Local anaesthesia

  • In facial wounds standard dental anaesthetic may be used – 2% lignocaine with 1 in 80,000 adrenaline
  • Long thin needle (dental needle)
  • Infiltration or regional block

Remember that putting a needle straight into the lip or tongue is extremely painful and the local anaesthetic distorts the soft tissues, so consider using a regional block.

Regional blocks (should be used by those with specific training):

Lower posterior teeth/Tongue / Lower lip– anaesthesia can be achieved by utilising an inferior dental nerve block, using a dental needle, syringe and dental local anaesthetic cartridge.

With the mouth open, follow the line of the lower teeth and just distal to the last standing tooth insert the needle for 5 mm, until it touches bone then pull back for 1-2 mm and press the dental syringe plunger lightly to see if blood from the inferior dental artery or vein is drawn into the glass anaesthetic cartridge, then slowly inject 1 ml of local anaesthetic and continue to inject a further 0.5 mls as the needle is withdrawn out of the tissues – this will anaesthetise the lingual nerve which supplies the lateral border of the tongue as well as the inferior dental nerve as it enters the mandible on the inner aspect of the ramus of the mandible.

To anaesthetise the lower cheek a buccal nerve block can be achieved by infiltration of dental local anaesthetic 1ml, 1cm lateral to the area of the wisdom tooth/3rd molar.

For the lower lip, palpate the buccal aspect of the mandible, in the region of the premolars – feel for a depression in the bone – this is the exit point of the mental nerve, which supplies the lower lip. Infiltration of anaesthetic here will give excellent anaesthesia of the lower lip.

Upper cheek / Lateral aspect of nose / Lower eyelid – anaesthesia can be achieved by using an infra-orbital nerve block.

Palpate the infra-orbital rim with the forefinger. With the thumb of the same hand, lift up the upper lip to reveal the canine tooth. Pass the needle in line with/parallel to the long axis of the canine, about 5mm out from the gum, into the labial sulcus and pass it upwards (but not so far that one feels the pressure on the finger on the infra-orbital rim). Infiltration of 1-2mls of anaesthetic here will give anaesthesia of the upper lip, lateral aspect of nose and lower eyelid.

Upper teeth – the upper teeth and adjacent buccal mucosa can be anaesthetised using 1-2 mls of dental local anaesthetic and a dental needle and syringe, by infiltration in the buccal sulcus above the teeth.