Local Complication of Local Anesthesia
1. Needle Breakage
2. Pain on injection
3. Burning on injection
4. Persistent anesthesia : paresthesia
5. Trismus
6. Hematoma
7. Infection
8. Edema
9. Sloughing of tissues
10. Lip-Chewing
11.facial nerve paralysis
12.Post anesthetic intraoral lesions
Introduction
1. Needle Breakage

Causes
Become rare 1. Sudden unexpected
due to the
movement of the pt.
introduction
as the needle
of
penetrates the muscle
disposable
or contacts
needle, but
periosteum.(esp. if
still occur..
the pt. moves
oppositely to the
needle)
2. Needles of smaller
gauge
3. Needle that have
previously bent
Problem


Prevention
No problem exists if
 Use larger gauge
the needle can be easily
needle for injection
retrieved without
25-gauge needles are
surgical intervention
appropriate for nerve
block of (inferior
Needles that break off
alveolar, mandibular,
within tissues & can't
posterior & anterior
be readily retrieved
superior alveolar&
usually enclosed by
maxillary)
scar tissue and rarely
produce infection
 Use long needle for
leaving it better than
injection
performing traumatic
Don't insert the
surgical removal
needle into tissue to
the hub(the point at
which the needle
shaft meets the hub
is the weakest point
of the needle)

Don't redirect the
needle once it is
inserted into tissues
Management



When the needle breaks:
be calm , don't panic
Instruct the pt. not to move; don't remove ur
hand from the pt's mouth and keep the mouth
opened & place the bit block if possible..
If the fragment is protruding  remove it
with cotton pliers or a small hemostat
if the needle is lost & can't be readily
retrieved:
Don't proceed with incision or probing if the
fragment invisible
Calmly inform the pt. and relieve his fears &
apprehension
Note the incident in the pt's records & inform
your insurance carrier
Refer the pt for oral surgeon consultation not
to remove the needle
When is needle breaks, consideration should
be given for it's immediate removal:
if the needle is superficial & easily located
through radiographic & clinical examination
 removal is possible by oral surgeon , so if
attempted retrieval is unsuccessful in
reasonable length of time  allow the
fragment to remain
if the needle is located in deeper tissues or if
it hard to locate  permit it to remain without
an attempt at removal.
Introduction
2. Pain on injection

Can be
prevented
through careful
adherence to the
basic rules of
atraumatic
injection
Introduction
3. Burning on injection

Burning
during
deposition of
the L.A is not
uncommon
Causes
1. Careless injection technique &
callous attitude; N.B: Palatal
injection always hurt..
2. Dull needle from multiple injections
with the same needle..
3. Rapid deposition of the solution
4. Needle with barbs; impaling the
needle on bone may produce a
''fishhook barb'' pain as the needle
withdrawn from the tissue..
Problem
Prevention
Management

Increase pt anxiety

May lead to sudden
unexpected
movement needle
breakage
1. carefully adhere to proper technique of
injection, both anatomically &
psychologically
2. Use sharp needles
3. Use topical anesthetic prior to injection
4. Use sterilized local anesthetic solutions
5. Practice slow injection of solutions
6. Be certain temperature of solution is
correct; N.B: too hot of a solution is more
uncomfortable than one which is too cold
No management
is required;
however, steps
should be taken
to prevent
recurrence with
future
injections.
Causes
1. PH of the solution
N.B: cause mild burning sensation , prepared
to be 5 and those containing vasoconstrictor
having more acidic
2. Rapid injection of the L.A solution esp. in
the denser more adherent tissue of the
palate
3. Contamination of the L.A cartilages with
sterilizing solution results when the stored
in alcohol or other sterilizing solution 
diffusion of this solution into the cartilage
4. Temperature of the solution even if it's
warm
Problem





Transient in nature
Indication of tissue
irritation
Rapidly disappears when
the L.A action develops
No residual sensitivity
after action termination
of the L.A
Greater opportunity of
the tissue damage to
develop with subsequent
postanesthatic trismus ,
edema , or paresthesia
Prevention



