Journal club presentation /certified fixed orthodontic courses by Indian dental academy

JOURNAL CLUB PRESENTATION
Occlusal device for diagnostic evaluation of
maxillomandibular relationships in edentulous
patients: A clinical technique

INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


INTRODUCTION
 complete denture wearers experience gradual

and continuous reduction of occlusal vertical
dimension (OVD) over time. This is primarily owing
to deterioration of the denture-supporting tissues and
denture tooth wear.
 Accompanying the loss of OVD is reduction of lower face
height and compromised facial esthetics.


 Potential problems associated with increasing the

OVD during fabrication of new complete dentures are
controversial. Sequelae may include altered phonetic and
masticatory function, unacceptable facial appearance,
muscular discomfort, accelerated alveolar bone loss, sore
residual ridges, premature and excessively audible denture
tooth contact, and exaggerated gagging.


 For patients wearing complete dentures that

demonstrate insufficient OVD, it is necessary to identify
an appropriate OVD prior to fabricating new prostheses.
Diagnostic evaluation of a new OVD may be
accomplished with the aid of a stable, durable, and
predictable intraoral device


 Diagnostic modification of OVD prior to complete

denture therapy is often indicated for patients who have
worn existing prostheses for many years. For these
patients, clinical examination may reveal the following
conditions: severe decrease in lower face height yielding
poor facial esthetics, inadequate fit of complete
dentures, worn denture teeth, clinically discernible
deficiency in OVD, acquired protrusive maxillomandibular
relationship and angularcheilitis.


 This article describes a procedure for fabricating

a diagnostic occlusal device for edentulous patients. The
procedure involves modification of existing or duplicate
complete dentures to evaluate proposed alterations
of the existing OVD.


TECHNIQUE

Wax sprues attached to
distal extension of denture
bases


Polished denture surface placed in
impression material to level of denture
borders

Reverse side of second impression
tray and impression material is
adapted to tissue denture surface
and first layer of material

Separated trays show negative
impression of denture

TECHNIQUE


 After conditioning the denture-bearing tissues,

subject the prostheses to definitive laboratory reline
or rebase procedures using a functional impression
technique. Prior to making occlusal modifications,
ensure that the diagnostic prostheses accurately
contact the denture-bearing tissues with acceptable
border extensions to assure optimal support, stability,
retention, and comfort.


 Clinically evaluate the patient to estimate appropriate

vertical and horizontal maxillomandibular relationships.
Use an ink marker to place a small dot on the tip of the
patient’s nose and on the anterior prominence of the chin.
With diagnostic prostheses in place and the patient sitting
upright, instruct the patient to breathe in and out
several times, open the mouth wide, and then slowly
close the mouth until lip contact is first perceived.


 This mandibular posture will approximate the rest

vertical dimension (RVD). Practice this sequence of
maneuvers several times. Use a Boley gauge (William
Dixon Co, Carlstadt, NJ) to record the distance
between the marks on the nose and chin. When a
repeatable distance is established, subtract approximately
4 mm, accounting for the necessary interocclusal
distance, to arrive at the diagnostic OVD.


 With the mandible in the CR position and the

central bearing pin contacting the bearing plate, evaluate
the space between opposing posterior occlusal surfaces to
assure that at least 2-3 mm is available to mold new
functional surfaces.


 If adequate interocclusal distance is not available,

reduce the occlusal surfaces of the mandibular posterior
denture teeth using conventional laboratory rotary
instrumentation. Also, reduce the vertical length of the
facial cusps on the maxillary posterior denture teeth to
dimensionally accentuate the palatal cusps as the dominant
functional cusps.


 Instruct the patient to close to the predetermined OVD,

bringing the central bearing point into contact with
the bearing plate. Direct the patient to perform
mandibular movements through all eccentric jaw
positions while maintaining contact between the
central bearing point and the bearing plate. Prompt
the patient to continue mandibular movements until
polymerization results in a perceivable exothermal
reaction.


 Remove the prostheses from the patient’s

mouth. Place the mandibular occlusal device in
a polymerization vessel for 30 minutes. Assure that the
vessel contains warm water and is pressurized to 20
pounds per square inch.


 Following complete polymerization, trim excess acrylic

resin using standard laboratory rotary instrumentation to
establish acceptable facial and lingual denture contours.
Finish and polish the dentures in preparation for
placement.


At the placement appointment, adjust the maxillary
complete denture and mandibular occlusal device
for optimal fit, form, and function.
 Assure that the functional occlusal objectives of this
diagnostic therapy are met, including:
(1) multiple, even occlusal, contacts coincident with CR at the
established OVD,
(2) bilaterally balanced occlusion, if desired.



 Instruct the patient to wear the occlusal device throughout

the diagnostic phase of therapy and report complications.
Inform the patient that use of the occlusal device will be
continued until stable and comfortable maxillomandibular
relationships are achieved. Monitor patient progress at
biweekly examinations and accomplish adjustments when
indicated.


SUMMARY
 Critical examination of appropriate maxillomandibular

relationships is indicated prior to fabricating new
complete dentures. This is particularly true for long term
edentulous patients wearing ill-fitting dentures that
demonstrate severe occlusal disharmony


 In these situations, the use of an occlusal device will serve

to: (1)aid in neuromuscular deprogramming of habitual
mandibular posturing influenced by the malocclusion
of existing ill-fitting complete dentures, and (2) facilitate
diagnostic evaluation of the patient’s esthetic, phonetic,
and functional tolerance of maxillomandibular
relationships proposed for complete denture therapy.


Achieving these diagnostic objectives may take weeks or
months.


REFERENCES
 Occlusal device for diagnostic evaluation of maxillomandibular

relationships in edentulous patients: A clinical technique
J Prosthet Dent 2004;91:586-90.

 Denture duplication technique with alternative materials

J Prosthet Dent 1997;77:-8.
 A review of traditional therapies in complete dentures

J Prosthet Dent 1994;72:538-42.
 The continuing reduction of the residual alveolar ridges in complete

denture wearers: A mixed-longitudinal study covering 25 years
J Prosthet Dent 2003;89:427-35


THANK YOU


Journal club presentation /certified fixed orthodontic courses by Indian dental academy

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