Gothic arch tracing/prosthodontic courses

INTRODUCTION
The method of recording the jaw relationships using base plates and
occlusion rims, is widely carried out in clinical practice. However, as many dentures
with an unstable occlusion are seen, it is thought that minor errors tend to occur
easily using this technique. There are various reasons to explain this. If the clinician
is not accustomed to the procedure of softening the wax, it will be difficult to soften
the rims evenly. Without uniformly softened rims, an exact record cannot be
expected. When the base plates poorly fit the alveolar ridges, they are displaced by
sliding over the occlusal plane during recording and thus the jaw registration is
carried out with displaced rims. In addition, as the mucosa of the alveolar ridge is
compressible, some portions of the base plate settle into the mucosa slightly and
another portion is raised up. In a case with severe ridge resorption, the base plate will
be easily displaced. In a patient with a loose temporomandibular joint or wearing an
existing denture with a malocclusion for a long time, the eccentric relation might be
easily recorded by a little undue pressure.
INDIAN DENTAL ACADEMY
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In any case, it requires great skill for the horizontal and vertical jaw
relations to be recorded simultaneously just by using the baseplates to
establish an exact jaw relationship. The chair time will also be
prolonged, and thus the physical fatigue of the patient will increase. To
solve these problems, the author divides the procedure into two stages.
The gothic arch tracer is used for recording the horizontal jaw relation.
The patient must come to the clinic once more, but as the final decision
can be left to the use of the gothic arch tracer, the procedure for
recording the vertical relation using base plates can be performed stress-
free and moreover the total chair time for the recording jaw relations is
shortened.
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HORIZONTAL PLANE BORDER MOVEMENTS
A mandibular element to be understood before recording
maxillomandibular relationships and making tooth arrangements for
complete dentures is border positions. Border refers to the boundary
of a surface and may imply the limiting line. Border position is defined
as the most posterior position of the mandible at any specific vertical
relation.
The border positions are limited by nerves, bones, muscle, teeth when
present and ligaments. The limiting is not a simple mechanical
stoppage but a physiologic control through the neuromuscular system.
The envelopes of motion of the mandible in the border positions has
been recorded in three planes horizontal, frontal and sagittal and are
usually described as three dimensional.
Traditionally, a device known as a Gothic arch tracer has been used to
record mandibular movement in the horizontal plane. It consists of a
recording plate attached, to the maxillary teeth and a recording stylus
attached to the mandibular teeth. As the mandible moves, the stylus
generates a line on the recording plate that coincides with this
movement. The border movement of the mandible in the horizontal
plane can therefore be easily recorded and examined.

When mandibular movements are viewed in the horizontal plane,
a rhomboid-shaped pattern can be seen that has a functional
component, as well as four distinct movement components.
 Left lateral border
 Continued left lateral border with protrusion
 Right lateral border
 Continued right lateral border with protrusion
Left Lateral Border Movements
With the condyles in the CR position, contraction of the right
inferior lateral pterygoid will cause the right condyle to move
anteriorly and medially (also inferiorly). If the left inferior lateral
pterygoid stays relaxed, the left condyle will remain situated in CR
and the result will be a left lateral border movement (i.e., the right
condyle orbiting around the frontal axis of the left condyle).
Therefore the left condyle is called the rotating condyle, because
the mandible is rotating around it.www.indiandentalacademy.comwww.indiandentalacademy.com

The right condyle is called the orbiting condyle, because it is
orbiting around the rotating condyle. The left condyle is also called
the working condyle, because it is on the working side. Likewise, the
right condyle is called the nonworking condyle, because it is located
on the nonworking-side. During this movement the stylus will
generate a line on the recording plate that coincides with the left
border movement.

Continued Left Lateral Border Movements with Protrusion
With the mandible in the left lateral border position, contraction of
the left inferior lateral pterygoid muscle along with continued
contraction of the right inferior lateral pterygoid muscle will cause
the left condyle to move anteriorly and to the right. Because the
right condyle is already in its maximal anterior position. The
movement of the left condyle to its maximum anterior position will
cause a shift in the mandibular
midline back to coincide with
the midline of the face.

Right Lateral Border Movements
Once the left border movements have been recorded on the
tracing, the mandible is returned to CR and the right lateral border
movements are recorded.
Contracting of the left inferior lateral pterygoid muscle will
cause the left condyle to move anteriorly and medially (also
inferiorly). If the right inferior lateral pterygoid muscle stays
relaxed, the right condyle will remain situated in the CR position.
The resultant mandibular movement will be a right lateral border
movement (e.g., the left condyle orbiting around the frontal axis of
the right condyle).

The right condyle in this movement is therefore called the rotating
condyle, because the mandible is rotating around it. The left
condyle during this movement is called the orbiting condyle,
because it is orbiting around the rotating condyle. During this
movement the stylus will generate a line on the recording plate
that coincides with the right lateral border movement.

Continued Right Lateral Border
Movements with Protrusion
With the mandible in the rightWith the mandible in the right
lateral border positionlateral border position
contraction of the right inferiorcontraction of the right inferior
lateral pterygoid muscle alonglateral pterygoid muscle along
with continued contraction ofwith continued contraction of
the left inferior lateral pterygoidthe left inferior lateral pterygoid
will cause the right condyle towill cause the right condyle to
move anteriorly and to the left.move anteriorly and to the left.
BecauseBecause the left condyle isthe left condyle is
already in its maximum anterioralready in its maximum anterior
position, the movement of theposition, the movement of the
right condyle to its maximumright condyle to its maximum
anterior position will cause aanterior position will cause a
shift back in the mandibularshift back in the mandibular
midline to coincide with themidline to coincide with the
midline of the face. Thismidline of the face. This
completes the mandibularcompletes the mandibular
border movement in theborder movement in the
horizontal planehorizontal plane..

Lateral movements can be generated by varying levels of mandibular
opening. The border movements generated with each increasing
degree of opening will result in increasingly smaller tracings until, at
the maximally open position, little or no lateral movement can be
made.
Mandibular movements in
the horizontal plane:-
1)Left lateral
2)Continued left lateral
with protrusion
3)Right lateral
4)Continued right lateral
with protrusion.
CR– centric relation
ICP –intercuspal position.www.indiandentalacademy.comwww.indiandentalacademy.com

Horizontal relations are those that are established anteroposteriorly and
mediolaterally and so are classified as :
Centric Relations
Eccentric Relations Protrusive Relations
Lateral right lateral
left lateral

CENTRIC RELATION is defined as the maxillomandibular
relationship in which the condyles articulate with the thinnest
avascular portion of their respective discs with the complex in the
anterior –superior position against the slopes of the articular
eminences.
Features and Significance Of Centric Relation
Centric relation is the ideal arch to arch relationship and an
optimum functional position of the jaws for the health, comfort and
function of the musculature.
It is a mandibular position where the condyle disc assembly is
seated in anterior superior position against the posterior slope of
articular eminence, which was believed by many to be the rearmost,
upmost, midmost position in the glenoid fossa. (RUM position).
Centric relation of the mandible is a hinge position. In Centric
relation condyles exhibit only pure rotation without translation.

