anthropometric
TRANSCRIPT
ANTHROPOMETRIC MEASUREMENTS IN COMPLETE
DENTURE CONSTRUCTION
Introduction
Esthetics is a primary consideration for patients seeking prosthodontic
treatment. For obtaining an optimal dentolabial relations in harmony with the
overall facial appearance, the dentist should have a thorough knowledge about the
various facial proportions in the population and use these proportions as
guidelines during the construction of complete denture.
Anthropometry is the branch of science that deals body both living and
dead. Various anthropometric measurements are used in the jaw relation stage and
selection and arrangement of teeth in the fabrication of complete Denture
prosthesis.
Facial landmarks and planes used in complete denture construction
Rima oris: - The opening between the lips.
Philtrum: - The vertical furrow in the midline of the upper lip bonded laterally by a
slight ridge.
Labial tubercle: - Is the slight midline protrusion in the red zone of upper lip.
Mentolabial Sulcus: - The horizontal depression midway between the lower
vermillion border and bottom of the chin.
Nasolabial sulcus: - Is a depression in the skin on each side of the face, which runs
angularly outward from the ala of the nose to approximately just outside the
corners of the mouth.
Tragus: - Of the ear is a useful guide to toxate the arbitrary hinge axis point for the
placement of the condylar extension of fascia type of arbitrary face bow. Some
believe the arbitrary centre of condylar rotation is situated 10-13 mm interior to
the posterior margin of tragus on a line joining the superior border (or the middle
of ) the tragus to the outer canthus of eye.
Ala of the nose :- A part of complete denture technique to make tentative on the
actual occlusal plane parallel with the horizontal plane.
Nasion :- It is a skull landmark
It is the deepest part of the midline depression just below the level of eye
brow.
Orbitale :- Lowest point of the infra orbital rim.
Beyron’s point :- On a line extending from the tragus of the ear to the canthus of
eye a point is marked 13 mm interior of posterior margin of the most prominent
point of the tragus. The presumed transverse horizontal axis is assumed to pass
through these point which was termed Begron’s point.
Incisive papilla :- Is a useful landmark for judging the likely site of upper anterior
teeth.
Facial planes used in complete denture construction
Basically the skull is having 3 planes
1. Saggital plane
2. Horizontal plane
3. Frontal plane
THE HYPOTHETICAL AVERAGE POINT
A hypothetical point of known measurements must be established to serve
as a standard to evaluate one technique with other. The hypothetical point is
derived by mathematics and permits evaluation of comparison.
The orientation of the mandible of an upright point in the above mentioned
3 planes of space .
The protrusive condylar inclination is given as 40 degree to the horizontal
plane.
The second molar is located 50mm from the hinge axis as measured along
the horizontal plane and 32 mm below it. The incisal edge of the mandibular
central incisor is 100cm from the hinge axis measured along the horizontal plane
and 32 mm below it.
Frankfort Horizontal plane :- This plane connects the lowest point of the orbit
(orbitale) and superior point of the external auditory meatus (porion).
Camper’s line or Broom well plane
A line from the superior border of the tragus of the ear to the inferior border
of the ala of the nose.
Axis –orbital plane:-
One orbitale and the two posterior points that determine the horizontal axis
of rotation will define the axis orbital plane.
PROPORTIONS USED IN COMPLETE DENTURE CONSTRUCTION
Facial proportion :- A well proportioned face can be divide into 3 equal vertical
Thirds using 4 horizontal planes at the level of
Hair line
Supra orbital ridge
Bone of the nose
Inferior border of chin
With in the lower face, the upper lip occupies a third of the distance while
the chin occupies the rest of the space.
Golden proportion
The ration between the width of the central incisor and lateral should be
established and continue this ratio in the placement of the remaining teeth and
spaces . The golden mean is 1.618.
Lombardi
Was the first to emphasize the importance of order in the distal
composition, with a recurring ration noted between all teeth from central incisor to
the first premolar.
Recurring Esthetic dental proportion
This recently introduced concept states that clinicians may use a proportion
of their own choice as long as it remains consistent, proceeding distally in the
arch.
