of age. In approximately 2% of the Swedish population they fail to erupt, and are then referred to as impacted. One severe complication of impacted maxillary canines is damage (root resorption) to the roots of adjacent teeth. The root resorption may be so severe that neighboring teeth are lost. If the impaction is detected early (at 9-10 years of age), the recommended treatment is to extract the deciduous canine, to help the permanent canine to resolve its unfavorable position. If there is no improvement of the position of the canine 1 year after the extraction, surgical and orthodontic treatment is indicated. Surgical exposure is followed by orthodontic treatment with fixed appliance for 2 to 3 years to bring the canine into correct position.
Two different main principles of surgical exposure in palatally impacted maxillary permanent canines are the so called closed versus open surgical techniques.
Closed technique involves surgically uncovering of the canine with a mucoperiosteal flap dissected off the bone. The bone covering the canine is being removed and an attachment with a chain is bonded to the tooth. The flap is repositioned and sutured back with the chain above the mucosa. Shortly after the surgery, orthodontic force is applied via the chain. The canine is orthodontically moved beneath the palatal mucosa by forced eruption.
Open technique involves surgically uncovering of the canine, removing a window of tissue around it and placing pack to cover the exposed area. Then the treatment approaches vary depending on whether the attachment with a chain is bonded to the exposed tooth at surgery or if spontaneous eruption of the palatally impacted canine is expected postsurgically. In both alternatives orthodontic force is applied via the chain and the canine is orthodontically moved above the mucosa. These two techniques of surgical exposure of palatally impacted canines seem to be the two routinely used in Sweden.
The purposes of this study are to examine, describe and compare the treatment outcomes in regard to success and duration of treatment, complications, side effects, cost-benefit aspects and patients´ perceptions in closed versus open surgical exposure techniques, in cases with palatally impacted canines.
The objective is to test the null hypothesis that there are no differences in the above outcomes between open or closed surgical exposure of palatally impacted canines.
Methods of exposing canines are today left to the personal choice of the surgeon and orthodontist. According to an unpublished survey among orthodontists in Sweden 2012, 80% of them use the closed technique only, 9% use the open technique only and 11% use both techniques. This result may be compared to a similar survey performed in the UK, where 29% selected a closed surgical technique only, 40% selected an open surgical technique only and the remainder chose combinations of techniques.
Mentioned reasons for preference of the closed technique are less pain and need for analgesics and faster recovery of pain, postsurgically. Some orthodontists that prefer the open exposure technique have experienced more patient related pain or discomfort in the closed exposure technique, in association with activation in orthodontically forced eruption, because the palatally impacted canine is moved beyond the mucoperiosteal flap. There are no previous studies in this aspect, though.
Factors as operation time, total treatment time and periodontal health measurements after surgical exposure and orthodontic forced eruption of impacted canines, have shown heterogeneity in different retrospective studies.
The management of the palatally impacted canines is a multidisciplinary, time consuming treatment, contributing to relatively high society costs, why this study is taking place, trying to clarify some issues in the choice of method and treatment.
Subjects Patients with diagnosis of uni- or bilateral palatally impacted canine/-s planned for surgical exposure are included consecutively at three orthodontic centers of the Public Dental Health Service in the towns of Orebro, Eskilstuna and Jönköping, Sweden.
Procedure At the appointment for treatment information, the orthodontist gives potential study participants and their parents verbal and written information about the trial. The potential study participants and their parents will be allowed at least one week to decide whether to participate in the trial and if they agree to participate, the written consent will be submitted to the orthodontic centre.
After informed consent is obtained, the participants are randomly allocated to 1 of 2 interventions.
A computer generated randomization is undertaken to ensure that there are equal numbers allocated to each intervention. Allocation concealment is held by one individual per centre, not involved with the trial, who will be contacted by the consenting clinician when the patient is going to be referred for surgical exposure. There will be no stratification for age or gender into the two different groups.
If maxillary deciduous canine are present; they are removed at the time of surgical exposure. The two different surgical exposure techniques are described under "Intervention arms".
The patients are given verbal and written postsurgical information.
Verbal pre-/postsurgical information consists of the recommendation of:
Together with the written postsurgical information, a questionnaire is handed out at the surgical clinic to the patients, for assessment of their experience of pain and discomfort in the evening of the day of surgical exposure and one week there after. The postsurgical questionnaire contains questions that are validated. This questionnaire is submitted to the orthodontic centre at the first postsurgical control.
After surgical exposure orthodontic force is applied; in the closed technique group no later than 2 weeks post surgically and in the open technique group when bonding attachment is possible. In both surgical exposure groups orthodontic force is applied to the palatally impacted canine via the chain attached to the bonded attachment on the canine, to a fixed orthodontic appliance.
Questionnaires are handed out to the patients every 3rd month at the orthodontic clinic, to evaluate the patients´ perceptions of pain and discomfort, until the impacted canine is orthodontically positioned in the dental arch. These questionnaires are submitted at the orthodontic clinic the same day, in association with orthodontic appointment. Questionnaire to assess patients´ perceptions of dental anxiety is handed out to the patient before treatment, when the impacted canine has erupted and when active treatment is finished in each surgical exposure group, at the orthodontic centre. Dental anxiety will be evaluated and described according to Cuthbert MI and Melamed BG. The patients are followed until the active orthodontic treatment is finished and an orthodontic retainer is fitted.
