Assessment of Edentulous Patients










Application of the Neutral Zone in Prosthodontics, First Edition. Joseph J. Massad, David R. Cagna,
Charles J. Goodacre, Russell A. Wicks and Swati A. Ahuja.
© 2017 John Wiley & Sons, Inc. Published 2017 by John Wiley & Sons, Inc.
Companion website: www.wiley.com/go/massad/neutral
Chapter No.: 1 Title Name: Massad c01.indd
Comp. by: Vijayakumar E Date: 25 May 2017 Time: 11:00:54 AM Stage: Printer WorkFlow:
<WORKFLOW> Page Number: 1
1
Introduction
A critical and somewhat perplexing aspect
ofthe management of the edentulous condi-
tion is the prediction of therapeutic out-
comes and patient satisfaction. The most
fundamental factor determining a precise
prognosis is a thorough and accurate pre-
treatment examination [1–3]. Even though
patients may receive the best therapy, the
treatment will fail if underlying conditions
remain undiagnosed.
This chapter reviews a method for
the pretreatment evaluation of edentulous
patients and existing prostheses to arrive at a
sound understanding of factors that will
affect therapy and the probability that the
treatment’s objective can be achieved. Using
appropriate assessment tools, the practi-
tioner can better determine if the patient’s
expectations can be met.
Much has been published in the dental
literature regarding anatomic [4, 5] and
psychological variations [6, 7] in edentulous
patients. Before considering management of
these challenging patients, objectives include
thorough examination, diagnosis of existing
conditions, consideration of available therapy,
and assessment of the prognosis of each
available treatment option [1, 2]. Both sub-
jective and objective patient factors must
be taken into consideration [1]. A rational
stepwise pretreatment protocol will help to
prevent critical diagnostic information from
being overlooked. Detailed documentation
of findings is essential from a dento‐legal
standpoint.
The pretreatment protocol provided is
relatively easy to follow, quick to perform,
and easy to reproduce. It yields summary
findings that correspond with specific prog-
nostic conclusions. The protocol is divided
into: (i) patient interview; (ii) examination
of existing facial characteristics; and (iii)
examination of edentulous conditions, i.e.,
anatomic, morphologic, and muscular status.
The Patient Interview
Successful therapy is facilitated by the pro-
vider coming to know the patient, from both
personal and logistical perspectives; this
includes how the patient arrived in the prac-
tice. If the patient was referred, the referral
source should be known and contacted, and
the reason for the referral noted. If the patient
arrived due to marketing of the practice, care
must be taken to investigate if the patient’s
needs are consistent with therapy provided
by the practitioner.
The initial patient interview permits the
patient and the practitioner to know one
another [8]. Quality time spent at the beginning
sets the stage for an optimized patient‐provider
relationship. Both the physical and psychologi-
cal status of the patient should be triaged
during the first appointment [8]. Anticipation
of communication problems and interception
of commonly encountered interpersonal
1
Assessment ofEdentulous Patients

Application of the Neutral Zone in Prosthodontics
2
problems are frequently as important as
clinical findings. Discerning the primary
etiology of existing patient dissatisfaction
isessential for breaking the cycle of unsuc-
cessful treatment attempts. Complaints and
expectations expressed by the patient, and
treatment obstacles encountered by previous
dentists, can provide a critical influence on
the acceptance of the patient into the prac-
tice and the treatment offered.
Be aware that the pretreatment protocol
provided might initially appear to consume
an inordinate amount of time and effort.
Some might say that this is financially
unjustifiable. However, once understood and
skillfully conducted, the protocol reduces
overall management time, permits appre-
ciation of the treatment rendered, and sig-
nificantly contributes to overall therapeutic
success.
Some patients may be fearful, nervous, or
shy, and inadvertently fail to respond directly
to questions. Recognition of these individuals
early in the interview process is critical.
Inmany cases, a dental auxiliary can better
elicit patient responses than the practitioner.
Obtaining honest and accurate patient
responses will affect outcomes. The pre-
treatment protocol and associated electronic
documentation presented incorporate data‐
gathering processes designed to elicit thor-
ough, concentrated, and accurate answers
from patients.
Patient Interview: Age
The patient’s chronological age should be
critically compared with general physical
health and existing oral conditions. Older
patients may be afflicted with poor neuro-
muscular coordination [9, 10], suboptimal
nutritional status [11, 12], diminished adapt-
ability [9, 10], and salivary secretion (both
quantity and quality) [11], and highly vulner-
able denture‐bearing tissues [10, 11]. These
factors adversely influence aging edentulous
patients’ ability successfully to tolerate and
function with conventional complete den-
tures, which should be discussed prior
toinitiating treatment [8]. Analogies such as
“when dentures move and there’s limited
saliva, the pink plastic acts like sand paper
against your gums creating irritation” help
patients to understand better the problems
that they face.
Patient Interview: Attitude
Coming to appreciate patient attitude may be
as simple as presenting nonleading questions
and permitting the patient time to respond.
Questions that may be used to gauge patient
attitude include:
How are you feeling today?
How was your experience with the previous
dentist that treated you?
What do you think about your current and
previous dentures?
Based on patient responses and ensuing dis-
cussions, qualifications of patient attitude as
good, average, or poor may be made. Of
course, additional questioning may be neces-
sary to arrive at a reasonable determination.
Patient Interview: Expectations
If not thoroughly investigated prior to initiat-
ing treatment, patient expectations may not
be apparent until problems unexpectedly
emerge in the course of therapy, and the
patient’s demeanor begins to decline [9, 13].
Direct and specific questioning of the patient
regarding expectations will permit docu-
mentation of responses and qualification of
expectations as high, medium, low, or still
unsure. Patients can also be asked the follow-
ing questions to understand further the
nature of their expectations:
What kind of improvement in appearance
do you expect from your new dentures? In
response to this question, a 50‐year‐old
patient may provide a picture of an
18‐year‐old celebrity stating, “I want
my teeth to look like hers.” This would
indicate that the patient possesses unre-
alistic expectations. A subsequent patient
may suggest, “I want perfect teeth,

Assessment of Edentulous Patients
3
necessitating a better understanding of
what is meant by “perfect.
What kind of improvement in chewing abil-
ity do you expect from new dentures?
What kind of improvement in fit do you
expect from the new dentures?
How long do you expect new dentures to
last?
How often do you expect to return to the
dentist for examinations and adjustments?
The nature of the patient’s desires and
demands relative to proposed treatment
must be considered by the practitioner within
the context of his / her level of experience
and expertise. If the patient expects more
than the practitioner can comfortably pro-
vide, definitive treatment should not com-
mence and referral to a more experienced
colleague should be in order. Additionally,
ifthe patient is unable to appreciate the limi-
tations of the therapy offered, it is inappro-
priate to initiate treatment.
It is the responsibility of the practitioner to
address unattainable expectations fairly and
honestly, through frank discussion with the
patient, communicating what can and cannot
be accomplished with treatment; this is par-
ticularly true with complete denture therapy.
Failure to address unrealistic expectations
often leads to treatment failure and rapid
deterioration of the patient‐provider rela-
tionship. Patients that refuse to accept known
limitations of therapy and express inflexibil-
ity in this regard are generally challenging to
manage successfully. Not initiating definitive
treatment for these individuals is ethically,
professionally, and financially appropriate.
Patient Interview: Chief Complaint
Providing state‐of‐the‐art treatment that
does not manage the patient’s main concerns
may provide a level of personal satisfaction
for the provider but is rarely successful in the
long run. It is therefore important to: (i)
request that patients specifically voice their
greatest dental concern / concerns; (ii) docu-
ment these chief concerns using the patients’
exact words, and (iii) review the chief
concern / concerns, as documented, with the
patients to confirm accuracy [13].
