As undergraduate students we took everything we were told by our professors and teachers as facts. Sometimes what they taught us was evidence based and sometimes they were just passing on their ‘expert opinion’. As we evolve as clinicians we begin to question more the clinical decisions we make.
As a general dentist I believe providing orthodontic treatment is essential in order to deliver complete dentistry in a minimally invasive way. My initial teaching in adult orthodontics was that all cases should be finished with both a fixed and removable retainer. I was told that this was the ‘gold standard’. But is this true?
The literature is clear that continued tooth movement will occur, whether there is orthodontic treatment or not. It is therefore advisable for life-long retention. But what retainers should we use?
‘The only certain things in life are death, taxes and continued tooth movement’
An ‘evidence-based’ approach combines scientific evidence; dentist’s clinical experience and expertise and the patient’s needs and preferences.
Let’s start with the scientific evidence. Two of the ‘best’ literature reviews on retention are the Royal College of Surgeons Clinical Guidelines on Orthodontic Retention (Johnston et al., 2008) which were revised in 2013 (Pavizi et al., 2013) and the Cochrane Retention Procedures for Stabilising Tooth Position after Treatment with Orthodontic Braces (Littlewood et al., 2016). The literature recognises that there is just ‘not enough high-quality evidence to recommend any one approach to retention over another’. This leaves us basing our retention protocol on our own clinical experience/expertise and our patient’s needs and preferences.
My current approach is not to use fixed retainers in most cases. Why?
My current experience is that:
- Many patient’s who are given a fixed retainer see their removable retainer as optional (even when instructed otherwise). Failing to wear their removable retainers means that any movement beyond the canines is often no longer retained e.g. arch expansion.
- Debonds of the fixed retainer often go unnoticed by the patient. By the time a dentist detects the problem these teeth have often relapsed e.g. rotated upper lateral incisors.
- Patient’s with fixed retainers generally have more issues with oral hygiene control and calculus accumulation, particularly on the lower anterior region.
- Fixed retainers involve instructing patients to modify their lifestyle e.g. dietary restrictions. Many of my patient’s do not want this.
- Fixed retainers often involve a piece of metal stuck to the back of the teeth. Many of my patient’s do not want this…particularly when they have completed the whole orthodontic process metal-free (Invisalign).
- Debonded fixed retainers become an ‘emergency’ situation. This can be very uncomfortable and inconvenient for patients if it occurs (usually when they are on holiday).
Most of the time I use Vivera retainers. Patient’s are provided with 3 retainers per arch and instructed clearly to order new retainers once they get down to their last set. It is essential that patient’s do not have to rely on 1 retainer which could be lost or damaged. My patients are instructed to wear the retainers for 6 months full time and then ‘every night for the rest of your life’. This is a clear instruction and I generally find that clear instructions are easy to follow. I do not suggest a weaning off process. If the patient chooses to do this then this is at their own risk. There are certain situations where the literature does recognise a fixed retainer is beneficial. For these situations I do use a fixed retainer e.g. periodontal cases, space closures and extreme rotations.
Right now, I don’t think there is a ‘gold standard’ in retention. We should select appropriate retention for each individual. A number of factors should be considered e.g. relapse risk, caries risk, periodontal risk and patient’s wishes. Fixed retainers should be used in certain situations, but I certainly don’t think they should be used in every case.