Mandibular movements return or terminate in centric. It is thus a
reproducible position and therefore serves as a reliable reference to
develop centric occlusion in artificial dentures. It is a starting point for
the arrangement of artificial teeth in articulator to develop maximum
intercuspation in complete dentures.
It is a position where upper and lower teeth are braced against each
other during deglutition.
It serves as a reference position for the occlusal reconstruction in
dentulous situations.
It is the posterior border position and the posterior limit of the
envelope of mandibular motion.
To summarize Centric relation is a reproducible, recordable, consistent
reference position, and a physiologically acceptable position for
deglutition.

Recording Centric Relation in Edentulous Subjects
In edentulous subjects, centric jaw relation is generally recorded by
Wax closure method
Functional chew in technique
Graphic method
Anterior deprogrammers
Wax closure method of recording centric relation with swallowing,
phonetics and manual guidance is quick and a simple method.
The arrow point tracing method is a reliable and scientific procedure of
recording the mandibular border movements in the horizontal plane and
captures the mandible at its posterior reproducible border position.

Limitations of Wax Occlusal Rim Method to Record Centric
Relation
Inconsistency of the record: two centric records taken for the same
patient may not always be identical. Patient co-operation and
operator-induced errors should be considered.
Possibility of occlusal rims sliding over the other to any eccentric
position either before , during or after sealing the occlusal rims in
centric relation.
Tilting, leverage and displacement of record bases is very common
and this may result in inaccurate centric record.
There is a tendency for the patient to bite and protrude the
mandible. The term bite registration is therefore objectionable and
obsolete.

ECCENTRIC RELATIONS
Is defined as any relationship of the mandible to the maxilla other
than centric relation.
The eccentric relations that are recorded and used in complete denture
construction are protrusive and right and left lateral.
Protrusive relation is the relation of the mandible to the maxilla when
the mandible is thrust forward. If the motion in every part of the
mandible as it is thrust forward has simultaneously the same velocity and
direction, the motion could be correctly termed translatory. The
movement in the joint is downward and forward. The condyles disk
assemblies are guided downward by the articular eminences of the
glenoid fossae. The angle of slide varies from patient to patient and from
side to side. The muscles responsible for a straight protrusive movement
are the inferior pterygoid muscles acting simultaneously. Protrusive
relation is a bone-to- bone relation, which can be recorded.

Right and left lateral maxillomandibular relations are the relations of
the mandible to the maxillae when the mandible is moved either to the
right or to the left side. The movement of the mandible is the result of the
contraction of contra lateral inferior external pterygoid muscle. When the
external pterygoid of one side contracts, the corresponding side of the
mandible is pulled forward and inward, while the other side remains
comparatively fixed. The side that is pulled forward is termed the
nonworking, balancing, or orbiting side, whereas the side that remains
comparatively fixed is termed the working, or rotating side.
The movements in the non-working side are downward, forward, and
inward. The movement is both sliding and rotary. The movements in the
working side are rotational.

The question of necessity for eccentric records is controversial,
because accuracy is a problem in the recording methods and the
capabilities of the articulator to receive and reproduce the record. The
following factors contribute to inaccuracy:
(1) Instability of records,
(2) Resiliency and displaceability of denture-bearing tissues,
(3) Materials used in record making,
(4) Equipment used in record making,
(5) Lack of muscle coordination in the patient, and
(6) The use of articulators that do not accurately adjust to all lateral
interocclusal check records.

The controversy about the merits of eccentric records will exist as long
as there are differences in the concepts of occlusion and posterior tooth
form required for complete dentures. Prosthodontists who prefer a cusp
form posterior tooth and balanced occlusion in eccentric jaw positions or
organic occlusion will require eccentric maxillomandibular relation
records. Prosthodontists who prefer a noncusp form posterior tooth and
balanced occlusion in centric jaw position will not require eccentric
maxillomandibular relation records.

GRAPHIC METHOD
The graphic methods record a tracing of mandibular movements in one
plane, an arrow point tracing. It indicates the horizontal relation of the
mandible to the maxilla. The apex of a properly made tracing
presumably indicates the most retruded relation of the mandible to the
maxilla from which lateral movements can take place.
Graphic records are either intra oral or extraoral, depending on the
placement of the recording device.
Even though Balkwill, and Englishman, in 1866 illustrated the right and
left intersection arcs of lateral movement, it was Hesse from Germany,
in 1897 introduced the graphic method of recording centric relation,
which was later popularized by the Swiss professor Gysi in 1910.
It became known as Gysi gothic arch tracing since it resembled Gothic
architecture characterized by high pointed arches.

The Glossary of Prosthodontic terms recommends
Central Bearing Tracing, Gothic Arch Tracing, Needle-point Tracing as
the pattern obtained on the horizontal plate used with a central bearing
tracing device.
Central bearing tracing device is a device that provides a central point of
bearing or support between maxillary and mandibular dental arches. It
consists of a contacting point that is attached to one dental arch and a
plate attached to the opposing dental arch. The plate provides the
surface on which the bearing point rests or moves and on which the
tracing of the mandibular movement is recorded. It may be used to
distribute the occlusal forces evenly during the recording of the
maxillomandibular relationships and /or for the correction of
disharmonious contacts.
All movements in the horizontal plane initiate from the apex of the
Gothic arch. The apex of tracing is a reproducible reference point, which
represents centric relation. Gothic arch tracing ensures that the centric
record is made with minimal closing force equally distributed over the
supporting tissues.

HISTORY
The earliest graphic recordings were based on studies of mandibular
movements by Balkwill in 1866.
The first known “needle point tracing” was by Hesse in 1897 and the
technique was proved and popularized by Gysi around 1910.
Clapp in 1914 described the use of a Gysi-tracer, which was attached
directly to the impression trays.
In 1926 Sears used lubricated rims for easier movement and placed the
needlepoint tracer on the mandibular rim and the plate on the maxillary
rim. He believed this made the angle of the tracing more acute.
Philips in 1927 recognized that any lateral movement of the jaws
would cause interference of the rims, which could result in the distorted
record. He developed a plate for the upper rim and a tripoded balls bearing
mounted on a jackscrew for the lower rim. This was named the “central
bearing point”, which produced equalization of pressure on the edentulous
ridges.

In 1929, Stansbery introduced a technique, which incorporated a
curved plate with a 4" radius mounted on the upper rim and central
bearing screw of 3" radius on the lower rim. Plaster was injected after
tracing was made.
HalI in 1929 use the Stansbery technique but he used compound as
record. Later graphic recording methods were developed which used the
central bearing point to produce the gothic arch tracing .
Hardy 1942 and Pleasure 1955 described the use of the Coble
balancer The patient would hold the bearing point in the depression
while plaster was injected for the centric record.
Pleasure1955 used a plastic disk, which was attached to the tracing
plate with a hole over the apex of the Gothic arch. The centric relation
record could then be made without a change of vertical dimension and
Hardy later designed a modified intra oral trace similar to the Coble.

The Sears Recording Trivet had an intraoral central bearing point
and two extraoral tracing plates.
Robinson designed the equilibrator in 1952 , a tracing device with a
hydraulic system and 4 bearing pistons, one each in the bicuspid and
molar region. It produced a functional record of centric relation with a
uniform distribution of stress over the basal seat.
Silverman 1957 used an intraoral Gothic arch tracer to locate the
"biting point" of a patient. The patient was told to bite hard on the
tracing plate. This developed the functional resultant of the closing
muscles, which would retrude the mandible. The indentation made by
the patient would be used for the centric record whether or not it
corresponded to the Gothic arch apex.
Another change in the graphic method was using the central bearing as
a tracer to register intra oral gothic by Blanchad, Musseinan, Copie,
Wastrow.