Most dental patients are not familiar with
professional and dental terminology. It is
therefore important to ensure that the practi-
tioner understand clearly the patient’s chief
concerns as expressed. Asking the following
questions may permit a greater appreciation
for the nature of the chief concerns:
Are your dentures loose?
Can you eat most foods?
Do your gums get sore?
Do you have pain now?
Are you happy with the appearance of your
smile?
Is there anything else that bothers you?
Patient Interview: General Health
General health is a significant factor that can
affect the overall success of dental therapy [9].
A thorough medical history questionnaire is
an essential tool in pretreatment diagnosis.
Patients with complicated medical conditions
(e.g., uncontrolled diabetes, Parkinsons dis-
ease, Huntingtons disease, Tourette’s syn-
drome, other neuromuscular disorders, etc.)
should be informed that these conditions may
affect their ability to retain and function with
conventional complete dentures [14]. Many
systemic conditions (e.g., iron deficiency
anemia, Sjogrens syndrome, pemphigus /
pemphigoid, erythema multiforme, etc.) can
adversely affect oral tissues, oral function,
and in turn the success of complete denture
therapy [14]. Obtaining information regard-
ing current medication type and dosage is
important, particularly because so many
medications significantly contribute to xeros-
tomia. Patients should be referred to their
primary physicians for review of medical
conditions or medications expected to affect
dental therapy adversely.
Patient Interview: Complete
DentureExperience
In order to assess patients’ ability to wear
removable prostheses and the apparent rate
of alveolar bone resorption, they should

Application of the Neutral Zone in Prosthodontics
4
report the number of years they have worn
complete dentures [9, 13]. They should be
questioned if the maxillary and mandibular
dentures were fabricated at the same time or
at different times. It is also important to note
the reasons for tooth loss. As a general rule,
longer durations of edentulism correspond
to greater alveolar bone loss and increased
complexity of treatment.
Patient Interview: Denture
RemakeFrequency
Information should be collected on the num-
ber of different complete dentures worn by
the patient since loss of the natural teeth.
The date of fabrication of the most recent
complete dentures should be determined.
Reasons for seeking new prostheses, both
historically and currently, should be noted.
The American Dental Association recom-
mends that complete dentures be replaced
every 5–7 years, or when they can no longer
be worn comfortably [15]. Acquiring one
new denture over the past 10 years is rea-
sonable; two new dentures in 10 years may
be justifiable, but three or more complete
dentures within a 10‐year period may indi-
cate particularly challenging conditions or a
challenging patient who is difficult to treat
successfully.
Patient Interview: Patient
Satisfaction
Satisfaction level with previous complete den-
tures is important diagnostic information [9].
Satisfaction should be qualified as successful,
reasonably successful, or unsuccessful. The
following specific questions should be asked:
Describe your satisfaction with previous
dentures?
What is your opinion regarding your smile
with your existing dentures?
Were you able to function with previous
dentures?
Did your dentures fit well in your mouth?
Patient Interview: Photographs,
Diagnostic Casts, andRadiographs
Photographs, diagnostic casts accurately
mounted in an articulator, and radiographs
are essential to complete the patient inter-
view and information gathering. Properly
composed photographs help to visualize
smile symmetry, incisal display, lip support,
size and form of edentulous ridges, and pres-
ence of undercuts. Mounted diagnostic casts
present three‐dimensional information on
oral contours of the edentulous jaws, ridge
relationships, and available restorative space.
Important objective diagnostic informa-
tion is discernable with panoramic radiology.
Relative alveolar height and resorptive
patterns can be assessed. Hypertrophied
tuberosities, pneumatized sinuses, and
extruded ridge segments may be identified.
Approximately 20% of edentulous patients
present with radiographic signs of bone
cysts, retained root tips, impacted teeth, and
residual pathology [13, 16]. Incorporation of
a properly made, diagnostic‐quality pano-
ramic radiograph early in the pretreatment
protocol is essential in identifying these
treatment concerns.
The Facial Analysis
Esthetic outcomes in modern dentistry
are essential to perceived success [9].
Unfortunately, appreciating patient esthetic
expectations and determining esthetic prog-
nosis during initial assessment can be chal-
lenging. A detailed facial analysis involving
patient interaction and acceptance is a criti-
cal element of the pretreatment protocol.
Identification of dental midline asymmetries,
lip irregularities, tooth and excess denture
base displays, face shape, and vertical / hori-
zontal residual ridge relationships influence
both the treatment rendered and prognosis.
Patient and dentist appreciation for these
esthetic factors prior to initiation of treat-
ment is best accomplished using carefully
composed clinical photographs.

Assessment of Edentulous Patients
5
Facial Analysis: Facial Tissue Tone
Aging and the loss of teeth correspond to
deterioration of tonicity in facial tissues and
masticatory muscles. Decreasing muscle
mass alters the appearance of the face from
relatively convex to concave (Figure1.1a and
b). Development of surface wrinkles, deep
nasolabial folds, and concave cheek contour
(Figure1.2), are indicative of poor skin tone
and underlying muscle mass. Digital palpa-
tion and patient history (e.g., complaint of
reduced bite force) provide information on
the tone and functional capacity of facial and
masticatory muscles. When performing digi-
tal palpation, a thumb is placed near the com-
missures (Figure 1.3a) and the index and
middle fingers on the opposite cheek surface
(Figure1.3b). The patient is asked to pucker
the lips (Figure 1.3c) and then smile
(Figure 1.3d). If these movements displace
the fingers and the thumb, muscle tone is
deemed adequate.
The tone of the oral and facial muscles fol-
lowing the loss of teeth may be near normal
or subnormal but never normal [3]. The mas-
ticatory force and efficiency for complete
denture wearers are therefore substantially
reduced compared to those with natural den-
titions [3]. The timing and sequence of tooth
loss will affect muscle groups to varying
degrees. If anterior teeth have been missing
for some time, the muscles of facial expres-
sion will exhibit a poor tone. If posterior
teeth have been missing for a long time, the
muscles of mastication are more likely to
exhibit a poor tone [3].
Adequate muscle tone contributes to den-
ture stability. Patients with substantially poor
muscle tone may find it difficult to stabilize
complete dentures. Normal tension, tone,
and placement of muscles in the absence of
degenerative changes is ideal. However, mus-
cle degeneration in edentulism is common.
(a) (b)
Figure1.1 (a) A female patient with convex appearance; (b) a female patient with concave appearance.
Figure1.2 Patient demonstrating presence of deep
wrinkles, nasolabial folds, poor muscle mass and tone.

Application of the Neutral Zone in Prosthodontics
6
An important function of complete den-
tures is to provide support for the muscles
and soft tissues of the cheeks and lips.
Denture flange borders and cameo surface
contours should be developed to facilitate
this support.
Facial Analysis: Tooth and Denture
BaseDisplay
Lip length and lip mobility affect tooth and
soft tissue (denture base) display during
both repose and smile. A long upper lip
and reduced lip mobility during smile
results in minimal maxillary tooth and gin-
gival display (Figure 1.4a). A short upper
lip and excessive lip mobility lead to maxi-
mum maxillary tooth display, particularly
during full smile (Figure1.4b). Tooth and
denture base display of the existing
prostheses during repose and full smile
should be recorded to indicate no show,
slight show, average show, or excess show.
Recording this information helps to
improve vertical denture tooth positioning
in planned prostheses.
Facial Analysis: Midlines
The patient’s maxillary denture midline
should coincide with the facial midline.
Deviations should be noted.
