Do later risks outweigh early cost savings?
by Dr. Jay B. Reznick
Whenever we do a consultation for
removal of wisdom teeth, we discuss
with the patient the potential risks and
complications of the surgery. We try to
do a thorough job so the patient can make the
best-informed decision about their treatment
course. But how much time do we spend discussing
the risks of not removing third molars,
especially when that patient is younger than
25 years old?
We know the hazards include development
of caries, infection, periodontal problems, bone
loss, development of cysts and other pathology,
fracture of the mandible and damage to adjacent
teeth. But how common are these risks, and how
heavily should they weigh in our recommendations
to our patients?
So, that brings up the age-old question: Should
asymptomatic third molars be prophylactically
removed? As Assael eloquently put it, it depends
on how you ask the question, who is asking the
question, and who is providing the answer.1
Insurance carriers and public health systems
tend to argue against their removal; we clinicians
generally argue in favor of prophylactic surgery
with the goal of preventing disease and minimizing
the surgical morbidity to our patients.
What does the literature say about this question,
and how does our personal clinical experience
influence whether we recommend removal of
asymptomatic third molars or not?
The case against removal
Those who argue against preventive surgery have
two basic arguments. First, the incidence of complications
from retained third molars—including
pain, infection, caries, bone loss, periodontal
issues, development of cysts and tumors, and
mandible fracture—is so low that prophylactic
removal for those reasons is not warranted. The
second relates to the financial cost, recovery
time and risk of significant complications such
as permanent paresthesia.
Stanley et al. evaluated 11,598 cases of
impacted third molars in patients older than
20 using panoramic radiographs. Their study
showed the incidence of cyst development
around third molars to be 0.25%. Internal resorption
was visible in 0.13%, 0.72% had periodontal
bone loss behind the second molar, and caries
were seen in 0.72%.2
Friedman (a retired dentist who is opposed to
prophylactic third-molar removal and frequently
is an advocate for third-party payers) states
that internal resorption is present in 0.85% of
asymptomatic wisdom teeth; 1.65% are associated
with the development of cysts; 4.72% show
periodontal bone loss; and 4.78% show resorption
on the distal of second molars. He equates this
to the incidence of appendicitis and cholecystitis
(10%–12%) in the adult population and
argues that prophylactic appendectomies and
cholecystectomies are not the standard of care.
When including an approximately 8% incidence
of pericoronitis, Friedman still argues that a
20% incidence of pathology around third molars,
across all age groups, is not justification for their
routine removal, because of the risk of postoperative
sequalae such as pain, swelling, infection,
days lost from work or school, paresthesia and
A frequently cited study is the Cochrane
database review of randomized clinical trials
that compared removal versus retention of
asymptomatic, disease-free impacted third
molars in adolescents and in adults ages 24–84.4
Studies included those from the United Kingdom
(public sector dental care) and the United States
(private sector). The review concluded there
was insufficient evidence to determine whether
impacted asymptomatic wisdom teeth should be
removed, and suggested that decisions should be
In 2000, the National Institute of Clinical
Excellence, using data from the U.K. National
Health Service, issued guidance to NHS dentists
on the management of third molars. The institute
stated that up to 40% of wisdom teeth had been
removed without clinical indication and that
prophylactic removal should not be performed;
treatment should be limited to patients with
evidence of disease. This reduced the number
of third-molar removals by more than 30%
compared to the 1990s, and saved the NHS more
than £5 million per year in treatment costs.
However, by the last half of the 2000s, the
number of patients getting third molars removed
doubled compared to the 1990s. By 2010, wisdom
tooth removal was at its highest level in 20 years.
What caused this dramatic increase was not
that prophylactic removal was becoming more
common; it was that older patients in their 20s
and 30s were now presenting with symptomatic
and pathological third molars requiring removal.
The article concluded that any financial savings
to the NHS was only short-term, and that NHS
expenditure for third molar surgery became
greater than before the introduction of NICE
The case for removal
Most of us in clinical practice would tend to
agree that if a third molar will not fully erupt,
will come into full function, and may compromise
adjacent teeth and not be able to be
kept caries- and infection-free for the life of the
patient, it should be removed—preferably before
the patient turns 25 or becomes symptomatic.
We need to remember that “asymptomatic” does
not mean “disease-free” (Fig. 1). About 25%
of patients who deny any symptoms around their
third molars have inflammatory periodontal
disease around those teeth.7
We all have experience seeing the consequences
of third-molar retention, including
caries, bone loss, infection and other pathology
around nonerupted or partially erupted wisdom
teeth. We also appreciate the increased morbidity
of treating these patients past 30 years of age.
