Pacific Coast Society of Orthodontists Bulletin Fall 2017 - 26

Let's Talk About That

phenomenon) and devices that produce pulsation to the teeth are being used by some practitioners. Are there any predictable pharmacologic
agents that can help increase the rate of tooth
movement? Might some of our adult patients
already be taking medications for medical reasons that can help in this regard?
JZ: At this time, no medications are recommended for the sole purpose of increasing tooth
movement. However, nicotine (used to stop
smoking), thyroid hormone (used to treat hypothyroidism), growth hormone (used to increase
skeletal growth), and teriparatide (used to treat
osteoporosis) have the potential to increase
tooth movement. Teriparatide treatment usually
lasts for two years, which provides an appropriate
timeframe for orthodontic treatment. Be aware
that the next drug used after teriparatide (such
as a bisphosphonate) will probably slow tooth
movement.
PT: Might some of our adult patients be taking
medications that can inhibit tooth movement?
JZ: Yes. However, most studies were performed in
animals, which is weak evidence. Two groups of
medications have the potential to slow tooth
movement: 1) medications decreasing inflammation, and 2) medications decreasing bone
resorption (decreasing osteoclastic activity).
Medications that decrease inflammation include
fish oil, antihistamines, oral allergy meds, NSAIDs,
and glucocorticoids. (Glucocorticoids are strong
anti-inflammatories, which initially slow tooth
movement. However, after six months of glucocorticoid use, osteoclastic activity is increased,
causing bone breakdown, which increases tooth
movement.) When taken chronically, anti-inflammatory medications have moderate potential to
slow tooth movement (about 20% to 30%). Medications that moderately decrease bone resorption
include estrogens, raloxifene, anti-hyperlipidemics

(-statin), and angiotensin II blockers (-artan). These
potentially have a moderate 20% to 40% decrease
in tooth movement.
There are two medications that might alter
orthodontic treatment plans, especially in extraction cases, by severely decreasing bone resorption
and decreasing tooth movement: bisphosphonates and denosumab. Orthodontic treatment is
not recommended if these medications are taken
in high doses for cancer treatment. However,
bisphosphonates and denosumab are more
commonly given in low doses for osteoporosis
treatment. The orthodontist should be aware
that these medications severely decrease osteoclastic activity (by 70% to 80%) and also decrease
osteoblastic activity (by 50% to 60%). Approximately 75% of bisphosphonate leaves the body
after three to four months, with the remaining
bisphosphonate integrating into the bone and
staying for decades. Denosumab does not integrate into the bone and will leave the body in
three to four months. Patients might have a variable clinical response to both of these drugs; it
may be difficult for the orthodontist to anticipate
the level of decreased orthodontic movement.
However, tooth movement will be decreased
with more tooth mobility, affecting extraction
cases more than non-extraction.7 Personally, I do
not start extraction cases while patients are
actively taking bisphosphonates or denosumab.
During low-dose bisphosphonate treatment, the
risk of osteonecrosis after extraction is 0.15%.8
However, radiographic signs of sclerotic lamina
dura or widened PDL, occurring first on lower
posterior teeth, may signify a much higher level
of bone dysfunction. These radiographic signs,
observed from an initial panoramic radiograph,
might warn of a much higher occurrence of
osteonecrosis (80%) after extraction.9 These signs
also might indicate that teeth are unable to be
orthodontically moved and/or will have excessive
mobility after orthodontics. Orthodontists should

PCSO Bulletin  Fall 2017

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Fall 2017