Download Sheet #17 / Dr.Iyad / Jumana

University of Jordan
Faculty of Dentistry
Fourth year – 2nd semester 2014-2015
Orthodontics
Sheet
Slide
s
Hand Out
Lecture No. 44
Date:
Doctor:
Done by:
24/2/2015
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Dr. eyad
Price & date of printing:
Jumanah alzoubi
Designed by: Hind Alabbadi
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
Introduction:
We should make proper orthodontic assessment to formalize proper treatment plan
,which involve step by step approach to reach proper diagnosis in order to put
accurate comprehensive treatment plan and this will be covered in 4 next lectures
summarizing all things that we took . all things are interrelated in a way that to reach
the diagnosis you have to use the etiology and classification .
 Assessment done by gathering information in systemic way
anything starting with history then clinical examination.
to avoid missing
 One of the main issues is to know how to assess and diagnose , to formalize
proper treatment planning for your patient for orthodontic purposes .
 So to achieve proper treatment plan we should go step by step approach and
proper records taking.
o Step by step approach ,need to collect all the information through history and
clinical examination then take records ,then we need to analyze the records
((making proper analysis + rapport for the records)).
 Proper treatment plan :
I. Records analysis
II. Problem lists :
-you should know what is normal and what is abnormal
-so you should think about what is the
possible
causes
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
-etiology of disease if we have abnormality
o
o
o
o
III. Objectives
Are we going to treat these causes or not??
Are we able to treat these causes or not ??
What is a proper treatment planning??
To know if the patient need appliances or not (fixed ,removable,functional)??
#these are sequential steps ,each time we should follow them .
 Summary:
History
clinical examination
records
data base
List of problems
Treatment
planning
Patient consultation

Note: records involve:
*radiographs *study models *photographs
 Treatment planning depends on:
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Analysis of diagnostic records
Treatment options
appliances used
stability and retention

diagnostic data-base:
o clinical examination: is very important ,this how to discover or inspect
the patient for the problem ,sometimes it is difficult to perform specific
measurements , specific analysis ,specific diagnosis to the patient mouth
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
o
24-2-2015
orthodontic records : so we need records in order to get accurate
diagnosis to the patients mouth .
**done by : -photographs
-dental casts ..how to perform the space analysis(precise objective space analysis)
-radiographs .. to help us to get most relative information as well
-other records
 space analysis : for assessment of crowding
-development assessment of crowding by :1- inspection 2- space analysis using study model
 space analysis :
 space available : - divides arch into segment -use brass wire
 space required: - MD width of all teeth .
-some study’s say that the crowding is the most common problems ,50 % of our
patients have this problem
-crowding …lack of space
*we need to know how much space is required
*how are we going to provide a space? By extraction of teeth mainly
*How we can analyze if there is a space and what is the required space to provide
it??
o Why do we need space in orthodontic??
A. To overcome skeletal problems
B. 20-30 % of patients have increased overjet (protraction of upper
anterior teeth or retraction of lower anterior teeth.)…we need to
correct it into class 1 .
*how much space we require??We will answer this question
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
Clinically, most practical way or method to measure crowding is to measure overlap
between teeth (clinical examination visits just to measure the overlap.
*so the overlapping between the teeth will give how much the crowding in mm?
We have examination about 5-6 mm of lower arch crowding (rough estimation )
Know we should discuss the treatment options with the patient and provide the
consultation, it is improper to do treatment to patient without any discussion the
treatment options with providing the consultation
5-6 mm of crowding ,it is a moderate crowding (the patient is needing extraction
to provide space)
So we should make proper space analysis by study models and discuss the
treatment options with patient.
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
Mixed dentition stage:
 Patient presented with crowding of primary teeth with deviation .(e.g)
 So how do you estimate the size of space for erupted teeth.
 We should make estimation whether there is a space tooth or not ,soit is
important to do proper estimation .
 If you are going to do space analysis ,we should do specific measurements
,to get specific records
 Occlusal planes should be flat or slightly curve of spee in order to have
sufficient space for the erupted teeth
 So space is required to level of the curve ( flat occlusal plane …anteriorly
Curve of spee …posteriorly)
*so again the assessment of crowding which is done by proper analysis
and determine of space required
*when you want to classify the crowding you have to determine :
 The severity (mild /moderate /severe ) according to space present and
space required
 The location ( generalized/ localized)
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 We always start our description with lower arch
 When we analyze ,we always consider PM unit ..equal to 7mm

