Round two of the Six Nations featured a historic moment as Scotland hooker George Turner became the first player in the championship’s history to be removed after his smart mouthguard detected a collision which could have caused a concussion.

Turner was removed from the pitch during the first half of Scotland’s defeat to France for a head injury assessment after his mouthguard alerted medical staff of a significant head acceleration event after a tackle made on Charles Ollivon. The front rower passed his assessment and returned to the field.

The mouthguards, also known as gumshields, have been incorporated into the existing HIA protocols as another tool designed to support the drive towards better player welfare with a particular focus on brain injuries.

Sensors within the mouthguard measure head impacts and accelerations/decelerations. Current regulations state that for men’s players, an impact above 70g and 4,000 radians per second squared will recommend a HIA. For players in the women’s game, the first threshold is lower – 55g.

The Six Nations is the highest-profile competition in which the technology has been used after it was introduced at WXV in the autumn. A more widespread implementation is considered likely.

Scotland coach Gregor Townsend said after the Turner incident that caution must be taken to ensure the mouthguards are used correctly.

Townsend said: “I don’t think there was any more that came out of it but we just have to watch what we’re doing here with bringing technology in that might have an influence for not the correct reasons, let’s say.”

The mouthguards are supplied by Prevent, with World Rugby announcing an investment of £1.7m in October to support implementation after supporting several recent studies.

All players must wear the devices to be eligible for an in-match HIA1 off-field assessment, which permits players to return to the field if passed. If a player chooses not to wear the mouthguard and suffers a suspected head injury, they will not be eligible to return and considered permanently substituted.

It is understood that all 36 England squad members are wearing the gumshields both in matches and training and are thus eligible for HIA1. A World Rugby spokesperson said that they are unaware of any players who have opted out of the scheme for the Six Nations.

Any player who wishes to apply for an exemption can do so via their team manager or doctor with evidence to support approval, such as a medical justification. These must be received at least two days before a match.

Among the teams to have benefitted from the use of mouthguard technology in the past are Harlequins, who used data from their Protecht gumshields to revamp, refine and reduce training loads during their Premiership title-winning season in 2021.