Hardy introduced a central bearing device with 2 heads. One end was
brass pointed and used in recording the tracing; the other end consisted
of a mounted steel ball bearing, which was used as an anatomical teeth
set to a flat plane of occlusion.
Height, Sears, House and many others who had devised tracing
procedures of their own which enabled them to secure dependable
centric relation.
To make a needlepoint tracing one condyle moves forward and inward
during a lateral movement followed by a movement in opposite direction
with rotation occurring around the opposite condyle, these movement cut
lines extending to the point representing the most retruded position of
both condyles. Therefore when both condyles are resting in the most
retruded position the needlepoint of the tracing will be resting at the apex
of the tracing thus created. A needlepoint tracing is fundamentally a
single representation of the portion of the mandible and its movements in
a horizontal plane. www.indiandentalacademy.comwww.indiandentalacademy.com

Limitations Of Graphic Method
Gothic arch tracing method is preferred in good edentulous ridges with
normal interarch relation.
Arrow point tracing is difficult in excessively resorbed and flabby
ridges as it causes instability of the recording bases and this restricts its
use.
Graphic method is not indicated when there is inadequate inter arch
distance, as it is difficult to accommodate the tracing device without
increasing the vertical dimension.
A sharp arrow point cannot be traced in persons with TMJ arthropathy.
In these instances conventional wax closure method is the alternative
choice.
Intra oral gothic tracing method is ideal in patients with habitual
centric. A few complete denture patients develop habitual centric either
due to faulty centric relation, or due to prolonged use of very old denture
with marked attrition which causes a forward habitual positioning of the
lower jaw. www.indiandentalacademy.comwww.indiandentalacademy.com

This is a case of "habitual eccentric occlusion". When the patient has
worn inappropriate dentures for a long time, the occlusion is habitually
out of the centric occlusal position due to the functional adaptation of the
body in which one masticates in a position comfortable to him/herself. In
these patients it is difficult to record centric relation with wax closures as
they tend to move the jaw to habitual centric relation position, which is
anterior to the actual centric. The Gothic arch method is indicated in
these patients. With intra oral gothic arch tracing method, the stylus
eliminates occlusal contact from occlusal rims and therefore the habitual
neuromuscular memory or engram is absent. The likelihood of sliding
the lower jaw forward and laterally is hence eliminated.

PARTS OF THE GOTHIC ARCH TRACER
The device used is called a gothic arch tracer which essentially
consists of
1 A marking or recording and a tracing or recording table attached to
the upper or lower arches.
2.Stabilized base plates to prevent lateral movement and rocking thus
ensuring minimum errors in recording.
3 A central bearing device/screw to provide a central point of bearing
or support between the maxillary and mandibular occlusal rims. It
consists of a contracting point which is attached to one occlusal rim
and a plate attached to the other occlusal rims which provide the
surface on which the bearing point rests or moves without any change
in the vertical dimension. The device is placed at the central bearing
point, which is located as the center of the supporting areas of the
maxillary and mandibular jaws.

Hight extra oral tracer assembly Sears extra oral tracer assembly
Swissdent ball bearing bite recorder Microtracer for intra oral use

It is used for the purpose of distributing closing forces, evenly
throughout the areas of the supporting structures during recording of
maxillomandibular relations. The central bearing helps to maintain the
unstrained relation of the base plates to the supporting mucosa, with an
almost ideal distribution of contact pressure.
Means of locking the tracer at the apex of the needle point tracing:
1) a hole or a depression into which the needle point would fall.
2) a plastic/ metal disk with a hole which was placed over the apex of the
tracing.
This served as a convience and as a guide for the patient to hold a centric
position while the registration was secured.

Positioning Of The Central Tracing Point
It is important to direct the force uniformly to the basal structures and
thereby ensuring stability of the base plates and uniform vertical
contact.
The central bearing point can be placed at the midline of the upper
arch at the point where it is intersected by a line joining the distal
surfaces of the second premolars.
Stansberry has suggested placing the central bearing point at the point
of intersection of the lines drawn from the cuspid on the side to the
second molar on the other side.
Positioning the tracer (H.Villa)
The tracer is locted in a vertical position in some procedures, while in
others it is at variable inclinations. To obtain correct gothic arch
tracing stabilized base plates and central bearing point must be used
and it must be perpendicular to condylar hinge axis of mandible.

EXTRA ORAL TRACINGS AND DEVICES
A Gothic arch tracing, as the name implies, is a pinpoint tracing on
soot or carding wax that is shaped after a type of architecture known as
the Gothic arch. It sometimes is referred to as the arrow point tracing.
When one condyle moves out in lateral, the movement approximately
rotates around the other condyle. This movement cuts a line starting
from a point, which is the most retruded position of the rotating condyle.
When the opposite condyle is caused to move on its path, it starts from
the same point and cuts a line at an angle to the other line. Therefore,
when both condyles are resting in their most retruded positions, the
needlepoint of the tracer will be resting on the apex of the Gothic arch
thus created.
A Gothic arch tracing is fundamentally a single representation of the
position of the mandible and its movement on one plane. This statement
should be modified if several pins are used, such as the Sears trivet and
further modified if the tracing is of the type suggested by Phillips. The
Phillips tracer indicates the condyle path as well as the direction and
centric position of the mandible.

Techniques Of Graphic Tracings
Gysi suggested 3 main point of movement of mandible namely, the 2
condyles and the incisal point.
If a recording device is used to record the incisor point as the mandible is
moved laterally a V shaped tracing is obtained. This is called by Gysi as
the gothic arch. The apex of which is most retruded position of the
mandible from which lateral movements are made. Different technique
were designed since 1910.
EXTRA ORAL:
Gysi tribyte This technique omits the use of central bearing plates
which necessitates special care in establishing the contacting areas of the
two bite plates. Failure to produce equal contact over the entire occlusal
area of the opposing bite planes in centric relation introduces tilting
forces on the bases.

Gysi technique
In the original Gysi technique the occlusal plane is determined by
locating the correct height of the upper occlusion rim. Then the lower
occlusion rim is adapted to the upper rim at the correct vertical
dimension of occlusion. The Gothic arch tracer is fixed to the upper rim
at the occlusion rims with the tracing table paralell to, or continous with,
the plane of occlusion. The central bearing point is not used. No mention
is made of the inclination of the tracing point. No cusp height is
introduced. This means that even contact of the occlusion rims is lost
when the patient makes forward or lateral excursions of the mandible
because of the forward and downward movement of the condyles.

The Sears trivet is a central
bearing point tracer with two
registration pins. The pins are
attached to the mandibular
plate therefore they will give
a reverse gothic arch as
compared to those with the
pin attached to the maxillary
plate.
It traces 2 gothic arches
simultaneously. It has the
facility of making the records
extra orally with plaster of
paris.

A Boos Bio-meter with
tracing table and marker is
another extra oral method
for obtaining gothic arch
tracing. The biometer
provides an indication of the
position of the mandibular
by tracing and records the
forces of closing. (The V.R.
is adjusted using biometer).