Management
Difficult or even impossible but
Formal therapy
with short duration & low intensity is usually not
indicated only if
Slow injection ideal rate is
there is post
1ml/min , don't exceed 1.8 ml in 1 injection
min
discomfort or
edema, or
Proper care & handling of the L.A paresthesia
cartilage :
@ room temperature
suitable container without alcohol
or any sterilizing solution
Introduction
4. Persistent anesthesia ( Paresthesia)
*Rare
*Disturbing
complication
Causes
1. Trauma to any nerve or the nerve
sheath  electrical shock &
paresthesia
2. Injection of contaminated L.A
cartilage by alcohol or sterilizing
solutions near the nerve  irritation
& edema  increase pressure on the
region  paresthesia
3. Hemorrhage into or around the neural
sheath  increase pressure on the
nerve  paresthesia
Problem


Sometimes total but
mostly partial  tissue
injury
Biting or thermal or
chemical insult can
occur without a patient's
awareness
Prevention
Management
*Proper injection
technique

*Proper care &
handling of the
dental cartilage
1.
2.
3.
4.
Most paresthesia resolves in 8 weeks
without ttt& will be permanent only
if there is severe nerve damage.
Reassure the pt
a. The dentist must talk to the pt
b. Don't relegate the duty of
reassuring
c. Explain that it's not uncommon
after injection
d. Arrange appoint 4 examining the
pt
e. Record the incident in the dental
chart
Examine the pt
a. Determine the paresthesia degree
b. Explain to the pt that paresthesia
may persist at least 2 months or
may be prolong to 1 y
c. Tincture of time is the
recommended medicine
d. Record the finding in the pt's chart
Reschedule the Pt for examination
every 2 months as long as sensory
deficit persists
Should sensory deficit still be
evidence 1 y after that consult the
surgeon or neurologist to mange
Introduction
5. Trismus


Causes
Motor
disturbance
of the
trigeminal
nerve esp.
spasm of the
masticatory
muscles with
difficulty in
opening the
mouth.
1. Trauma to muscles or
Although
post injection
pain is the
most
common L.A
complication,
trismus can
become one
of the more
chronic &
complicated
problem to
manage.
3.
2.
4.
5.
6.
blood vessels in the
infratemporal space is
(the most common
cause following the
dental injections)
Contaminated dental
cartilage by diffusion of
alcohol or any
sterilizing agent 
irritation to the muscle
 potential trismus
Hemorrhage (large
volume of blood)
tissue irritation 
muscle dysfunction as
blood is slow resorbed.
A low grade infection
Multiple needle
penetrations.
Overly large amount of
L.A solution deposited
in restricted area.
problem
In the acute phase of
trismus:
Pain produced by hemorrhage
 muscle spasm & limitation
of movements.
In the chronic phase of
trismus:
Usually develops if the ttt is not
begun.
Hypomobility can be due
to:
1. secondary to hematoma
with subsequent fibrosis &
scar contracture
2. infection through increase
tissue reaction (irritation )
& scarring
In most cases a pt will
repost pain and difficulty in
opening the mouth the day
after the dental
appointments in which
posterior superior alveolar
or inferior alveolar nerve
blocks are administered.
Prevention
1. use sharp , sterile ,
2.
3.
4.
5.
6.
7.
disposable needles
properly care for &
handle dental L.A
cartilage
Cleanse the site of
injection with an
antiseptic solution prior
to needle penetration
Use a septic technique ;
contaminated needle
should be changed
immediately
Practice atraumatic
insertion & injection
technique
Avoid repeat injections &
multiple insertions
through knowledge of
anatomy & proper
technique ( use regional
block instead of
infiltration wherever
possible & rational)
use minimal effective
volumes of L.A solutions;
refer to specific
techniques for
recommended volumes
Management

