Decision #121/20 - Type: Workers Compensation


The worker is appealing the decision made by the Workers Compensation Board ("WCB") that he is not entitled to benefits after May 26, 2017. A teleconference hearing was held on November 5, 2020 to consider the worker's appeal.


Whether or not the worker is entitled to benefits after May 26, 2017.


The worker is entitled to benefits after May 26, 2017.


The worker filed a Worker Incident Report with the WCB on February 15, 2018 indicating his left jaw was injured in an incident at work that occurred on May 26, 2017. He reported that he was assaulted by a co-worker on that date and on May 29, 2017, his jaw started swelling and he sought medical attention at a local emergency department. Included with the Report was a letter from the worker’s advocate noting that the worker did not believe the assault caused a serious injury however, “Gradually over the next weeks and months pain and swelling led to the discovery that his jaw was broken.”

The worker’s treating oral surgeon also provided a letter dated February 2, 2018 advising that the worker had been receiving treatment for recurrent cysts in his left jaw beginning in 2006, culminating in a resection and placement of a metal plate with 5 screws in September 2015. The worker’s treatment was detailed, along with the advice that the plate in the worker’s jawbone had become loose and required surgery, which occurred on January 31, 2018. The oral surgeon noted that during the surgery, it was discovered that the worker’s jawbone was fractured in the area of the steel plate “…which may have been the result of the physical impact of [the worker’s] assault.”

The hospital report from the emergency department dated May 30, 2017 noted the worker’s reporting of being hit in the jaw on the left side of his face and noted “some swelling and tenderness” of the worker’s left jaw. A CT scan conducted on May 30, 2017 found the metal plate and screws appeared intact and no fractures were identified. A follow-up report from the hospital dated June 14, 2017 indicated the worker returned on that date for further treatment due to pain and swelling and was diagnosed with a soft tissue infection and treated with antibiotics.

Witness statements and incident reports were provided by the employer on February 23, 2018. On February 27, 2018, the WCB discussed the claim with the worker. The worker confirmed the workplace accident and the treatment he had been receiving and advised that after the January 31, 2018 surgery, he returned to work on modified duties with reduced hours commencing on February 20, 2018. The worker further confirmed that other than the recurrent cysts and the resulting surgery in 2015, he had not had any issues with his left jaw prior to the workplace accident. The worker advised that he had not filed his claim earlier as he was not aware anything was wrong with his jaw until his appointment with the oral surgeon in January 2018.

After additional medical information was requested and received by the WCB, the WCB medical advisor provided an opinion on July 29, 2018 (the report is dated June 29, 2018). She noted that the worker’s diagnostic imaging was reviewed by an external neuroradiologist who opined that the loosening of the hardware in the worker’s jaw predated the May 26, 2017 workplace accident as “The bony sclerosis and bony resorption indicate that the loosening process is at least a few weeks in age prior to the date of the CT…” Accordingly, the WCB medical advisor determined that the medical evidence did not support the May 26, 2017 incident caused any structural change, including a bony fracture, to the worker’s left jaw. Further, with respect to the soft tissue infection, the WCB medical advisor opined that the medical information did not support that a “laceration/abrasion/skin or mucosa break” occurred as a result of the incident.

In correspondence dated September 4, 2018, the worker was advised by the WCB that his claim was accepted for an incident that occurred in the workplace on May 26, 2017. However, he was not entitled to any benefits related to the incident as the WCB was unable to establish his soft tissue infection and surgery were related to the incident. The worker’s advocate requested reconsideration of the WCB’s decision to Review Office on January 8, 2019. The advocate noted the worker’s treating healthcare providers supported the infection and the subsequently discovered jawbone fracture were the result of the May 26, 2017 workplace accident.

Review Office determined on February 22, 2019 the worker was not entitled to benefits. Review Office accepted and relied on the opinion of the WCB medical advisor and neuroradiologist that the changes seen on the May 30, 2017 CT scan were


Applicable Legislation and Policy

The Appeal Commission and its panels are bound by The Workers Compensation Act (the "Act"), regulations and policies of the WCB's Board of Directors. The Panel considered the following sections of the Act:

Section 4(1) of the Act provides that where a worker suffers personal injury by accident arising out of and in the course of employment, compensation shall be paid to the worker. Under s 4(2), a worker who is injured in an accident is entitled to wage loss benefits for the loss of earning capacity resulting from the accident, but no wage loss benefits are payable where the injury does not result in a loss of earning capacity during any period after the day on which the accident happens.

Section 27(1) of the Act provides that the board may provide a worker with such medical aid as the board considers necessary to cure and provide relief from an injury resulting from an accident.

WCB Policy, Pre-existing Conditions (the “Pre-X Policy”) outlines that the WCB will not provide benefits for disablement resulting solely from the effect of a worker’s pre-existing condition as such a condition does not fall within the definition of personal injury by accident arising out of and in the course of employment.

Worker’s Position

The worker participated in the hearing along with his spouse for support as well as his previous advocate/sister. He was represented by a worker advisor who submitted a written submission prior to the hearing. The worker answered questions posed to him by the worker advisor as well as by the panel.

At the beginning of their presentation, the worker advisor stated:

It is our position that the assault the worker endured on May 26, 2017 caused more serious damage to the worker’s jaw than was assessed at the commencement of the file.

