Kate Scheer examines orthodontic obstacles to oral hygiene
Oral biofilms can adversely affect surrounding tissues. Biofilm accumulation below the gingival margin leads to inflammation of the gum, which can progress from gingivitis to periodontitis, ultimately leading to edentulism if left untreated. Biofilms forming on the teeth demineralise the enamel, initially causing white spot lesions due to subsurface decalcification, with the potential to progress into cavities .
Tooth brushing is critical to preventing and removing oral biofilm, and the use of fluoride toothpaste aids remineralisation. Because biofilm requires time to form and produce harmful effects, regular brushing can keep it in check and prevent plaque becoming tartar.
However, various factors and circumstances can frustrate patients’ efforts to maintain their oral hygiene, leading to accumulation of biofilm in difficult to clean areas, including interproximal spaces. Even when a patient is diligent in their tooth brushing, more than 40% of plaque can remain .
Where this persistently occurs, intervention from a dentist or hygienist can be necessary in order to bring the patient’s oral hygiene back to a benign state.
In the UK, it is thought that approximately a third of 12-year-olds could benefit from orthodontic treatment, and in recent years there has been a significant increase in adults seeking orthodontic treatment [3,4]. For a great many patients, orthodontic treatment is valued and sought for its long-term benefits – both clinical and cosmetic.
However, fixed orthodontic appliances can make it difficult for patients to adequately maintain their oral hygiene. Quite simply, the placement of fixed orthodontic appliances physically impedes tooth brushing – providing an ideal environment for biofilm to form and grow. Additionally, the presence of an orthodontic appliance alters the dynamics of the salivary flow, resulting in areas where it is reduced .
Saliva confers significant benefits within the oral cavity, not least of which is the protection it affords hard and soft tissues. Saliva boasts antimicrobial properties and the ability to remove debris within the mouth. It also provides lubrication, dilutes sugars, and aids in neutralising oral pH, repairing tissue, and remineralising teeth – among other beneficial actions . Localised reduction in salivary flow can, therefore, create a potentially more carious environment over time in affected areas.
Across the general population, biofilm accumulation is usually greater in the molar region than in the anterior teeth, and the mandible typically harbours more biofilm than the maxillary teeth. The presence of an orthodontic appliance has been found to alter this distribution pattern, with the upper lateral incisors and upper canines exhibiting more biofilm than the upper and lower premolars.
Likewise, among these patients, more biofilm accumulates in the maxillary arch than in the mandibular arch. The physical obstruction caused by the hooks and elastics of a fixed appliance is likely the main factor behind this change given the locations involved . Furthermore, the composition of the bacterial flora within the oral cavity changes after a fixed orthodontic appliance is introduced, resulting in increased levels of Streptococcus mutans and Lactobacilli within plaque .
S. mutans is widely regarded as a major bacterial driver of caries. While not the sole cause, S. mutans increases the level of acidity in the mouth, and is capable of producing large quantities of extracellular polymers from sugars (the bacteria is also generally more resistant to stressful environments than less harmful colonisers, enabling it to displace more benign bacteria).
Increased acidity can contribute directly to enamel erosion, and the combination of the aforementioned traits can create biofilms that are more favourable for other potentially harmful acidogenic and aciduric species of bacteria. The insoluble glucans produced by S. mutans provide more adhesive and stable biofilms that facilitate bacterial colonisation of affected surfaces .
With tooth brushing made more difficult and an increased prevalence of harmful bacteria such as S. mutans, it should be little surprise that patients undergoing orthodontic treatment are at substantially greater risk of developing white spot lesions (WSL) in short order. Numbers vary across studies, but are quite consistent on a majority of orthodontic patients exhibiting new and/or worsening WSL (50-95%), and this correlates with the duration of treatment [10,11]. ,
From these numbers, it is clear that orthodontic patients face substantial difficulty in maintaining their oral hygiene. Regularly visiting a practice for observation and professional cleaning when needed will help ensure best results for patients.
Some patients may be under the impression that tooth cleaning and polishing is a purely cosmetic endeavour, but it does serve a prophylactic purpose –removing soft deposits. It should however be noted that excessive polishing can cause abrasion and wear on the outer layers of the tooth, which could result in long-term problems.
