Drinking Coffee Accelerates Orthodontic Tooth Movement

What is orthodontic tooth movement?
A unique process where a solid object (tooth) is made to move through a solid medium (bone). Orthodontic tooth movement occurs due to the pressure that is transmitted to the clinical crown of the tooth, down to the root, and ultimately to the periodontal ligament (the tissue that attaches the tooth to the bone) and alveolar bone surrounding the root.

On the surface of the tooth in the direction where the tooth is being moved, the periodontal membrane is squeezed, resulting in compression of the periodontal fibers within the membrane. The bone surface contacting the periodontal membrane begins to resorb due to the activation of cells called osteoclasts.

On the surface of the root from which the tooth moves, the periodontal membrane becomes stretched. This activates cells called osteoblasts. These cells regenerate new alveolar bone in the area where the tooth was once located. That is why teeth may be slightly loose during orthodontic treatment. Once the movement has stopped, the ligaments are no longer stretched or squeezed and the bone regenerates and fills in around the periodontal ligament, causing the tooth to be more secure in the bone.

The following article shows that daily coffee consumption enhances orthodontic tooth movement, and consequently can shorten the duration in which patients have to wear braces.

The Study
Caffeine has been shown to affect bone metabolism through regulation of osteoclast, osteoblast, and calcium balance. This study investigated the effects of drinking coffee on orthodontic tooth movement (OTM). Drinking coffee, as a daily habit of many people, can be an effective accelerator of tooth movement with little side effects. Caffeine can break the calcium balance in bone tissue and directly inhibit the development of osteoblasts, leading to temporary decreased bone mineral density and consequently inducing faster orthodontic tooth movement.

Why is it important?
Developing new methods to enhance orthodontic tooth movement and shorten the duration of treatment has always been desired. However, to date, no therapies have been widely used in clinics. Much effect has been made to explore therapies to shorten the orthodontic treatment period with limited success. Daily coffee consumption may be a promising approach to enhance orthodontic tooth movement for its reversible effect on bone mineral density and calcium balance.

The setup
30 male Wistar rats were randomly divided into two groups:

1. regular OTM = rO
2. coffee + OTM = cO

At 5 weeks of age, the cO rats began receiving daily intragastric administration of coffee according to body weight.

At 13 weeks of age, the left maxillary first molar of the both groups was moved mesially with a nickel-titanium coil spring

After 3 weeks, the OTM amount was measured. 

How was it measured?
The alveolar bone mineral density (BMD) was analyzed with micro-computed tomography (uCT).
Immunohistochemical staining was done for TRAP and RANKL expression in the periodontium. The periodontal ligament (PDL) tissue model was established through 3D culturing human PDL cells in poly lactic-co-glycolic acid (PLGA) scaffolds.

What did they find?
Compared with rO, the cO rats had significantly larger tooth movement. Meanwhile, the cO had significantly lower alveolar BMD, indicated decreased bone mineralization. Moreover, in the compression periodontium, the cO had significantly more TRAP+ osteoclasts and higher RANKL expression, indicating increased osteoclastogenesis. 

Summary
This study found that drinking coffee accelerates OTM, probably through the effects of caffeine on osteoclastogenesis enhancement via RANKL elevation. This research was supported by the National Nature Science Foundation of China.

Click here to read the study.

Click on this link to read another study about how carbonated soft drinks DECREASES the rate of orthodontic tooth movement. "The role of soft drinks in decreasing tooth movement might be related to its effects on bone metabolism."