(a) (b)
(c)
(d)
Figure1.3 (a) Evaluation of muscle tone by digital palpation; (b) evaluation of muscle tone by placing the
index finger and middle finger on the cheek; (c) evaluation of muscle tone by asking patient to pucker their
lips; (d) evaluation of muscle tone by asking patient to smile.

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Application of the Neutral Zone in Prosthodontics, First Edition. Joseph J. Massad, David R. Cagna, Charles J. Goodacre, Russell A. Wicks and Swati A. Ahuja. © 2017 John Wiley & Sons, Inc. Published 2017 by John Wiley & Sons, Inc. Companion website: www.wiley.com/go/massad/neutralChapter No.: 1 Title Name: Massad c01.inddComp. by: Vijayakumar E Date: 25 May 2017 Time: 11:00:54 AM Stage: Printer WorkFlow:<WORKFLOW> Page Number: 11 IntroductionA critical and somewhat perplexing aspect ofthe management of the edentulous condi-tion is the prediction of therapeutic out-comes and patient satisfaction. The most fundamental factor determining a precise prognosis is a thorough and accurate pre-treatment examination [1–3]. Even though patients may receive the best therapy, the treatment will fail if underlying conditions remain undiagnosed.This chapter reviews a method for the pretreatment evaluation of edentulous patients and existing prostheses to arrive at a sound understanding of factors that will affect therapy and the probability that the treatment’s objective can be achieved. Using appropriate assessment tools, the practi-tioner can better determine if the patient’s expectations can be met.Much has been published in the dental literature regarding anatomic [4, 5] and psychological variations [6, 7] in edentulous patients. Before considering management of these challenging patients, objectives include thorough examination, diagnosis of existing conditions, consideration of available therapy, and assessment of the prognosis of each available treatment option [1, 2]. Both sub-jective and objective patient factors must be taken into consideration [1]. A rational stepwise pretreatment protocol will help to prevent critical diagnostic information from being overlooked. Detailed documentation of findings is essential from a dento‐legal standpoint.The pretreatment protocol provided is relatively easy to follow, quick to perform, and easy to reproduce. It yields summary findings that correspond with specific prog-nostic conclusions. The protocol is divided into: (i) patient interview; (ii) examination of existing facial characteristics; and (iii) examination of edentulous conditions, i.e., anatomic, morphologic, and muscular status. The Patient InterviewSuccessful therapy is facilitated by the pro-vider coming to know the patient, from both personal and logistical perspectives; this includes how the patient arrived in the prac-tice. If the patient was referred, the referral source should be known and contacted, and the reason for the referral noted. If the patient arrived due to marketing of the practice, care must be taken to investigate if the patient’s needs are consistent with therapy provided by the practitioner.The initial patient interview permits the patient and the practitioner to know one another [8]. Quality time spent at the beginning sets the stage for an optimized patient‐provider relationship. Both the physical and psychologi-cal status of the patient should be triaged during the first appointment [8]. Anticipation of communication problems and interception of commonly encountered interpersonal 1Assessment ofEdentulous Patients Application of the Neutral Zone in Prosthodontics2 problems are frequently as important as clinical findings. Discerning the primary etiology of existing patient dissatisfaction isessential for breaking the cycle of unsuc-cessful treatment attempts. Complaints and expectations expressed by the patient, and treatment obstacles encountered by previous dentists, can provide a critical influence on the acceptance of the patient into the prac-tice and the treatment offered.Be aware that the pretreatment protocol provided might initially appear to consume an inordinate amount of time and effort. Some might say that this is financially unjustifiable. However, once understood and skillfully conducted, the protocol reduces overall management time, permits appre-ciation of the treatment rendered, and sig-nificantly contributes to overall therapeutic success.Some patients may be fearful, nervous, or shy, and inadvertently fail to respond directly to questions. Recognition of these individuals early in the interview process is critical. Inmany cases, a dental auxiliary can better elicit patient responses than the practitioner. Obtaining honest and accurate patient responses will affect outcomes. The pre-treatment protocol and associated electronic documentation presented incorporate data‐gathering processes designed to elicit thor-ough, concentrated, and accurate answers from patients.Patient Interview: AgeThe patient’s chronological age should be critically compared with general physical health and existing oral conditions. Older patients may be afflicted with poor neuro-muscular coordination [9, 10], suboptimal nutritional status [11, 12], diminished adapt-ability [9, 10], and salivary secretion (both quantity and quality) [11], and highly vulner-able denture‐bearing tissues [10, 11]. These factors adversely influence aging edentulous patients’ ability successfully to tolerate and function with conventional complete den-tures, which should be discussed prior toinitiating treatment [8]. Analogies such as “when dentures move and there’s limited saliva, the pink plastic acts like sand paper against your gums creating irritation” help patients to understand better the problems that they face.Patient Interview: AttitudeComing to appreciate patient attitude may be as simple as presenting nonleading questions and permitting the patient time to respond. Questions that may be used to gauge patient attitude include: ● How are you feeling today? ● How was your experience with the previous dentist that treated you? ● What do you think about your current and previous dentures?Based on patient responses and ensuing dis-cussions, qualifications of patient attitude as good, average, or poor may be made. Of course, additional questioning may be neces-sary to arrive at a reasonable determination.Patient Interview: ExpectationsIf not thoroughly investigated prior to initiat-ing treatment, patient expectations may not be apparent until problems unexpectedly emerge in the course of therapy, and the patient’s demeanor begins to decline [9, 13]. Direct and specific questioning of the patient regarding expectations will permit docu-mentation of responses and qualification of expectations as high, medium, low, or still unsure. Patients can also be asked the follow-ing questions to understand further the nature of their expectations: ● What kind of improvement in appearance do you expect from your new dentures? In response to this question, a 50‐year‐old patient may provide a picture of an 18‐year‐old celebrity stating, “I want my teeth to look like hers.” This would indicate that the patient possesses unre-alistic expectations. A subsequent patient may suggest, “I want perfect teeth,” Assessment of Edentulous Patients3necessitating a better understanding of what is meant by “perfect.” ● What kind of improvement in chewing abil-ity do you expect from new dentures? ● What kind of improvement in fit do you expect from the new dentures? ● How long do you expect new dentures to last? ● How often do you expect to return to the dentist for examinations and adjustments?The nature of the patient’s desires and demands relative to proposed treatment must be considered by the practitioner within the context of his / her level of experience and expertise. If the patient expects more than the practitioner can comfortably pro-vide, definitive treatment should not com-mence and referral to a more experienced colleague should be in order. Additionally, ifthe patient is unable to appreciate the limi-tations of the therapy offered, it is inappro-priate to initiate treatment.It is the responsibility of the practitioner to address unattainable expectations fairly and honestly, through frank discussion with the patient, communicating what can and cannot be accomplished with treatment; this is par-ticularly true with complete denture therapy. Failure to address unrealistic expectations often leads to treatment failure and rapid deterioration of the patient‐provider rela-tionship. Patients that refuse to accept known limitations of therapy and express inflexibil-ity in this regard are generally challenging to manage successfully. Not initiating definitive treatment for these individuals is ethically, professionally, and financially appropriate.Patient Interview: Chief ComplaintProviding state‐of‐the‐art treatment that does not manage the patient’s main concerns may provide a level of personal satisfaction for the provider but is rarely