This document summarizes potential complications from local anesthetics, separating them into local and systemic complications. Locally, complications include needle breakage, paresthesia, facial nerve paralysis, trismus, soft tissue injury, hematoma, and infection. Systemically, complications are overdose, allergy, syncope, asthma, and hyperventilation. For each complication, the document discusses causes, problems, prevention, and management. Overall, it provides an overview of risks from local anesthetics and ways to minimize complications.

1. Dr.Faisal K A
Tutor
Malabar Dental College and Research Centre

2.  A number of potential complications are
associated with the administration of local
anesthetics
 For purposes of convenience , these
complications separated into those that
occur locally in the region and thosethat are
systemic

3. LOCAL COMPLICATION SYSTEMIC COMPLICATION
NEEDLE BREAKAGE OVERDOSE
PARESTHESIA ALLERGY
FACIAL NERVE PARALYSIS SYNCOPE
TRISMUS ASTHMA
SOFT- TISSUE INJURY HYPERVENTILATION
HEMATOMA
PAIN ON INJECTION
BURNING ON INJECTION
INFECTION
EDEMA
SLOUGHING OF TISSUE
POST ANAESTHETIC INTRA ORAL
LESION

4.  Needle breakage
 Paresthesia(persistant anesthesia)
 Facial nerve paralysis
 Trismus
 Soft tissue injury
 Hematoma
 Pain on injection
 Burning on injection
 Infection
 Edema
 Sloughing of tissue
 Post anesthetic intraoral lesion

5.  Porgel has estimated the risk of needle
breakage
 CAUSES:
 Weakening of dental needle by bending it
before inserting into the patients mouth
 Smaller needles are far more likely to break
than larger needles
 Needle may proven to be defective in
manufacture(exceedingly rare and unlikely
cause)
 Forceful contact with bone
 Usually seen with inferior alveolar nerve block
or posterior superior alveolar block

6.  If the needle can be retrieved without
surgical invention then no emergency exists
 Infection rarely occurs
 If exist in soft tissue there will formation of
scar tissue
NOTE: Magill intubation forceps or hemostat
used to grasp visible proximal end of needle
fragment an remove it from soft tissue

7. 1.When a needle breaks
 Remain calm ; do not panic
 Instruct patient not to move
 If fragment visible try to remove it with small
hemostat or a Magill intubation forceps
2.If needle is lost and cannot be retrieved readily
 Don’t proceed with incision or probing
 Calmly inform the patient: attempt to allay fears
 Note the incidence on patients chart
 Refer patient to oral and maxillofacial surgeon
 The fragments can be diagnosed by clinical
examination or computed and panoramic
topography

8.  Use larger gauge needles for techniques
 Do not use short needles for inferior alveolar
nerve
 Do not bend needles when inserting them to
tissue
 Do not insert the needle into tissue to its hub
 Do not redirect the needle once its inserted into
tissues
 Do not inject needle if not sure about
anatomical regions of nerve block
 Introduction of non reusable stainless steel
dental local anesthetic needle ,needle breakage
has become an extremely rare complication

9.  Paresthesia is defined as persistent
anesthesia
Or
altered sensation well beyond expected
duration of anesthesia.

10.  Trauma to nerve.
 Contamination of local anesthetic solution by
alcohol or sterilizing solution. Alcohol is
neurolytic which prolong the trauma to nerve.
 Trauma to nerve sheath causes electric shock
throughout its distribution.
 Hemorrhage into or around the neural sheath.
 Lead to self inflicted nerve injury.

11.  Be reassuring
 Examine patient in person
 Reschedule the patient for examination
every 2 months as long as sensory deficit
persists.
 Tincture of time is the prescribed medicine.
 Avoid readministration of local anesthetic
into that region

12. CAUSE
 Introduction of local anesthetic into capsule of parotid
gland
 During intra alveolar nerve block and vazirani akinosi nerve
block.
PROBLEM
 Loss of motor function of muscles of facial expression
 Unilateral parlysis of facial nerve
PREVENTION
 Do not direct needle too posteriorly during IANB
 Do not overinsert during Vazirani – Akinosi nerve block

14.  Reassure the patient
 Contact lenses should be removed untill
muscular movement occurs.
 Eye patch should be applied until the muscle
tone returns.
 Manually close the lower eyelid to lubricate
cornea.

