A great study on patients’ perceptions of open v closed exposure for unerupted canines?
Patient-centred research is becoming increasingly important. This new study examines patients’ perceptions of two competing treatments for exposing palatally positioned canines.
Orthodontic research is hopefully shifting its focus from the treatment outcomes of orthodontists to the outcomes experienced by patients. One of the most significant aspects of this shift is the patients’ perception of pain and discomfort, which is particularly important when considering the effects of surgery.
When we need to expose an unerupted canine that is positioned palatally, we can opt for either open or closed surgical procedures. Both methods have similar success rates; however, we know very little about patients’ preferences regarding these treatments. This topic was the focus of an interesting new randomized trial.
A team from Norway, Sweden and Switzerland did this study. The AJO-DDO published the paper. This is an open-access paper, so anyone can read it.
Lucete Faerovig et al.
Am J Orthod Dentofacial Orthop 2025;167:382-98. https://doi.org/10.1016/j.ajodo.2024.11.014
What did they ask?
They did this study to ask
“What are the patient perceptions of recovery, duration of procedure and complications of closed or open exposure of palatally displaced canines”?
What did they do?
The team did a 2 centre RCT with 2 parallel groups and a 1:1 allocation ratio.
The PICO was
Participants
Orthodontic patients from 2 centres with unilateral or bilateral palatally displaced canines, aged under 16 years with canine tips in sectors II-IV on panoramic radiographs.
Intervention
Closed exposure of canine
Comparison
Open exposure of canine
Outcomes.
Patient reported experiencing pain and discomfort, as well as analgesic intake and complications observed over the three weeks following surgery. Data were collected through questionnaires that included pain documentation using visual analogue scores and open and closed questions.
They collected data 10-15 days after surgery and then 1-2 weeks later.
They carried out a clear sample size calculation based on a 15 mm difference in pain perception on the VAS scores. This indicated that they needed to include 100 participants randomised into two groups.
An orthodontist recruited the participants. They used a pre-prepared block randomisation. An independent person not involved with the trial concealed allocations in each centre.
It was not possible to blind the operator. However, data was analysed blind.
What did they find?
They enrolled 100 participants in the study. Eight were excluded for various reasons, such as moving away from the area. Consequently, 92 completed the trial with a mean age of 13 years. Fifty-nine were female, and thirty-three were male. There were 47 canines in the closed group and 45 in the open group. No pre-treatment differences existed between the two groups.
87 participants returned the first questionnaire, and 75 participants returned the second, for a response rate of 94% and 81%, respectively.
The main findings were:
- The pain response scores were highly variable. The open-group participants recorded higher levels of pain and discomfort.
- There was no difference in analgesic consumption between the groups.
- The operative time was shorter for the open group with no flap replacement.
- When they looked at complications, 5/47 of the closed and 12/45 of the open groups had a complication. Importantly, bleeding was the most common complication in the open exposure group (8 patients).
The overall conclusions were
“Participants in the open group experienced more pain and discomfort than those in the closed group. However, complications were sparse and more common with the open technique”.
What did I think?
This was a well-conducted and ambitious randomized trial involving numerous participants, which must have required significant effort. Notably, the team reported relevant outcomes to our patients, and I would like to congratulate them on their study. I have no criticisms of their methods.
The results are both interesting and clinically significant. We can use this information when discussing treatment options with patients. It lets us inform them that the open technique may result in more pain. There is also a higher risk of minor postoperative complications, such as bleeding. Therefore, this study is highly useful.
We need more studies of this nature.
Emeritus Professor of Orthodontics, University of Manchester, UK.
Dear Kevin,
This is indeed a useful and well-conducted study. The findings and the conclusions in the study noted that the open-group participants recorded higher levels of pain and discomfort. Unfortunately, your reported wrongly
credited the open technique with illiciting a lesser degree of pain. This is in addition to the open technique being the more prone to post-surgical complications. Perhaps this could tip the choice for technique preference in the opposite direction. The investigation underlines the continued need for further study in this area.