Multiple studies confirm that the risk of complications
and morbidity associated with surgical
removal of third molars increases with age.4,8,9
Even when third molars are fully erupted, they
are frequently more difficult to clean because
of their location at the back of the mouth. As
a patient ages, the likelihood of caries and
periodontal pathology increases. Garaas et al.
reviewed the data on 6,793 patients who participated
in the Dental Atherosclerosis Risk in Communities
study. The average age of the subjects
of this study was 62 years and all subjects had
at least one visible third molar. Only 2% of the
subjects had third molars that remained free of
caries or periodontal disease.10
Erupted third molars also have a negative
impact on the periodontal health of the adjacent
second molars, especially in middle-age and
older adults. The risk of periodontal pockets of at
least 5 mm around a second molar is 1.5–2 times
greater when an erupted third molar tooth is
present.11,12 When an impacted third molar—especially a mesioangular or horizontal impaction—is in close proximity to the distal root of
the second molar, it is not uncommon for there
to be significant bone loss, which increases as
the patient ages (Figs. 2a and 2b).
Nunn et al. followed 416 men at the Veterans
Affairs dental clinic in Boston for 25 years and
found that the lowest incidence of second molar
pathology occurred when the third molar was
absent.13 In a study by Moss et al. with middleage
and older subjects, not only was the prevalence
of second molar periodontitis higher, but
there was more severe periodontal disease in
teeth more anterior in the mouth.14
Pericoronitis is another risk of retained third
molars (Fig. 3). This condition, which can cause
significant pain and morbidity for patients,15
is frequently the presenting complaint of
patients when they seek care. About 25%–30% of
impacted third molars are extracted because of
acute or chronic periocoronitis.16 If not treated
in a timely manner, infection can spread through
the soft tissues into the fascial spaces, resulting
in a possibly life-threatening situation, requiring
hospitalization and aggressive treatment (Fig. 4).
The development of cysts and tumors around
retained, unerupted wisdom teeth is also a factor
to be considered when discussing prophylactic
removal of third molars. Although rare in
comparison to the incidence and prevalence
of infections, periodontal disease and caries,
these lesions can result in significant morbidity,
destruction of bone and adjacent teeth, and
increase the risk of serious complications such
as mandible fracture (Fig. 5) and permanent
The majority of pathological findings are cystic,
including dentigerous cysts (Fig. 6) and more
aggressive odontogenic keratocysts. A smaller
percentage are solid tumors, most commonly
ameloblastoma (Figs. 7a and 7b). These lesions
are seen radiographically in approximately
1%–2% percent of patients with impacted third
molars.17 The prevalence of cysts and tumors
was seen to increase after the age of 50 years,
especially in males, reaching 18.6% in patients in
their seventh decade in a review of 20,802 third
molars in a single institution.18
One of the greatest risks of not removing
asymptomatic third molars is that they will
eventually need to be removed when the patient
is in middle age or beyond (Fig. 8). Bouloux et al.
reviewed seven studies that followed patients
with retained third molars up to 18 years. The
mean age at the beginning of the studies was 25.
The researchers found that the incidence rate for
third-molar removal was on average 3% per year,
and that after 18 years, 64% of patients who had
been initially asymptomatic developed pathology
that resulted in the necessary removal of at least one wisdom tooth because of periodontal
infection, caries, pericoronitis and other causes.19
Increasing age is associated with a higher risk
of persistent postoperative pain, swelling,
prolonged recovery and iatrogenic injury to the
mandibular nerve and mandible fracture. These
risks increase dramatically beyond age 35.20
Another argument in favor of prophylactic
removal of third molars relates to the cost,
time and radiation exposure of lifelong “active
surveillance.” Because the incidence of third-molar
pathology increases with each year that
surgical management is delayed, a reasonable
approach would be to reevaluate patients on a
biannual schedule. These clinical visits to monitor
third-molar status require patients taking
time off work to be seen, as well a biannual
radiographic imaging of each retained tooth.
This would not be necessary had the patient had
their wisdom teeth removed in adolescence.20
The socioeconomic costs of this approach are
not insignificant, especially when at least 60% of
patients will ultimately need to undergo surgical
management because of pathology, when the
risks are greater and their medical history will
likely be more complex.6
And finally, some personal thoughts on the subject.
I remember throughout my residency hearing
multiple times the adage “Let sleeping dogs
lie” in relation to asymptomatic wisdom teeth.
I was told it was repeated often by an attending
surgeon who retired just before I started my
OMFS training. It seems like our philosophy has
changed over the past 50 years; we are now routinely
seeing patients up to their 80s who have
had that sleeping dog wake up, and that puppy is
not happy (Fig. 9)!
It made me think about what has changed over
that time and why we now recommend prophylactic
removal of all impacted third molars. The
first change was the replacement of the chisel
and mallet with the high-speed, high-torque surgical handpiece. This began with the introduction
of the pneumatic Hall drill in 1964,
which allowed impacted teeth to be removed
more easily and with a much lighter touch.
