Post on 08-Feb-2017
Complications of local anasthesia in dentistry (part I)
Dr.Mohamed Rhael Ali2016 - 2017
I. Local complications :1. Failure to obtain anasthesia 2. Pain during and after injection 3. Hematoma formation at the site of injection4. Intravascular injection 5. Blanching6. Trismus7. Facial paralysis8. Lip trauma9. Prolonged impairment of sensation10. Broken needle 11. Infection 12. Visual disturbance
II. General complications : 1. Fainting 2. Drug interactions3. Homologous serum jaundice4. Sensetivity reaction5. Occupational dermatitis6. Cardio- respiratory emergencies
Local complications
Failure to obtain anasthesia
It may be complete or partial
Causes :Operator experience Inadequate amount of the local anasthesia Injection in to the blood vesselPresence of infectionExpire date of local anasthesia solutionPatient response to drugs
pain during and after injection
Suggested causes :
a. Injection of either non isotonic or contaminated solutions .
b. Neurological pain during injection due to penetration of nerve sheath by the needle
c. Use of excessive force during deposition of anasthesia solution
Hematoma formationBleeding in the tissue due to injury to blood vessels during
injection
Hematoma formationMainly occure with block injection
• Mostly superior posterior block injection • Less common inferior alveolar and infa-orbital block injection • Bleeding from pterygoid venous plexus clinically appear as
swelling in the cheek followed by discoloration of the overlying skin due to break down of the blood within 24 -48 hours .
• Bleeding from the infraorbital vessels appear as above with black eye
• Bleeding in to the pterygo-mandibular space not show any swelling in the cheek but it may show trismus
Management :
• Reassurance of the patient • Antibiotic to avoid infections• Follow - up
Hematoma formation
Intra – vascular injection• Result in Increase the toxicity of
local anasthetic solution or vasoconstrictor in the blood .
• Clinically patient may show fainting , pale,clammy skin and even decrease in the level of consciousness .
• Can be avoided by using aspiration injection technique
Blanching at the site of injection
Ischemia of the area as aresult of decrease in blood supply
Causes :
• Increase tissue tension due to the deposition of fluid .
• Local effect of local anasthesia
Blanching at the site of injection
Blanching at the site remote from that of injection
Blanching at the site remote from that of injection
Causes :• Intra-vascular injection• Interferance with the autonomic nerve supply of
the blood vessels
Treatment :• No treatment is needed just reassurance to the
patient . Its usually transit
Trismus Difficulty in opening of the mouth due to muscle
spasm
Causes : Injection in to the medial pterygoid muscle may cause injury to the
blood vessels inside the muscle and hematoma formation or infection
Inflamation in the pterygomandibular space
Blood that escape during injection in the pterygomandibular space may cause irritation to the muscle and produce trismus
• Note : if trismus associated with pain ,fever so its due to infection and should treated by drainage of pus , antibiotic , and mouth wash by warm saline
Trismus
Facial paralysis May be partial or complete
Causes :Due to deposition of anasthetica solution in the
parotid which occure when the tip of needle inserted too far back and behind the ramus
Facial paralysis
Facial paralysis
Treatment • Reassurance , and if
eyelids envolved than eye protection is necessary (protective pad or eye shade)
Prolonged impairment of sensation
Occure due to nerve injury
Main causes :Direct trauma from the nerve Injection of a solution contaminated with a
neurotoxic substances as alcoholHemorrhage and infection near the nerve Surgery near the nerve fibers as mental nerve
Prolonged impairment of sensation
• Testing the degree and extent of parasthesia or anasthesia can done by measuring the reactions to pin – prinks and passing of cotton wall wisps over the skin
Prolonged impairment of sensation
Treatment : In case of infection .. Drainage of pus and
anti-biotic coverage Follow up to check the improvement If no improvement then refer the patient to a
specialist
Broken needles
Prevention • The needle must kept straight during injection .• If resistance is encounterd , force must not be applied to
overcome it .• The direction of the needle should not changed within the
tissue .• Bending of the needle should be avoided .• The needle should never embeded completely within the
tissue , at least 5 mm must project from the mucosal surface .
Broken needles
Treatment• If fracture occure the patient should told to stop any
movment to prevent displacemnt of needle within the tissue .
• The needle graspes by artery forceps or pleir and withdrawn .
• If the needle displaced within the tissue then its position must determined radiographically ( two x-ray films must be taken one perpendicular to other ) to confirm the exact position of needle and then removed it surgically by dental surgeon .
infection• Use of contaninated needle may cause infection
especially in pterygomandibular space during inferior alveolar nerve block
Lip trauma
• Anasthetised lip after injection may suffer from trauma by chewing it espcially in children or thermal injury by hot drink or cigarrete in adult .
Visual disturbance
• Rare complication of unknown causes but suspected to be due to vascular spasm or accidental intra-arterial injection
Treatment • Reassurance , usually normal vision retained
within 30 minute
Thank you for listening ….