trigminal nerve v3 slides
TRANSCRIPT
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Alex Forrest
Associate Professor of Forensic OdontologyForensic Science Research & Innovation Centre, Griffith University
Consultant Forensic Odontologist,
Queensland Health Forensic and Scientific Services,
39 Kessels Rd, Coopers Plains, Queensland, Australia 4108
Oral Biology
Trigeminal Nerve: V3Trigeminal Nerve: V3
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Do not remove this notice.
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Mandibular Division V3Mandibular Division V3
Recall the area
supplied with
sensory innervation
by the mandibular
division of the
trigeminal nerve
(V3).
Grays Anatomy, Longmans, London,
38th Ed 1989 p. 1106
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The mandibulardivision of the
trigeminal nerve,
often known simply
as the mandibularnerve, contains both
sensory fibres and
motor fibres.
Modified from: Evers, H & Haegerstam, G.
Introduction to Local Anaesthesia, Mediglobe SA,
Fribourg, 2nd Edition 1990. P. 60
Mandibular Division V3Mandibular Division V3
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The sensory portion of
the mandibular nerve
passes into thetrigeminal ganglion and
from there to the
brainstem along with
the sensory fibres fromV2 and V1.
Modified from Grays Anatomy, Longmans, London, 38th Ed 1989p. 1107
Mandibular Division V3Mandibular Division V3
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Modified from Grays Anatomy, Longmans, London, 38th Ed 1989p. 1107
The somatic motornerve fibres leave the
pons in a separate
motor root, which joins
the main trunk of themandibular nerve just
after it exits the
cranium throughforamen ovale in the
greater wing of the
sphenoid bone.
Mandibular Division V3Mandibular Division V3
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Here it forms a common
trunk for a very short
distance, before givingoff its first branch.
Modified from: Evers, H & Haegerstam, G.
Introduction to Local Anaesthesia,
Mediglobe SA, Fribourg, 2nd
Edition, 1990.P. 60
Mandibular Division V3
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This is a small twig
containing sensory fibres,
and it dives back into the
cranium with the middle
meningeal artery through
foramen spinosum of thesphenoid bone to supply
most of the dura mater
with sensation. It is known
as the recurrentmeningeal nerve, or
nervus spinosus.
Modified from Grays Anatomy, Longmans, London, 38th
Ed1989 p. 1105
Mandibular Division V3
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The common nervetrunk now gives off
small muscular
branches containing
motor fibres to thetensor palati and
tensor tympani
muscles, and the
medial pterygoid
muscle.
Modified from Grays Anatomy, Longmans, London, 38th Ed 1989
p. 1105
Mandibular Division V3
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It also acquires smallcommunicating
branches from the
otic ganglion, a
parasympatheticmotor ganglion which
lies deep to it in the
infratemporal fossa.
Modified from Grays Anatomy, Longmans, London, 38th Ed 1989
p. 1105
Mandibular Division V3
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The nerve now divides into a larger posterior division and a
smaller anterior division. A general (and inaccurate) rule:
The posterior division is entirely composed of sensorybranches except for one motor one.
The anterior division comprises entirely motor branches
except for one sensory one.
Mandibular Division V3
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Posterior DivisionPosterior Division
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Posterior DivisionPosterior Division
The branches of the posterior division of the
mandibular nerve are:
Auriculotemporal nerve (sensory)
Inferior dental nerve (sensory)
Lingual nerve (sensory)
Nerve to mylohyoid and anterior belly of digastric (motor)
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Auriculotemporal NerveAuriculotemporal Nerve
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Auriculotemporal NerveAuriculotemporal Nerve
The auriculotemporalnerve or nerves are
important because it is
the sensory nerve to
the TMJ and carries
secretomotor fibres
from the otic ganglion
to the parotid gland.
Modified from Grays Anatomy, Longmans, London, 38th Ed 1989p. 1105
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It leaves the main trunk of
the mandibular nerveshortly after the motor root
attaches to it, and passes
posteriorly towards the
middle meningeal artery.
It splits into two, the two
branches pass around the
middle meningeal arteryand circle it, and then they
join up again to form a
single branch.Modified from Grays Anatomy, Longmans, London, 38th Ed 1989
p. 1105
Auriculotemporal NerveAuriculotemporal Nerve
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Modified from Grays Anatomy, Longmans, London, 38th Ed 1989
p. 1105
Auriculotemporal NerveAuriculotemporal Nerve
It continues to runposteriorly, lying on the
tensor palati muscle,
and reaches the deep
aspect of the neck of themandible past which it
runs, between the bone
and the
sphenomandibularligament.