Arrange an appointment for examination.
Heat therapy:
Placing moist eat with towels to the affected area
about 20 min every hour.
Analgesics
Aspirin is usually adequate in damaging pain
associated with trismus.
Codeine (30-60 mg every 3 hours) if the discomfort is
more intense.
Muscle relaxants
Diazepam (about 10 mg every 12 hours)
 Advice the pt. t initiate physiotherapy for 5 min
every 3-4 hours by opening and closing the mouth
as well as lateral excursions & chewing
gum(sugarless)
 Record the incident, finding, ttt in the pt's dental
chart.
 Avoid any further dental ttt in the involved region
till symptoms resolves & pt is more comfortable
 7 full days Antibiotics is required if the pain and
dysfunction continued beyond 48 hours due to
possibility of infection.
 Refer the pt to oral surgeon if no improvement
within 2-3 days without antibiotics or 5-7 days
with antibiotics or severe limited mouth opening.
 TMJ involvement is quite rare in the 1st 4-6 weeks
following injection.
 Surgical intervention may be indicated in some
instance.

 It's the effusion of blood into extra vascular spaces
6. Hematoma



Causes
The inadvertent nicking
of a blood vessel, either
artery or vein during an
injection of L.A
Nicking of the artery
usually increase in size
rapidly till the ttt is
instituted
Nicking of the vein
may or may not cause
hematoma
The density y of the
tissue surrounding the
injured vessel will be a
determining factor e.g.
hematoma is rarely
developed after palatal
injection but usually
following nicking of
the B.V in posterior
superior or inferior
alveolar nerve block
coz the tissue
accumulate the blood in
these areas blood
effusion until extra
vascular pressure
exceed pressure within
the B.V
Problem
* Rarely
produce
significant
problem
1.
* Possible
complication
include
trismus &
pain
* The
swelling &
discoloration
usually
subsides
within
several days
2.
3.
4.
Prevention
Knowing the
normal anatomy
of the proposed
injection; certain
technique has a
greater risk of
hematoma like
posterior superior
alveolar nerve &
inferior alveolar
nerve in second.
Modify the
injection
technique as
indicated by the
pt's anatomy e.g.
lessen the
penetration of
posterior superior
alveolar nerve
block in pt with
smaller facial
characteristics
Minimize the
number of needle
penetrations of
tissue
Never use needle
as probe in
tissues
Management(Time is the most important element of hematoma ) it presents 7-14 days with or without ttt
Immediate :
When swelling becomes evident Direct pressure should be applied to the site of bleeding for not less
than 60 sec. against bone
 Inferior alveolar nerve block
- Pressure is applied to the medial aspect of the mandibular ramus.
Intraoral clinical manifestation which are tissue discoloration & swelling in the medial (lingual)
aspect of the mandibule ramus
 Infraorbital nerve block
- Pressure in applied to the skin directly over the infraorbital foramen.
- Extraoral clinical manifestation which is discoloration of the skin below the lower eyelid
 Mental & incisive nerve block
- Pressure is applied directly over the mental foramen, either on the skin or on the mucous membrane.
- Clinical manifestation is observed @ the skin over the mental foramen and/or by swelling in the
mucobuccal fold in the region of the mental foramen
 Buccal nerve block or any palatal injection
- Place the pressure @ the site of bleeding.
- Only intraoral clinical manifestations are visible
 Posterior superior alveolar nerve block
- Usually produce the largest & most esthetically unappealing hematoma& can accommodate large
volume of blood.
- Not recognized till the swelling appears on the side of the face progressing inferiorly & anteriorly
toward the lower anterior region of the cheek.
- Difficulty in applying pressure @ the site of the bleeding in this region (post.super.alveolar & facial
arteries & pterygoid plexus of vein)
- They r located posterior Superior & medial to the maxillary tuberosity
- Bleeding normally halts when external pressure of blood exceed the internal one.
- Digital pressure can be applied to the soft tissues in the mucobuccal fold as far as it can be tolerated by
the pt. without gagging.
- Apply pressure in a medial & superior direction .
Subsequent:
* Avoid any additional dental therapy in hematoma region till the sign & symptoms relived.
* Advice the pt about possible trismus ttt as previously mentioned_ Discoloration resorbed over 714 days_ soreness ttt by analgesic e.g. aspirin, no heat application at least 4-6 hr. till the next day by
warm towels 20 min every hr., Ice is applied immediately (analgesic & vasoconstrictor)
* become extremely rare since the introduction of sterile, disposable
needles.
7. Infection
Intro
Causes
1. The major cause is the
contamination of the needle
prior to administration of the
L.A. & it's always occurring
when the needle touches the
mucous membrane in the
oral cavity.
2. Improper technique in the
handling of the L.A
armamentarium & improper
tissue preparation for
injection.

