COMPLETE DENTURE ESTHETICS

Introduction

Denture esthetics is defined as the cosmetic effect produced by a dental

prosthesis which affects the desirable beauty, attractiveness, character and dignity

of the individual.

The subject of esthetics is not a totally scientific and objective discipline nor

is it 100% an art form . Esthetics is a combination of the art and the science of

prosthodontics.

Hardy said it best when he wrote "make the teeth look like natural teeth. If a

dentist is to make a denture, where in the teeth look they grew there, teeth must be

set in an esthetic and convincing arrangement that also meets the patients functional

needs.

It appears that beauty really does lie in the eye of the beholder and more

often is a matter of genetic programming of course, there are individual as well as

cultural variation. A denture is usually perceived as esthetic when the teeth and

bases are in harmony with the facial musculature as well as size and shape of the

head. Pre extraction records, old casts, photographs or Immediate dentures can be

extremely helpful both for tooth selection and arrangement.

The subject of esthetics should be examined from 3 points of view -

biological - physiological, biomechanical and psychological.

Biological - physiological

It is necessary to have an understanding of facial musculature, normal facial

appearance, and the physiological limits within which esthetic compromises are to

be made. A proper impression procedure is necessary to provide the dentist with a

final maxillary cast that has an accurate representation of the labial vestibule and all

of the other remaining structures.

1) The dentist should also have a visual concept of the cause and effect

relationship. eg: - If an edentulous patient has a tight, drawn & thin lips,

proper support with a fully formed occlusion rim and lip support by the

labial 2/3 of the artificial maxillary anterior teeth, should evert the

vermillion border of the lip. This would -afford a much more natural

appearance.

2) As patients become older the natural lines of farce tend to deepen and to

appear accentuated and the elasticity of the facial musculature is lost. There

is a tendency to want to plump out the face with additional thickness of the

denture base material and the musculature tends to loosen the denture or the

facial appearance, becomes strained.

3) Another approach to removing facial wrinkles is to Increase the VD. This

approach is fraught with the greatest of dangers and must be used with

caution. The actual process of trial placement of the maxillary anterior teeth

and the function of the maxillary and mandibular anterior during the

production of speech give one of the best guidelines for creating and

maintaining an adequate inter occlusal distance. The following principles

should be followed in the placement of anterior teeth.

1) The lower anteriors should be placed lower in order to maintain an adequate

interarch space. This will necessitate lowering of the occlusal plane

posteriorly. This will have the effect of placing the teeth closer to the

mandibular ridge giving stability to the lower denture.

2) The maxillary teeth should be moved slightly more anteriorly at the incisal

edges. Tilting the incisal edges of the mandibular incisors; lingually should

be avoided. According to Muysigmes for every lmm the incisal edges of the

mandibular anterior teeth are posterior to their normal arrangement, the

tongue is deprived of approximately 100cub mm of space in which to

function.

Biomechanical

There are certain mechanical limitations in the placement of anterior teeth

that must be taken into account. The anterior teeth should be placed closely in

relation to the residual ridge as were the original natural teeth. Fish says the proper

position for the teeth is not necessarily on the ridge, inside the ridge, or outside the

ridge, but at a point where the tongue and cheek pressures balance.

Psychological

Patient's self image is an important factor in esthetics. -:A patients

perception of his or her appearance may result in a broad simle (if it is a positive

self evaluation.) or a tight - lipped, small, controlled smile, A patient with a poor

self image may appear done, unsure, questioning and introverted,. A patient with a

more positive feeling tends to smile more broadly.

Camper’s line may be thought of as a psychological plane of orientation. In

a person who appears happy this line tends to rise and in a person who to depressed

it may slant downward.

The occlusal plane established by the dentist has an effect in determining the

appearance of a patients psychological state. eg: - by effecting a downward slant to

the plane posteriorly an observer may gain a negative impression of the patients

emotional or phychological state.

ANTERIOR TOOTH SELECTION

There are many methods of choosing anterior teeth for the edentulous

patients. Anterior tooth selection is a tentative step, which can be verified only by

the dentist utilizing the trial base and confirmed by the patient and family or

friends.

The best time to gain insight into the esthetic problems of a patient is the

first time we meet the patient. The decision should be made at the first visit about

the shape, shade, position and mold of the teeth to be used. If the patient had a

previous set of dentures, changes to be made can be discussed with the patient.

A smile is the most visible record of a dentists care of an edentulous patient.

interior tooth selection is the area of prosthodontic care in which the patient should

be given a primary responsibility to determine the esthetic outcomes.

A.T.S. has been based on theories that, tooth shape relates to head shape and

tooth appearance, is influenced by patient aye, sex and personality. Our aims is to

achieve a harmonious blending of shade, shape, arrangement and position so that

the final result is a removable restoration that creates an illusion of being what it is

not shade Krajicek states, is not so important what shade is selected, but a variety

of shades of teeth be used in a single 6 tooth composition .