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Modified from Grays Anatomy, Longmans, London, 38th Ed 1989
p. 1105
Auriculotemporal NerveAuriculotemporal Nerve
It then curves around
behind the
temporomandibular jointwhich it supplies with
sensory fibres and runs
into the parotid salivary
gland.
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It gives off sensory and parasympathetic secretomotor fibres
acquired from the otic ganglion to the gland, and then curves
to run superiorly in the gland, and terminates in the superiortemporal branches, which supply common sensation to the
skin and underlying structures in the posterior temple area and
the side of the scalp.
Auriculotemporal NerveAuriculotemporal Nerve
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Inferior Dental NerveInferior Dental Nerve
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Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd
Edition,1990. P. 60
Inferior Dental NerveInferior Dental Nerve
The inferior dental nerve, also
known as the inferior alveolarnerve, is of great importance
because it provides the
sensory nerve supply to the
pulps of the lower teeth.
To do so, it must enter the
body of the mandible.
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It does this by passing through the
mandibular foramen on the internal
surface of the mandibular ramus,
and running in the inferior dental
canal.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd
Edition,1990. P. 60
Inferior Dental NerveInferior Dental Nerve
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Initially, the nerve lies in the mandibular canal as a single trunk,
but soon divides into numerous smaller branches which form a
plexus within the body of the mandible.
Inferior Dental NerveInferior Dental Nerve
From Shigeru Tajiri, An Atlas of Anatomy of the Head and Neck, Aproman 1998
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J.M. Sanchis, Miguel Penarrocha, and F. Soler, Bifid
Mandibular Canal. J Oral Maxillofac Surg 61:422-424, 2003
Purpose: To determine the incidence and characteristics of bifidmandibular canals.
Methods:A retrospective study was performed using panoramicradiographs of 2012 patients subjected to dental treatment in the Dental
Clinic of the Valencia University Dental School (Valencia, Spain) between1996 and 1999. The goal was to investigate the presence of double
mandibular canals.
Results: The extraoral panoramic radiographs revealed a total of 7 imagessuggestive of bifid canals. Mandibular computed tomography revealed the
existence of this anatomic variant in 2 of 3 patients. An analysis wasperformed on the incidence of this type of image in extraoral panoramic
radiography, itspossible interpretations, and the clinical implications of bifid mandibular
canals.
Conclusions: In this study, 0.35% of canals were bifid. All cases were in
women.
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The nerve suppliesthe pulps of the lower
teeth and their
periodontal
ligaments, the
mandibular bone, and
the labial gingivae
and buccal gingivaeback about as far as
the second premolar.
Inferior Dental NerveInferior Dental Nerve
Evers, H & Haegerstam, G. Introduction to Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition, 1990. P. 85
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While in the body of the
mandible, the nervesplits into two branches.
Grays Anatomy, Longmans, London, 38th Ed 1989 p. 1101
Inferior Dental NerveInferior Dental Nerve
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One of these continues
forwards in the body of
the mandible to supplylabial gingivae and
pulps of the lower
anterior teeth, and it is
known as the incisivenerve, or more
correctly, the incisive
plexus, because it hasceased to be a single
nerve trunk by this
stage.
Grays Anatomy, Longmans, London, 38th Ed 1989 p. 1101
Inferior Dental NerveInferior Dental Nerve
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The other exits the
mandible through asmall backwards-
directed foramen in the
external surface of the
body of the mandible
called the mental
foramen, usually found
between the roots of thelower first and second
permanent premolar
teeth.
Inferior Dental NerveInferior Dental Nerve
Grays Anatomy, Longmans, London, 38th Ed 1989 p. 1101
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This branch is called the
mental nerve, and it
supplies commonsensation to the lower
lip and the front of the
chin.
Inferior Dental NerveInferior Dental Nerve
Grays Anatomy, Longmans, London, 38th Ed 1989 p. 1101
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Nerve to the MylohyoidNerve to the Mylohyoid
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Nerve to the MylohyoidNerve to the Mylohyoid
The nerve to the mylohyoid
muscle and anterior belly of the
digastric branches off from theinferior dental nerve just before
it passes into the mandibular
foramen.
It is the only motor branch of
the posterior division, which is
why it supplies muscles instead
of other tissues.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
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Frommer and colleagues,however, showed that
histologically, the mylohyoid
nerve contains both sensory
and motor nerve fibres.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
Frommer, J, Mele, FA, & Monroe, CW. 1972.
The possible role of the mylohyoid nerve in
mandibular posterior tooth sensation. J.