successful in the long run. It is therefore important to: (i) request that patients specifically voice their greatest dental concern / concerns; (ii) docu-ment these chief concerns using the patients’ exact words, and (iii) review the chief concern / concerns, as documented, with the patients to confirm accuracy [13].Most dental patients are not familiar with professional and dental terminology. It is therefore important to ensure that the practi-tioner understand clearly the patient’s chief concerns as expressed. Asking the following questions may permit a greater appreciation for the nature of the chief concerns: ● Are your dentures loose? ● Can you eat most foods? ● Do your gums get sore? ● Do you have pain now? ● Are you happy with the appearance of your smile? ● Is there anything else that bothers you?Patient Interview: General HealthGeneral health is a significant factor that can affect the overall success of dental therapy [9]. A thorough medical history questionnaire is an essential tool in pretreatment diagnosis. Patients with complicated medical conditions (e.g., uncontrolled diabetes, Parkinson’s dis-ease, Huntington’s disease, Tourette’s syn-drome, other neuromuscular disorders, etc.) should be informed that these conditions may affect their ability to retain and function with conventional complete dentures [14]. Many systemic conditions (e.g., iron deficiency anemia, Sjogren’s syndrome, pemphigus / pemphigoid, erythema multiforme, etc.) can adversely affect oral tissues, oral function, and in turn the success of complete denture therapy [14]. Obtaining information regard-ing current medication type and dosage is important, particularly because so many medications significantly contribute to xeros-tomia. Patients should be referred to their primary physicians for review of medical conditions or medications expected to affect dental therapy adversely.Patient Interview: Complete DentureExperienceIn order to assess patients’ ability to wear removable prostheses and the apparent rate of alveolar bone resorption, they should Application of the Neutral Zone in Prosthodontics4report the number of years they have worn complete dentures [9, 13]. They should be questioned if the maxillary and mandibular dentures were fabricated at the same time or at different times. It is also important to note the reasons for tooth loss. As a general rule, longer durations of edentulism correspond to greater alveolar bone loss and increased complexity of treatment.Patient Interview: Denture RemakeFrequencyInformation should be collected on the num-ber of different complete dentures worn by the patient since loss of the natural teeth. The date of fabrication of the most recent complete dentures should be determined. Reasons for seeking new prostheses, both historically and currently, should be noted. The American Dental Association recom-mends that complete dentures be replaced every 5–7 years, or when they can no longer be worn comfortably [15]. Acquiring one new denture over the past 10 years is rea-sonable; two new dentures in 10 years may be justifiable, but three or more complete dentures within a 10‐year period may indi-cate particularly challenging conditions or a challenging patient who is difficult to treat successfully.Patient Interview: Patient SatisfactionSatisfaction level with previous complete den-tures is important diagnostic information [9]. Satisfaction should be qualified as successful, reasonably successful, or unsuccessful. The following specific questions should be asked: ● Describe your satisfaction with previous dentures? ● What is your opinion regarding your smile with your existing dentures? ● Were you able to function with previous dentures? ● Did your dentures fit well in your mouth?Patient Interview: Photographs, Diagnostic Casts, andRadiographsPhotographs, diagnostic casts accurately mounted in an articulator, and radiographs are essential to complete the patient inter-view and information gathering. Properly composed photographs help to visualize smile symmetry, incisal display, lip support, size and form of edentulous ridges, and pres-ence of undercuts. Mounted diagnostic casts present three‐dimensional information on oral contours of the edentulous jaws, ridge relationships, and available restorative space.Important objective diagnostic informa-tion is discernable with panoramic radiology. Relative alveolar height and resorptive patterns can be assessed. Hypertrophied tuberosities, pneumatized sinuses, and extruded ridge segments may be identified. Approximately 20% of edentulous patients present with radiographic signs of bone cysts, retained root tips, impacted teeth, and residual pathology [13, 16]. Incorporation of a properly made, diagnostic‐quality pano-ramic radiograph early in the pretreatment protocol is essential in identifying these treatment concerns. The Facial AnalysisEsthetic outcomes in modern dentistry are essential to perceived success [9]. Unfortunately, appreciating patient esthetic expectations and determining esthetic prog-nosis during initial assessment can be chal-lenging. A detailed facial analysis involving patient interaction and acceptance is a criti-cal element of the pretreatment protocol. Identification of dental midline asymmetries, lip irregularities, tooth and excess denture base displays, face shape, and vertical / hori-zontal residual ridge relationships influence both the treatment rendered and prognosis. Patient and dentist appreciation for these esthetic factors prior to initiation of treat-ment is best accomplished using carefully composed clinical photographs. Assessment of Edentulous Patients5Facial Analysis: Facial Tissue ToneAging and the loss of teeth correspond to deterioration of tonicity in facial tissues and masticatory muscles. Decreasing muscle mass alters the appearance of the face from relatively convex to concave (Figure1.1a and b). Development of surface wrinkles, deep nasolabial folds, and concave cheek contour (Figure1.2), are indicative of poor skin tone and underlying muscle mass. Digital palpa-tion and patient history (e.g., complaint of reduced bite force) provide information on the tone and functional capacity of facial and masticatory muscles. When performing digi-tal palpation, a thumb is placed near the com-missures (Figure 1.3a) and the index and middle fingers on the opposite cheek surface (Figure1.3b). The patient is asked to pucker the lips (Figure 1.3c) and then smile (Figure 1.3d). If these movements displace the fingers and the thumb, muscle tone is deemed adequate.The tone of the oral and facial muscles fol-lowing the loss of teeth may be near normal or subnormal but never normal [3]. The mas-ticatory force and efficiency for complete denture wearers are therefore substantially reduced compared to those with natural den-titions [3]. The timing and sequence of tooth loss will affect muscle groups to varying degrees. If anterior teeth have been missing for some time, the muscles of facial expres-sion will exhibit a poor tone. If posterior teeth have been missing for a long time, the muscles of mastication are more likely to exhibit a poor tone [3].Adequate muscle tone contributes to den-ture stability. Patients with substantially poor muscle tone may find it difficult to stabilize complete dentures. Normal tension, tone, and placement of muscles in the absence of degenerative changes is ideal. However, mus-cle degeneration in edentulism is common.(a) (b)Figure1.1 (a) A female patient with convex appearance; (b) a female patient with concave appearance.Figure1.2 Patient demonstrating presence of deep wrinkles, nasolabial folds, poor muscle mass and tone. Application of the Neutral Zone in Prosthodontics6An important function of complete den-tures is to provide support for the muscles and soft tissues of the cheeks and lips. Denture flange borders and cameo surface contours should be developed to facilitate this support.Facial Analysis: Tooth and Denture BaseDisplayLip length and lip mobility affect tooth and soft tissue (denture base) display during both repose and smile. A long upper lip and reduced lip mobility during smile results in minimal maxillary tooth and gin-gival display (Figure 1.4a). A short upper lip and excessive lip mobility lead to maxi-mum maxillary tooth display, particularly during full smile (Figure1.4b). Tooth and denture base display of the existing prostheses during repose and full smile should be recorded to indicate no show, slight show, average show, or excess show. Recording this information helps to improve vertical denture tooth positioning in planned prostheses.Facial Analysis: MidlinesThe patient’s maxillary denture midline should coincide with the facial midline. Deviations should be noted.