The Orthodontics Professors
the latest in contemporary & evidence-based orthodontics
BY TATE H. JACKSON
A group from Belgium has published results of a Randomized Controlled Trial to evaluate the effect of flapless corticotomies on tooth movement.
24 consecutively-treated adult patients were randomized to 2 groups: 1) a control group treated with non-extraction alignment or 2) an intervention group treated with non-extraction alignment and piezocision one week after brackets were bonded. All participants had similar malocclusions with only mild – moderate crowding.
Both groups were treated using self-ligating brackets (Damon) and a standardized archwire sequence with a 2 week recall interval. A single blinded orthodontist validated readiness for appliance removal – or gave guidance for further adjustments to be made – based on an evaluation of dental casts and “5 criteria”.
For the intervention group, piezocision was accomplished using a 5mm x 3mm piezoelectric device apical to each interdental papilla. An incision was created before the corticotomy, but no sutures were used. Where root proximity might be a concern, corticotomy was avoided.
For the piezocision group, treatment was 43% faster. That means that the total treatment time was about 7 months less (about 11 months of total treatment time vs. 18 months in the control group). As treatment proceeded, the difference decreased between the two groups in terms of time spent in each archwire, suggesting a decreasing effect of the corticotomies over time.
No adverse outcomes in terms of periodontal health or root resorption were reported – nor were there any apparent differences (increase or decreases) in alveolar bone support or thickness, as assessed by CBCT. 50% of patients experienced some degree of scarring.
WHAT THE PROFESSOR THINKS
Despite some minor drawbacks, this study is one that provides some useful information to clinicians with a patient population who demand accelerated treatment. A description of the randomization process and the “5 criteria” used to determine if treatment was complete would be very helpful.
Nonetheless, using a single blinded examiner who evaluated casts and used objective criteria to determine when treatment was complete for both the piezocision and the control groups was a clever design. Using total treatment time as the outcome, rather than just the time to initial alignment, makes the study results more relevant to practicing clinicians.
As in previous reports, the acceleratory phenomenon was limited to a period of time early in treatment (the authors suggest about 4 months). For non-extraction patients with mild-moderate crowding, a single procedure was enough to yield a clinically-relevant reduction in treatment time of 7 months. It is imperative to note that the reported recall rate during treatment was 2 weeks. That means treatment is accelerated, but it is no more efficient for the patient or the orthodontist – since an increased number of office visits would be required.
The findings presented in this study suggest that less-invasive piezocision may carry with it a low risk of adverse outcomes. No participants experienced a loss of root structure or bony support, as judged using CBCT. Interestingly however, half of the piezocision participants did experience scarring of the gingiva, an outcome that could have very negative effects on a patient with a high esthetic demand.
For the practicing orthodontist, this study carries with it some helpful information to guide patients when they ask for quicker treatment:
Will treatment time be shorter? Yes.
By how much? About 7 months.
Are there risks? Yes – and we still do not know the full extent of those risks, including the esthetic risk of scarred gingiva.
Will it be more convenient? No. (Remember, the reported recall interval in this study was 2 weeks.)
Article Reviewed: Charavet C, et al. Localized Piezoelectric Alveolar Decortication for Orthodontic Treatment in Adults: A Randomized Controlled Trial. J Dent Res. April 2016.
Tate H. Jackson, DDS, MS