An 'Idiot’s' guide to root fractured teeth and orthodontic treatment
As a Dental Core Trainee at Pinderfield’s hospital - trying to get experience and develop my skills - I jumped at the chance to write a blog for the Orthodontic Digest. After chatting with my supervisor about potential blog topics, he suggested an ‘Idiot’s guide to trauma and orthodontics’ could be an interesting and slightly jovial angle on a generally poorly understood and confusing subject. Guided by my obliging supervisor, I started the research for the blog and I (like other dental trainees, generalists, paediatric specialists and orthodontic specialists, alike?) quickly realised the limits of my knowledge on the subject. I began to wonder who the idiot in the title referred to…
The scientific research on trauma and its implications for orthodontic treatment can be described in one word - limited. Studies on the subject are few and far between. Those that do exist have small sample numbers and contain multiple different types dental injuries, appliance types and other confounding factors. No wonder there’s confusion surrounding the subject, really! However, there are a few reviews that have attempted to collate the minimal evidence and give as helpful conclusions as possible, based on the limited information we have.
I came to realise that the proverbial idiot - when correctly informed - could be the ideal person to attempt to explain the facts in simple and understandable terms. For the purpose of this blog, I have focussed on root fractures. I have detailed all documents used for the blog below.
The Background
- I had once presumed that every root-fractured tooth would end up sitting - blackened and broken - in a GDP’s tooth pot, just a few years after its initial injury. But no! Prognosis for root-fractured teeth is actually pretty good (well, apical and mid-third types anyway). See below:
| Survival at 10 years1 | |
|---|---|
| Apical third | 89% |
| Mid third | 78% |
| Cervical mid root | 67% |
| Cervical third | 33% |
| Pulp Vitality2 | |
|---|---|
| Coronal third | 30% |
| Mid-third/ apical third | 51% |
The Concerns
- Risks of orthodontic treatment include pulp necrosis and root resorption.
- Traumatised teeth may be at an increased risk of resorption and necrosis during orthodontic treatment. But no study has been able to demonstrate this conclusively.
- However, teeth showing signs of root resorption after injury have been shown to be at an increased risk of further resorption during orthodontic treatment.
The Types of Root Fracture Healing
The Management
- Teeth with a history of root fracture should be observed and monitored for at least 1 year prior to starting orthodontic treatment. If a root fracture occurs mid orthodontic treatment, no active orthodontic forces should be placed on the tooth for 12 months.
- If the tooth has healed by hard tissue – treat as normal but with extra vigilant monitoring. Vitality is maintained, but pulp canal obliteration may occur in the coronal fragment.
- If the tooth has healed by connective tissue – the coronal root fragment should be treated as a tooth with a short root (i.e. the root fragments move independently). But, a word of caution! Short roots are at greater risk of further resorption, leaving the root even more vulnerable and at risk of persistent mobility.
- If the tooth has healed by granulation tissue - the coronal fragment is non-vital and root canal treatment up to the fracture line is required. If successful, granulation tissue will convert to connective tissue. Orthodontic treatment should not be carried out until endodontic treatment and connective tissue healing has occurred.
Conclusion
Without wanting to sound like your typical Cochrane review – there is insufficient evidence to decide with any clarity whether root fractured teeth are at a higher risk of root resorption and pulp necrosis. But, as *cough* well reasoned decision makers, we can surmise that stringent clinical and radiographic monitoring of teeth with previous root fracture prior to, during and after orthodontic treatment is both sensible and essential.
References
1Andreasen J., Ahrensburg S. and Tsilingaridis G. Root fractures: the influence of type of healing and location of fracture on tooth survival rates - an analysis of 492 cases. Dental Traumatology, 2012, 28(5), pp. 404-409
2Welbury R.R., Kinirons J.R., Day P.F., Humpherys K. and Gregg T.A. 2002. Outcomes for root-fractured incisors: a retrospective study. American Journal of Paediatric Dentistry, 2002, 24(2), pp.98-102.
Brin I., Ben-Bassat Y., Heling I. and Engelberg A. The influence of orthodontic treatment on previously traumatized permanent incisors. European Journal Orthodontics, 1991; 13: pp. 372–77.
DiAngelis A., Andreasen J., Ebeleseder K., Kenny D., Trope M., Sigurdsson A., Andersson L., Bourguignon C., Flores M., Hicks M., Lenzi A., Malmgren B., Moule A., Pohl Y. and Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth. Dental Traumatology, 2012, 28(1), pp.2-12.
Kindelan S., Day P., Kindelan J., Spencer J. and Duggal, M. Dental trauma: an overview of its influence on the management of orthodontic treatment. Part 1. 2008. Journal of Orthodontics, 35(2), pp. 68-78.
Levander E. and Malmgren O. Evaluation of the risk of root resorption during orthodontic treatment: A study of upper incisors. European Journal of Orthodontics 1988; 10: pp. 30–38.
Malmgren O., Goldson L., Hill C., Orwin A., Petrini L. and Lundberg M. Root resorption after orthodontic treatment of traumatized teeth. American Journal Orthodontics, 1982; 82: pp. 487–91.
Malmgren O., Malmgren B. and Goldson L. Orthodontic management of the traumatised dentition, taken from Andreasen JO, Andreasen FM, Andersson L. Textbook and Color Atlas of Traumatic Injuries to the Teeth, 4th edition. 2007. Oxford: Blackwell Munksgaard, pp. 669–715.
Millet D. and Day P.F. Clinical Problem Solving in Orthodontics and Paediatric Dentistry. 2016. Oxford: Elsevier Health Sciences UK.