American Dental Assoc. 85, 113-117.
Nerve to the MylohyoidNerve to the Mylohyoid
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Other studies have shown that
it may pass through small
lingual foramina in the mandible
with varying frequency in the
anterior and premolar regions.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,1990. P. 60
(Madeira, MC, Percinoto, C, & Silva, M. 1978.
Clinical significance of supplementaryinnervation of the lower incisor teeth: a
dissection study of the mylohyoid nerve. Oral
Surg. 46: 608-614.
Wilson, S, Johns, P, & Fuller, PM. 1984. The
inferior and mylohyoid nerves: an anatomicstudy and relationship to local anaesthesia of
the lower anterior teeth. J American Dental
Assoc. 108: 350-352).
Nerve to the MylohyoidNerve to the Mylohyoid
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If the nerve branches from the
main trunk of V3 high enough in
the infratemporal fossa to avoid
being bathed in anaesthetic
solution, then such patientsmay show signs of successful
anaesthesia and still show
sensitivity when dental
procedures are undertaken.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
Nerve to the MylohyoidNerve to the Mylohyoid
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Bennett and Townsend have
shown that the mean height of
the nerve branch in their seriesof 6 dissections was 13.4 mm
with a maximum height of 20.7
mm, high enough in some
cases to avoid anaesthesia witha conventional block.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
(Bennett S and Townsend G. Distribution of the
mylohyoid nerve: anatomical variability andclinical implications. [online].Aust Endod J,
2001 Dec; 27 (3): 109-11).
Nerve to the MylohyoidNerve to the Mylohyoid
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This would seem to suggest a
possible accessory nerve
supply for anterior and premolar
mandibular teeth.
Additional anaesthesia of the
mylohyoid nerve can be
obtained with a lingualinfiltration injection in the
premolar region.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
(Bennett S and Townsend G. Distribution of the
mylohyoid nerve: anatomical variability and
clinical implications. [online].Aust Endod J,
2001 Dec; 27 (3): 109-11).
Nerve to the MylohyoidNerve to the Mylohyoid
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Indeed, Sillanpaa and
colleagues anaesthetized the
mylohyoid nerves of volunteerdental students and in 21%
reported obtaining partial
anaesthesia of the lower teeth,
including the first mandibular
molar.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
(Sillanpaa M, Vuori V & Lehtinen R. The
mylohyoid nerve and mandibular anaesthesia.Int J Oral Maxillofac Surg. 1988 Jun; 17(3): 206-
207).
Nerve to the MylohyoidNerve to the Mylohyoid
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A specific cutaneous sensory
branch of this nerve supplying
an area of the chin has recently
been recognized.
Modified from: Evers, H & Haegerstam, G. Introduction to
Local Anaesthesia, Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 60
(Hwang K, Han JY, Chung IH & Hwang SH.
Cutaneous sensory branch of the mylohyoid
nerve. J Craniofac Surg. 2005 May; 16(3): 343-345 (Discussion 346)).
Nerve to the MylohyoidNerve to the Mylohyoid
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Lingual NerveLingual Nerve
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Lingual NerveLingual Nerve
The lingual nerve leaves the
anterior aspect of the main
trunk of the posterior division
well above the mandibular
canal, and runs parallel to the
inferior dental nerve for aconsiderable distance.
It often goes numb when the
inferior dental nerve isanaesthetized.
Modified from: Evers, H & Haegerstam, G.
Introduction to Local Anaesthesia, Mediglobe
SA, Fribourg, 2nd Edition, 1990. P. 60
Li l NLi l N
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Lingual NerveLingual Nerve
Modified from: Evers, H & Haegerstam, G.
Introduction to Local Anaesthesia, Mediglobe
SA, Fribourg, 2nd Edition, 1990. P. 60
It comes to lie a little deeper
than the inferior dental nerve
though, and does not runinto the mandible.
Li l NLi l N
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Lingual NerveLingual Nerve
Instead, it curves gently above the mylohyoid muscle, passingbetween the body of the mandible and the duct of the
submandibular gland to pass beneath the duct, rising again
medially to terminate in the substance of the anterior part of the
tongue.
Netter, F.
1989,
Atlas of
Human
Anatomy,
Summit,
New
Jersey,
Ciba-
GeigyMedical,
Plate 53.
Li l NLi l N
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The lingual nerve is the
major sensory nerve of
the anterior two-thirds of
the tongue, and thereforealso carries the special
sensation of taste, as well
as common sensation.
Lingual NerveLingual Nerve
Modified from: Evers, H & Haegerstam, G.