A study by Hallarman showed that there is apparently little correlation

between either natural hair or eye colour and tooth colour. There is also little

correlation between skin colour of the forehead or cheek and patients own anterior

teeth. His study also confirmed that canines are darker than the central incisors and

colour darkens with aye. Females tends to have lighter natural teeth than to males.

Colour has basically 3 qualities hue saturation and brilliance.

Hue is the dimension of colour by which the eye distinguishes different wave

length of the visible spectrum. It is specific colour produced by a specific wave

length of light acting on the retina of the visible spectrum. It is possible to

recognize 2 different hues in artificial teeth one yellow and one red. The individual

teeth of each set, although of the same hue, should vary in their purity the central

incisors being more pure than the lateral incisors and canines. If artificial teeth are

to resemble pleasing natural teeth they, too under all conditions of lighting should

appear to be warm and living.

Saturation (Chroma)

It is the amount of colour/unit area of an object eg: some teeth appear more

yellow than others.

When more of the hue or less of white is present, there is said to be greater

saturation. A tooth is said to be darker because of an increase in saturation or a

decrease in brilliance. Both brilliance and saturation must be held within limits and

must be related to each other in correct proportions for each hue natural tooth

colours are to be imitated.

Brilliance (Value)

Refers to the lightness or darkness of an object. It is the quantity of light

reflected from the surface. The inclination of surfaces, position of surfaces,

character of surfaces and the intensity of the projected light all affect the lightness

of an object.

Curved surfaces appear more darker than the surfaces at right angles to light.

Surfaces closer to the observer will be lighter than similar surfaces further away.

Polished surface will reflect more of than light received and will be lighter than

roughened surfaces. Surface appear lighter when it is illuminated by Intense light.

People with fair complexions generally have teeth with less colour and are lighter.

People with dark complexions usually have darker teeth. However a light teeth in

the mouth of a patient with very light complexion may appear dark. Likewise dark

teeth in dark complexion appear to be lighter than they are.

Translucency

It is the property of an object that permits passage of light through it.

Translucency of artificial teeth has the effect of mixing the various colours of teeth.

This results in teeth that look alive. A natural tooth is composed of a slightly

translucent ivory colored body covered with a jacket of almost colourless material

of greater translucency. Because the enamel jacket varies a great deal in thickness

in different parts of the mouth, many characteristic visual effects are produced.

Shade Selection

Colour of the teeth should be in harmony with that of the face. Women

usually tend to have lighter teeth.

Other factors are

1) Hair colour 2) Colour of the eyes 3) Age Hair Colour according to Bcucher

is not a constant factor and can be unreliable & inaccurate Colour of the eyes; Ace

to Heart well it is an excellent guide but is not quite so according to Boucher as

he says that

- The iris of the eyes is so small compared to the area of the total face

& the eyes are not close to the teeth.

Age & Tooth colour

Natural tooth colour changes with age. In youth the pulp chamber are large

and the red colour of the pulp affects the tooth colour. later the pulp chamber

becomes smaller due to deposition of secondary dentin. This makes the tooth more

opayue.

The general rule is that darker teeth are more appropriate in older patients

and lighter teeth in younger patients.

Shade guides are useful in the shade selection observation of the shade guide

should be made in 3 positions.

1.) Outside the mouth along the side of the nose

2.) Under the lips with only the incisal edge exposed.

3.) Under the lips with only the cervical end covered and mouth open.

The first step will establish the basic hue, brilliance & saturation. the 2nd

will reveal the effect of the colour of the teeth when the patients mouth is relaxed.

The third will stimulate exposure of the teeth as in a smile.

The colour selected should be so inconspicuous that it will not attract

attention to the teeth. The colour of the teeth should be observed on a bright day

when possible with the patient located close to natural light. The 'squint test' may

be helpful in evaluating colours of teeth with the complexion of the face with the

eyelids partially closed the dentist compares prospective colours of artificial teeth

held along the face of the patient. The colour that fades from view first is the one

that is least consipicious in comparison with the colour of the face.

Size

The size of the teeth should be in proportion to the face and head . Generally

larger persons have larger teeth. Men usually have larger teeth than women. This

is especially true of the CI, which normally should be more delicate in women.

Clinical judgement and experience are the criteria in selection of the proper

width and mold. The widely used methods for anterior tooth selection based on

facial and tooth size proportion are A. Pre extraction records.

1) Diagnostic casts prior to extraction

2) Most recent photographs of the patient before loss of his teeth.

3) Radiographs of the teeth.

B. Post extraction examination

If the patient is edentulous and wearing CD examine the patient with the

dentures and ask the patient what changes to be done in the new denture.

