Download sheet #6 / Dr.Sukaina / Farah Alhares

19/10
LA sheet #6
Farah Al-Hares
Administration of local anesthesia in Maxilla
Most of the techniques in maxilla based on infiltration rather than
nerve block because the bone in maxilla is soft (almost cancellous
bone) that allows infiltration and the roots of maxillary teeth are
separated from the soft tissues on the buccal aspect by bone that
has fine cortical plate (while in mandible it is thick dense cortical
plate) so the thin buccal cortical plate doesn’t represent a barrier
againt LA diffusion.
The objective of local anesthesia infiltration is to deposit the LA
solution close to the pulpal nerve supply as it enters the apex of
the root.
The patient is rclined at 30 degrees to the vertical,,the operator
stands or sits at the right side of the patient when giving LA for
the maxilla. We always stand and the only exception is when the
operator’s length is 190 cm or more .
**note : the sitting positions in the book is not included for the
first exam.
The patient initially opens his mouth widely to allow the operator
to insert his thumb finger of the non-dominat hand into the
buccal sulcus ,,when we give LA we don’t use the mirror ,we
depend on the non-dominant hand.
Throught the injection , the mouth is only half-opened.
The methods are described for retraction: by holding the tissues
between the thumb and index and by using the middle finger
Page 1
19/10
LA sheet #6
Farah Al-Hares
alone this leaves the index finger and the thumb free to act as a
rest for the syringe.
The needle used is short..lips and cheeks are retracted upward
and outward to reveal the sulcus ,,to stretch the mucosa which is
to be pierced by the needle ( we should stretch the mucosa in
order to decrease pain >> the penetration of the needle will be
less painful )
Needles should be always inserted through taut tissues ‫ مشدودة‬not
loose.
Small balls of tissues similar to frenae should be avoided , it will
be highly painful because frenum is a fibrous tissue.
We should avoid areas of inflammation (this is the main
contraindication for infiltration) because these areas are acidic
and so anesthesia will never work and you will disseminate the
infection so in this case we go for block anesthesia.
Nerve block anesthesia is more common in mandible ,, but there
are also techniques for nerve block in maxilla.
Most common needle is 30 gauge needle , narrow , used for
maxillary buccal infiltration anesthesia .
The point of penetration of the needle is high in the sulcus
because the roots are long in maxillary jaw , this allows the
deposition of solution into the loose submucosal tissue in the
upper anterior region.
Page 2
19/10
LA sheet #6
Farah Al-Hares
The needle is advanced to the apex by aligning the syringe
parallel to the long axis of the tooth in the mesiodistal plane (but
still we can do inclination of the needle).
**The needle is angled toword the apex in the labioplatal plane
(the picture) ↓↓
The point of needle entry to be dried with gauze and topical
anesthesia is applied with a cotton bud.
The needle is inserted through mucosa to a depth of few
millimeters , aspiration (although aspiration is not usually used
with infiltration) , if touched the bone to be withdrawn a little to
avoid the subperiosteom.
When giving the local anesthesia we should give it slowly(about
20 sec) .
When bleeding on the site of injection happens ,we pressure with
gauze, wait 2-3 min then proceed. Bleeding may occur because
when giving LA we enter blood vessels.
We should avoid areas of inflammation and ulcerations .
Page 3
19/10
LA sheet #6
Farah Al-Hares
Basically when we give infiltration in the upper jaw BUCCALY , we
give anesthesia for 3 nerves : posterior superior alveolar nerve ,
middle superior alveolar nerve and anterior superior alveolar
nerve . while for palatal infiltration , we give anesthesia for :
nasopalaine nerve ( from canine to canine) and greater palatine
nerve posteriorly.
To give LA palataly, the needle should be short because if we use
long one , deflection of the needle will occur .
We have two ways to give palatal anesthesia: fisrt method >> we
go 5 mm away from the free gingival margin toward the palate for
any tooth and give the LA . the second method >> we draw two
imaginary lines ; the first line crossing the vault of the palate , and
the second one along the free gingival margin and crossing the
first line ..then I go perpendicular on the bisecting line. [except for
the third molar]
Anesthesia of the pulp of the tooth of interest and pulps of the
adjacent teeth will be anesthetized because of the decussation of
the fibers.
What are the structures that will be anesthetized (numbness)
when we give LA buccaly ? Buccal gingival , buccal peridontium ,
buccal mucosa and part of the cheek ,,palatal gingival will not be
anesthetized so we do palatal anesthesia. Palatal injection is very
important for surgery.
Palatal injection techniques :
Greater palatine nerve block : greater palatine supplies the
palatal mucosa from the molars region to the canine ..the
Page 4
19/10
LA sheet #6
Farah Al-Hares
anesthesia of this nerve is done by block or infiltration techniques
; if it is infiltration it’s done by injecting the needle 5 mm away
from the free gingival margin ,however for nerve block we go to
the canal that the nerve comes out from (greater palatine canal)
and give the LA there,, this is very difficult and its rarely used .
