Why do we need to accelerate orthodontic teeth movement (OTMs)?
· On average, comprehensive orthodontic treatments take 19.9 months (Tsichlaki et al., 2016).
· 6 months increase in the treatment duration could significantly decline patients’ compliance by 23% (Bukhari et al., 2016).
· Therefore, short treatment is on-demand (Uribe et al., 2014) to reduce direct and indirect costs of treatment as well as the risk of iatrogenic damages (Dindaroğlu and Doğan, 2016).
How we can accelerate OTMs?
Several approaches have been developed to harness OTMs including:
· Mechanical external stimuli such as vibrating appliances.
· Laser and light stimulation therapies.
· Biological approach is based on locally or systemic injection of biomodulators and activation of osteoclasts (Abu Arqub, 2021).
· Gene therapy approach which is based on delivery of specific manufactured proteins to the periodontal tissue.
· Surgical adjunctive procedures (SAPs)
· Many other approaches.
How SAPs work?
· Activating local inflammatory mediators, hence, optimize bone remodeling and fasten OTM, a phenomenon known as regional acceleratory (RAP) (Vargas and Ocampo, 2016).
· Reduction of bone density at the region where OTM is desired which in turn might accelerate OTMs (Alikhani et al., 2013).
What are the commonly used type of SAPs?
· Corticotomy, a procedure of raising mucoperiosteal flap combined with inter-radicular osteotomies (Kole, 1959).
· Piezocision involves a flapless trans-mucogingival bony cut (1-3 mm in depth and 5-10 mm in width) which is performed using an ultrasonic micro-saw (Vercellotti and Podesta, 2007).
· Micro-osteoperforation (MOPs) procedure which includes flapless trans-gingival shallow bony perforations (2-3 mm in depth and 1.5 mm in diameter) (Sivarajan et al., 2020).
· Many other approaches.
What is the solution if studies' outcomes are inconsistent with regard to the effectiveness of SAPs?
· Generally, randmosied controlled trials (RCTs) are the gold standard to answer clinical uncertainties.
· If multiple RCTs show inconsistent outcomes, a systematic review and meta-analysis (SRMA) would be the second resort.
· But if SRMAs also showed inconsistent outcomes, then, umbrella review (UR) is the last resort. UR is a synthesis of existing systematic reviews compiling evidence from multiple reviews into one accessible and usable document.
To my knowledge, there are handful number of orthodontics URs that included meta-analysis and I am honored to be a co-author of one of these URs.
Journal of Orthodontics in their February 2021 issue published our UR which is titled (The effectiveness of surgical adjunctive procedures in the acceleration of orthodontic tooth movement: A systematic review of systematic reviews and meta-analysis).
A team from Syria, Scotland and Pakistan undertook this UR which was led by Dr Samer Mheissen.
This UR included 14 systematic reviews, four of them were combined in meta-analysis.
Based on low-level evidence, there are 7 take home messages:
1. Upper canine retraction: Overall, SAPs fasten upper canine retraction by 0.65 mm/month for the first month, the more invasive the SAPs, the greater would be the OTMs. It is important to remember that, on average, the effect of almost all types of SAPs on OTMs lasts for 3 months and should be repeated if its effects need to be extended for a longer period of time.
2. Lower canine retraction: MOPs mildly and temporally accelerate lower canine retraction by 0.25 mm/month.
3. Enmass and incisors retraction: Piezocision non-significantly shortens the duration of enmasse retraction (4.30 months, P>0.05), but significantly shortens incisors retraction (101.64 days, P<0.001). MOPs mildly and temporally accelerate enmasse retraction by 0.31 mm/month.
4. Molar anchorage loss (MAL): There was no significant effect (P>0.05) in terms of molar MAL between control and MOP groups. MAL is mild but significantly less in the piezocision group compared to the control group (MD = 0.53 mm, P=0.03).
5. Adverse effects: Weak evidence suggested that SAPs have minor adverse effects on roots and periodontal structures.
6. Cost analysis: Cost of SAPs was not fully assessed by the literature.
7. Future plan: A well-designed and robust randomised controlled trials with large sample sizes and long-term follow up taking in consideration risks and cost versus benefit of SAPs, are recommended.