Stansberry cheek bite method - Stansberry developed and
popularized the use of central bearing point in connection with
the tracing device for recording positional relations of the jaw.
With the Stanberry’s cheek bite appliance records can be made
of centric jaw relations and protrusive relations. The tracing
device is removable from its attachment locations on the
maxillary and mandibular bearing plates.
The Phillips Graphic record registers the centric relation and
the condylar paths.
Phillips tracer is another type of tracing device that registers
centric relation and the condyle path simultaneously.

The technique for an arrow point tracing using a Hight tracing
device
Make accurate, stable
maxillary and
mandibular record
bases.
Attach occlusal rims of
hard base plate wax
Contour the wax
occlusion rims
Establish the vertical
dimension of jaw
separation with the
mandible at physiologic
rest.
Reduce the mandibular
occlusion rim to provide
excessive interocclusal
distance

Make a face bow transfer and mount the maxillary cast
With the soft wax make a tentative centric relation record at a
predetermined vertical dimension of occlusion.
Adjust the articulator with the condylar elements secured against
the centric stops
Relate the maxillary occlusion rims of the soft wax record and
attach the mandibular cast to the articulator with plaster.
Mount a central bearing device. Exercise care to center the central
bearing point in relation to the plate, both anteroposteriorly and
laterally.
Mount the tracing device. Be sure to attach the devices securely to
the occlusion rims. The stylus is attached to the maxillary rim and
the recording plate to the mandibular. This arrangement develops
an arrow point tracing with the apex anteriorly. The reverse
develops an arrow point tracing with the apex posteriorly.

Seat the patient with the head upright, in a comfortable position in
the dental chair
Place the record bases in the patient’s mouth with the attached
recording devices. Inspect the record bases and the recording
devices for stability. Make sure that there is no interference between
the occlusion rim when the mandible is moved in any direction.
Lower the stylus to the recording plate and determine that the stylus
maintains contact with the recording plate during mandibular
movements.
Retract the stylus and conduct the training exercises with the
patient. Place the tips of the index fingers under the mandible in the
bicuspid areas. Place the tip of the thumb under the mandible near
the chin. Calmly and quietly instruct the patient to move the jaw
forward, backward and to the right and left while gently applying
guiding pressure with the thumb. It is possible to dislodge the
mandibular record base by improperly placing the thumbs or by
exerting excessive pressure. The Ney Excursion Guide is an aid in
training the patient.

When the patient is proficient in executing the mandibular
movements, prepare the tracing plate to record the tracing. A thin
coating of precipitated chalk in denatured alcohol applied evenly
with a brush provides a medium that offers no resistance to the
movement of the stylus and produces a clearly visible tracing.
Develop an acceptable tracing by dropping the stylus to the record
plate.
When a definite arrow point tracing with a sharp apex is made,
have the patient retrude the mandible to centric relation. The point
of the stylus should be at the point of the apex of the arrow point
tracing. Inject quick setting dental plaster between the occlusion
rims and allow the plaster to harden.
Remove the assembly and mount with the mandibular cast with
the new record.
This record is a tentative record and will be checked with an
interocclusal check record when the teeth are arranged and the wax
is contoured. www.indiandentalacademy.comwww.indiandentalacademy.com

The appliance used consists
of two bearing plates to which a
stylus holder and graph plate
may be attached. A template for
proper spacing of the bearing
plates and a glass syringe to aid
in placing plaster.
 Technique
 1)The occlusal rims adjusted to
the correct vertical relation
 2)They are mounted on an
articulator with the screw
tightened to maintain the
relation of the casts.
STANSBERRY FUNCTIONAL POSITION CHECK BITE METHOD

2)The central bearing plates are placed in the template which has been
placed on the bite plates that had been shortened to provide space for it.
3)With the central bearing plates attached to the bite plates, the central
bearing screw is brought into contact and the tracing table and the stylus
are attached.
4)A gothic arch tracing is developed by the patient. This relation is
maintained and the plaster is injected when the plaster is injected. When
the plaster has set the record is marked and set aside for later use.
5)Accommodation for cusp height in lateral movements is accomplished
by raising the screw in the bearing plate by one and 1/2 turn. A second 9
inch is developed due to the increased vertical dimension. From the apex
of this tracing a mark 1/4 inch or 6mm distant is made on each lateral
path. This marks the position of the needle point for lateral records.
6)The central bearing point is raised one half turn more for the protrusive
registration.

Classification Of Arrow Point Tracing
Gerber described six different types of Gothic arch tracings.
Typical – seen as a welldefined apex with a symmetrical left and right
lateral component. The mean Gothic arch angle is about 120 degrees. It
reflects a healthy TMJ without interferences in condylar path and a
balanced muscle guidance. The symmetrical form indicates an undisturbed
movement of the condyle in fossa and distal slope of eminence with
symmetrically balanced muscle guidance.
Flat form – it is similar to typical arrow point except that it has more
obtuse left and right lateral tracings. This type of arrow point signifies a
marked lateral movement of condyle in the fossa. The Gothic arch angle is
more than 120 degrees.
Asymmetrical form – the left and right tracings meet in an arrow point,
however their inclination to the protrusive path is not symmetrical one of
the lateral tracing is shorter. This form of tracing indicates an inhibition of
the forward movement, either in the left or right joint.

Apex absent /round form – instead of a sharp arrow point, the tracing is
rather round. It shows a weak retrusive movement. Tracing should be
repeated till a definite arrow point is obtained. Patient training is
necessary.
Miniature arrow point – similar to the typical arrow point, however the
extension of tracing is very limited. This can be due to restricted
mandibular movements, improper seating of record bases and painfully
fitting record bases during registration. It is also an indication of a long
period of edentulous ness with an inhibition in condylar movements.
Double arrow point – it is a record of habitual and retruded centric
relation. Allow patient training and repeat till a single gothic arch is
obtained. It is also seen when vertical dimension is altered during
registration.

Dorsally extended arrow point – the protrusive path extends beyond the apex
of the gothic arch. This signifies a forced strained retrusive movement of the
lower jaw either by the patient or the operator. During registration procedure
lower jaw is either forcibly retruded by patient (active retrusion) or forcibly
retruded manually by the operator (passive retrusion). It is sometimes an
artifact caused by the forward displacement of upper occlusal rim or backward
dislodgement of the lower rim while moving them in the mouth. The arrow
point tracing is correct but at a particular stage there was sliding of upper
occlusal rim forward and lower displacing backward.
It can occur when the head of the patient is tilted too far posteriorly. Gerber felt
that occasionally the distal extension is correct, but the tracing was obtained
with the mandible in protruded position.
Interrupted Gothic arch – break or loss of continuity of lateral incisal path of
gothic arch. This happens due to posterior interference at heels of occlusal rims
during lateral movements.
Atypical form – protrusive component does not meet at apex but on one of the
lateral path. This may happen in dentulous because of faulty muscular pattern
due to parafunctional habits like bruxism. Also seen in very old edentulous
patients, who are using complete dentures with incorrect centric relation.

Classical, pointed form
The symmetry indicates an undisturbed
movement sequence in the joints and uniform
muscle guidance.
EVALUATION OF GOTHIC ARCH TRACING
Classical flat form
The picture indicates distinct lateral
movements of the condyles in the fossae.
Weak Gothic arch tracing
The picture indicates a lax and negligent
performance of the movements, most of all of the
backward components. The registration must be
repeated. Stronger movements must be
demanded from the patient.