(a) (b)(c)(d)Figure1.3 (a) Evaluation of muscle tone by digital palpation; (b) evaluation of muscle tone by placing the index finger and middle finger on the cheek; (c) evaluation of muscle tone by asking patient to pucker their lips; (d) evaluation of muscle tone by asking patient to smile. Assessment of Edentulous Patients7Facial Analysis: Lip MobilitySymmetrical lip movement should be assessed during smile and full animation. Asymmetric lip movements should be classi-fied as normal, slight, medium, or extreme. Photographs (e.g., repose and smile) and patient history (e.g., complaints of asym-metric tooth display) are valuable aids. Unilateral reduction of mobility (Figure1.5a and b) and unilateral irregular contours should be noted (e.g., stroke or Bell’s palsy) [9]. The position of anterior denture teeth and the cameo denture base contour can be manipulated to modify asymmetric lip positions and movements subtly, although complete correction may not be possible. Patients should be made aware of any lip asymmetries and the potential for corrective measures prior to initiating treatment. Referral for tissue fillers and plastic surgical procedures may be indicated.Facial Analysis: Lip DimensionBoth upper and the lower lip dimension should be examined and classified as full, reduced, or minimal. Thin lips and vermil-lion borders become less visible with age (Figure 1.6). Labial inclination of maxillary anterior teeth can enhance the upper ver-million display. However, significant forward (a) (b)Figure1.4 (a) Inadequate maxillary incisal display in smile; (b) excess maxillary incisal display during full smile in an old male patient.(a) (b)Figure1.5 (a) Asymmetric movement of the upper lip; (b) asymmetric movement of the lower lip. Application of the Neutral Zone in Prosthodontics8positioning of maxillary incisal edges can thin the upper vermilion border, similar to stretching a flat rubber band, the greater it elongates the more it thins. Vermillion dis-play can also be enhanced by tissue fillers. Prosthetic FactorsProsthetic Factors: Vertical DimensionsWith the current complete dentures in place, the patient’s occlusal vertical dimen-sion (OVD) and rest vertical dimension (RVD) should be compared. The RVD is recorded by marking a dot on the tip of the patient’s nose and on the forward promi-nence of the chin [17]. The patient is asked to take a deep breath and relax. Once relaxed, a caliper is used to record the dis-tance between dots (Figure1.7a) [17]. It may help to have patients breath in and outsev-eral times, close their eyes as if to fall asleep / relax, and permit jaw muscles to relax in order to obtain RVD. This technique may be particularly helpful for patients who present with an apparently overreduced ver-tical posture. This measurement represents the patient’s RVD or the physiological rest position. Next, thepatient’s existing OVD is recorded by having the patient occlude their denture teeth. Once again the caliper is used to record the distance between the two dots(Figure1.7b) [17, 18].Subtracting the OVD from the RVD yields the dimension commonly known as freeway space. It is generally accepted that physiolog-ically acceptable interocclusal distance (free-way space) for complete denture patients ranges from 2.0 to 4.0 mm [17]. Inadequate or excessive OVD / interocclusal distance can adversely affect the success of complete denture therapy [17, 18]. Inadequate OVD may result in mandibular overrotation with relative forward positioning, known as pseudo‐Class III relationship (Figure 1.7c), compromising esthetics, masticatory effi-ciency, and denture stability [17, 18]. Management of patients with reduced OVD may be complex (this topic will be discussed in Chapter 2). Excessively increasing OVD beyond physiologically acceptable limits maylead to esthetic and phonetic problems, irritation of the denture foundation, general-ized patient discomfort, and neuromuscular symptoms [18].Prosthetic Factors: Existing DenturesCritical appraisal of existing prostheses may indicate what should be designed into the new complete dentures and what should be avoided. This information also helps to gauge the limitations of such treatment and deter-mine if patient complaints related to existing complete dentures are justified.The existing dentures should be assessed carefully for comfort, retention, stability, and support. Occlusion, denture tooth arrange-ment, and any discrepancy between centric occlusion and maximum intercuspal posi-tions should be evaluated critically. Dental midline placement, arrangement of anterior denture teeth, shade, and type of teeth, occlusal plane orientation, border exten-sions, cameo surface contours, phonetics, and incisor display should be evaluated and noted in detail. The occlusal surfaces, the intaglio surface, and the cameo surface should be examined for evidence of deterio-ration and previous repair and / or reline. Figure1.6 Inadequate display of the vermillion border of upper and the lower lip in a male patient. Assessment of Edentulous Patients9Current dentures should also be examined to assess the patient’s capacity and motivation for meticulous denture hygiene [3, 13]. Limitation in this area must be addressed.Prosthetic Factors: Skeletal RelationshipThe anterior‐posterior relationship of the maxilla to the mandible should be evaluated in profile to ascertain the relative class I, class II, or class III skeletal relationship [19]. Interarch discrepancies in size and position typically lead to problems establishing ade-quate occlusion and denture stabilization [19, 20]. For patients with severe Class II, Class III, or transverse skeletal relation-ships, it is critical to achieve adequate posterior tooth occlusion to avoid denture instability during empty mouth random occlusal contact [20].Prosthetic Factors: SalivaClinical examination must include assess-ment for xerostomia (e.g., quality and quan-tity of saliva, dry lips, shiny and dry intraoral mucosa, angular cheilitis, dorsal fissuring of the tongue). A dental mouth mirror adhering to the tongue or buccal mucosal surfaces during intraoral examination indicates dry mouth. Generally, the patients with signifi-cant medical histories including multiple prescribed medications will demonstrate signs of reduced salivary flow [21]. A reduc-tion in salivary flow may be associated with (a) (b)(c)Figure1.7 (a) Measurement of RVD using calipers to gauge distance between nose and chin in rest position; (b)measurement of OVD using calipers to gauge the distance between nose and chin when teeth are in contact; (c)patient presenting with pseudo class III appearance due to inadequate OVD. Application of the Neutral Zone in Prosthodontics10local factors (e.g., salivary gland disorders), systemic factors (e.g., Sjogren’s syndrome, AIDS, systemic lupus erythematosis, rheu-matoid arthritis, scleroderma, uncontrolled diabetes, thyroid dysfunction, and some neurological disorders), and / or prescription medications [22].The quantity and quality of saliva affects denture success. Reduced salivary output will interfere with complete denture reten-tion and cause generalized soreness in thedenture‐bearing soft tissues due to fric-tional irritation [2, 22, 23]. The quality of saliva should also be considered. Saliva that is ropy, viscous, and mucinous has poor cohesive and adhesive properties prohi-biting optimal denture retention. Patients should be informed about these conditions, educated regarding implications, and instructed about necessary treatment, to include the use of denture adhesives, saliva substitutes, and implants for improving the prognosis [13].Prosthetic Factors: Oral ToleranceTo gauge the patient’s oral tolerance (i.e., tendency to gag), a large stock impression tray can be inserted in the patient’s mouth. The tray should be inserted gradually, keep-ing contact / pressure on the ridge crest until the posterior aspect of the tray contacts the soft palate. Reaction of the patient should be observed closely. Slight reaction is normal, but hypersensitivity is a concern. Areas typically related to reflexive gagging include posterior palate, base of tongue, and poste-rior‐lateral tongue borders. Various dist-raction techniques have developed over the years to overcome the tendency to gag, including asking the patient to lift one of their legs off the chair, or having them chew on ice immediately prior to dental proce-dures. Prescription of antianxiety medica-tions or application of topical anesthetic (sprays, lozenges, and lollipops) to the soft palate and tongue has been recommended and may be useful in patients with extreme gag reflex.Prosthetic Factors: Temporomandibular JointsThe temporomandibular joints (TMJs) must be carefully assessed via patient history, joint auscultation, digital palpation, and manual load testing. Radiographs may also be used to investigate symptomatic TMJs. Often patient accommodation and joint adaptation permit relatively normal and pain‐free function of TMJs with clinically discernable clicking, popping, and crepitus. The pres-ence of prolonged and debilitating symptoms necessitates further evaluation and referral to a practitioner specializing in the diagnosis and management of