Uses of Anthropometric measurements in complete denture
Mainly in the
1. Jaw relation stage
2. Selection and arrangement of teeth
Uses in jaw relation stage
Vertical jaw relation
Measurements are made as – Pre extraction record & post extraction
records.
Pre extraction records
Made using
1. Dakoneter: - records both the vertical dimension with the natural teeth
in occlusion and position of the upper central incisors.
2. The Willis Gauge: - used for recording the vertical height before
extraction.
3. Profile tracing :- A piece of soft lead wire is contoured to the face
starting on the brow, following down the nose and lips and ending just
below chin and a profile cut out is made. Two marks are made, one on
incisive edge of centrals.
A line is drawn from this mark at right angles to the straight edge of the card
and on this line 2nd mark is made. The distance from the 2nd mark to the labial
surface of the central incisor is noted.
Post extraction measurements
1. Niswonger (1930) suggested a technique used to measure free way space.
Patient is seated with ala tragal line parallel with the floor. Two marks are
made – one on the upper lip and one on chin.
Measurements are made in relaxed position and with the patient biting the
occlusal rim.
2-4mm freeway space should be obtained.
2. Willis believed that the distance from the pupil of the eye to the rima oris
should be equal to the distance from the base of the nose to the inferior
border of chin, when the bite rims are in contact.
3. Wright (1939):- Suitable photographs of patient are made. He measured
the distance between the pupils and distance from the eye brow to the lower
border of the chin on the photograph. On the patient he measured the
Interpupillary distance. Then he set up a proportional relation of photograph
to patient using the interpupillary distance and applied this proportion to
brow chin distance.
Interpupillay distance of the : photograph
Patients interpupillay = distance
Brow chin distance of : photograph
Patient’s brow –chin distance
4. Distance from the incisive papilla to mandibular incisors
The distance of the papilla to the maxillary central Incisal edge is 6mm.
Usually the vertical (overbite) is 2mm. Hence the distance between the incisive
papilla and lower incisors will be approximately 4 mm. Based on this value the
vertical dimension at occlusion can be calculated.
Measurements used to estimate the location of the terminal hinge axis
Many techniques have been suggested
One popular method is that at a point 13 mm anteriorly from the posterior
border of the tragus along a line connecting the most posterior border of the
tongue to the outer canthus of eye.
Another technique locates it 11mm anteriorly and 3 mm inferiorly to a line
connecting the superior edge of the tragus to the outer canthus of eye.
The Whipmix ear bow- estimates the terminal hinge axis to be 6 mm anteriorly
and 2 mm inferiorly from the anterior border of the external auditory meatus.
It is assumed that an estimated axis location using any of the accepted
techniques will place the position within ± 6 mm of the true axis at 80% level.
Anthropometric measurements used in the selection of anterior teeth
o Anthropometric Cephalic index :- The transverse circumference of
the head is measured using a measuring tape at the level of the
forehead.
o Width of the upper CI= Circumference of head 13
o Berry’s Biometric index :-
The width of the maxillary
Central incisor = Bizygomatic width
16
The width of the maxillary central
Incisor = length of face 20
The bizygomatic width is the distance measured between the molar
prominences on either side, 1-1 ½ inches back of the lateral corner of the eye.
Length is a measure of the distance from the hairline to the lower edge of
the base of chin with the face at rest.
3. A face bow may be utilized to obtain this measurement
Bizygomatic width = Approximal3.3
Width of the 6 anterior teeth arranged on the curve of the properly
contoured occlusal rim .
4. H.Pound’s formula
The width of the mazillary
Central incisor = Bizygomatic width
16
The length of the mazillary
Central incisor = Bizygomatic width
16
5. Based on the width of the nose :-
The width of the nose is measured by Vernier caliper. This
measurement is transferred to the occlusal rim. The width of nose is equal to
the combined width of the anterior teeth.
6. Size of the maxillary arch
The distance between the incisive papilla and hamular notch on one side is
added with the distance between two hamular notches. This given the combined
width of all anterior and posterior teeth of the maxillary arch.
7. Location of canine eminences : A canine eminence is formed in the region
between the canine and the first premolar after extraction of teeth.