Assymmetrical form
The tracing indicates a distinct
inhibition of the forward movement in the right
joint.
Miniature Gothic arch tracing
The tracing points to cramplike
movements, badly fitting and paincausing
record blocks, edentulous state of long standing
with inhibited movement in the joints, badly
constructed prosthetic appliances, etc.
Vertical line protrudes beyond the arrow
point
This tracing was produced either by
forcible retraction or pushing of the mandible. It
is, however, possible that the Gothic arch was
obtained with a protruded mandible.

Vincent R Trapozzano (1955) When making a tracing for establishing
centric relation on a patient with a normal temporomandibular joint,
the apex of the initial tracing will be mounted frequently instead of
having a definite apex. Aside from the technical factors the rounded
apex may result from the patient’s failure to understand what is
required when the right and left lateral movements are made, habit or
a slight filling in of tissues behind one or both of the condyles.
With some persistence on the part of the patient and operator, the
patient may produce a needle point tracing with a definite apex.
Sedation may be indicated to relax the patient.
Suppose the blunted apex of the needle point tracing had been
accepted as the position of centric relation, and that occlusal
reconstruction, correction of occlusal disharmony of natural teeth, or
denture reconstruction had been completed.

a definite malocclusion would result whenever the patient decided to
close in the more retruded position (at the apex). In complete denture
construction , the resulting area of malocclusion would produce an
inevitable shifting and sliding of the denture bases, which would result in
instability of the dentures and all of its undesirable sequalae.
Since it is recognized that the individual will undoubtedly make many
initial tooth contacts which vary from the most retrusive position (at the
apex) to a slightly anterior (eccentric) position (on the blunted apex),
provision must be made to avoid “grooving” the patient to the most
retruded position before inclined plane contact is made. If the cusp teeth
are used, this is accomplished by allowing for “free play”, a slight
widening of the central grooves or fossa of the posterior teeth is made to
provide an area larger than the size of the cusp which fits into the groove
or fossa when initial tooth contact is made. Thus, provision is made for a
limited range of horizontal movement of the mandible without engaging
the inclined planes of the teeth.

Howard F. Smith (1975)
A class III jaw relationship classically exhibits little anteroposterior
movement, while a class II exhibits much. One may suggest little
importance for anteroposterior precision, while the other may suggest
great importance. An arthritic patient may exhibit limited movement in
either direction.

Significance Of Gothic Arch Tracing
It is important not to accept any other part of the tracing except the
very apex as an indication of centric relation. When the patient chews
lightly, they may often close their jaws in eccentric positions. However,
patients will pull the mandible to complete retrusion many times under
heavy closing pressure exerted during function of mastication. Therefore
if the dentures are not constructed with centric occlusion in harmony
with centric relation, the teeth will not contact evenly when under
considerable closing pressure. This uneven or premature contacting is a
disturbing factor in the retention and stability of dentures, and it can
cause soreness of the tissues supporting the dentures. On the other hand,
if centric occlusion is in harmony with centric relation, the patient can
function properly with his mandible in all positions under light and
heavy chewing pressures.

Extra oral tracings made without a central bearing point are not
considered satisfactory because although they indicate the correct
anteroposterior position of the mandible, they may not record the
correct maxillomandibular relation (superioinferior relation of the
jaw). It is extremely difficult to maintain equalized pressure on the
blocks of wax. Therefore there is not much to be gained by securing a
tracing without using a central bearing point.

SIGNIFICANT POINTS IN MAKING A GOTHIC ARCH
TRACING
1. Displacement of the record bases may result from pressure, if the
central bearing point is off center when the mandible moves into
eccentric relation to the mouth.
2. If a central bearing device is not used the occlusal rims offer more
resistance to horizontal movements.
3. It is difficult to locate the center of the arches to centralize the forces
with a central bearing device when the jaws are in favorable relation and
far more difficult if the jaws are in excessive protrusive or retrusive
relation
4. It is difficult to stabilize a record base against horizontal forces on
tissues that are pendulous or other wise easily displaceable.
5. It is difficult to stabilize a record base against horizontal forces on
residual ridges that have no vertical height.
6. It is difficult to stabilize a record base or bearing device with patients
who have large tongues.

7. Recording devices are not considered compatible with normal
physiologic stimulation in mandibular movements.
8 The tracing is not acceptable unless a pointed apex is developed, a
blunt apex usually indicates an acquired functional relationship.
9. Double tracing usually indicates lack of coordinated movements or
recording at the different vertical dimension of jaw separation. In either
events additional tracing should be made.
10. A graphic tracing to determine centric relation is made at a
predetermined vertical dimension of occlusion. This harmonizes centric
relation with centric occlusion and the antero-posterior bone, to bone
relation with the tooth - tooth contact.
11. Graphic methods can record eccentric relation of the mandibular to
the maxillary.
12. Graphic methods can be considered the most accurate visual means
of making a centric relation record with mechanical instrument, however
all graphic tracings are not accurate.

INTRA ORAL TRACING DEVICE
Intra oral tracings combine a central bearing point with a pinpoint
tracing. The bearing point is pointed and records a tracing on the
opposing plate. A hole is drilled in the plate at the apex of the Gothic
arch in some techniques that employ intra oral tracing devices. This hole
or depression is used to hold the patient in this retruded position while
the registration is being recorded with plaster or some such material.
The Seidel, Ballard and the Messerman tracers are examples of intraoral
tracing devices. Another type of intraoral registration is afforded by the
Needles technique in which three pins attached to the maxillary rim, one
in the anterior portion and one on either side in the posterior region,
register the movements of the mandible by means of three Gothic arches.
They indicate both the centric position and the condylar paths .

Needles method
Make accurate record bases with occlusal rims.
Three pieces of wire are now imbedded in the rim of the upper base
plate. One end of the wire is heated and forced into the modeling
compound in the incisal region and the soft compound is packed firmly
about the base of the wire. A wire is similarly placed on each side about
the position of the distal side of the first molar. The wires are then cut off
about 1.5 mm. above the surface of the bite rim. The incisal wire should
strike the lower bite rim near the anterior border with the plates in
centric occlusion, and the molar wires should strike slightly outside the
middle of the lower bite rim, so that the tracing will not run off the edge
of the lower bite rim. Each of these wires acts as a stylus to trace the
paths of the respective points upon the surface of the lower bite rim.
The insides of the bite plates are dusted with powdered gum tragacanth
to help maintain them firmly on the ridges. They are then placed in the
patient's mouth and the patient is requested to close until one or more of
the pins come into light contact with the lower bite rim.www.indiandentalacademy.comwww.indiandentalacademy.com

The patient is then asked to move the mandible forward and back in the
median line, maintaining a light pressure on the bite rims, the pins come
into equal bearing and each cuts a record of its path in the lower bite rim,
which gives the path of straight protrusion. Before these paths are cut too
deep, the patient is requested to retrude the mandible to its fullest extent
and slide it to one side and back again, slight contact of the pins being
maintained. This movement is repeated a few times and then the same is
performed on the opposite side. Thus the three paths are deepened
evenly, thoroughly cut to the full depth of the respective pins; in this way
a balanced three point contact has been maintained and the path of each
point has been recorded for protrusion and for working bite on each side,
while any separation that has taken place between the bite rims at any
point during these movements has been recorded by a shallower tracing
at that point. The form of the tracings will be found the same as Gysi's
three-point tracing. The depth of the tracings also gives a record of the
vertical relations. When the three pins are in the anterior angles of their
respective tracings, the bite plates are accurately held in centric
occlusion without the need of guide lines.