With best wishes,
Adrian Becker
Hi Adrian, thanks for the comments. I have now corrected my typo and I am sorry that I was careless in this post. I think that I must have been distracted when I wrote the post by the unusually sunny UK weather! Best wishes: Kevin
I think a interesting follow up study will be the longer term evaluation of pain and discomfort during the activation phase of erupting the teeth comparing the two techniques.
Hi Thinus Groenewald. Thank you for your comment. The findings presented in this article are related to the surgical part of the treatment to align palatal impacted canines in the dental arch. It included the surgical intervention, the intervention to remove sutures/ surgical dressing and the week after each intervention, until orthodontic traction of canine in the closed technique started. Findings related to the orthodontic part of the treatment where the canine is being actively moved with orthodontic appliances will be presented in another publication in the near future. Thank you again for your appreciation and interesting comment.
Did both groups have orthodontic hardware in the post-surgical timeframe? In the pre-surgical timeframe? For whatever reason it is not obvious in my reading of the AJO article.
thanks
Hi Tomas. Thank you for your question. No subjects had orthodontic hardware during the follow-up time of this study. In the inclusion criteria section it is mentioned that no subjects undergoing orthodontic treatment or who have had orthodontic appliances could be included in the trial. I hope I answered you question. Thank you again for your interesse in our research.
Regarding the open exposure technique: it would be interesting to know if using an upper removable appliance to hold the Coe-pak in place for a period of time, rather than suturing the Coe-pak in place, reduces the level of post-operative pain and bleeding.
Hi John Kerrigan. Thank you for your remark. It would definitely be interesting to make a study on that! Thank you for your interesse in our research.
As an aside to this, and regarding pain experienced with fixed adjustments after open/closed surgery: I have two cases of fixed adjustments for palatal canines following both open and closed surgery. Both patients had undergone closed exposures of palatal canines in the first instance, but it subsequently became necessary to repeat the exposure. The open method was chosen for the second procedure. Both patients reported that the adjustments on the openly exposed canines were more comfortable than the closed. There could be more than one reason for this (tough overlying mucosa being one). I guess we may never find out why this was is as it is, fortuitously, unusual to have two procedures. I only asked my patients out of interest about the levels of discomfort when adjusting their appliances as I had noticed it can often be uncomfortable for them when pulling on covered palatal canine.
Hi Polly Muir. Thank you for sharing your experience. What you have experienced with those patients of yours has been reported previously (Bjørksved et al. 2021). Our trial continued throughout the orthodontic phase until the impacted canines were aligned in the dental arch so we have that type of information that will be published in the near future. Thank you again for your message.
Great paper, thanks to the group, regarding Polly’s comments, – once the canines are fully erupted, following the open technique, it is clinically no different to aligning an instanding upper lateral incisor in cross bite. These rarely give any more symptoms that ordinary orthodontic tooth movements and adjustment. at least that’s my clinical experience.
Lucete, it will be good to have the followup study on these research cases to validate that view or not. Looking forward to that.
Very good point of view Tim. Thank you for your enthusiasm and interest in our research.
Dear Kevin,
I just finished reading this nicely done paper, followed by your critical appraisal. Compared to other research, this study sheds light on new outcomes for assessing patients’ perceptions longitudinally, which is indeed very useful for understanding how patients feel over time.
However, I’d like to point out a discrepancy regarding the main findings you mentioned. You wrote that “there was no difference in analgesic consumption between the groups,” but the paper actually states that “after the removal of the surgical dressing and/or sutures, patients in the closed group consumed significantly more analgesics than those in the open group.”
Best regards,
Alaa Al Khatib
What you say is correct Alaa Al Khatib. Patients in the closed group consumed more analgesics after the intervention to remove the surgical dressing and/ or sutures than patients in the open group. I think Kevin was referring to the surgical exposure itself. Thank you for your comment that led us to clarify this point.