Problem
Prevention
Contaminated needle of 1. Use disposable syringe
solution may lead to
low grade infection
2. Properly care for & handle
when there is in deeper
needles:
tissue  trismus =>
- Recap the needle when not in
initiation of proper ttt
use to avoid contamination
through contact with non sterile
surfaces.
- Avoid multiple injections with
the same needle.
3. Properly care for 7 handle of the
-
dental cartilage of L.A solution.
single use only
store aseptically in original
container , covered at all times
Cleanse the diaphragm with
sterile, disposable alcohol wipes.





4. Properly prepare the tissues prior
to penetration; dry the tissue &
apply topical anesthesia.


Management
Low grade infection (rare) will
seldom be recognized immediately &
the pain will report post injection pain
& dysfunction one or more days
following the dental therapy
Rarely will be overt signs & symptoms
of infection present.
Immediate ttt should consist procedures
for trismus management (heat, analgesic
& if needed muscle relaxant &
physiotherapy
Trismus produced by factors other than
infection will normally respond with a
lessening of signs & symptoms within
1-3 days , but if trismus signs &
symptoms don't respond to the
conservative therapy so a 7 day course
antibiotic is started.
Prescribe 29 tablets of penicillin V250
mg tablets; the pt. takes 500 mg
immediately then 250 mg four times a
day until they are gone.
Erythromycin for allergic pt. to
penicillin
Report the progress & management of
the patient on the dental chart.
Causes
8. Edema
* Edema is the swelling of tissues.
* Edema isn't a clinical syndrome but represents a clinical sign of some
disorder.
1. Trauma during
Problem
1. Airway obstruction
injection
2. Infection
3. Allergy
Angioedema is a
common reaction to topical
anesthesia in an allergic pt.
Localized tissue
swelling occurs due to
vasodilatation secondary to
histamine release
4. Hemorrhage; effusion
of blood into soft
tissues  swelling
5. Injection of irritating
solution (alcohol or
cold sterilizing solution
–containing cartilage)
Prevention
2. Pain & dysfunction of
the region & personal
embarrassment for the pt.
3. Angioedema swelling in
allergic responded pt. 
lead to compromised
airway
4. Edema of the tongue,
pharynx, and larynx may
develop  life- threatening
situation need vigorous
management.
Management
-
1. Properly care for & handle the L.A armamentarium.
2. Use atraumatic injection technique.
3. Complete an adequate medical examination of the pt. prior to drug
administration.
Intro
-
-
-
Management is predicated to reduce the swelling as quickly as
possible.
Edema due to traumatic injection or introduction of irritating solution
 have a minimal degree of edema & resolved within 1-3 days
It's necessarily to prescribe analgesics for pain due to edema
Follow the management of hematoma if the edema is followed by
hemorrhage & it will resolved within 7-14 days
Edema produce by infection will not resolved spontaneously but may
be become progressively more intense. if the sign of infection ( pain,
mandibular dysfunction , edema) don't appear to resolved within 3
days  Antibiotic therapy as mentioned in the infection ttt
Edema produce by allergy is the most potentially life threatening. The
degree of the edema & its location is highly significant. If the swelling
is develops in the buccal soft tissue & there is no airway obstruction
 ttt is I.M & oral antihistamine administration & a medical
consultation to an allergist to determine the precise cause of the
edema.
When edema compromised breathing :
1. Epinephrine 0.3 mg IM or IV
2. Antihistamine IM or IV
3. Corticosteroid IM or IV
4. medical assistance summoned
5. pt. positioned supine position if unconscious
6. Basic cardiac life support
7. preparation of cricothyrotomy if total airway obstruction
develops
8. Through evaluation of the patient prior to next appointment to
determine the cause of the reaction.
Problem
Epithelial desquamation :
1. Application of topical anesthesia agents to the
gingival tissues for a long period of time
2. heightened sensitivity of tissues to chemical
agents ( L.A)
3. Reaction in area where the topical anesthetic
is applied.
Sterile abscess:
1. secondary to prolonged ischemia resulting
from the use of L.A with vasoconstrictors
2. Almost always occurs in the firm soft tissue
of the hard palate.
Prevention
1. use topical anesthesia as
2. Possibility of infection developing in these area