The Needles technique modified by the use of a Messerman central-
bearing point tracer is suggested by Frahm. In this procedure the
occlusion rims are constructed in exactly the same manner as was
described by Needles. Four pins are, attached in the first bicuspid and
second molar region on the right and left sides of the maxillary occlusion
rims. By placing the pins in this position we are enabled to cut away the
anterior portion of the maxillary occlusion rim to provide a window for
observing the tracing appliance. The stylus portion of the tracer is
attached to the vault of the maxillary trial base by imbedding the tripod
prongs into Compound or wax.
The graph plate is attached to the mandibular rim flush with the
occluding surface of the rim. The two units should be mounted in a
manner, which will permit the point of the maxillary appliance to rest
near the center of the mandibular graph plate.

The relationship plates are
returned to the mouth, and the
screw on the maxillary appliance
is adjusted so that it makes contact
with the graph plate
simultaneously with the contact of
the maxillary occlusion rim pins
on the mandibular occlusion rim.
The patient then is instructed to
make lateral and protrusive
movements. As the pins scribe the
Gothic arches on the mandibular
rim, the vertical dimension is
diminished a little at a time by
means of the setscrew on the
maxillary appliance. This is
continued until the surfaces of the
occlusion rim make contact.www.indiandentalacademy.comwww.indiandentalacademy.com

COBLE INTRA
ORAL TRACING
DEVICE
Coble Balancer is a
type of intraoral central
bearing device. The
central bearing point is
attached with modeling
compound to the upper
Base plate in the center
of the palate at the
intersection of the
midline and a line
joining the centers of
left and right chewing
areas.

When placed in the mouth, the upper and lower base plates makeWhen placed in the mouth, the upper and lower base plates make
contact only through the central bearing point at or very near the centercontact only through the central bearing point at or very near the center
of the supporting areas of the upper and lower ridges.of the supporting areas of the upper and lower ridges.
The central bearing screw is raised or lowered to establish the verticalThe central bearing screw is raised or lowered to establish the vertical
dimension that provides an adequate free way space and the clearancedimension that provides an adequate free way space and the clearance
between the base plates at the distal borders is checked.between the base plates at the distal borders is checked.
At the chosen vertical dimension, the central bearing point, acting as aAt the chosen vertical dimension, the central bearing point, acting as a
stylus, quickly draws a Gothic arch tracing as the patient performsstylus, quickly draws a Gothic arch tracing as the patient performs
excursive gliding jaw movements. To lock the patients jaw in centricexcursive gliding jaw movements. To lock the patients jaw in centric
relation at the apex of the Gothic arch tracing without changing therelation at the apex of the Gothic arch tracing without changing the
vertical dimension, use a thin sheet about 1mm of clear Lucite as anvertical dimension, use a thin sheet about 1mm of clear Lucite as an
overlay, and drill a small hole through it down to, but not into, theoverlay, and drill a small hole through it down to, but not into, the
aluminum graph plate. The patient is then asked to perform a glidingaluminum graph plate. The patient is then asked to perform a gliding
jaw movement and to stop when the central bearing point drops intojaw movement and to stop when the central bearing point drops into
the hole which was drilled over the apex of the tracing.the hole which was drilled over the apex of the tracing.
At the time of insertion of the processed dentures, the Coble Balancer
is used again to integrate the gliding movements of the jawwww.indiandentalacademy.comwww.indiandentalacademy.com

with the occlusion of the teeth, to perfect occlusal balance, and to
eliminate cuspal prematurities and collisions. At first the central bearing
screw is adjusted to keep all teeth out of contact in all gliding
movements. With the sole point of contact between the upper and the
lower dentures located where the central bearing point touches the graph
plate, the patient can perform jaw movements that are uninhibited by
occlusal interferences. And a Gothic arch tracing is quickly scribed. The
central bearing screw is shortened by half turn (0.5mm) at a time until a
tooth to tooth contact occurs somewhere on the arch during the excursive
gliding movements. Usually the first contact occurs on one or both
second molars or on the canines. Sometimes it occurs between the
denture bases behind the second molars if the interridge space is small.
These occlusal contacts occur while the remaining teeth are still held out
of contact by the central bearing point. They are treated as functional
prematurities, and are ground down until they no longer interfere. The
central bearing point is then shortened by one-fourth turn, and
articulating paper is reinserted to mark the contact areas during the jaw
excursions. www.indiandentalacademy.comwww.indiandentalacademy.com

All the prematurities are thus located, marked and reduced until the
majority of the teeth make contact during the gliding movements, with
the central bearing point still riding on the graph plate.
HARDY and PORTER Hardy introduced a central bearing device with 2
heads. One end was brass pointed and used in recording the tracing. The
other end consisted of a mounted steel ball bearing which was used as an
anatomic teeth set to a flat plane of occlusion.
made a depression on the tracing plate with a round bur at the apex of the
tracing. The patient would hold the bearing point in the depression while
plaster was injected for centric record.
PLEASURE improved this technique by using a hole which was attached
to the tracing plate after the tracing was made, with the hole coinciding
over the apex of the Gothic arch tracing. The central bearing point was
held in a hole when a plaster was injected the centric would then be
made without a change of vertical dimension.

Ballard intra oral tracing
device
Metal points attached to the
upper modeling compound rim
will cut pathways in the
occlusal surface of the lower
modeling compound rim as the
patient moves the mandible
from side to side.
1. Palatal bearing plate
2. Rounded head of correlator pin
3. Tension spring
4. Adjustable screw
5. Mounting plate
6. Pointed end of correlator pin

ADVANTAGES AND DISADVANTAGES
The intra oral tracing device has less assembly. Hence it is more
comfortable for the patient. Also it makes the procedure of assembling
the device and recording procedure easier for the operator.
Since the intra oral tracing are small, it is difficult to find the apex
compared to the extra oral tracing.
The tracers must be definitely seated in the hole made by a round
bur to assure accuracy when plaster is injected between the rims. Any
shift in the position of the stylus from the position of the apex of the
tracing cannot be prevented or corrected when plaster is being
injected. Since any shift made is not seen and the procedure has to be
repeated.
The intra oral tracings cannot be observed properly during the
tracing procedure and hence the method loses some of its value.