o Incisor A/P change :
Increased overjet
Allow 2mm space for each 1mm change
Assess lower arch first
Aim to reduce the overjet to 2mm
e.g: 10 mm overjet
the amount of increased overjet is 10-2=8mm
1mm change in overjet …we should leave 2mm as
space, and this is applied per arch.1mm per quadrant .
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
*so we have 8mm of overjet ,amount of space that is needed per area
8*2 ..16mm per arch .
*1mm per quadrant the change
*this to achieve normal overjet
*5mm overjet
-3mm is increased
-we neen 3mm of space per quadrant /3*2=6mm space per arch to get normal
overjet
How to measure the overjet :
Proper size ruler with proper measurement
Highest record we take
From labial surface of upper incisal edges …to labial surface of lower incisors
Dental centerline :
For teeth alignment …the upper midline should coincide with lower midline
Ideally we should diagnose in the pts mouth
*clinically not in the models
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
*so any center line shift need to be corrected by providing space .
*so we should observe molars movement occurred (anterior or posterior )
* how much space we need??
Study models:
A. Pre-treatment record (study models )
B. 3D-assessment of occlusion from all aspects (digital method ,we take
impression by alginate then use ct scanner laser scanners to give an
accurate method design (very accurate method )
C. Considered as reference to assess treatment progress
D. For space analysis (most important one)
 Standardized study models
 Digital: -2D…have distortion ,it is difficult to do measurements