The greater palatine foramen is found palataly to the distal aspect
of upper second molar . the needle is inserted few millimeters ,
aspiration is performed , very little aneshthesia (0.2 ml is needed
to obtain greater palatine nerve block).
** note : always the amount of anesthesia used for nerve block is
much less than that used for infiltration.
More pressure is needed to inject at this site , when blanching is
seen to radiate from the needle , the injection can stop.>> when
we give palatal injection we see blanching because the
mucoperiosteom is adherent to the underling bone ,, once the
blanching stops don’t proceed more because if we proceed ,
necrosis or sloughing (especially in patients who have pemphigus )
to the palatal tissue may occur .
The injection anesthetizes soft tissues , the hard palate
When we block maxillary nerve , both right and left sides will be
anesthetized.
Some fibers from nasopalatine may encroach upon the canine
area ( the canine area may be a decussating area ) so when we
want to anesthetize the central incisor , we five LA for both sides
right and left due to decussation
Page 5
19/10
LA sheet #6
Farah Al-Hares
This applies also on the lower jaw as well,, due to encroachment
in the midline of the other side nerve fibers.
When operating on one tooth , the aspiration of few drops of
solution half way between the midline of the palate and free
palatal free gingival margin distal to the tooth of interest
(remember the two imaginary lines) except in one case which is
the upper third molar where infiltration must be performed
toward the mesial aspect of the tooth because giving the LA
distally will enhance the gag reflux.
Nasopalatine nerve anesthesia : either by infiltration ,or nerve
block ( we search for the canal).
The mouth is widely opened ,,the neck is extended..topical
anesthesia on a cotton bud may be applied with pressure on the
incisive papilla .
The needle is inserted at one side of the papilla to a few
millimeters , aspiration injection 0.2 ml is enough .
Infiltration of few drops palatal to the lateral incisor or canine
may be used instead of nasopalatine nerve block if one tooth to
be removed .
As we know , the injection through the incisive papilla is very
painful , so sometimes we inject few drops of anesthesia around ,
then we enter to negotiate the canal.
The nasopalatine block technique anesthetizes the soft tissues
and bone of the anterior hard palate adjacent to the six anterior
teeth .
Page 6
19/10
LA sheet #6
Farah Al-Hares
>>as we said Some fibers of the greater palatine nerve in the
canine region may provide accessory supply.
Palatal papillary injection technique : it’s done through the buccal
papillae between teeth ,,the aim of this technique is to
anesthetize the palatal gingival margin by an approach through
the buccal papillae recently anesthetized (buccal papillae was
anesthetized by infiltration directly as we said earlier) .
extra-short needle is introduced through the distobuccal papilla
at right angle then injection begins.
The needle is advanced through the interdental space toward the
palatal papillae while still injecting ,,the same is repeated in the
mesiobuccal and distobuccal anesthesia .
We said earlier that there are three main buccal nerves in the
maxilla : anterior superior alveolar nerve , middle superior
alveolar nerve and posterior superior alveolar nerve .
Anterior superior alveolar nerve block ( also called infra-orbital
nerve block) : the soft tissues are retracted with the nondominant hand , the index finger palpates the infra-orbital
foramen extra-orally..then we try to find the point where this
nerve enters the oral cavity (intra-orally) from the end of the
infra-orbital foramen.>> the needle (we use long needle 35 mm)
pierces the height of buccal sulcus between the first and second
premolars , the needle is advanced superiorly parallel to the
premolar roots to avoid premature contact with the bone. We
should take the shape , size and dimensions of the face into
consideration in order to estimate how far you should enter the
Page 7
19/10
LA sheet #6
Farah Al-Hares
needle. Advancement continues until bone contact (we enter 16
mm approximately) then we aspirate and give slowly half of the
carbol.
*In the past , they used to block this nerve extra-orally by injecting
at the site of infra-orbital foramen through the skin directly.
Infra-orbital nerve block also serves to anesthetize anterior
superior alveolar nerve on one side , this nerve leaves the infraorbital about 5 mm before , supplies the pulps of maxillary
anterior teeth , the upper lip ,side of the nose and the lower eye
lid.. all these areas will be numb.
The extent : pulps of maxillary incisors , canines and premolars
will be also anesthetized when the middle superior alveolar nerve
is absent. Mucosa and skin of the upper lip to the midline , skin
mucosa ,anterior part of the cheek , lower eye lid and lateral
aspect of the nose.
** the middle superior alveolar nerve is absent in most cases
(present only in 28% of the population)
Insert the needle into the height of muccobuccal fold above the
second premolar ,, penetrate the mucosa , aspirate and then
inject slowly .
The extent : pulps of maxillary premolars , mesiobuccal pulp of
maxillary first molar , buccal bone gingiva and peridontium
Page 8
19/10
LA sheet #6
Page 9
Farah Al-Hares