Dentist suspended for 11 months after causing patient to suffer nerve injury that has lasted 5 years

A dentist has been suspended for 11 months after an implant procedure he carried out left the patient with a nerve injury that still causes him to experience numbness on his lip and chin five years later.

Dr Kenji Chin Choon Tsze was found guilty in October 2023 of two charges of professional misconduct, according to published grounds of decision on the Singapore Dental Council’s (SDC) website.

The 61-year-old patient, known only as “Mr DT” in the disciplinary inquiry, had on May 22, 2018, consulted Dr Chin about a painful tooth at the 1728 Dental Practice in Ang Mo Kio.

Dr Chin did an X-ray of the jaw area and recommended replacing one tooth with an implant and placing a second implant next to it.

He then extracted the tooth that same day. Dr Chin told the patient that as there was insufficient bone height in the tooth area for both implants, he was to return in three months.

On Aug 4 that year, the patient returned to the clinic.

Dr Chin did another X-ray of his jaw, but the disciplinary committee said he did not take any appropriate pre-surgery measurement of the height of the alveolar bone – a bone in the jaw which contains tooth sockets.

Instead, he simply made estimations based on the X-ray images and proceeded with the tooth implant surgery.

He placed two implants, one measuring 10mm long and the other 8.5mm. These were significantly longer than the actual alveolar bone height of the two teeth, the disciplinary committee noted.

During the procedure, the patient said he felt some pain, prompting Dr Chin to unscrew one of the implants slightly.

An X-ray after the procedure showed one of the tooth implants superimposed on a nerve canal, while the other implant was just above the same nerve canal. This exposed the patient to direct trauma to the nerve.

The disciplinary committee said that from this X-ray, Dr Chin should have known that the patient’s nerve may have been injured. He ought to have monitored and reviewed the patient within 24 to 48 hours of the procedure, but he saw the patient only 16 days later.

During this subsequent visit, the patient complained of numbness on his lower right lip.

Dr Chin removed one of the implants three weeks later. He also refunded the treatment fee of $2,200 in January 2019.

The patient went for multiple consultations with another dentist, who removed the other implant and gave him two new shorter implants.

A third dentist who saw the patient on March 26, 2020, 20 months after the implant surgery, said his nerve injury could improve but may not recover completely.

The patient filed a complaint with the SDC against Dr Chin on June 21, 2019.

The SDC, represented by Ms Chang Man Phing and Ms Dorcas Ong of WongPartnership, argued for a suspension of 14 months.

Calling Dr Chin’s misconduct a deliberate departure from guidelines, the lawyers said he caused serious personal injury to the patient, which led him to spend significant time and effort to rectify the harm.

The lawyers also noted that Dr Chin was a senior dental practitioner with 20 years’ experience, who has focused his area of practice on dental implants.

They added that he would be given a higher level of trust and confidence by his patients, which made his failures particularly egregious.

The dentist’s lawyers, Mr Charles Lin and Ms Tracia Lim of Charles Lin LLC, called his actions “out of character” and asked for a shorter suspension of not more than eight months.

They said he had mistakenly thought that the patient did not suffer from a nerve injury because he did not report any pain or sensitivity after the surgery.

The lawyers also said their client had relied on the clinic’s protocol to check on patients post-surgery, instead of checking personally.

The disciplinary committee said Dr Chin should not have done so, adding that it was not a valid excuse for his failure to monitor and review the patient timeously.

Nevertheless, the committee noted that his conduct appeared to be a one-off incident regarding a single patient.

The disciplinary committee comprised Dr Chan Siew Luen, Dr Tan Tien Wang and Dr Lui Jeen Nee, as well as Dr Tyrone Goh as an observer. Mr Kenny Chooi of Adsan Law acted as legal assessor.

In addition to the suspension, Dr Chin will have to pay for the cost of the hearing. He will also be formally reprimanded and will have to submit a written undertaking to the SDC that he will not engage in such conduct in the future.