In response to questions from the worker advisor, the worker explained the history of his pre-existing condition that resulted in the worker having a steel plate surgically implanted in his lower left jaw in 2015. The worker explained that, as a result of the 2015 surgery, he lost some of the feeling in his lower left jaw where the steel plate had been implanted. The worker confirmed that, other than the loss of feeling in his lower left jaw area, he had experienced no other problems in his jaw after the 2015 surgery until the May 26, 2017 injury.

The worker also described the events that occurred on May 26, 2017. He confirmed that he was struck several times in his head including his left jaw. He confirmed that he initially had no pain or bruising after the incident until May 30, 2017 when he woke up and his lower left jaw was swollen and painful, which resulted in him obtaining medical treatment on that date.

The worker outlined the subsequent medical problems he experienced after the workplace injury, which included recurrent episodes of infections in his left jaw that was treated with several courses of medication. The worker described his ongoing medical treatment he received after the May 26, 2017 workplace injury. In particular, he described the medical attention he received just after the workplace injury on May 30, 2017 and June 14, 2017 as well as his surgery and subsequent recovery from that surgery.

In sum, the worker’s position, as submitted by his worker advisor, was that the May 26, 2017 workplace injury resulted in his subsequent medical issues he developed with his jaw including the resulting surgery and that he was entitled to benefits that were required to treat those injuries.

Employer’s Position

The employer was represented by their Administrator who advised the panel at the outset of the hearing that her participation was to answer any questions that the panel might have of the employer. The employer’s representative took no position regarding the claim.


The worker has an accepted claim for a workplace injury that took place on May 26, 2017. The question before the panel is whether the worker is entitled to benefits after May 26, 2017 as a result of that injury. The panel determined the worker is entitled to benefits after May 26, 2017.

The panel is satisfied that the medical issues that arose within a very short time after the assault were causally connected to the injuries the worker incurred on May 26, 2017.

The information on file confirms that the worker was struck in the side of his head several times by a co-worker as well as being placed in a headlock by the same individual.

With respect to the infection in the worker’s lower left jaw that was first identified during his June 14, 2017 exam, the panel considered the opinion provided by the worker’s general practitioner in her April 27, 2020 correspondence where she stated the following:

First of all, oral mucosa heals quite quickly. For example, when flossing, if one is not a regular flosser, microtrauma and bleeding occurs. This bleeding, however, tends to resolve quickly, and there is often no sign of the microtrauma even hours later. I would argue that an examination that occurred 3-4 days after the work-related event that shows no mucosal trauma does NOT rule out the possibility of an injury that allowed bacteria access into the jaw, and therefore seeding the titanium plate. When a metal foreign body is present, we know it takes much less of a bacterial exposure for an infection to take hold, as antibiotics are not as effective on the metal surface.

The panel finds that the opinion provided by the worker’s general practitioner is reasonable and consistent with the facts before the panel and supports that the infection is causally related to the May 26, 2017 workplace injury.

Further, the panel accepts that the worker’s absence of pain at the time of the injury is accounted for by the nerve deficiencies in his lower left jaw area he described to the panel during the hearing, and that occurred as a result of his 2015 surgery.

Based on the evidence before us, the panel accepts that the worker’s ongoing infections in his left lower jaw that commenced after the May 26, 2017 workplace injury are the result of his workplace injury.

With respect to the failure of the worker’s left lower jaw surgical implant, an external neuroradiologist examined the worker’s CT scan from May 30, 2017 as well as a follow-up CT scan that occurred on September 29, 2017 and provided an opinion on June 28, 2018 that the imaging demonstrated signs the surgical screws on the mandibular condyle side of the surgical plate were loosening and that “The bony sclerosis and bony resorption indicate that the loosening process is at least a few weeks in age prior to the date of the CT.” The external neuroradiologist also provided an opinion that by the September 29, 2017 imaging, the two screws previously noted had failed.

The panel notes the opinion of the neuroradiologist that the metal plate in the worker’s lower left jaw had become problematic prior to the May 26, 2017 workplace injury; but on the basis of the totality of the evidence, concludes that the workplace injury either caused or enhanced the worker’s surgical plate failure, resulting in the need for the surgery that occurred on January 31, 2018.

In making this determination, the panel relies on the fact that the worker was struck in the head and jaw several times on May 26, 2017. Based on the available information and the sequence of events, the panel finds it is likely that the failure of the worker’s surgical implant in his lower left jaw is causally related to the workplace injury on May 26, 2017.

With respect to the fracture that was identified by the worker’s surgeon in his February 2, 2018 correspondence, the panel notes that there is little information on file regarding this issue. The worker’s surgeon reported in his February 2, 2018 document that the jaw fracture was identified during the worker’s January 31, 2018 surgery, which was approximately eight months after the workplace injury and that the fracture “…may have been the result of the physical impact of [the worker’s] assault.” The panel also notes that a fracture was not identified on any of the previous imaging taken shortly after the worker was injured. The relationship between the workplace injury and the worker’s fractured jaw was not fully investigated by the WCB given their position that the worker’s surgical plate failure and resulting surgery were not a consequence of the May 26, 2017 injury. As a result, the panel takes no position on whether the worker’s fractured jaw is related to his May 26, 2017 injury and refers that matter back to the WCB for adjudication, taking into account the panel’s findings in this decision.

The worker’s appeal is accepted.

Panel Members

K. Dyck, Presiding Officer
D. Loewen, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

M. Kernaghan - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 4th day of December, 2020