relation to the distolabial surface of the central incisors in
Cuspids are more visible and prominent The distal surface of the cuspids is rotated posteriorly
Maxillary bicuspids are less visible than in
Maxillary bicuspids are more visible during expressive
FIGURE 7-7 Feminine smile characterized by curvature of
incisal line coinciding with the lower lip.
FIGURE 7-8 Masculine smile characterized by straighter
Third dimension depth grinding
• Denture look is mostly due to the flat appearance of the artificial
• Depth grinding is required to impart natural appearance.
• Depth grinding is moderately done for men and women and should
be increased or decreased depending on the individual
• Depth grinding depends on the following features:
• Flat, thin, narrow tooth indicated for delicate
women: Little depth grinding is required.
• Thick, bony, big-sized tooth heavily indicated for
men: Severe depth grinding may be required.
• For an average patient, healthy women or less
vigorous men: Average depth grinding is required.
Soft, delicate personality is associated with women, whereas bold and
vigorous personality is associated with men.
Factors influencing the personality of patients are (i) personal
grooming, (ii) cleanliness, (iii) occupation, (iv) physical appearance
and (v) aggressive/regressive behaviour pattern.
Divisions of personality spectrum are as follows:
(ii) Medium pleasing: Normal, moderately robust, healthy and
(iii) Vigorous: Hard, aggressive, muscular type, almost primitive, ugly.
• An intelligent manipulation of the size, shape and
form of the teeth, and supporting structures can
successfully satisfy the objective and subjective
Based on their experience, J.P. Frush and D.R. Fisher described the
patients according to personality as follows:
(ii) Delicate or soft women: 5%
(iii) Medium or average both men and women: 85%
• By overaccentuating the upper central incisor, strength and
boldness are depicted in the smile.
• Arranging the central and lateral incisors that are of nearly same
• Arranging lateral incisor shorter than the central incisor tends to
The objective of age factor is to maintain high degree of conformity
between the restorations and patient’s physiological age structure.
• Selection of appropriate shade is important in denture construction.
Lighter shades are selected for young and darker shades for old
• Ageing is depicted in the denture by mould refinement. Wear
pattern, attrition can be included in the denture teeth.
• In young patients, mamelons are present at the incisal edge of the
central and lateral incisors. The cuspids present a pointed tip which
• Teeth abrade with age. Central and lateral incisors abrade in straight
line and cuspids abrade in a curve. Abrasion of the incisal edges of the
anterior teeth flattens the arch.
• Interincisal distance increases with age, i.e. visibility of the mandibular
teeth increases with age. Increased visibility is due to loss of muscle
tonus, allowing the lower lip to sag and the upper lip to drop.
• Wearing away for the natural teeth at the contact point creates
• Smile line is sharp in young patient and less sharp in the old.
• Gingival tissues recede with age. This recession can be reproduced by
selecting a long tooth, contouring the wax and proper positioning of
• Effects of erosion in the artificial teeth can be imparted by carefully
grinding and polishing the teeth.
• It involves personal grooming.
• Dentist should strive for refinement in the arrangement of the
artificial teeth in a well-groomed and dressed person.
• Similarly, refinement should also be done in shabbily dressed bushy
person. However, this gives an artificial look.
• Modification of the natural appearance is helpful in improving the
• Artistic ability of the dentist is tested to achieve a composition of
teeth that harmonizes with the surrounding features and is also
• Patient desires are always given due considerations after the
physiological requirements are satisfied.
Posterior teeth should be selected for an edentulous patient on the
basis of colour, size, form and material. The selected teeth should be in
accordance with the size and contour of the mandibular residual
ridge. Selection of the posterior teeth should satisfy not only the
masticatory efficiency but also aesthetics, comfort and preserve the
Factors influencing selection of posterior teeth for moderate ridges
The following factors are considered during size selection of the
• Buccolingual width should be greatly reduced than the width of the
• Narrow buccolingual width of the posterior teeth aids in development
of the correct form of the polished surface of the denture by
allowing the buccal and lingual denture flanges to slope away from
the occlusal surfaces (Fig. 7-9).
• This helps to maintain the denture in position over the residual
• Narrow occlusal table reduces the degree of stress on the supporting
tissues of the basal seat on mastication.
• Although narrow occlusal table is desired, it should have adequate
width in order to hold the food during mastication.
FIGURE 7-9 Narrow buccolingual width of the posterior teeth.
• The mesiodistal length of the mandibular ridge from the distal
position of canine to the anterior border of the retromolar pad is available
for posterior teeth arrangement (Fig. 7-10).