temporomandibular dysfunction (TMD).TMD can beassociated with instability of occlusal relationships, oro‐facial pain, and functional discomfort. It may also be associ-ated with decrease oral opening (i.e., <60 mm from maxillary anterior ridge to mandibular anterior ridge in edentulous patients is con-sidered to be reduced opening) and deviation of the mandible upon opening. It has been proposed that openings of less than 35–40 mm warrent further investigation [24].Patients experiencing TMD and TMJ pain are less likely to adapt favorably to new complete dentures. It is therefore important to resolve TMJ pain before initiating defini-tive complete denture therapy [25]. The TMJposition, range of motion, and function should be appropriate, comfortable, and stable before definitive dental rehabilitation is attempted [25].Prosthetic Factors: Oral Cancer ReviewThe lips, cheeks, lateral / ventral tongue sur-faces, floor of the mouth, tonsils, soft palate, oropharynx, and neck must be carefully examined and palpated for suspected lesions. Lymph nodes draining the head and neck are of particular interest. Suspected lesions should be digitally palpated to identify bumps, roughness, irregularities, and indura-tion. Not all lesions need to be biopsied, but suspicious findings must be regularly moni-tored by a dental professional, knowledgeable Assessment of Edentulous Patients11in pathologic disease progression. Oral cancer screenings should be accomplished periodi-cally for all patients, not just new patients. Oral CharacteristicsOral Characteristics: Palatal ThroatFormTo examine the character, location, and extent of the tissue contour at the junction of the hard and soft palate (i.e., palatal throat form) the patient is asked to open the mouth widely so that this critical palatal area can be observed at relative physiologi-cal rest. In order to appreciate the impor-tance of this clinical determination, two concepts must be understood. The first, postpalatal seal area (PPS area), is the soft tissue area at or beyond the junction of the hard and soft palate on which pressure, within physiologic limits, can be applied by a complete denture to aid in denture reten-tion [26]. The second concept, postpalatal seal (PPS), is the region along the posterior border of a maxillary complete denture spe-cifically contoured to facilitate peripheral seal of the prosthesis [26].Palatal throat form affects peripheral seal of the maxillary complete denture along its posterior border or PPS [3]. Patients pos-sessing a broad band of relatively immova-ble tissues at junction of the hard and soft palate (Class I) (Figure1.8a) present a good opportunity to develop a sound PPS facili-tating excellent retention of the maxillary denture [3]. Those having a narrower band of immobile tissue and more significant soft palate drape (Class II) (Figure 1.8b) have reduced surface area upon which to develop an effective PPS [3]. Patients that demon-strate severe soft palate drape, even at phys-iologic rest (Class III) (Figure 1.8c), have minimal surface area at the hard and soft palate junction available for an effective PPS, thus jeopardizing peripheral seal and maxillary denture retention [3]. For indi-viduals with Class III palatal throat form, precise positioning and careful develop-ment of the PPS is critical toachieving and maintaining predictable maxillary denture retention.Oral Characteristics: Arch SizeArch size can be measured intraorally or on a cast. A ruler or a Boley gauge can be used to measure the crest‐to‐crest width and the anterior‐posterior length of the edentulous ridges. Large arches (>45 mm width and >55 mm anterior–posterior) offer the poten-tial for optimal retention and stability of complete dentures. Medium‐sized arches (approximately 40 mm width and 50 mm anterior‐posterior) provide good, but not ideal, characteristics for denture retention and stability. Small arches (<35 mm width and <45 mm anterior‐posterior) do not lead to predictable denture retention and stabil-ity. A small edentulous arch where the teeth must be positioned facial to the ridge for optimal esthetics and soft tissue support, presents a substantial challenge to pros-thesis retention and stability. Arch‐size measurements also aid in impression tray selection.Oral Characteristics: Maxillary RidgeHeightTo assess maxillary residual ridge height, a measurement is made from the depth of the labial vestibule to the crest of the edentulous ridge at the midline with the lip gently retracted (Figure1.9) [4, 5, 27–29]. The verti-cal ridge dimension undergoes a continuous resorption once the teeth are lost. The amount and rate of ridge resorption in the anterior maxilla depends in large part on thepresence of teeth in the mandible. If only anterior mandibular teeth are present, resorption in the anterior maxilla may be sig-nificant due to increased and continuous loading forces [30]. This is believed to be thecase for patients affected by combination syndrome [31].Reduced residual ridge height adversely impacts the potential for maxillary denture Application of the Neutral Zone in Prosthodontics12retention and stability [5, 32], which, in turn, has a detrimental effect on muscle tone and esthetics of the patient. Complete denture prognosis could be affected by anterior and posterior maxillary ridge height.Oral Characteristics: ThePalateTooth loss and alveolar resorption may lead to alteration of the depth and contour of thepalatal vault. Depth and cross‐sectional contour of the palatal vault can be evaluated on a dental cast, by intraoral observation, or through intraoral photographs. A flexible transparent ruler is used to record the distance between the deepest aspect of the palate and the most reduced aspect of theridge crest (Figure1.10). Broad (i.e., U‐shaped) palatal vaults are ideal, offer-ing the potential for excellent support and stability of the maxillary complete denture. (a) (b)(c)Figure1.8 (a) Broad palatal throat form, Class I; (b) class II palatal throat form; (c) class III palatal throat form.Figure1.9 Maxillary anterior ridge height measured from depth of labial vestibule to crest of edentulous ridge. Assessment of Edentulous Patients13Tapered (i.e., V‐shaped) palatal vaults pro-vide less denture stability and are associated with increased processing distortion (i.e., increased denture tooth movement and reduced palatal contact). Flat palatal form provides adequate vertical denture sup-port, but contributes minimally to com-plete denture stability [20]. Maxillary complete dentures made to fit flat palatal form, particularly when accommodating large labial frenula, render the prosthesis susceptible to fracture. The presence of tori may complicate prosthesis structural integ-rity and retention. Conventional or zygo-matic implants may be necessary to provide adequate prosthesis support, stability, and retention for these patients.Oral Characteristics: Maxillary RidgeContourRidge resorption or surgical intervention can affect the cross‐sectional form of the residual ridge. Residual ridge resorption (RRR) progressively alters ridge form and size from relatively U‐shaped (Figure 1.11a) to knife edged (Figure1.11b). Further RRR may lead to flat ridges, eventually resulting in depressed or negative ridge form [5]. Maxillary ridge cross‐sectional form can be character-ized as U‐shaped, V‐shaped (tapered), round (bulbous), flat, depressed (negative), or any combination of these forms [3, 20, 33]. The shape and contour of the ridge affects reten-tion and stability of the complete dentures.U‐shaped ridges with medium to tall paral-lel walls and broad, flat ridge crests provide excellent denture retention and stability. U‐shaped ridges with short parallel walls and flat ridge crests provide less stability. V‐shaped ridges with thin crests or extremely short to flat ridges are typically associated with rela-tively poor denture support, stability, and retention [33].Oral Characteristics: TheMaxillary Denture FoundationOral examination, digital palpation, diagnos-tic casts, and intraoral photographs (occlusal views) are used to evaluate characteristics of Figure1.10 Use of a transparent ruler to measure depth of palatal vault.