C. Anthropometric studies indicate

Measurement of the bizygomatic width and dividing it by 16 to arrive at the

approximate width of the maxillary central incisior. Dividing this measurement by

3.3 will give the total width of the 6 anterior teeth.

D. Mark the corner of the mouth on the wax occlusion rim and this will

give the width of the maxillary anteriors.

E. Pound evaluates tooth width by measuring the distance from zygoma to zygoma,

1 – 1.5 inches back of the lateral corner of the eyes. Length is , measure of the

distance from the hairline to the lower edge of the bone of the chin with the face a;

rest. Dividing it by 16 will give the length of the central incisor.

frush considers mold, lip support, midline labial version, (speaking line),

smiling line, C position, LI position, cuspid position, spaces embrasures, buccal

corridor, long axis, gum line, and inter dental papillae.

(Among the more significant factors are the treatment of the incisal edge and

prominance an position of the teeth. Rounded corners & Curve contours give

feminine appearance. Prominent wide central with a great deal of incisal abrasion

an worn cuspid tips indicate the wear of aging combine with the projection of a

personality of strength an vigor)

Sharry, Boucher & found all agreed that size selection should be based on

facial measurements proportions. Two popular methods are there for selecting

the size of the tooth.

1. Based on the space available for placement of the teeth. The length of the-

maxillary central Incisor is measured from the Inclsal edge of the maxillary wax

rim upto the high lip line. Then vertical lines are scribed on the wax rim directly

down from the

right & left ala of the nose. The distance between these lines give a good

approximation of the width of the 6 max, anterior teeth and places the canine near

the commissures.

2) Based on the facial & tooth size proporation

Pound advocated the same 1:16 ratio described by House & Loop. Levin

observed that the width of the maxillary anterior teeth when viewed in the frontal

plane lie within the golden proportion of 1.681 ie, the CI is 1.681 times wider than

the LI in a frontal view.

Frush & fisher varied incisor length from the ideal according to the

dentogenic guidelines of age, sex & personality. The incisors tend to be longer in

young individuals and is shorter in males than in females . Frush & fisher

emphasized the Importance of the incisal edges of the maxillary anteriors following

the contour of the smile line of the lower lip.

Tooth form (shape)

Berry in 1930's was probably the first to demonstrate correlation

between outline form of maxillary central incisor and inverted outline form of

face J. Leon Williams classified facial form as square, tapering, square tapering and

ovoid.

Follwing 18 years study on extracted teeth House. & Loop classified teeth

according to form. Their classification was based not only on the facial outline

form of tooth but also on mesio distal and gingivo incisal contours. They proposed

3 pure typical forms - square, tapering and ovoid along with 6 other combination

forms ie, square - tapering, reverse tapering, ovoid - square, ovoid tapering and

square - tapering - ovoid. House hold that good esthetics could be achieved only if

the facial arches, and tooth shapes all were in harmony. In addition he classified

arch forms as square, tapering and ovoid.

Found also believed that harmony was the key to good esthetics. He not only

evaluated outline form of face in frontal plane but also in the sagittal plane.

Boucher also states that shape of tooth should be in harmony with facial

form . frush & fisher considered dentogenic factors when selecting tooth form, as

well as tooth size & shade. They advocated selective reshaping of artificial teeth to

account for the influence of age, sex and personality. eg: -to simulate the attrition

seen in old age,' soft delicate look of feminine dentition or the bold vigorous look

of a masculine dentition.

Each denture tooth was treated as an individual in terms of both form &

position. Over accentuate maxillary central incisors produce strength an boldness in

smile. This can be reinforced o softened by reshaping & positioning of maxlllary

lateral Incisors. Position & shape of maxillary canine is of paramount importance in

achieving good esthetics.

Frush & Fisher recommend ovoid teeth for females and square teeth for

males. Frush also considers lip support, midline, labial version speaking line,

smiling line, spaces, embrasure, buccal corridor, aum line and interdental papilla in

esthetics.

Hallarman in the 1970's noted the attempts to correlate tooth form with

facial form, sex and personality do not stand up under scientific investigation. But

these give guidelines t translate esthetic concepts into technique.

Tooth Arrangement

Nelson, and later french wrote that the arrangement of the teeth is a far more

importer esthetic factor than mold selection. French illustrates how the same

dentures tooth mold c appear as either square, tapering or ovoid depending. on how

the individual teeth are arranged and how tt base is fabricated to frame the teeth.

There are 4 steps in arranging denture teeth.