Causes
1. Pain
Prolonged irritation to the gingival soft tissue may lead to  number of
unpleasant complications including epithelial desquamation & sterile
abscess.
9. Sloughing of tissues
Intro
Management
-
Usually no formal
management is required for
both epithelia d desquamation
or sterile abscess.
-
Management may be
symptomatic
-
For pain  analgesic (aspirin
, codeine 7 a topically applied
ointment such as Orabase to
minimize the irritation of the
tissue .
-
Epithelial desquamation will
resolved within few days.
-
Sterile abscess run for 7-10
days
-
Record dada in the pt's chart .
recommended ; Allow the solution
to contact mucous membrane for 1-2
min to maximize its effectiveness &
to minimize toxicity.
2. When using vasoconstrictors for
homeostasis  don't employ overly
concentrated solutions
- Epinephrine 1:50,000
- Levophed (nor epinephrine)
1:30,000
Are the 2 agents most likely to produce
ischemia of a long enough duration to
produce tissue damage & a sterile
abscess.
N.B: the palatal tissues are virtually the
only tissues in the oral cavity where this
phenomenon might occur.
10. Lip-Chewing
* Trauma of the lips & tongue
of the anesthetized pt. is
frequently caused by the pt.
inadvertently biting or
chewing these structures.
* Trauma occurs most
frequently in children &
mentally handicapped
children & adult.
Causes
The primary cause is the use of long acting L.A in pt. undergoing
shorter dental procedures.
Intro
Problem
Prevention
 Swelling & pain
when the anesthetic
action dissipate.
- Selection of proper
duration of L.A action
depends on the duration
of the dental procedures.
- A cotton roll can be
placed between the lips
pf the pt. if they are still
anesthetized @ the time
of discharge.
- Warn the pt. & adult
guardian against eating
while still anesthetized,
against drinking hot
fluids, and against biting
on the lips & tongue to
test for anesthesia.
- A self-adherent warning
sticker is available that
states "Watch me, my lip
& cheek are numb"
placing in the pt's
forehead.
 Behavior
management
problems in the
young child or
handicapped
individual copying
difficulty with this
situation
Management (is
symptomatic)
1. Analgesic for
pain.
2. Antibiotics, in the
unlikely situation
that infection
results.
3. Lukewarm saline
rinses to aid in
decreasing any
swelling that may
be present.
4. Petroleum jelly
or other lubricant
to cover the
lesion (on the
lips) to minimize
irritation.
11. facial nerve paralysis
1.
2.
3.
4.
Introduction
The facial nerve is the 7th cranial
verve which is a motor nerve to
the muscle of facial expression,
scalp & external ear & others.
Occasionally it can anesthetized
by the inadvertent deposition of
L.A into its vicinity, always occur
when the solution introduce in the
deep lobe of the parotid gland.
The nerves supplied by these
branches & the muscles they
innervate are listed:
Temporal branches
- frontalis muscles
- Orbicularis oculi muscle
- Corrugator muscle
Zygomatic branches
- Orbicularis oculi muscle
Buccal branches(supply region
inferior to orbit & around the
mouth)
- Procerus muscle
- Zygomatic muscle
- Levator labii superioris muscle
- Buccinator muscle
- Orbicularis oris muscle
Mandibular branch (supplies
muscles of lower lip & chin)
Causes
* Transient facial nerve
paralysis is commonly
caused by the
introduction of L.A
solution into the capsule
of the parotid gland ,
which is located @ the
posterior border of the
ramus of the mandible ,
clothed by the medial
pterygoid & masseter
muscles.
* Directing of the needle
toward or its inadvertent
deflection in a posterior
direction during an
inferior alveolar nerve
block may place the
needle tip within the
substance of the parotid
gland paralysis may
result.
-
-
-
-
-
Problem
Loss of facial expression
muscles function will last
from 1-several hours depending
o the L.A agent, volume
injected, & its proximity to the
facial nerve.
The primary
problemUnilateral paralysis
during this time with inability to
use theses muscle normally
(cosmetic appearance problem )
No ttt except waiting till the
action wears off
The secondary problem  the
pt. unable to close the eye,
winking & blinking become
impossible to perform.
The cornea retains to its
innervation so if irritated
corneal reflex & the pt. will be
able to lubricate the eye during
this period of time.
With sec. – min following
deposition of L.A  the pt. will
sense a weakening of the muscle
of the affected side of the face.