15.  DEFINITION: prolonged tetanic spasm of jaw
muscle by which normal opening of mouth is
restricted
 Trauma to muscles or blood vessels
 Contamination of solution with alcohol or
cold sterilizing agent
 Intramuscular or supravascular injection
 Hemorrhage
 Low grade infection.

17.  Use aseptic technique
 Practice atraumatic insertion and injection
technique
 Avoid repeat injections and multiple
insertions into same area
 Use minimum effective volumes of local
anesthetic
 Use sharp sterile disposable needle

18.  Heat therapy
 Warm saline rinses
 Analgesics
 Muscle relaxants
 Physiotherapy
 Vazirani – Akinosi nerve block
 Antibiotics

19. CAUSE
 Persistence of soft tissue anesthesia than
pulpal anesthesia
PROBLEM
 Swelling & pain
PREVENTION
 Selection of local anesthetic of appropriate
duration
 Placing cotton roll between lips & teeth
 Warning the patient & parent

20.  Analgesics
 Antibiotics
 Lukewarm saline rinses
 Petroleum jelly

21. CAUSE
 Effusion of blood into extra vascular spaces
 Arterial or venous puncture
PREVENTION
 Knowledge of normal anatomy
 Modifying injection technique according to
patients anatomy
 Minimizing number of needle penetrations
into tissue
 Never use needle as a probe in tissues
 Use a short needle for PSA nerve block

23.  Careless injection technique
 Use of dull needles
 Rapid deposition of local anesthetic solution
 Use of needle with barbs

24.  Adhere to proper techniques of injection
 Use sharp needles
 Use topical anesthetic before injection
 Use sterile local anesthetic solutions
 Using solution of correct temperature
 Use of buffered local anesthetic

25. CAUSES
 Acidic pH of solution
 Rapid injection of local anesthetic solution
 Contamination of local anesthetic catridges
 Buffering to a pH of 7.4
 Slowing the speed of injection( recommended –
1.8ml/min)
 Catridges should be stored at room temperature in the
container in which it was shipped or in a container
without alchohol or other sterilizing agents

26. CAUSES
 Contamination of needle before
administration
 Improper technique in handling local
anesthetic
 Improper tissue preparation for injection
 Injecting local anesthetic agent into an area
of infection

27.  PROBLEM
 Low grade infection
 Trismus
PREVENTION
 Use sterile disposable needles
 Properly care for and handle needles
 Properly care and handle dental catridges
of local anesthetic
 Properly prepare the tissues before
penetration

28. MANAGEMENT
 Heat
 Analgesics
 antibiotics – pencillin V(250 mg-29 tablets)
 physiotherapy

29. CAUSES
 Trauma during injection
 Infection
 Allergy
 Hemorrhage
 Injection of irritating solutions
 Heriditary angioedema
 Pain
 Dysfunction
 Airway obstruction

30. Prevention
 Proper care & handle of local anesthetic
 Use of atraumatic injection technique
 Complete an adequate medical evaluation of
patient before drug administration
MANAGEMENT
 Resolves in several days
 Analgesics
 Antibiotics
 Histamine blockers

31. CAUSES
epithelial desquamation
 Application of topical anesthetic to gingival
tissue for a prolonged period
 Sensitivity of tissue to anesthetic
STERILE ABSCESS:
oSecondary to prolonged ischemia resulting
from use of anesthetic
Develops in hard palate

32. PROBLEM
 Pain
 Topical anesthetics
 Do not use overly concentrated solutions
containing vasoconstrictorGEMENT
 symptomatic

33. CAUSES
 Recurrent aphthous stomatitis or Herpes simplex
 Trauma to tissues by a needles
PROBLEM
 Acute sensitivity in the ulcerated area
prevention
 Risk of secondary infection minimal Antiviral
drugs
MANAGEMENT
 Reassure the patient
 Topical LA
 Orabase without Kenalog
 Tannic acid preparation (Zilactin