Cases & Commentaries
Mark My Tooth
A 45-year-old healthy man was scheduled to have
two teeth extracted for progressive dental caries. The patient
underwent the extractions, awoke from the anesthesia, and then
realized that his upper left molars had been extracted instead of
his right. The error was recognized and acknowledged immediately
following the procedure. The patient still required extraction of
the diseased teeth, which occurred a few weeks later. He developed
no significant complication from either surgical procedure other
than enduring two rounds of anesthesia because of the error.
Wrong-site tooth extraction is both a significant
medical error and one of the major reasons for litigation against
oral and maxillofacial surgeons. This case illustrates a typical
scenario where a surgical extraction was performed on the incorrect
side. Through a root cause
analysis, we might find that the unfortunate event occurred as
a result of a cognitive error, the lack of a clear dental diagram
(Figure) with the correct teeth marked, an unclear
referral slip for the requested services, inadvertent reversal of
the radiographs posted on the light box, or disregard of the
Universal Protocol. Whatever its cause, once the error is
identified, the surgeon should disclose the error and arrange for
tooth replacement without any cost to the patient.
Prevalence of Wrong-Site Tooth
Despite anecdotal reports and known medico-legal
implications, few data exist about the prevalence of wrong-site
However, most believe that, like other medical errors, these events
Common etiologies of wrong-site tooth extraction include cognitive
failure and miscommunication, multiple contiguous carious teeth
(rather than one identifiable diseased tooth), partially erupted
teeth mimicking third molars, teeth with gross decay that the
restorative dentist wants to save, reversed radiographs, and
nebulous tooth numbering systems.
Data from the Oral and Maxillofacial Surgeons
National Insurance Company (OMSNIC) Risk Retention Group (Rosemont,
Illinois) characterized the nature and extent of wrong-tooth or
wrong-site surgery performed by its 4300 members. In the database,
the most common reasons for filed claims were paresthesia from
third molar extractions and implant placement, infection, and
wrong-site tooth extraction. Wrong-site tooth extractions accounted
for 14% of all claims and 30% of the claims in which indemnity
payments were made. The company identified internal communication
problems in the surgeon's office and with the referring dentists as
the root causes for many wrong-site surgeries. They also reported
no pattern regarding sites and teeth involved in these claims and
that the surgeon's age and experience were not important predictors
of errors or safety. Unfortunately, no clear trends were identified
that would help reduce the number of wrong-site surgeries, and the
number of claims has stayed fairly constant despite risk management
seminars and online courses sponsored by OMSNIC.
Minimizing the Risk
Most cases of wrong-site tooth extraction can be
prevented by the development of an educational program, an
informative and unambiguous referral form, a preoperative
checklist, and incorporation of the Joint Commission's "Universal Protocol for Preventing Wrong Site, Wrong
Procedure, Wrong Person Surgery" into daily clinical
The following comprise the Universal
- Preoperative verification process
(correct patient, chart, x-ray, referral slip, dental diagram)
- Marking the operative site
- "Time out" immediately prior to
beginning the procedure
The American Dental Association (ADA) has
supported national efforts to eliminate wrong-site surgery,
including wrong-site tooth extraction. However, many of the Joint
Commission's safeguards currently in place apply to practitioners
in hospitals and ambulatory surgery centers. Very few guidelines or
methods for prevention have been established for the primarily
office-based practitioners who routinely perform dental procedures.
For example, more than 70% of procedures, including dental
extractions and other dentoalveolar procedures, occur in this
Improving the safety of tooth extraction and
other types of dental surgery begins with a highly reliable
preparatory procedure. The process by which dentists and oral and
maxillofacial surgeons typically prepare patients for dental
extractions in the office setting involves the following steps:
- Review the treatment plan (or if
referred, the referral slip) regarding which tooth is to be
- Review the medical history and record
the vital signs.
- Perform the oral evaluation to assess
the surgical site.
- Obtain written informed consent
(generally, a pre-printed form with a notation of the tooth to be
- Administer the local anesthesia with or
without sedation or general anesthesia.
- Perform the procedure.
- Give postoperative instructions and
dispense prescriptions as required.
- Discharge patient when stable and
arrange for follow-up.
Recommendations for Safe
In order to improve the quality of care provided
in dental offices and avoid dental errors, particularly wrong-site
tooth extraction, I would suggest that the following guidelines be
Develop an educational program for
the entire staff on preventing wrong-site tooth extraction.
Cognitive failure is the most frequent form of active failure in
wrong-site tooth extractions, whereas communication and training
factors contributing to these errors. A carefully designed
staff education program may reduce the risk of cognitive
Elements of an educational program include case-based materials,
information feedback, and clinical guidelines.
Design a more informative referral
slip without ambiguities. Any question or confusion about the
correct tooth to be extracted should prompt a call to the referring
dentist for clarification. The dentist should also be aware that
missing teeth allow for drifting of the remaining teeth into an
altered position and can add to potential
confusion—particularly if different numbering systems are
used to annotate teeth. The ADA recognizes two different tooth
numbering systems. The dental practitioner should describe the
tooth/teeth to be extracted in longhand (e.g., lower left first
molar) on the referral slip and on the consent form, in order to be
sure that both the health professionals and the patient understand
- Inform the patient/parent/guardian
verbally, and with a hand-held patient mirror, which tooth/teeth
are to be extracted at the initial consultation
Confirm that the patient, chart, and
x-ray (properly oriented) are correct and confirm which tooth is to
be extracted at the surgical appointment. There is no practical
or reliable way to mark teeth prior to the procedure. The Joint
Commission and ADA have acknowledged alternatives such as marking
the radiograph or a dental diagram visible to the surgeon. A
"time-out" should be conducted to confirm the above using the
two-person rule. The relationship between the dentist and the
hygienist may determine whether the latter can comfortably disagree
with the dentist without fear of retribution. The referral form
should be checked prior to placing the dental elevator or forceps
on the tooth. If there is prosthesis to be inserted after
extraction (to replace the extracted tooth), the surgeon should
verify that the prosthesis design is compatible with the extraction
If a wrong tooth is extracted, regardless of
whether the error was identified immediately or delayed, full
disclosure and possible remedies must be presented to the patient.
Any judgment or settlement that requires a dental licensee or their
insurer to pay damages in excess of $3000 because of negligence or
error in practice must be reported to the State Dental Board. The
Dental Boards also investigate any patient-generated
- Incorporate the preoperative
verification process into clinical practice (correct patient,
chart, x-ray and its orientation, referral slip, and dental
- Communicate directly with the referring
dentist whenever clarification is required about the procedure
- Use a "time out" immediately prior to
beginning the procedure to verify patient, tooth, and procedure
with the assistant at the time of extraction (two-person
- Check the tooth position before and
after application of the forceps.
Richard A. Smith, DDS
Clinical Professor Emeritus
University of California, San Francisco
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Figure. Dental Diagram.
Click on thumbnail for larger view.