-3D…we use it (laser scanners/ct-scan/photographs)
 We can perform precise and accurate measurement on models
Casts: we look for alignment /space /tooth size analysis and shape of teeth.
Compare between space available inarch+ space required to accommodate the
teeth .
*also we need to compare if we have : excess of space or space shortage
(crowding).
*we also need to compare the size of teeth/shape of teeth ..so we should have
proper molarand incisor relation
*we should make proper space analysis to consider size of the teeth
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
* the study model can be either :
- plaster ( conventional ) .
- digital studying model (3D) :
taking the impression send it to a company which pour it and scan it by laser
scanner and then keep it as a digital record which is very accurate and solve a
storage problem because according to ethics you have to keep the records for at
least 10 years , and for teenager until they become adult so you will end up
having thousands of records. It is also give you 3D on the screen with automated
measurements , faster and time saver
so study models are very important to take , keep and use them .
space analysis
ideally at the end of clinical examination and assessment of study model
you have to determine whether the arch has adequate space to
accommodate all teeth , shortage of space or excess of space .
for permanent dentition
1- the average numbers
according to Weller anatomy we use the average width of the teeth ( for
example the premolar width = 7 mm , the canine width = 8 mm ) .
if the canine is unerupted and we need to be sure that the available space
will be enough for eruption without crowding we measure the available
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
space then compare it with average width and accordingly we decide if
there is any need for intervene or use a space maintainer .
this method only acceptable for quick clinical examination and
consultation , but it is not used for treatment plan .
2- the cast
use it for space analysis for permanent dentition either the arch as whole
or each individual tooth by
1- gauge with two sharp pointed peaks from the distal of the five ( mesial
of the 6 ) on one side to the distal of the 5 on the other side then compare
it with arch shape by segments or arch as whole .
2- brace soft wire
used from the mesial of the 6 in one side to the mesial of the 6 on the
other side
then we compare it with clinical arch space .
inter-molar width not very important .
 To determine the amount of crowding or spacing in an arch :
Subtract the sum of widths of the teeth mesial to the first molars from
sum of arch lengths mesial to the first molars
 Arch length is measured from mesial surface of the first molar on the
right side around arch to the mesial surface of the first molar on the
left side by brass wire or by dividing arch into segments
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
 The amount of crowding can be measured by summing the overlap
between the contact points of the teeth anterior
So assessment of space requirement:
 Crowding and spacing
 Leveling of occlusal planes
 Arch expansion and contraction
24-2-2015
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
 Incisor A/P change: assess the lower arch first and then correct the upper
incisors to overjet 2mm
 Angulation (mesiodistal tip)
Space analysis in mixed dentition:
In the mixed dentition ,the permanent incisors and first molars are erupted ,the
permanent canines and premolars have not erupted. Their mesial-distal widths
can be measured by one of the following :
a. Measurement of the teeth on radiograph
*this requires an undistorted radiograph image ,which is more easily
achieved with individual periapical radiograph than panoramic radiograph
.
True width of primary molar/apparent width of primary molar =
true width of unerupted premolar/apparent width of unerupted
premolar
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
we use the study model to measure the width of erupted tooth then we measure the
width of the same tooth on the radiograph and use it to determine the magnification of
the radiograph ( if the width of the tooth on the radiograph= width of the tooth on the
study model then there is no magnification )
then we measure the width of unerupted tooth on the radiograph and according to
magnitude of magnification we can predict the space needed for the tooth and
compare it with the actual space in the arch.
we can't use the panoramic radiographs because the magnification differ in different
parts but we can use PA's .
using the average number
for example the average space needed for permanent premolars and
canine is 21 and the available arch space is 18 mm there is shortage of
space so we expect crowding .
**used only for consultation.
b. proportional tables
*give good estimation and it is accurate
problems with it:*race sensitive (different between races in the size of
the teeth ))no correlation between sizes
*female and male differences (gender differences))
*in same individual (weak correlation between the teeth themselves
(PMs differ from canines).
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
it is based on longitudinal studies on population to know the
average of all teeth one of the most popular studies in America
and Canada is Moyer 's study
which use the space occupied by erupted permanent lower incisors
( centrals and laterals )- which erupted early - to predict the space
needed for unerupted (3,4,5 )according to certain proportion.
for example we measure the width of lower incisors then we look
for the corresponding number in the table to know the estimated
width of (3,4,5) .
the problems of these tables that they are not friendly used , they
based on estimation , it is race specific so all population need their
own measurements .
3-estimation from equation:
Tanka and Johnson developed another way to use the width of the lower
incisors to predict the size of unerupted canine and premolar as following :
½ of the mesiodistal width of the four lower incisrs + 10.5 =estimated width of
mandibular canine and premolars in one quadrant
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
½ of the mesiodistal width of the four lower incisors +11=estimated width of
maxillary canine and premolars in one quadrant
for example if the width of lower incisors is 20 mm then
the space needed for upper permanent (3,4,5 )= (20/2) + 11 = 21
and the space needed for the lower ( 3,4,5 ) = (20/2 )+ 10.5 = 20.5
we have our own version of Tanka and Johonston ( Jordanian study ) which is
very close to Caucasian of American.
tooth size discrepancy
The tooth size was important to ideal occlusion. In order to obtain the
proper interdigitation and arch coordination when the molars and incisors
are in a Class I relationship, the dimension of the lower teeth has to be
proportional to the dimension of the upper teeth , if there is a tooth size
discrepancy the teeth will not fit each other.
Overall ratio:
Sum of mesiodistal width of mandibular 12 teeth/ sumof mesiodistal width
of maxillary 12 teeth
Mean =91.3%
Anterior ratio:
Sum of mesiodistal width of mandibular 6 teeth /sum of mesiodistal width
of maxillary 6 teeth *100 %
Mean=77.2%
 If the ratio is more than mean then the mandibular tooth material is
excessive
 If the ratio is less than mean value ,then the maxillary tooth material
is excessive
as a general dental practitioner you should be able to examine and diagnose
orthodontics problem then summarize the case in systematic approach
Jumana al-zoubi
lec. # 4 .orthodontic assessment and diagnosis
24-2-2015
we start with history then chief complain( CC ) ,extra oral examination , intra
oral examination , gingival condition , teeth condition ,teeth in occlusion
,describe the lower arch then the upper ( crowded or well aligned ) then
problem list .
good luck
sorry for any mistake
jumanah alzoubi