(a) (b)Figure1.11 (a) U shaped maxillary residual ridge; (b) knife edged maxillary residual ridge. Application of the Neutral Zone in Prosthodontics14the denture foundation. The presence of depressed irregularities, exostoses, palatal tori, hypertrophic tuberosities, and signifi-cant undercut areas in the maxillary denture foundation should be noted. Surgical inter-vention should be considered for defects expected to cause chronic soft tissue irrita-tion, restrict normal function, prohibit opti-mal impression making, or interfere with proper denture border extensions [31, 34].Oral Characteristics: Mandibular Ridge HeightTo assess mandibular residual ridge height, a measurement is made from the depth of thelabial vestibule to the crest of the edentu-lous ridge at the midline with the lip gently retracted (Figure1.12) [4, 5, 27–29]. It is impor-tant to avoid distending the vestibule while recording this measurement. The amount of force imparted to the mandible during normal functional loading may be twice that for the maxilla due to the reduced surface area of the denture foundation. This,in part, is believed to account for the increased RRR experienced by the mandible as compared to the maxilla [5, 29].Loss of residual ridge height adversely affects the complete denture retention and stability [5]. For some patients, mandibular RRR can be so extreme that the mandible is susceptible to pathologic fracture. Advanced RRR complicates both the dentist’s ability to fabricate adequate complete dentures and the patient’s ability to manage new prostheses successfully. It is therefore always prudent to consider means of maintaining and improv-ing the denture foundation by the retention of natural tooth roots for conventional com-plete overdentures to slow the rate of RRR, or strategically place dental implants to improve the mechanics of denture support, retention, and stability.Complete denture prognosis on the basis of radiographic mandibular bone height may be determined as follows: ≥21 mm (Class I) favorable, 16–20 mm (Class II) acceptable, 11–15 mm (Class III) compromised, and ≤10 mm (Class IV) guarded [4].Oral Characteristics: Mandibular Ridge ContourRidge resorption or surgical intervention canaffect the cross‐sectional form of the man-dibular residual ridge. RRR progressively alters ridge form and size from relatively robust (inverted U‐shape) (Figure 1.13a), to signifi-cantly diminished (inverted V‐shape), to knife edged (Figure 1.13b) [5]. Further mandibular RRR resorption may produce flat (Figure1.13c) or even depressed (negative) ridge form [5].Therefore, mandibular ridge cross‐sectional form can be characterized as square (inverted U‐shape), tapered (inverted V‐shape), round (bulbous), flat, depressed (negative), or any combination of these forms [3, 20, 33]. The shape and contour of the ridge affects expected retention and stability of the complete dentures.Oral Characteristics: Mandibular Muscle AttachmentsMuscle attachments affect the contour and extension of mandibular complete denture flanges [2]. Unfavorable location of muscle attachments will have a detrimental effect ondenture stability. In such circumstances, surgical correction should be considered [14,35]. The amount of RRR alters the rela-tive relationship of the muscle attachments Figure1.12 Measurement of height of mandibular anterior ridge using transparent ruler. Assessment of Edentulous Patients15to the residual ridge crest. It is important to appreciate that this relationship changes with ongoing ridge resorption [3]. Mandibular muscle attachments are there-fore classified as low (near the vestibular reflection), middle, or high (near the ridge crest) [3].Oral Characteristics: Mandibular Denture FoundationThe existence of depressed irregularities, exostoses, lingual tori, and significant under-cut areas within the mandibular denture foundation should be noted. Surgical correc-tion is considered for defects expected to cause chronic soft tissue irritation, restrict with normal function, prohibit optimal impression making, or interfere with proper denture border extensions [31, 34].In extreme cases, mandibular resorption is so advanced that the ridge appears flat, or even concave, and palpation of the mylohy-oid ridge reveals a sharp spinelike projection with thin soft tissue covering. This area is highly susceptible to functional stress imparted by the denture, and surgical cor-rection must be considered [35].Oral Characteristics: Maxillary Tuberosity CurveContours of the maxillary tuberosities, from ridge crest to vestibular depth, are assessed by digital palpation or dental mirror place-ment into the distal extent of the maxillary vestibule and instructing the patient to open their mouth and move their jaw from side to side. This space has been called the retrozygomatic space or the corono‐maxillary (a) (b)(c)Figure1.13 (a) Inverted U shaped mandibular residual ridge; (b) knife edged mandibular residual ridge; (c) flat mandibular residual ridge. Application of the Neutral Zone in Prosthodontics16space [36]. The vertical height and width of this space varies with mouth opening and must be carefully considered when molding borders and making impressions [36]. Definitive denture borders in this area should account for the dynamic nature of this space during mandibular movements. Failure to doso willresult in an inadequate peripheral seal. Excessive flange thickness in this area will result in discomfort and / or denture displacement as the coronoid pro-cess impinges on the denture flange during lateral mandibular movements. Maxillary tuberosity curvature in this region is char-acterized as flat, moderately curved, steep, orundercut.Oral Characteristics: VestibuleBoth RRR and the location of the muscle attachments affect relative vestibular depth [2, 5]. Unfavorable (shallow) vestibular depth has a detrimental effect on the complete denture stability and due consideration should be given to corrective preprosthetic surgery (i.e., vestibuloplasty) [35] or dental implant placement. The vestibular depth is classified as deep, average, or short.Oral Characteristics: Frenula AttachmentsFrenula attachments affect the shape and the extension of the complete denture flanges [2]. Frenula attached near the edentulous ridge crest can be a focus of irritation if not accommodated by flange contour [35]. Overrelief of the flange during denture adjustment may lead to the ingress of air, loss of peripheral seal, and compromised denture retention [35]. Excessive flange notching to accommodate frenula attached near the ridge crest can concentrate loading stress, resulting in premature denture‐base failure [35]. Therefore, corrective prepost-hetic surgery for frenulum attachments near the ridge crest should be considered [14]. Maxillary frenulum / muscle attachments are therefore classified as high (near the ves-tibular reflection), middle, and low (near the ridge crest).Oral Characteristics: Pterygomandibular RapheThe pterygomandibular raphe is a vertically positioned tendinous band coursing bilaterally from the hamuli of the medial pterygoid plates to the posterior limit of the mandibular retro-molar trigones. It serves as a facial raphe between a portion of the buccinator muscle and the ipsilateral superior pharyngeal constrictor. The nature of attachment ofthe pterygoman-dibular raphe within the pterygomaxillary (hamular) notch will affect the shape and the extension of the posterior‐lateral aspects of the maxillary complete denture. Unfavorable pterygomandibular raphe attachment (i.e., near the ridge / tuberosity crest) will have a detri-mental effect on the stability and retention of the denture. Attachment of the pterygoman-dibular raphe is therefore classified as high (deep in the pterygomaxillar notch), average, or low (near the ridge / tuberosity crest).Oral Characteristics: Denture BearingSoft TissuesCompressibility of the soft tissues of the denture foundation can be assessed by digital palpation and qualified as severely compress-ible, moderately compressible, slightly com-pressible, or thin and delicate (Figure1.14a). Figure1.14 (a) The compressibility of denture‐bearing soft tissues based on thickness. (b)Characterization of soft tissue displaceability.(a)(b)>0.5 >0.5–1.5 >1.5 Assessment of Edentulous Patients17Mobility or soft tissue displacement may be characterized as severely displaceable (>1.5 mm), moderately displaceable (between 0.5–1.5 mm), or slightly displaceable (<0.5 mm) (Figure 1.14b). Mobilizing the tissue using two mouth mirror handles permits assessment of soft tissue displace-ment. Clinical softtissue thickness may be qualified as severely compressible and easily displaceable (thick and spongy), moderately compressible and moderately displaceable (2–3 mm thick), or noncom-pressible and nondisplaceable (relatively thin). Soft tissues that are noncompressible and nondisplaceable offer little denture support, are highly susceptible to irritation under pressure, and compromise denture retention [10]. Severely compressible and easily displaceable tissues are associated with excessive denture move-ment and should be considered for surgical correction [27].Oral Characteristics: Retromolar PadsCompressibility of the retromolar pads can be assessed through digital palpation or exploration with a blunt instrument, as severely compressible, moderately compress-ible, slightly compressible, or thin and deli-cate. Lateral mobility or displacement of retromolar pads can be classified in similar fashion as severely displaceable (>1.5 mm), moderately displaceable (between 0.5–1.5 mm), or slightly displaceable (<0.5 mm).Oral Characteristics: Maxillary Ridge Crest toResting Lip Length (Esthetic Space)A lip ruler (Figure1.15a) is used to measure the distance between the