The distance between the two canine eminences is measured the residual
ridge . This measured value gives the combined width of the anterior teeth.
8. Location of the buccal frenal attachment: - The attachments of the buccal
frenum are marked on the residual ridge . The distance between the two markings
recorded along the residual ridge gives the combined width of the maxillary
anteriors .
9. Location of the corners of the mouth :- The corner of the mouth are recorded
on the occlusal rim and the distance is measured between these markings. The
anterior teeth are set with these markings .
10. Location of the ala of the nose :- The patients is asked to sit upright and look
straight if line passing through the midpoint between the eyebrows and the
lateral end of the ala of the nose extruded on to the occlusal rim gives the
combined width of the anterior teeth .
Arrangement of anterior teeth
Schiffman has shown that the maxillary incisors. Fall approximately 8-10
mm anterior to the point of intersection of a line that bisects the midline of the
palate perpendicularly through the incisive papilla. This perpendicular bisecting
line also extends outward approximately through the midline of the maxillary
canines.
STUDIES REGARDING THE ANTHROPOMETRIC MEASUREMENTS
Byron.E.Kern (1967):- Examined 509 skulls and concluded that
1. There was no high percentage consistency ratio between bizyagomatic
width of skull and width of crown of the maxillary central incisor .
2. Nasio-menton measurements of the skull was related to the length of the
maxillary central incisor.
3. Measurement of cranial circumference of skulls was related to the width of
maxillary anterior teeth.
4. Extremely high percentage of skulls showed equal measurements between
the nasal width of the four maxillary incisors .
Brain Smith (1975):- Concluded a study on 80 subjects with radiographs
correlating interalar and interalarfold widths of the nose width that of the
intercanine distance and showed that no significant correlation existed
between the inetrcanine distance and the width of the nose would not be a
reliable guide for selecting or arranging anterior tooth .
Harold.R.Ortman(1979):- Studied the relationship between incisive papilla
and maxillary central incisor . He found out that the mean distance
between the most anterior point on the maxillary central incisor and
posterior border of incisive papilla was 12.454mm with a standard
deviation 3.867mm.
Mauroskoufis (1981):- On investigation of 64 dental students showed that
the interalar nasal width could be used as a reliable guide for selecting the
width of anterior teeth and that incisive papilla provides a stable anatomic
land mark for arranging the labial surface of central incisor at 10mm
anterior to the posterior border of papilla. The mesiodistal width of the
set of anterior teeth (4 incisors and mesial halves of the canine) should be
determined by adding 7 mm to the patient’s nasal width.
Ray me Arthur (1985):- conducted a study to determine the relationship
of the maxillary central incisors width when mandibular teeth were
present . He concluded that a factor of 1.62 could be used to select the
appropriate width for missing maxillary central incisor.
G.H. Latta et al (1991) conducted a study measuring the width of the outh,
interalar width, Bizyqomatic width and interpapillary distance in edentulous
patients. No correlation was found between widths for the population as a
whole nor when the population was further divided by races, sex or groups.
Daniel .H.Ward (2001):- He stated that when golden proportion is used,
lateral incisor seems to be too narrow and canine is not predominant
enough. This author has proposed a RED proportion ie recurring Esthetic
Dental proportion . According to this the dentist can establish his own
proportion and remain consistent while moving distally .
In Endomorph – use higher proportion
Ectomorph – use lower proportion
REFERENCE:-
Zarb G A, Bolender C L, Carlsson G E : Bouchers Prosthodontic
treatment for edentulous patients 11th Ed, Mosby Inc 1997.
Rahn A O, Heartwell C M: Textbook of complete dentures 5th Ed
Sheldon Winkler: Essentials of complete denture prosthodontics 2nd Ed,
Ishiyaku Euro America Inc 1996.
Bernard Levin: Impressions for complete dentures Quintessence
publishing Co 1984.
Neill D J, Nairn R I: Complete denture prosthetics 3rd Ed, Wright
publishing Co 1990.
David Lamb: Problems and solutions in complete denture prosthodontics,
Quintessence publishing Co 1993.
Halperin A R, Graser G N, Rogoff G S: Mastering the art of complete
dentures, Quintessence publishing Co 1988.