2. Bolton analysis:
“developed by Wayne A. Bolton”
“Also known as tooth size analysis”.
DEFINATION;
A type of analysis use to determine the difference in size
between mandibular and maxillary teeth.
It helps in determining the ideal relationship within the
interarch.
4. Bolton Analysis:
Method;
Measure mesiodistal width of all teeth in maxilla and
mandible from first molar to first molar
Add the widths of teeth in mandible and maxilla
separately
5. Bolton Analysis
Overall RatioX:
Desired sum of mandibular 12 = actual sum of
maxillary12/100×91.3.
If X>91.3
Overall mandibular tooth excess =
Actual sum of mandibular 12 - desired sum of
mandibular 12 = ------mm
6. Desired sum of max 12 = actual sum of mandibular 12
× 100/91.5
if X<91.3
Overall maxillary tooth material excess =
Actual sum of max 12 – desired sum of max 12 = ------
mm.
7. Anterior Ratio Y;
Measured from canine to canine
Y = Sum of mesodistal width of mandibular anterior teeth 6/sum of
maxillary 6 of posterior teeth ×100
Anterior ratio=
Desired sum of mandibular 6 =actual sum of maxillary 6 ×
77.2/100
if y<77.2 indicates mandibular tooth excess;
Anterior mandibular tooth excess =
Actual sum of mandibular 6 - desired sum of mandibular 6 = ---
mm
8. If ratio of Y > 71.2 indicates maxillary teeth excess.
Anterior maxillary tooth material excess =
Actual sum of max 6 – desired sum of max 6 = -------mm
9. Exception; Excludes second and
third molar.
A standard table is then used to compare to
summed up widths of maxillary and mandibular
teeth(canine to canine).