• If the residual ridge anterior to it slopes upward, smaller or fewer
• Smaller number of teeth prevent the lower denture from sliding
forward when pressure is applied in the molar region.
• The total mesiodistal width of all the four posterior teeth is
• The posterior teeth should not extend too close to the posterior
border of the maxillary denture, as there are chances of cheek
• The posterior teeth should not be placed on the slope of the residual
ridge, as this will displace the denture. Forces directed to the
inclined plane are more displacing than the vertically directing
• These teeth are never arranged over the retromolar pad because the
pad is too soft and is easily displaced allowing the denture to tip
FIGURE 7-10 Mesiodistal length of the edentulous ridge.
• Posterior teeth are selected on the basis of the available interarch space
and the length of the anterior teeth (Fig. 7-11).
• Artificial teeth are available in varying occlusogingival height.
• Length of the maxillary first premolar should be comparable to the
maxillary canine in order to give a proper aesthetic effect. Failure to
do this results in unaesthetic visibility of the denture base.
• Form of the dental arch should simulate the arch form of the natural
FIGURE 7-11 Height of the posterior teeth selected on the
basis of available interarch space.
Form of the posterior teeth is selected on the basis of the occlusal
surfaces desired. The occlusal surface depends on the type of
occlusion planned for a particular patient.
Factors that control the selection of the form of posterior teeth are:
(ii) Shape and height of the residual ridge
Types of posterior teeth form are:
• If teeth are arranged in balanced occlusion in centric and eccentric
positions, anatomic teeth are desired.
• If posterior teeth are desired to disocclude in the eccentric jaw
movement and occlude in centric position, anatomic or nonanatomic
• If the posterior teeth are arranged on a flat plane and are desired to
be balanced only in the centric position, nonanatomic teeth are used.
• If a nearly horizontal incisal guidance is selected, shallow posterior
tooth inclines should be selected.
• Try-in of all the anterior teeth aids in the selection of the sizes and
inclines of the posterior teeth.
• Commonly used posterior teeth have cuspal inclines of 33°, 20° or
• The cuspal inclination is measured as the angle formed by the incline of
the mesiobuccal cusp of the lower first molar with the horizontal plane.
• Nonanatomic teeth are used when it is difficult to record jaw relation
or if the patient has abnormal jaw relationships (Table 7-2).
COMPARISON BETWEEN CUSPED AND NONCUSPED TEETH
• It should harmonize with the colour of the anterior teeth.
• Maxillary premolars are more often used for aesthetic purpose than
• Their shade is lighter than other posterior teeth; however, their
shade should never be lighter than that of the anterior teeth.
Material of the posterior teeth
• Artificial posterior teeth can be of various types such as air-fired or
vacuum-fired porcelain, acrylic resin, all-metal or metal occlusal
• Commonly used posterior teeth are the acrylic resin and porcelain
Arrangement of the anterior teeth
• The carved occlusal rims provide a reliable guide for placement of
the anterior teeth in the arch.
• The occlusal rims indicate the anteroposterior and vertical position
of the incisor teeth on the basis of support they provide to the lips
• Period of edentulism is in direct relation with the amount of
resorption which is to be expected.
• As a general rule, in well-rounded ridges, the teeth are placed closer
to the ridge and in highly resorbed ridge the teeth are arranged
farther away from the ridge (Fig. 7-12).
• This is done in order to place the occlusal plane of the teeth in the
same position it occupied when the natural teeth were present.
FIGURE 7-12 Arrangement of tooth in normal and resorbed
Relationship of anterior teeth with the incisive
• Incisive papilla has a constant relationship with the upper central
incisors. It is found in the lingual embrasure between the incisors. It
is used as a guide to position the midline of the upper dental arch.
• It is used as a guide to the anteroposterior position of the teeth.
Relationship of anterior teeth with the soft tissue
• Relationship of the labial surfaces of the anterior teeth with the
reflection of the soft tissues can be used as a guide to place two
• Labial surface of the ridge acts as a guide to determine the
inclination of the anterior teeth.
• Accuracy of this guide decreases as the resorption of the ridge
Factors influencing the positions of the artificial teeth are:
• Functions of surrounding tissues
• Quality of the basal seat tissues
Factors that guide the positioning of the teeth in complete dentures
• Horizontal relation with the residual ridges
• Vertical positions of the occlusal surfaces and the incisal edges
Horizontal relation with residual ridges
• Anteroposterior relations of the maxillary and the mandibular
ridges influence the amount of overjet between the maxillary and
• The cervical end of the maxillary anterior teeth is placed anterior to
• The necks of the mandibular anterior teeth are placed to direct the
vertical force towards the crest of the ridge.