maxillary edentu-lous ridge crest at the midline and upper lip at rest (Figure1.15b) and during smile [37]. This measurement provides information on the potential for and extent of maxillary ante-rior denture tooth display and provides infor-mation to laboratory technician regarding wax rim length and denture tooth setup [37].Oral Characteristics: Mandibular Ridge Crest toResting Lip Length (Esthetic Space)A lip ruler is used to measure the distance between the mandibular edentulous ridge crest at the midline and the lower lip at rest and during smile [37]. This measurement permits the practitioner to gauge the display of the mandibular anterior denture teeth, and provides important information for the laboratory technician [37].Oral Characteristics: Maximal OralOpeningA triangular measuring gauge is used to measure the interarch distance at the midline during maximum oral opening (Figure1.16a, (a) (b)Place onPre-Maxillary Ridge CrestFigure1.15 (a) Lip ruler; (b) Measurement of maxillary esthetic space made with a lip ruler at rest. Application of the Neutral Zone in Prosthodontics18b and c). Maximum interarch (ridge‐to‐ridge) distance of ≥60 mm is considered acceptable for edentulous patients. An interarch (ridge‐to‐tooth) distance of ≥50 mm is considered acceptable for patients edentulous in one arch. An interarch (tooth‐to‐tooth) distance ≥45 mm is considered acceptable for dentate patients [38].Oral Characteristics: Retromylohyoid SpaceThe retromylohyoid space, commonly referred to as lateral throat form, is a bilateral poten-tial space immediately lingual to the retro-molar pads bounded anteriorly by the mylohyoid ridge and muscle, posteriorly by the retromylohyoid curtain, inferiorly by the floor of the lingual vestibule, and lingually by the anterior tonsillary pillar, when the tongue is relaxed [39, 40]. The degree to which this potential oral space can be occupied by pos-terior extension of the mandibular complete denture lingual flange will influence mandib-ular denture stability [39].Lateral throat form is evaluated by plac-ing a dental mirror into the retromyloyoid space (Figure1.17), instructing the patient to project the tongue tip to the contralat-eral oral commissure, and observing the degree of mirror displacement. Lateral throat formis qualified as deep (no mirror displacement), medium (minor mirror dis-placement), or shallow (maximal mirror displacement). Extension of the mandibular (a) (b)(c)Figure1.16 (a) Triangular shaped measuring gauge used to measure interarch (ridge to ridge) distance during maximum oral opening; (b) triangular shaped measuring gauge used to measure interarch (ridge to tooth) distance during maximum oral opening; (c) triangular shaped measuring gauge used to measure interarch (tooth to tooth) distance during maximum oral opening. Assessment of Edentulous Patients19denture lingualflange deep into the lateral throat form contributes favorably to den-ture stability [39, 40].Oral Characteristics: Tongue SizeTo examine tongue size and characterize it as extra large, large, average, or small, the patient is instructed to open the mouth as if to receive food [41–43]. Patients who have been edentulous for an extended time tend to develop a flat and broad (large) tongue [2]. Placement of a mandibular complete denture in such patients results in complaints of crowding, discomfort, and inadequate tongue space [44]. Initially, these patients find it difficult to adjust to the new mandibular denture and constantly dislodge the denture through uncoordinated tongue movements. Fortunately, with the passage of time and experience in denture wearing, patient and tongue adaptations permit relatively success-ful mandibular denture stability and function.Oral Characteristics: Tongue PositionTo observe the natural tongue position, the patient is instructed to open the mouth as if to receive food [41–43]. Care should be taken toavoid mention of the word “tongue” so as not to draw the patient’s attention to the pur-pose of the examination [41–43]. Observation of tongue position will permit qualification as normal or retracted. Normal position is demonstrated when the tongue completely fills the floor of the mouth, the lateral borders rest over the posterior edentulous ridges, andthe tip of the tongue rests on or just lin-gual to the anterior mandibular ridge crest (Figure1.18a). Retracted posture is indicated when the tongue is pulled back into the mouth exposing the floor of the mouth and lateral tongue borders lie medial or posterior to the edentulous ridge (Figure 1.18b). In addition, the tip of the tongue in retracted posture is either located in the posterior aspect of the oral cavity or withdrawn intothe body of the tongue. Approximately two‐thirds of patients present with normal Figure1.17 Head of the mirror placed in retromylohyoid space for assessing lateral throatform.(a) (b)Figure1.18 (a) Normal tongue position; (b) retracted tongue position. Application of the Neutral Zone in Prosthodontics20tongue posture and one‐third with retracted tongues[41–43].Tongue position influences mandibular complete denture flange design and general denture stability [41–43]. Normal tongue position favorably postures the floor of the mouth for predictable lingual flange exten-sion and contour, permitting maintenance of peripheral denture seal, and increasing denture stability and retention. Denture prognosis for patients with retracted tongues may be improved by making the patient aware of this condition and instructing them to consciously maintain normal tongue posture for improved denture retention andstability. The use of tongue exercises and training contours have been suggested to aidin improved tongue posture [41–43, 45].Oral Characteristics: TheNeutralZoneThe neutral zone is an area within the oral cavity where outward forces originating from the tongue are neutralized by inward forces originating from the lips and cheeks [46–49]. The approximate facio‐lingual width of the neutral zone can be evaluated by instructing the patient to open the mouth, permitting assessment of available space between the tongue and adjacent lips / cheeks. In so doing, the neutral zone may be qualified as restricted (Figure1.19a), reduced (Figure1.19b), or opti-mal (Figure1.19c). As will be detailed later in this text, the neutral zone is used as a conveni-ent guide to develop physiologic contours forthe polished surfaces of the mandibular denture and for determining physiologically appropriate facio-lingual tooth positions.(a) (b)(c)Figure1.19 (a) Restricted neutral zone; (b) reduced neutral zone; (c) optimal neutral zone. Assessment of Edentulous Patients21 SummarySpecific factors discernible during careful and detailed examination of edentulous patients permit development of an accurate therapeu-tic prognosis and provide critical information for optimal treatment. Following thorough patient assessment, the treatment prognosis should be classified as optimal, moderate, compromised, or guarded. Improvement of the denture foundation by tissue conditioning, preprosthetic surgery, and / or placement of dental implants may enhance the prognosis. Healthy and stable temporomandibular joints improve the overall prognosis and are a pre-requisite for definitive prosthodontics therapy.The assumption that patients understand our diagnostic findings and treatment rec-ommendations can be a major cause of patient dissatisfaction. Patients must be thor-oughly educated and regularly reminded with respect to compromising factors identi-fied during the initial assessment that will adversely affect treatment and expected out-comes. Patients informed early in the thera-peutic process appreciate obstacles to optimal treatment, whereas explanations provided only after problems are encoun-tered tend to be looked upon as excuses. It is important to avoid initiating therapy for patients who do not understand, or refuses to accept, limitations of proposed treatment. Additionally, patients must appreciate fees, prosthesis replacement frequency, and regu-lar maintenance requirements as a critical element of informed consent prior to initiat-ing treatment. To this end,a software appli-cation incorporating a carefully organized examination form has been developed by the authors to aid in examination, diagnosis, treatment planning, and prognosis for com-plete denture patients. References1 Sato, Y., Tsuga, K., Akagawa, Y., and Tenma,H. (1998) A method for quantifying complete denture quality. J Prosthet Dent, 80, 52–57.2 Barone, J. V. (1964) Diagnosis and prognosis in complete denture prosthesis. JProsthet Dent, 14, 207–213.3 House, M. M. (1958) The relationship oforal examination to dental diagnosis. JProsthet Dent, 8, 208–219.4 McGarry, T. J., Nimmo, A., Skiba, J. F. et al. (1999) Classification system for complete edentulism. J Prosthodont, 8, 27–39.5 Atwood, D. A. (1971) Reduction of residual ridges: A major oral disease entity. 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