Introduction to Local Anaesthesia, Mediglobe
SA, Fribourg, 2nd Edition, 1990. P. 60
Lingual NerveLingual Nerve
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It also supplies common
sensation to the tissues ofthe floor of the mouth, and
to the lingual gingival
tissues.
It must therefore be
anaesthetized if extraction
of a lower tooth is required.
Lingual NerveLingual Nerve
Modified from: Evers, H & Haegerstam, G.
Introduction to Local Anaesthesia, Mediglobe
SA, Fribourg, 2nd Edition, 1990. P. 60
Lingual NerveLingual Nerve
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It is commonlyanaesthetized along
with the inferior dental
nerve during the
inferior dental nerve
block.
Modified from: Haglund, J. & Evers, H Local
Anaesthesia in Dentistry, Astra Lkemedel
Sdertlje, 2nd Edition, 1975. p. 52.
Lingual NerveLingual Nerve
Lingual NerveLingual Nerve
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Grays Anatomy, Longmans, London, 38th
Ed 1989 p. 1101
Lingual NerveLingual Nerve
During its path as it
descends towards the
mylohyoid, it picks up asmall branch called the
chorda tympani, which
carries secretomotor
parasympathetic fibres
which it distributes to the
submandibular and
sublingual salivary glands,as well as to minor salivary
glands in the floor of the
mouth.
Lingual NerveLingual Nerve
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These are preganglionic
fibres initially, and they
synapse in the
submandibular ganglion
which is located just inferior
to the lingual nerve close to
the submandibular gland.
The postganglionic fibres
pass to the submandibular
gland and some hook a ridewith the continuing lingual
nerve to reach the
sublingual gland.
Lingual NerveLingual Nerve
Grays Anatomy, Longmans, London, 38th
Ed 1989 p. 1101
Accessory Nerve SuppliesAccessory Nerve Supplies
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The lingual nerve can often provide accessory innervation to
anterior teeth, as can small branches from the ascending
branch of the transverse cutaneous nerve of the neck.
Depositing a small amount of anaesthetic lingually (with
aspiration to avoid intravascular injection) will often solve the
problem.
Accessory Nerve SuppliesAccessory Nerve Supplies
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McGeachie JK. Anatomy of the lingual nerve in relation topossible damage during clinical procedures. Ann R
Australas Coll Dent Surg. 2002 Oct;16:109-10.
Oral Health Centre of Western Australia. [email protected] to the lingual nerve, resulting in transient or permanent
paraesthesia or anaesthesia, is a common undesirable complication ofsurgical interventions to the lower third molar region. The anatomy of thenerve, as it travels from its origin high in the infra-temporal fossa, to the
floor of the mouth is quite variable. The most critical part of its course iswhere it enters the sublingual region just alongside the lingual alveolar
plate of the lower third molar.
A significant number of lingual nerves are located above the alveolar
bone in the gingival tissues, or very close to the bone. Retraction ofthe lingual mucosa can lead to lingual nerve trauma. There is no doubt thatthe lingual nerve is extremely vulnerable in this region and clinicians must
assume that it is closely adjacent to the lingual region of the lower thirdmolar, in all cases, in order to minimize possible damage.
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Anterior Division of V3Anterior Division of V3
Anterior Division of VAnterior Division of V
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Anterior Division of V3Anterior Division of V3
The branches of the anterior division of the
mandibular nerve are:
Nerves to masseter (motor)
Nerves to temporalis (motor)
Nerve to lateral pterygoid (motor)
Nerve to medial pterygoid (motor)
Buccal nerve (Sensory)
Buccal NerveBuccal Nerve
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Buccal NerveBuccal Nerve
The buccal nerve,sometimes known as the
long buccal nerve (especially
in oral surgery), is the
source of common sensationto most of the cheek and the
buccal gingival tissues of the
lower posterior teeth.
Modified from: Haglund, J. & Evers, H Local
Anaesthesia in Dentistry, Astra Lkemedel
Sdertlje, 2nd Edition, 1975. p. 53.
Buccal NerveBuccal Nerve
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Buccal NerveBuccal Nerve
It must therefore
also be
anaesthetized if alower posterior
tooth is to be
extracted.
Modified from: Haglund, J. &
Evers, H Local Anaesthesia in
Dentistry, Astra Lkemedel
Sdertlje, 2nd
Edition, 1975. p. 53.
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
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Nerve Supply to Lower TeethNerve Supply to Lower Teeth
Pain sensation to the dental pulps of the lower teeth and
common sensation to buccal and labial gingival tissues is
supplied by the inferior dental nerve.
