Hi I'm dr. John Alonge I'm a practicing oral and maxillofacial surgeon and I'd
like to give you some tips to achieve successful mandibular block anesthesia
my mantra in practice as well as my teaching responsibilities and a dental
school there is no substitute for profound local anesthesia if you can't
get someone profoundly numb I consider that a complication of
treatment so there's nobody myself included that gets the inferior alveolar
nerve block a hundred percent of the time as you see on the on the slide this
is the landmark this is where we want to deposit our anesthetic Indian despite
our technique many times patients do not get profoundly known maybe here's why
and here's some tricks armamentarium typically in dental education we are
taught to use local anesthesia administration with a 27 gauge long
needle there are very few schools that teach the 25 gauge long and even others
that will only allow us to use a 30 gauge long on pediatric patients the
whole thinking on that is the needle causes more pain
Stanly moment has professed for years the patients cannot perceive the
difference between a 30 gauge 27 gauge 25 gauge long the funny cartoon from
Larson is pull out Betty pull out you hit an artery well it may be funny but
when you have an aspiration it's not and Melamed has also professed for years
that the 25 gauge diameter is the only one that we can accurately aspirate with
so that being said back to the tip start with a 25 gauge long needle for more
accuracy and less deflection next to consider is buffering of local
anesthetics it's new to dentistry but it's not new to medicine and anesthesia
the pH of local anesthetics without vasoconstrictors is approximately 6.5
the pH of local anesthetics with vasoconstrictors is between 3.5
and 3.9 very acidic when we add sodium bicarbonate to the mix it
decreases the discomfort and markedly increases the onset of action there are
two companies that have come on to the market both initiated by brilliant
dentists one uses the dental cartridge and that's the onset system
and the other is the Nutri system which has a proprietary syringe and uses a
multi-dose vial the possible downside is the increased cost per injection however
the part from local anesthesia there really should be no cost so this is a
busy slide that shows the red and the yellow articaine and lidocaine
respectively if you look at the access it on average non buffered takes 15
minutes and 45 seconds to achieve approximately 70% local anesthesia when
you buffer lidocaine in this instance at 2 minutes and 15 seconds you're already
at 85% and in a few minutes after that you plateau at about 95% that is a
game-changer now in in 1989 in the Journal of anesthesia and analgesia
raymond explained the differential nerve block stating that there's a clear
relationship between the length of the nerve the nerve exposed to the local
anesthetic and the resultant type of anesthesia that is produced they further
stated that if the length of the nerve is bathed by the anesthetic is
sufficient depolarization. depolarization will diminish over a distance until it
becomes too weak to activate sodium channels well what does this mean what
it means is why not bathe the mandibular nerve in two locations so you give the
initial inferior alveolar nerve block with lidocaine with Evacaine, artacaine
your choice and then you have these adjuncts in gal Gates's technique which
he published in 1973 it required the mandible to be maximally
opened and in the original article he used 3% mepivacaine no vasoconstrictor
low iron pH and in Australia New Zealand where he's from
that area used a 2.2 ml carbon cartridge which is what his standard down under in
1960 and then again in 1977 Vazirani and Akinosi taught the and published
the closed mouth technique with a high incidence of success I am proposing you
consider a hybrid this is a dry human skull using a 25 gauge long needle and
so anatomically you see the media poll of the condyle very close to the beveled
end of the 25 gauge long there's no bone that you contact what you do is you're
parallel and just above the mucilage interval junction of the maxillary
gingiva you take the hub as far back to the third molar area you aspirate and
then you slowly inject and the next slide is the technique it's a leap of
faith the other thing that I show that will help you facilitate this is as you
inject it as you insert the needle you apply pressure of the shaft along the
lateral maxillary wall which you helps you deflect the 25 gauge needle closer
to the medial Pole of the condyle I guarantee you'll have improved success
and happier patients