• Arch form is used as a guide for the initial teeth arrangement.
• In tapered arches, the central incisors are arranged further forward
• In square-shaped arches, central incisors are arranged nearly
• In ovoid arches, the anterior teeth are arranged in a gentle curve.
• If anterior teeth are placed too far posteriorly, there is insufficient
support of the lips which will result in drooping down of the
corners of the mouth, deepening of the nasolabial sulcus, wrinkles
above the vermilion border of the upper lip and reduction in the
• If the anterior teeth are placed too far anteriorly, there is excessive
support of the lips resulting in stretched or tight appearance of the
lips, tendency of lips to dislodge the denture during function,
distortion of philtrum, and elimination of the normal contours of
• Past photographs of the patient can be useful during arrangement of
the teeth in correct position.
Positioning of the teeth anteroposteriorly and mediolaterally helps in:
• Providing adequate stability
• Directing forces to the most favourable areas for support
• Providing adequate support to lips and cheeks for aesthetics
• Harmonizing with function of the surrounding tissues
Vertical positions of the maxillary anterior teeth
• Aesthetics and phonetics are used as a guide in arranging the
• When the patient says ‘fifty-five’ the incisal edges of the maxillary
central incisor should contact the vermilion border of the lower lip
at the junction of the moist and dry mucosa.
• The amount of visibility of the upper anterior teeth during speech
and facial expression depends on the length and the movement of
the upper lip in relation to the vertical length of the dental arch.
• If upper lip is long, the visibility of the upper teeth is very less or
• In cases of relatively short upper lip, full crown may be visible (Fig. 7-
• In some cases, the entire crown and the mucous membrane may be
visible while smiling (gummy smile).
• With age, the visibility of the mandibular incisors increases and the
tendency is more in men than in women.
• Lower lip is a better guide for orientation of the anterior teeth than
• In most cases, the tip of the lower canine and the first premolar are
located at the level of the lower lip at the corner of the mouth when
• If the lower teeth lie above the corner of the mouth, one or more of
the following conditions may exist:
• Plane of occlusion may be too high.
• Vertical overlap of the anterior teeth may be
• Vertical space between the jaws may be excessive.
FIGURE 7-13 Diagram showing visibility of teeth in different
lip lines: (A) high lip line; (B) medium lip line; (C) low lip line.
Arrangement of the posterior teeth
• Arrangement of the posterior teeth is greatly influenced by
• Setting of the posterior teeth depends on the following factors:
• Orientation of the occlusal plane
• Shape and position of the arch
• Inclination and rotation of teeth for aesthetics
• Mechanics to obtain proper tooth inclination for
Anatomical landmarks which aid in relocating the centre of the
mandibular alveolar ridges are:
• These are triangles formed by the external oblique lines and the
• This area corresponds to the middle of the retromolar pad in the
• It is a small pear-shaped tissue which lies at the base of the
retromolar pad and is almost at the centre of the residual ridge.
• It is a triangular or pear-shaped pad that is located at the distal end of
• It consists of glandular tissues, fibres of superior constrictor,
buccinator and the temporalis muscle.
• The pterygomandibular raphe enters the pad at the superior medial
• Vertical distance between the base of the pad to the superior border
is the usable guide on the cast.
• It is the cornerstone of the arch.
• Distal surface of the canine is usually rotated in a posterior direction
in line with the centre of the ridge.
• Position of the distal surface of the canine is located by passing a
line parallel to the pupil of the eye and intraorally at the corner of
• These two points are recorded bilaterally on the occlusal rim and
transferred on the lower cast.
With these points, the crest of the alveolar ridge is located and
guide lines are placed on the cast for arrangement of the teeth.
Horizontal positioning of the posterior teeth
• The mandibular arch determines the posterior limit for placing
• Stress-bearing mucosa in the mandible terminates at the retromolar
• No posterior teeth should be placed distal to the retromolar region.
• The stress-bearing mucosa of the mandibular arch lies anterior to
• If the mandible has steep ascent, the distal most posterior teeth
should be placed anterior to this ascent.
• Posterior teeth should never be placed on the incline, as this will
cause dislodgement of the denture.
• The medial limit of mandibular posterior teeth placement is
determined by the medial extension of the mylohyoid ridge.
• If the teeth are placed more lingually, they will encroach into the
• The actions of the tongue, cheeks and aesthetics determine the
lateral limit of arranging the mandibular posterior teeth.