R.H. Kingery (1952)reviewed the problems associated with centric
relation which were
PROBLEMS OF REQUIREMENTS
Recording the correct anteroposterior or horizontal realtionship of the
mandible to the maxilla in a position.
Equalization of contact on the denture supporting areas – Equalization
of vertical contact
PROBLEMS OF ERRORS
Positional Errors caused by
Failure of the operator in his registration of the correct horizontal
relationship.
Failure of the operator to record equalized vertical contact
Application of excessive closure pressure by the patient at the time of
recording
Changes in the supporting areaswww.indiandentalacademy.comwww.indiandentalacademy.com

Technical Errors may be caused by
Ill fitting occlusal rims
Indiscriminate opening or closing of the occluding device or articulator
The slight shifting of the teeth which occurs between the stage of final
arrangement and the transfer to a permanent base material.
PROBLEM OF RECOGNIZING THE SYMPTOMS OF ERRORS
ASSOCIATED WITH CENTRIC REALTION
Symptoms Of Unequalized Vertical Contact
Loss of retention
Irritation on the crest of the lower ridge in the area of premature
contact
One tooth or several teeth on one side seem too long to the patient or
seem to strike first
The patient may complain of clicking if the teeth are porcelain
premature contact anteriorly or posteriorly

Symptoms Of Error In Horizontal Relationship Anterior to CR
o Looseness of lower denture
o denture consciousness
o Irritation under the anterior lingual flange of the lower denture
Symptoms Of An Error In Horizontal Relationship Posterior to CR
• Looseness, especially of lower denture
• Irritation under the anterior labial flange of the lower denture
(occasionally)

PROBLEMS OF RECORDING CENTRIC
1. The correctness of an individual registration is never assured
until it is checked and verified by the observation of the operator
2. Methods Of Recording Centric
• Limitations of Graphic recording
• No control over the amount of closure pressure
• Difficulty in placement of central bearing point when patients
present extreme protrusion or retrusion of the mandible
• Central bearing point is troublesome to use when patients
present large clumsy tongues, extreme resorption of ridges or
extensive amounts of displaceable tissues on the supporting
areas.

Comparsion between intra oral and extra oral devices
Heartwell states that intraoral tracings cannot be observed during tracing,
therefore the method loses some of its value of a visible method. Since
the intraoral tracings are very small, it is difficult to find a true apex. The
tracer must be seated in a hole at the point of the apex to assure accuracy
when recording the relation. If the patient moves the mandible before the
occlusal rims are secured, the records shift on their basal seat, this
destroys the accuracy of the record.
The extra oral tracings are larger and therefore the patient can be
directed and guided more intelligently during the mandibular
movements. The stylus can be observed in the apex of the tracing during
the process of injecting the plaster between the occlusal rims and
recording the relation and no holes are required. Boucher prefers the
extra oral device.
Boucher also recommended that centric relation should be made with
minimal pressure to prevent displacement of the tissues supporting thewww.indiandentalacademy.comwww.indiandentalacademy.com

Solomon claimed that in intraoral method the errors are likely to be less
because the tracing is situated closer to the centers of movements in the
temporomandibular joint in comparison to the flexible extra oral device
which inscribes mandibular movement in a plate situated outside the
mouth further away from the centers of mandibular movement. Further
the presence of extra oral tracer attachments prevents the lips from
meeting each other and remains passive. According to him , the distinct
advantage of intraoral tracing is the ability of the subject to perform
mandibular movements with the lips in passive contact position.

Kapur K K and Yurkstas A A (1957) compared the duplicability of
records using various techniques
The intra oral tracing procedure (hardy)
The wax registration procedure (hanau)
The extra oral tracing procedure (stansberry)
He concluded that
•The intra oral and extra oral procedures were more consistent compared
the wax registration method
•The intra oral and extra oral procedures became less consistent in
patients with flabby ridges as compared to patients with good and flat
ridges
•The consistency of the extra oral procedure did not vary significantly
with different types of ridges
•The degree of consistency with the intra oral procedure decreased to a
significant level in patients flabby ridges
•The wax method was less consistent than the other two procedures. It
showed least consistency on flat ridges and the highest consistency on
flabby ridges

REVIEW OF LITERATURE
In 1910 –Gysi stated needle points tracing has been accepted as
an accurate method of locating the centric maxillomandibular relation at
a given degree of jaw separation.
In 1940 – Boos in his study in maxillomandibular relations
established by biting power stated in his research on maxillomandibular
relationship with the use of the power point, reports that centric relation
is not at the apex of the gothic arch. He stated that he found by use of
resultant biting power (point) that the needle point tracing is extremely
accurate in some patient and in others it is unreliable, the resultant biting
point is located at apex of the needle point tracing in some patient,
anterior to the apex in others.
In 1952 – Granger stated that the apex of the Gothic arch tracing
shows a sharp apex. It does however have one value. In order to do an
accurate tracing it is necessary to do two tracing one on each side of the
mandible.

In 1954 – Stansbery proposes a method to check the
correctness of the central bearing position. One rod it passed through the
a needle holder and other placed on the tracing plate. They should be
parallel in all directions.

In 1959 – Elmer E Francis in his article jaw relation in C D construction
described vertical tracer is that which registers and determines the proper
vertical dimension, centric relation and condyle path records. This
vertical dimension is result of study of Gysi. Horizontal position of the
mandible is registered by the gothic arch tracing. Vertical tracer consist
of upper and lower metal plate which are shaped like balanced occlusal
guide plates. These two plates are attached to upper and lower base
plates, upper plate has a vertical plate and a gothic arch tracer. The lower
plate has a horizontal tracing table, an intra oral removable screw
attachment that constitute vertical stop and slip joints which holds Gysi
face bow and a vertical marker.
In 1961 – Huges and Regli : In his study of what is centric
relation observed that a sharp gothic arch tracing may be obtained with
the condyles in more than one location in the glenoid fossa.
When using a central bearing point for patients with prognathic
or orthognathic occlusions it is difficult, not if possible to secure
equalization of pressure.

In 1962 – Jones PM : In his study of eleven aids for a better CD
stated in intra oral gothic arch tracer is used to determine the centric
relation at the established vertical relation. The needle point tracing
device is a reliable, accurate and practical method for locating centric
relation. The apex of a tracing is indented with a bur. A plaster intra
occlusal record is made by injecting plaster into the patients mouth with
the Stanberry plaster syringe.
In 1965 – Mohammed A, W Arthur George and Russel H Scott :
summarized Needle point tracing were obtained from ten subjects at five
different degree of jaw separation. Two subject showed negligible lateral
deviation at any degree of opening when one subject showed consistent
deviation from midline when the vertical dimension between the jaw was
increased The needle point tracing at a given vertical dimension of jaw
separation under same controlled condition, on the same individual at
same sitting were not significantly different. So needle point tracing is
reliable.

In 1968, Joseph E Grasso and John sharry in the study of the
duplicability of arrow point tracing in dentulous patients did a study with
15 white men (Detail students between age group of 20 – 35) tracing
were obtained at a fixed vertical dimension for each subject. The vertical
jaw separation varied from subject to subject depending upon the cuspal
teeth height of the posterior teeth and or the vertical overlap of the
anterior teeth.
Variation pattern of the apex position of the needle point tracing
were greater in an anteroposterior direction than in a mediolateral
direction.

In 1969 – A langer and J. Michmann studying the intra oral technique for
recording vertical and horizontal maxillomandibular relation in complete
dentures wrote that the instrument used the Barnae stylus tracer is an
intra oral tracing device. This technique is recording vertical and
horizontal maxillomandibular relation is suggested. This technique
fulfils basic requirements for correct complete denture construction. The
physiologic rest position is used as a reference for establishing an
acceptable interocclusal distance and the most retruded mandibular
position is recorded in centric relation. The use of central bearing point
ensures equal distribution of pressure throughout the basal seat while the
records are made.
In 1970 – Clayton, Kotowiez and Myers : conducted a research
on graphic recording of mandibular movements concluded the
orientation of styli and recording table affected graphic tracing of
mandibular movements when the vertical dimension is changed, cusp
gliding on inclines involves change in vertical dimension.www.indiandentalacademy.comwww.indiandentalacademy.com

In 1975 – Smith in study in comparison of empirical centric relation
record and location of terminal hinge axis and apex of the gothic arch
tracing concluded that average empirical determination provided a
centric relation point anterior to that determined by either the gothic arch
and the hinge axis location . Gothic arch method was the most repeatable
of the three methods.
In 1980 – Michael Myer in his article relation of gothic arch apex
to dentist assisted centric relation concluded that thumb pressure can
position the mandible consistently more posterior than the position
indicated by the gothic arch apex is unfounded. It also states that dentist
assisted jaw relation is more reproducible than relation indicating gothic
arch apex.