Prevention
Adherence to
proper
technique in the
inferior alveolar
nerve block.
If the needle tip
in contact with
bone (medial
aspect of
ramus) prior to
L.A deposition
 preclude the
possibility of
the deposition
of solution in
the parotid
gland.
If the needle
deflects
posteriorly 
should be
entirely
withdrawn &
direct it more
anteriorly till it
contacts bone.
Management
1. Reassure the pt.
2. Advice the pt. to
periodically close the
upper eyelid
manually to keep the
cornea lubricated.
3. Contact lenses should
be removed until
muscular movement
returns.
4. Record the incident
in the pt.'s chart.
5. Although there is no
contraindication for
re anesthetized the
pt.to achieve
mandibular
anesthesia, it may be
prudent to forego
further dental therapy
@ this appointment.
Causes
* Pt. might report painful ulceration of the mouth following 2
days of dental injection.
12. Post anesthetic Intraoral Lesions

Recurrent apthous stomatitis &/or herpes
simplex can develop intraorally following
L.A injection or any traumatic insult
Recurrent aphthous stomatitis is the
most frequently observed intraorally in the
movable gingival tissue (not attached to the
bone) e.g. buccal vestibule) not viral infection
but it might be autoimmune process or L-form
bacterial infection.
Herpes Simplex can develop intraorally
but it's most commonly extra orally on the
fixed tissue (not attached to the bone)

Trauma to tissues by needle, L.A , cotton
swab, or any other instrument (R.D clasp ,
hand piece )  reactivate the latent form of
the disease process that has been present in
the tissue prior to the injection.
Problem
 Acute sensitivity in the ulcerated area.
 Developing of secondary infection risk is low.
Intro
Prevention
Management
- In the intraoral lesions No
 Primary management is symptomatic:
- Pain  approximately 2 days after injection
- If not severe no management
- If the pt. complain from pain:
1. keep the ulcerated area covered
2. topical anesthetic solution (viscous
lidocaine) can be applied to the painful
area
3. A mixture of equal amount of diphenhy
dramine & milk magnesia rinsed in the
mouth  effectively coat the ulcerated
area & provide relief of the pain .
4. Orabase , a protective paste without
Kenalog  provide degree of pain relief
.N.B: Kenalog is corticosteroid not
recommended because it's antiinflammatory action provide increase risk
of either viral or bacterial involvement.
5. Ulceration duration about 10 days with or
without ttt
6. Negatol chemical cauterizing agent for
pain relief
7. Keep adequate records in the pt's chart.
mean of prevention in the
susceptible pt.
- Extra oral herpes simplex
can be prevented or
minimizing its manifestation
if it's in its prodromal phase
- Prodrome consists of mild
burning or itching sensation
@ the site where the virus is
present (lip)
- Either applied topically by
cotton swab 3-4 times daily
 minimizes the acute phase
only extra orally.
Best of Luck
Strawberry