• Maxillary premolar teeth arranged in proper position enhance the
• Buccal surfaces of the maxillary premolar are placed continuous
with the arch of the anterior teeth.
• Mandibular premolars are placed in harmony with the anterior
• Posterior teeth arranged with the proper horizontal overlap support
the cheek and prevent cheek biting.
Vertical positioning of the posterior teeth
When teeth are placed in the correct vertical position, they:
• Provide stability to the denture
• Provide adequate support for the lips and the cheeks
• Enhance compatibility with the activities of the lips, cheek and
Anatomical guides used to establish vertical position of the
Orifice of the duct of parotid gland (Stensen’s duct): The occlusal surface
of the maxillary first molar is measured around quarter inch below
the orifice of the Stensen’s duct.
Retromolar pad: A mark is placed on top of the retromolar pad on
the cast and is extended on the lateral border of the cast to be used as
This is used as a guide to arrange the mandibular posterior teeth; the
occlusal surfaces of the posterior teeth should lie at the centre of this
• Vertical position of the posterior teeth determines the height of the
• The height of the occlusal plane extends from the incisal edge of the
canine to the anterior two-thirds of the retromolar pad. The lingual
cusps of the upper should conform to this line on the mandibular
If occlusal plane is too high, the following are witnessed:
• It causes additional tipping of the mandibular denture.
• It leads to the chances of angular cheilitis because of excessive
pooling of saliva in the lower buccal vestibule.
• It becomes difficult for the tongue and cheeks to maintain food
If the occlusal plane is too low, the following are witnessed:
• Greater chances of tipping of the maxillary denture as upper teeth
will be located at a greater distance from the ridge.
Buccolingual positioning of the posterior teeth
Correct buccolingual placement of the posterior teeth aids in
developing the correct contour of the buccal and lingual borders of the
denture. This aids in denture retention and stability.
Guides used to locate the buccolingual position of the posterior teeth
• Teeth should be placed in the neutral zone (Fig. 7-14).
• Buccal cusp should always be placed over the buccal turning point
of the crest of the lower ridge.
• Lingual cusp should be located within the triangle formed by the
line drawn bilaterally from the mesioincisal angle of the lower
canine to the lingual corner of the retromolar pad.
• Posterior teeth when placed too far buccally tend to dislodge the
denture when vertical forces are applied.
• Posterior teeth when placed too far lingually tend to encroach into
the tongue space and there is a tendency of the denture to be
displaced during normal tongue activity.
FIGURE 7-14 Teeth should be arranged in neutral zone.
Maxillary anterior teeth (fig. 7-15)
• The long axis of the tooth should lie parallel to the vertical axis
• The long axis of the tooth slopes labially when viewed from the side.
• Incisal edge of the tooth should contact the glass plate.
FIGURE 7-15 Arrangement of maxillary anterior teeth: (A)
• Long axis of the tooth slopes labially such that the distal surface is
turned lingually at the considerable angle when viewed from the
• This tooth is inclined distally at the cervical end than any other
• Incisal edge is 2 mm above the horizontal plane.
• Long axis tilts slightly towards the midline when viewed from the
• This tooth is inclined towards the distal end at the cervical end more
than the central incisor and less than the lateral incisor.
• It is rotated in such a way that the distal half of the labial surface
points in the direction of posterior arch form.
• The cervical third of the canine is more prominent than the incisal
• Cusp tip contacts the glass plate (horizontal plane).
Mandibular anterior teeth (fig. 7-16)
• Long axis of the tooth is parallel to the vertical axis when viewed
• Long axis of the tooth slightly tilts labially when viewed from the
• Incisal edge of the tooth is 2 mm above the plane of occlusion.
FIGURE 7-16 Arrangement of mandibular anterior teeth.
• Long axis of the tooth is parallel to the vertical axis when viewed
• Long axis of the tooth tilts labially less than the central incisor,
appears almost perpendicular when viewed from side.
• Incisal edge is 2 mm above the plane of occlusion.
• Long axis of the tooth tilts slightly lingually when viewed from
• Long axis of the tooth tilts slightly mesially when viewed from side.
• Canine tip is 2 mm above the plane of occlusion.
Maxillary posterior teeth (fig. 7-17)
• Long axis is parallel to the vertical axis when viewed from the front
• Buccal cusp contacts the occlusal plane and the palatal cusp is 1 mm
FIGURE 7-17 Transverse view of arrangement of maxillary
• Long axis of the tooth is parallel to the vertical axis when viewed
• Both buccal and palatal cusps are in contact with the horizontal
Comments
Post a Comment
اكتب تعليق حول الموضوع