Therefore, any procedure that requires anaesthesia of the
pulps of any lower tooth can be performed successfully if the
inferior dental nerve is blocked.
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
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We try to anaesthetizeit just before it enters
the mandibular
foramen, and this
ensures that tooth
pulps along the whole
of the anaesthetized
side remain numb.
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
Modified from: Haglund, J. & Evers, H Local
Anaesthesia in Dentistry, Astra Lkemedel
Sdertlje, 2nd Edition, 1975. p. 52.
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
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Because there is some
crossing over of nervesupplies from the right
and left inferior dental
nerves near the
midline, sometimes
infiltration anaesthesia
is also required in this
area.
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
Modified from: Evers, H & Haegerstam,
G. Introduction to Local Anaesthesia,
Mediglobe SA, Fribourg, 2nd Edition,
1990. P. 87
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
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If anaesthesia is required for extraction, however, then the
nerve supply of the gingival tissues must also beconsidered. The lingual nerve can be blocked to ensure
anaesthesia of the lingual gingivae.
Nerve Supply to Lower TeethNerve Supply to Lower Teeth
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Posteriorly, the buccal gingivae are supplied by the buccal
nerve, and this must therefore also be anaesthetised for
extractions in this region.For premolar and anterior teeth, the buccal and labial gingivae
are supplied by the inferior dental nerve, and they will
therefore have been successfully anaesthetised already by an
inferior dental nerve block.
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Accessory Nerve SuppliesAccessory Nerve Supplies
Accessory Nerve SuppliesAccessory Nerve Supplies
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Difficulty in anaesthetizing palatal teeth is most commonly due
to accessory innervation of those teeth by branches of the
greater palatine nerve or from the terminal branches of the long
sphenopalatine nerve.Injection of a small amount of anaesthetic palatally will normally
secure anaesthesia. Other techniques such as intra-ligamental
or intraosseous injections may also be useful, as may newer
methods of anaesthetic delivery such as the wand.
Accessory Nerve SuppliesAccessory Nerve Supplies
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Difficulty in anaesthetizing mandibular teeth is most commonly
encountered in the molar area.
It it recognized that the long buccal nerve, lingual nerve,
mylohyoid nerve, and branches of the inferior dental nerve may
all contribute to such problems. In addition, sensory fibres from
the muscles of mastication may also provide an accessory
innervation to these teeth.
Accessory Nerve SuppliesAccessory Nerve Supplies
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Problems due to the long buccal nerve can be overcome by
administering a buccal block injection.
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Those from the mylohyoid nerve or from accessory innervation
from muscles of mastication can usually be solved by injecting
into the floor of the mouth between the submandibular fold andthe mandible, taking care not to inject intravascularly, especially
into the facial artery. Inject through the mylohyoid muscle.
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The cortical bone here is sometimes porous and thin enough to
allow diffusion of anaesthetic into the bone to anaesthetize
accessory nerve bundles from the muscles of mastication.
Copyright
A. Forrest
2004
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The lingual nerve can often also provide accessory innervation
to anterior teeth, as can small branches from the ascending
branch of the transverse cutaneous nerve of the neck.
Depositing a small amount of anaesthetic lingually (with
aspiration to avoid intravascular injection) will often solve the
problem.
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Why is dental pulpal pain difficult to localize?The pulp contains only pain fibres (A-delta and C fibres),
therefore touch, temperature and pressure are only perceived
as pain. Any potentially damaging stimulus will cause
changes to the fluid in the dentinal tubules.
This pain is difficult to localize unless the inflammation
extends to the periodontal ligament where additional sensory
receptors (pressure, proprioception) give further information.
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In addition, the numerous pain fibres of the pulp converge onto
fewer fibres in the brainstem and information about the specific
tooth is lost.
Dental pain can be referred from one arch to the other arch,
but it never crosses the midline. It may also be referred to the
ear, neck etc.
Dental pain may sometimes be a pain referred to the teeth
from a non-odontogenic source e.g. sinuses, heart.
The only way to ensure accurate diagnosis of dental pain is by
thorough history taking, examination and testing.
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The following resources might be useful to you:
A good page on LA techniques is found at:
http://www.septodont.ca/Septodont/english/other/cea_di01.html
For a discussion on accessory foramina and innervation in themandible, see:
http://dmfr.birjournals.org/cgi/reprint/29/3/170.pdf
For a recent American discussion of LA in Dentistry, see:
http://www.cda.org/member/pubs/journal/jour0503/budenz.htm
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The End