This has led to the development of selective polishing (sometimes referred to as extrinsic or selective stain removal) as a treatment modality among hygienists; where only tooth surfaces that specifically require polishing receive it .
Patients undergoing fixed orthodontic treatment are temporarily at greater risk of inadequate oral hygiene, and the various complications that can bring. These patients must be encouraged to be strict in maintaining their oral hygiene and educated on best practice.
Kate Scheer is a Marketing Executive with W&H. She advises: “The new Proxeo AURA Air Polishing System from W&H facilitates effortlessly efficient and precise removal of plaque, biofilm and stains – supragingivally and subgingivally. This slender and ergonomic handpiece is ideally suited for cleaning fissures, cavities and orthodontic brackets in a non-abrasive, atraumatic way.”
1] Ren Y., Jongsma M., Mei I., van der Mei H. Orthodontic treatment with fixed appliances and biofilm formation – a potential public health threat? Clinical Oral Investigations. 2014; 18(7): 1711-1718. https://www.ncbi.nlm.nih.gov/pubmed/24728529 May 9, 2019.
2] Hayasaki H., Saitoh I., Nakakura-Ohshima K., Hanasaki M., Nogami Y., Nakajima T., Inada E., Iwasaki T., Iwase Y., Sawami T., Kawasaki K., Murakami N., Murakami T., Kurosawa M., Kimi M., Kagoshima A., Soda M., Yamasaki Y. Tooth brushing for oral prophylaxis. Japanese Dental Science Review. 2014; 50(3): 69-77. https://www.sciencedirect.com/science/article/pii/S1882761614000180 May 9, 2019.
3] Orthodontics. NHS Inform. 2019. https://www.nhsinform.scot/tests-and-treatments/non-surgical-procedures/orthodontics May 9, 2019.
4] The number of adults seeking orthodontic treatment in the UK continues to rise. British Dental Journal. 2018; 224(11): 847. https://www.nature.com/articles/sj.bdj.2018.455 May 9, 2019.
5] Mei L., Chieng J., Wong C., Benic G., Farella M. Factors affecting dental biofilm in patients wearing fixed orthodontic appliances. Progress in Orthodontics. 2017; 18(1): 4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5276803/ May 9, 2019.
6] Dodds M., Roland S., Edgar M., Thornhill M. Saliva a review of its role in maintaining oral health and preventing dental disease. BDJ Team. 2015; 2: 15123. https://www.nature.com/articles/bdjteam2015123 May 9, 2019.
7] Mei L., Chieng J., Wong C., Benic G., Farella M. Factors affecting dental biofilm in patients wearing fixed orthodontic appliances. Progress in Orthodontics. 2017; 18(1): 4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5276803/ May 9, 2019.
8] Khoroushi M., Kachuie M. Prevention and treatment of white spot lesions in orthodontic patients. Contemporary Clinical Dentistry. 2017; 8(1): 11-19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5426141/ May 9, 2019.
9] Lemos J., Palmer S., Zeng L., Wen Z., Kajfasz J., Freires I., Abranches J., Brady L. The biology of streptococcus mutans. Microbiology Spectrum. 2019; 7(1). http://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.GPP3-0051-2018 May 9, 2019.
10] Richter A., Arruda A., Peters M., Sohn W. Incidence of caries lesions among patients treated with comprehensive orthodontics. American Journal of Orthodontics and Dentofacial Orthopedics. 2011; 139(5): 657-664. https://www.sciencedirect.com/science/article/pii/S0889540611001296 May 9, 2019.
11] Hadler-Olsen S., Sandvik K., El-Agroudi M., Øgaard B. The incidence of caries and white spot lesions in orthodontically treated adolescents with a comprehensive caries prophylactic regimen – a prospective study. European Journal of Orthodontics. 2012; 34(5): 633-639. https://academic.oup.com/ejo/article/34/5/633/550033 May 9, 2019.
12] Sawai M., Bhardwaj A., Jafri Z., Sultan N., Daing A. Tooth polishing: the current status. Journal of Indian Society of Periodontology. 2015; 19(4): 375-380. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4555792/ May 9, 2019.