Observation schedule and material/registrations:
Before surgical treatment (T0):
The day of surgical exposure (T1):
Palatally impacted canine erupted; here: when bonding attachment is possible/ approximately ⅓-½ of the clinical crown of the impacted canine is exposed intraorally (T2):
Previously impacted canine positioned in the dental arch; here: canine ligated to .016x.022 nickel titanium/standard steel arch-wire in the .018-appliance system and .019x.025 nickel-titanium/ standard steel arch-wire in the .022-appliance system (T3):
Orthodontic retainer is fitted/ Active treatment finished (T4):
Within 2 months after active treatment is finished (retainer fitted):
Between the day of surgical exposure (T1) and the day when the previously impacted canine is positioned in the dental arch; here: canine inligated to .016x.022 nickel titanium/ standard steel arch-wire in the .018-appliance system and .019x.025 nickel-titanium/ standard steel arch-wire in the .022-appliance system (T3):
Ethical aspects The Regional Ethic Board of Uppsala University, Uppsala, Sweden, which follows the guidelines of the Declaration of Helsinki has approved the study. The Radiation Protection Boards of the County Councils of Örebro, Eskilstuna and Jönköping have approved the planned radiographic examinations in the study. Patientdata are processed according to the laws Personuppgiftslagen, PUL, (1998:204) and Patientdatalagen (2008:355). The examinations and treatments used in this trial are the current examinations and treatments of palatally impacted canines in Sweden, which have been practiced during several years. All surgical exposures and orthodontic treatments are performed by specialists in dental pediatrics/ clinicians and specialists in orthodontics, respectively, with many years of surgical experience.
122 studies on the registry are indexed under Tooth, Impacted; 15 are open to participants now.
This study's planned enrollment of 120 is above the median of 70 across 88 interventional studies indexed under Tooth, Impacted.
Browse Tooth, Impacted studies →Örebro County Council is the lead sponsor of 22 studies on the registry; none are open to participants now.
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Exclusion Criteria:
After randomization, the PDC:s randomized to this arm, are to undergo closed surgical exposure, which is an intervention to correct the position of PDC:s.
Procedure: Closed surgical technique
After randomization, the PDC:s randomized to this arm, are to undergo open surgical exposure, which is an intervention to correct the position of PDC:s.
Procedure: Open surgical technique
* Surgically uncovering of the impacted canine with a mucoperiosteal flap dissected off the bone * The bone covering the canine is being removed * Attachment with a chain is bonded to the exposed tooth * The palatal flap is repositioned and sutured back with the chain above the mucosa. Shortly after the surgery * The canine is orthodontically moved beneath the palatal mucosa
* Surgically uncovering of the impacted canine, removing a window of tissue from around the tooth * Pack/filling material is applied on the tooth * Spontaneous eruption of the palatally impacted canine is allowed expected * The canine is orthodontically moved above the mucosa
Treatment success; the previous impacted canine is positioned in the dental arch
"Positioned in the dental arch"; here meaning that the previous impacted canine has been treated with fixed orthodontic braces and is inligated in .016x.022 nickel titanium/ standard steel arch-wire in a .018- appliance system and .019x.025 nickel-titanium/ standard steel arch-wire in a .022- appliance system.
Time frame: Within 3 years after surgery
Duration from surgery until the previous impacted canine has erupted into the mouth
"Erupted into the mouth"; here meaning that approximately ⅓-½ of the clinical crown of the impacted canine is exposed intraorally.
Time frame: Within 1,5 year from surgery
Presence, type and number of complications/failures associated with the operation techniques
Time frame: Within 1,5 years from surgery
Operation time (hours, minutes)
Time frame: Within 6 months from allocation
Estimation of total treatment costs
Time frame: Within 3,5 years from surgery
Patients´perceptions of experienced pain, discomfort and consumption of analgesics.
Patients´perceptions of experienced pain, discomfort and consumption of analgesics is registered in questionnaires at the first evening and one week after surgical exposure and every 3rd month until the impacted canine is positioned in the dental arch.
Time frame: Within 3 years from surgery
Presence of dental anxiety (patient) and eventual change in dental anxiety during treatment
A Dental Subscale of the Children´s Fear Survey Schedule, CFSS-DS questionnaire will be handed out to the patients at three times (before start of treatment, after the impacted canine has erupted and when the canine is positioned in the dental arch). Dental anxiety and eventual change in dental anxiety will be described, compared and evaluated compared between the two surgical exposure group and individually.
Time frame: Within 3 years from surgery
Dental health comparison between the two groups of different surgical exposure
Dental health is measured before start of treatment and when treatment is finished, and compared between the surgical groups and also between the impacted and non impacted side in the individual, here as: * Periodontal health measured as pocket depth, bleeding on probing and recession of the gingival margin (clinical routine examination) * Crestal bone height and eventual root resorption (cone beam computed tomography)
Time frame: Within 3,5 years from surgery
The record gives a start of Jun 2013, a primary completion of Jan 2021 and a completion of Feb 2021. It does not say whether these dates are actual or estimated.
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This study is completed, as verified in Sep 2021. You cannot join it, but the record below documents what was studied.
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Örebro County Council