Imagine someone undergoing routine orthodontic treatment who takes fish oil supplements every day to maintain bone health. Without realizing it, the supplement may actually be working against the goal of their orthodontic treatment. This unexpected finding emerged from a study conducted by Dr. drg. Dyah Karunia, Sp.Ort. and a team of researchers from Universitas Gadjah Mada, published in the Journal of International Dental and Medical Research in 2019.
The study revealed something that had not been widely anticipated: DHA (Docosahexaenoic Acid) derived from microalgae, an omega-3 component commonly marketed as a dietary supplement, was shown to significantly slow the rate of orthodontic tooth movement in an animal model.
From Marine Algae to Alveolar Bone
DHA from microalgae is not an unfamiliar compound in the field of health. This compound, with the molecular formula C₂₂H₃₂O₂, has long been recognized for its protective effects against inflammatory bone diseases such as rheumatoid arthritis and osteoporosis. Its primary source is Schizochytrium sp., a type of microalgae containing approximately 40–45% DHA by total weight.
The key mechanism lies in a process known as osteoclastogenesis, namely the formation of osteoclasts, the cells responsible for resorbing or “breaking down” alveolar bone. In orthodontic treatment, bone resorption on the compression side is what allows teeth to shift position. Without osteoclast activity, teeth cannot move. DHA is known to inhibit the RANKL and M-CSF pathways, two critical pro-inflammatory cytokines involved in recruiting and activating osteoclasts.
This led to a clinically relevant question: if DHA suppresses osteoclastogenesis, could its consumption interfere with tooth movement in patients undergoing orthodontic treatment?
Rabbits, Braces, and Digital Calipers
To answer this question, Dr. drg. Dyah Karunia, Sp.Ort. and her team designed a quasi-laboratory experimental study at the Integrated Research and Testing Laboratory of Universitas Gadjah Mada. Fifteen male New Zealand rabbits aged 6–8 weeks were divided into three groups: A control group that underwent orthodontic tooth movement only, the DHA-750 group, which received 750 mg of DHA supplementation per dayand the DHA-1500 group, which received 1,500 mg of DHA supplementation per day.
An orthodontic appliance consisting of a nickel-titanium open coil spring was placed on the right and left lower incisors of each rabbit, applying a constant force of approximately 100 grams. DHA supplements derived from Schizochytrium sp. were administered every morning through a feeding tube for 14 consecutive days. Tooth movement distance was measured on days 3, 7, and 14 using a Vernier digital caliper with a precision of 0.01 mm.
The results were consistent across all measurement points. After 14 days, the control group showed the greatest tooth movement, reaching 5.50 mm. The DHA-750 group showed 4.80 mm, while the DHA-1500 group showed only 4.63 mm. The differences between groups were statistically significant at all observation points (p < 0.05).
“DHA microalgae has a potential to decrease orthodontic tooth movement.” — Dr. drg. Dyah Karunia, Sp.Ort., et al., Journal of International Dental and Medical Research, 2019
Higher Dose, Stronger Inhibition
An interesting pattern emerged when researchers compared the two DHA doses. On day 3, which represents the initial phase of orthodontic tooth movement, both doses produced inhibitory effects that were not significantly different from each other. This finding is understandable because, during the early phase, RANKL levels increase dramatically in the periodontal ligament within hours after orthodontic force application, and both doses appeared to suppress this increase at a similar level.
However, by days 7 and 14, when tooth movement entered the lag phase, differences between doses became more apparent. DHA-1500 demonstrated stronger inhibition compared with DHA-750, with statistically significant differences. Clinically, the reduction in total tooth movement caused by DHA was approximately 0.75 mm for the 750 mg dose and 0.92 mm for the 1,500 mg dose, equivalent to reductions of 13.5% and 16.5%, respectively, compared with the control group.
These numbers may appear small. However, in orthodontics, millimeters represent clinically meaningful measurements. A 13–16% reduction in tooth movement rate could potentially translate into a noticeable extension of treatment duration for patients.
Implications That Have Received Limited Attention
This study raises an important discussion that has rarely been addressed during orthodontic consultations: should dentists ask patients about omega-3 supplement consumption before initiating or during active orthodontic treatment?
Dr. drg. Dyah Karunia, Sp.Ort. and her team noted that these findings may also reveal another potential application. Because DHA has been shown to suppress alveolar bone resorption, this compound could potentially be developed as a protective agent against root resorption, one of the complications associated with long-term orthodontic treatment. Further studies involving human patients have been identified as the next research priority.
A supplement that has traditionally been considered purely beneficial may have a more complex role—at least for individuals whose teeth are undergoing orthodontic movement.
Authors: Nanda Ayu; drg. Achmad Zam Zam Aghasy, M.Kes.
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