The surgical handpiece gradually replaced the
traditional technique in training programs.21
Many doctors trained in the use of the chisel
and mallet for removing impacted teeth contend
that this method is less traumatic to bone and
soft tissues and is actually faster than using a
The other advancement was in the field of
ambulatory anesthesia. Intravenous thiopental
(Pentothal) was replaced with methohexital
(Brevital), and then by propofol (Diprivan) in
1989. Propofol has been found to be a safer
anesthetic drug than the barbiturates and is
associated with a more rapid recovery and lower
incidence of nausea, vomiting and cognitive
impairment.23 In ambulatory office anesthesia,
we have noted a near-elimination of postoperative
shivers (“Brevital shakes”) and intraoperative
laryngospasm. In addition, we now use intravenous
midazolam and fentanyl rather than diazepam
and meperidine in our balanced anesthetic
techniques. Both drugs offer faster onset and
We also have seen a revolution in the monitoring
equipment used during sedation and
general anesthesia. Pulse oximeters became
commonplace starting about 1987, and end-tidal
CO2 monitors became standard over the past
decade. Before these devices were available, the
only ways to monitor a patient’s ventilation and
oxygenation status was via precordial stethoscope
and monitoring the color of their lips. The
combination of safer anesthetic drugs and better
and more complete monitoring of patients in our
offices has allowed us to deliver sedation and
anesthesia in a much safer setting.
I propose that the shift in thinking that favors
prophylactic removal of asymptomatic third
molars in the adolescent years, rather than
waiting until they are problematic, is a result of patients living longer lives and living long
enough to develop significant medical issues.
We have all had these patients present to our
offices with decayed, infected, pathologic third
molars we wish had been removed decades
earlier. We currently have the ability to provide a
less traumatic procedure under general anesthesia
more safely and smoothly.
“Letting sleeping dogs lie” has been replaced
because of our increased knowledge and the use
of technology to give our patients a better overall
experience and better health.
1. Assael LA. Indications for Elective Therapeutic Third Molar Removal: The
Evidence Is In. Editorial J Oral Maxillofac Surg 63: 1691–1692, 2005.
2. Stanley HR, Alattar M, Collet WK. Pathological Sequelae of Neglected
Impacted Third Molars. J Oral Pathol 17(3): 113–117, 1988.
3. Friedman JW. The Prophylactic Extraction of Third Molars: A Public Health
Hazard. Am J Public Health 97(9); 1554–1559, 2007.
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Van der Sanden WJ, Mettes TG. Chochrane Database Syst Rev 2020 May 4;
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the United Kingdom’s Experience with Retention of Third Molars? J Oral
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with Asymptomatic Third Molars. J Oral Maxillofac Surg 60: 1227–1233, 2001.
8. Bui CH, Seldin EB, Dodson TB. Types, Frequencies, and Risk Factors for
Complications After Third Molar Extraction. J Oral Maxillofac Surg 61: 1379,
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Oral Surg Clinics No Am 19(1): 1–13, 2007.
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16. Rakprasitikul S. Pathological Changes in the Pericoronal Tissues of
Unerupted Third Molars. Quintessence Int 32(8): 633–638, 2001.
17. Patil S, Halgatti V, Khandelwal S, Santosh BS, Maheshwari S. Prevalence of
Cysts and Tumors Around the Retained and Unerupted Third Molars in the
Indian Population. J Oral Biol Craniofacial Res 4: 82–87, 2014.
18. Shin S-M, Choi EJ, Moon S-Y. Prevalence of Pathologies Related to Impacted
Mandibular Third Molars. SpringerPlus 5: 915–919, 2016.
19. Bouloux GF, Busaidy KF, Beirne OR, Chiang S-K, Dodson TB. What Is the Risk
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20. Vranckx M, Fieuws S, Jacobs R, Politis C. Prophylactic vs. Symptomatic Third
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Mandibular Third Molars: A Technique That May Prevent the Aerosolization
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Anesthesiology 109: 1132–1136.
Jay B. Reznick, DMD, MD, is a diplomate of the
American Board of Oral and Maxillofacial Surgery.
Reznick earned an undergraduate biology degree
from University of California, Berkeley, a dental
degree from Tufts University and an MD degree from
the University of Southern California. He interned
in general surgery at Huntington Memorial Hospital
in Pasadena, California, and trained in oral and
maxillofacial surgery at LAC + USC Medical Center.
Reznick is a consultant to a number of manufacturers
and suppliers of dental and surgical instruments and
equipment, and is on the editorial advisory boards
of a number of dental journals. He is the director of
the Southern California Center for Oral and Facial
Surgery in Tarzana, California.