Lingual Nerve Injury of Uncertain Etiology Leads to Malpractice Suit Against General Dentist

Background

Many malpractice suits against dentists result from care that seemed routine and unremarkable when rendered. However, when patient injury results—whatever the cause—the possibility of a lawsuit exists. This case illustrates how seemingly routine cases can become malpractice allegations.

Case Discussion

Dr. M, a residency-trained general dentist, had been in solo practice for about 4 years. In addition to regular dental services, Dr. M also promoted his oral sedation services on the practice’s website and in other advertising materials. 

The patient was a 55-year-old female with an unremarkable medical history, except for smoking one pack of cigarettes per day for 30 years. Because of her dental phobia, she avoided regular dental treatment and only consulted a dentist for emergency treatment.  She was not a regular patient of Dr. M's practice.

In this case, she sought dental treatment because she was having discomfort and swelling in her left mandible. She scheduled an appointment with Dr. M because the oral sedation services appealed to her.

At the appointment, an oral examination and radiographs showed that teeth 18 and 19 were infected and not salvageable. She made an appointment to get the teeth extracted. The dentist gave her an antibiotic and also a sedative to be taken the night before the treatment.

On the morning of the treatment, the patient received additional sedation following an antibiotic mouth rinse. She then signed an appropriate consent form for this treatment, and it was commenced. She received local anesthesia by means of three carpules of 4 percent anesthetic, and teeth 18 and 19 were extracted without difficulty. The patient was then taken to an observation area for monitoring.

After 3 hours in the observation area, the patient was still drowsy, so the dentist administered a sublingual sedation reversal agent. This agent worked as expected, and the patient was discharged with postoperative instructions about 30 minutes later.  

The following day, a staff member called the patient to check on her and the patient said that her tongue was still numb. The doctor requested to examine the patient, but she declined. Over the next 2 months, the doctor contacted the patient numerous times; and, although on each occasion she indicated that she was getting better, she refused to be seen. After 3 months, Dr. M’s practice received a request for records from another dental practice, and records were released.

In light of the continuing paresthesia, the new dentist referred the patient to an oral and maxillofacial surgeon (OMS), who then referred her to an OMS specializing in oral microsurgery and nerve repair. The second OMS diagnosed the patient with a lingual nerve injury of unknown origin and uncertain prognosis. The patient declined further treatment. However, she consulted an attorney and ultimately sued Dr. M for malpractice.

Dr. M, his defense attorney, and MedPro Group agreed that this case should be vigorously defended. Both the plaintiff and the defense experts agreed that the administration of the 4 percent anesthetic “most likely” caused the paresthesia. However, in the end, neither could state with sufficient certainty whether the ultimate cause was a chemical injury or a traumatic injury. Additionally, no imaging information was introduced to verify the exact cause. In their post-verdict report, the jurors indicated that they rendered a defense verdict because a traumatic injury is not preventable nor a risk of the procedure.          

Risk Management Considerations

Theodore Passineau, JD, HRM, RPLU, CPHRM, FASHRM

Given the significant and permanent nature of the patient’s injury, this kind of case might be expected to result in a dental malpractice lawsuit. The plaintiff must prove these four elements in a dental malpractice lawsuit: (1) a defined standard of care exists; (2) the doctor’s performance did not meet this standard; (3) the plaintiff suffered some type of compensable injury; and (4) the deviation from the standard of care directly caused the plaintiff’s injury. The failure to prove any of these four elements should result in a verdict for the defense.

In this case, the first two elements were disputed (i.e., whether the 4 percent anesthetic should have been used), and the fourth element (damage to the lingual nerve) was clearly proven.

However, the causal connection between the anesthetic used and the injury could not be established to the reasonable exclusion of all other potential causes of this injury. It appears “most likely” that the anesthetic caused the injury, but the legal standard is higher than “most likely;” it requires proof “to a reasonable medical certainty.”

Another potential contributing factor involved the informed consent process. Dr. M correctly engaged the patient in an informed consent process prior to treatment. The purpose of informed consent is to allow patients the opportunity to consider and choose the treatment option that they prefer, considering the risks, anticipated benefits, and more.

To make a reasoned decision regarding treatment options, the patient must have a clear mind (cognitive competency). However, in this case, consent to treatment was secured after the patient had been sedated. Given this sequence of events, the consent to treatment had no legal value. 

The argument supporting the patient being adequately informed was that she had consented (in writing) to similar treatment several times in the past, and therefore she was aware of the paresthesia risk following extractions. This is an attenuated argument at best; however, it was sufficient to convince the jury that the plaintiff was aware of this injury risk.                

Conclusion

Malpractice litigation is a systematic process whereby dental care is examined to determine whether the appropriate standard of care was met, and if not, whether the failure resulted in a compensable injury to the patient. Although the process can be intimidating, it usually results in a defense verdict when quality care has been rendered and can be proven. Attention to detail, combined with careful documentation of the healthcare delivery process, should allow dentists to practice with clarity and confidence.