1) Proper Orientation of occlusal plane

The oclusal plane lies parallel -.to the campers line in the sagittal plane

&parallel to the inter pupillary line in the frontal plane, Occlusal plane plate

designed by Dr. Frank. Fox is a most useful tool for determining these

relationships. The amount of incisal edge visible below the related upper lip may

range from 0 - several mm owing to variations in lip length from very short to very

long. The incisal length of the rim is adjusted (by having the patient enuncial F & V

sounds) to where the wet or dry line of the L/lip makes light contact with the incisal

edges of maxillary central incisor.

2) Careful development of wax rims in the space intended for artificial teeth.

Wax rims should be developed with great care to fill the space once occupied by

the patients natural teeth. The rims should offer adequate support for the soft

tissues. They should allow for esthetic buccal corridors. Orientation lines should be

scribed on the wax rim in the mldline, high lip line and 2 vertical lines in the canine

area directly down from the ala of the nose. Arch form should be harmonious with

facial & tooth forms.

Heart well & Rahn pointed out that mandibular teeth become more

visible with age. Vig & Brundo showed that the longer the upper lip, the

more visible the mandibular teeth become with age via & Brundo showed

that the upper lip, become of men displayed 1.23cm urban when the I/lip

was at repose, where as women, displayed 0.49mm Cade showed that there

is significant exposure of mandibular beyond age 40.

3. Placement of each tooth; in its correct anatomic position.

Should view the positon of each tooth in the frontal, sagittal & occlusal

planes. The incisal edges of the CI & canines rest on the occlusal plane. LI 1mm

short of the plane. In the frontal view the long axis of LI perpendicular to the

occlusal plane LI angle medially slightly, canines more medially than LI. The tips

of the canine should never be more labial than their necks. In occlusal view LI face

forward, where as the canines are rotated distally. In sagittal view LI flare slightly

in a labial direction. LI flare slightly more in the same direction. The long axis of

canines are nearly perpendicular to the occlusal plane.

Mandibular Teeth.

Frontal View - Long axis of CI perpendicular to the occlusal plane.

- LI tipped medially slightly

- Canines tipped more medially than LI

Sagittal view

LI are tipped in a labial direction slightly, long axis of LI nearly

perpendicular to the occlusal plane canines angle forward slightly.

4. Characterisation of the set up

Lombard! felt that the LI make the best statement of the patients age, LI

cannot the patients sex. Canines reflects the patients vigor. Frush & Fisher believed

that dentogenics influence tooth arrangement as well as shade of tooth selection. To

highlight age they accentuated diastemata and rotations. Probably the most popular

characterisation technique is to crowed and tilt the mandibular anterior teeth.

Denture Base

Sir Wilfred Fish in his extensive writing on the polished surface of dentures

elaborated on the direct influence of denture base contours on facial esthetics. He

says optimum esthetics depend on adequate soft tissue support which in turn is

directly related to proper base contours.

Frush & Fisher proposed convex, rounded and shortened papilla in older

patients. They also proposed the exposure of more of cervical root portions of

denture teeth in order to simulate ginglval recession in older individuals. They

recommended finer stippling for females and . heavy stippling for males. They

preferred to the tint the interdental pappila and muscle attachment areas with deep

shade of red. They used light shades to tint areas of hard tissue.

Characterization

A life like restoration can be obtained by simulating the anatomical

characteristics of oral mucosa with various stains.

It is of particular value in

1. Subjects with active upper lip

2. Persons with prominent pre maxllla

3. Persons like teachers & singers

4. Who expose more of denture base during talking < smiling.

5. Young edentulous patients

Many others have advocated festooning o. stippling and staining of the

denture base. They also suggested use of preformed anatomic palatal and facial

gingival forms.

Rugae can be reproduced in denture for natural feel. A 0.003 guage tin foil is

adapted over the rugae area of the edentulous cast of trimmed. This is adapted to

the base plate after wax up so as t reproduced the rugae properly.

Colour Distribution in Gingiva

Basic pink used over hard tissue as attached gingiva.

Light red used for papilla & muscle attachments Medium red tones in mucobuccal

folds, rugae etc Purple blue in heavily plgmented gingiva mostly attached gingiva

papilla & marginal gingiva. Brown for heavily pigmented gingiva.

CONCLUSION

Denture esthetics aim in creating artificial substitutes for lost natural teeth to

maintain harmpny, naturality and individuality. Every effort should be made by the

dentist to maintain true identity between artificial dentures and the sex, personality

and age of the patient.

REFERENCE

1. Bouchers prosthodontic treatment for edentulous patients - 9th edition

2. Essentials of complete denture prosthodontics Sheldon tinkler - 2nd edition.

3. Dental esthetics - John H. Lee

4. Complete denture esthetics - DCNA Jan. 1996 Vol. 40

5. Sheldon Winkler et al Characterization of denture bases for people of colour

JADA, Vol 81, 1970.

6. Characterization of denture bases DCNA April 1975 Vol 19.