In 1987 – Winstanly : In his article gothic arch tracing and condylar
inclination concluded that records and the patient referred for treatment
of temperomandibular joint disorders were used to compare condylar
inclination found by drawing a tangent and by using a mathematical
technique. Needle point tracing angles were also measured for the same
patient and were compared with the condylar inclination. It can be
concluded that the mathematical technique outlines records a more
accurate value between patient and L & R sides of the same patient and
there is no direct relationship between condylar inclination and the
needle point tracing angle.

In 1989 – Winstanly : in his article the gothic arch tracing and the
upper canine teeth as guide in the positioning of the upper posterior
teeth concluded that the relationship between the position of the buccal
cusps of the natural upper posterior teeth and the distance between the
upper canine teeth has been found to be constant within + 1-2mm this
may be of value when setting up artificial teeth for denture patients,
enabling them to be positioned close to the natural predecessors.

1996 Obrez A, Stohler CS conducted a study to test whether pain can
cause significant changes in position of the mandible and therefore form
the basis for any perceived changes in the maxillomandibular
relationship. A second objective was to determine whether pain can
cause changes in the mandibular range of motion. Five subjects who
rated pain intensity on a visual analog scale were used in a single-blind,
randomized, repeated-measures study design. Tonic muscle pain was
induced by infusion of 5% hypertonic saline solution into the central
portion of the superficial masseter muscle. Isotonic saline solution was
used as a control, with subjects blinded to the type of substance given.
The effect of pain on the position of the apex of the gothic arch tracing,
the direction of the lateral mandibular border movements, and the
mandibular range of motion was studied in a horizontal plane with
minimal occlusal separation. Pain significantly affected the position of
the apex of the gothic arch tracing in anterior Similarly, pain affected the
orientation of the mandibular lateral border movements and their
magnitude www.indiandentalacademy.comwww.indiandentalacademy.com

All pain-induced effects proved to be reversible. The observed effect of
pain can explain the perceived change of bite that is frequently noted by
patients with orofacial pain. This study provided evidence of an
alternative causal relationship between pain and changes in occlusal
relationship and questions occlusal therapy as treatment, directed toward
the elimination of the underlying cause in patients with masticatory
muscle pain.

1998 Raigrodski AJ, Sadan A, Carruth PL Clinicians have long
expressed concern about the accuracy of the Gothic arch tracing for
recording centric relation in edentulous patients. With the use of dental
implants to assist in retaining complete dentures, the problem of
inaccurate recordings, made for patients without natural teeth, can be
significantly reduced. This article presents a technique that uses healing
abutments to stabilize the record bases so that an accurate Gothic arch
tracing can be made.
1999 Watanabe Y Analyzed and evaluated the horizontal mandibular
positions produced by different guidance systems. Twenty-six
edentulous subjects with no clinical evidence of abnormality of
temporomandibular disorder were selected. Horizontal position data for
the mandible obtained by gothic arch tracing was loaded into a personal
computer by setting the sensor portion of a digitizer into the oral cavity
to serve as a miniature lightweight tracing board.

By connecting this with a digitizer control circuit set in an extraoral
location, each mandibular position was displayed in a distinguishable
manner on a computer display in real time, then recorded and analyzed.
The gothic arch apex and tapping point varied, depending on body
position. In the supine position, the gothic arch apex and the tapping
point were close to the mandibular position determined by bilateral
manipulation. This system provides effective data concerning
mandibular positions for fabrication of dentures.
2003 Keshvad A, Winstanley RB. conducted to determine statistically
the most repeatable mandibular position of 3 centric relation methods.
Three centric relation recording methods commonly reported in the
literature were selected: bimanual mandibular manipulation with a jig,
chin point guidance with a jig, and Gothic arch tracing. Fourteen healthy
adult volunteers (7 males and 7 females), with an average age of 26
years and no history of extractions, temporomandibular joint
dysfunction, or orthodontic treatment, were selected for the study.www.indiandentalacademy.comwww.indiandentalacademy.com

Accurate casts were mounted on an articulator (Denar D4A) by means of
a facebow and maximum intercuspation silicone registration record.
A mechanical 3-dimensional mandibular position indicator was
constructed and mounted on the articulator enabling the operator to
analyze the mandibular positions in 3 spatial axes (x, anteroposterior; y,
superoinferior; z, mediolateral shift). Each centric relation method was
recorded four times on each subject (at baseline, 1 hour, 1 day, and 1
week at approximately the same time of day). Records were transferred
to the articulator, and data were extracted using a stereomicroscope
modified to accept the mandibular position indicator. The results of this
study showed that of the 3 centric relation methods evaluated, the
bimanual manipulation method positioned the condyles in the
temporomandibular joint with a more consistent repeatability than the
other 2 methods, whereas the Gothic arch was the least consistent
method.

REFERENCES
•El-Gheriani AS, Winstanley RB.The Gothic arch (needle point)
tracing and condylar inclinationJ Prosthet Dent. 1987
Nov;58(5):638-42.
•El-Gheriani AS, Winstanley RB.The value of the Gothic arch
tracing in the positioning of denture teeth. J Oral Rehabil. 1988
Jul;15(4):367-71.
•El-Gheriani AS, Davies AL, Winstanley RB.The gothic arch
tracing and the upper canine teeth as guides in the positioning of
upper posterior teeth. J Oral Rehabil. 1989 Sep;16(5):481-90.
•Honorato Villa: Gothic arch tracing:JPD; 1959:9:624-628
•Howard F. Smith: A comparison of empirical centric relation
records with location of terminal hinge axis and the apex of the
Gothic arch tracing ; JPD 1975 : 33:511-520

•Keshvad A, Winstanley RB. :Comparison of the replicability of
routinely used centric relation registration techniques : Prosthodont.
2003 Jun;12(2):90-101.
•Max A Pleasure: occlusion of cuspless teeth for balance and comfort
JPD: 1955:5:305-312
•Obrez A, Stohler CS.Jaw muscle pain and its effect on gothic arch
tracings. J Prosthet Dent. 1996 Apr;75(4):393-8.
•Raigrodski AJ, Sadan A, Carruth PL.A technique to stabilize record
bases for Gothic arch tracings in patients with implant-retained
complete dentures. J Prosthodont. 1998 Dec;7(4):273-6.
•Vincent R Trapozzano: An analysis of current concepts of occlusion:
JPD: 1955:5 764-782
•Watanabe Y.:Use of personal computers for Gothic arch tracing:
analysis and evaluation of horizontal mandibular positions with
edentulous prosthesis.: J Prosthet Dent. 1999 Nov;82(5):562-72.

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