Seminar on,

Diagnostic Set up
Panoramic Radiography
Xeroradiography
Clark’s technique
INDIAN DENTAL ACADEMY
Leader in con...
DIAGNOSTIC SET UP
 Practical aid in treatment planning and
diagnosis.

 Proposed by H.D. Kesling
 It’s a procedure in w...
Advantages –
1. To determine and visualise the resultant
occlusion before the teeth have been extracted
2. Possible to cha...
4. Tooth size – arch length discrepancies can be
visualised by means of set up.
5. Also a step in construction of tooth po...
Procedure
A set of well trimmed models made of deep
impressions of teeth and soft tissues.
Lines are drawn through bucca...
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 The lower first permanent molars are replaced to a new
position they will occupy by mesial migration.
 Deciding lower f...
 After all the above points have been considered, the
orthodontist must anticipate the behaviour of anchor
molar during t...
 Maxillary teeth are arranged according to mandibular
teeth to obtain best possible occlusion.

 In most cases, same no....
‘A Simplified wax set up technique’
by R.W. Knierim JCO- 1975
According to his procedure –
 Plaster is filled to about 4 ...
 Teeth are then separated using discs on a lathe to
slice root area, most teeth will now snap apart.
 Root areas are the...
 The trimmed dies are then reinserted in air dried alginate
impression

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 Melted wax is then poured in impression holding the
dies, it should flow well in grooves.

.

www.indiandentalacademy.co...
 Similar grooves are then placed in surface of wax
as it hardens

 Plaster is poured over wax surface to make base for m...
‘A simplified Diagnostic set up technique.’ by Dr.
Barry N. Resnick; 1979 JCO
 According to his procedure –
 The plaster...
 Original study model.

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 Alginate impression with
selected teeth poured up
in stone to the extent of
their clinical crowns.

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 Dental units and model
base connected by
periphery wax.

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 Diagnostic set up with
mandibular left lateral
incisor removed and
remaining teeth aligned.

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Panoramic
Radiography

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Panoramic Radiography
 Also called as Ortho pantomograph (OPG)
 Rotational Radiography.
 It is a radiographic technique...
Advantages1. Broad anatomic coverage
2. Simple procedure
3. Better tolerated by pts with gagging problems
4. Low radiation...
Disadvantages
1.

Magnification, Geometric distortion and overlapped
images.

2.

Resolution of fine anatomic details of p...
Indications
1.
2.
3.
4.
5.
6.

To assess pattern and amount of root resorption of
deciduous teeth.
Useful in mixed dentiti...
7. To study morphology and angulations of roots of
permanent teeth.
8. To study the path of eruption of teeth.
9. To diagn...
 To interpret OPG competently one
must have a thorough understanding
of the following :
1. Principles of Panoramic image ...
Principles of Panoramic image formation
 First described by Numata and independently by
Paatero in late 1940s.

Movement ...
Movement of film and X- ray source about one
fixed center of rotation.

 While disc 2 moves, the film on this disc rotate...
Movement of the film and x-ray source
about the shifting center of rotation.

 Structures near the film will be sharply i...
Rotational Panaromic radiographic
machines.

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Focal Trough
 It’s a 3-D curved zone or image layer in which
structures are reasonably well defined on OPG.
 The images ...
 Ring at center
of FT.

 Ring 5mm
anterior to FT

 Ring 5 mm
posterior to FT

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Patient positioning and Head alignment.
 Prepration of Patients.
– Removal of earrings or any other metallic objects in h...
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If anterior teeth are located behind the FT
- Blurred
- Wide anterior teeth

If anterior teeth are located infront of the ...
If skull tipped too far backward

Position the skull according to FH plane and check for
www.indiandentalacademy.com
occlu...
Correct position using bite block

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If skull tipped too far forward

Position the skull according to FH plane and check for
occlusal plane
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Deviation in mid sagittal plane

Asymmetric image

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Positioning of the Tongue

Pt should press tongue against palate
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Radiation dose reduction
 By using rare-earth intensifying screens.
 Reduce the output by using filters infront of x-ray...
Positioning in mixed dentition stage
•The tooth buds should be in FT
•If additional supernumerary teeth
or impacted teeth ...
Radiographic appearance of
normal Anatomy

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The four Diagnostic regions in OPG
Dentoalveolar region

Mandibular region

TMJ,including retromaxillary
www.indiandentala...
Maxillary
region

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Mandibular
region

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Dentoalveolar region

• Shape and angulation of roots.
• Alveolar bone and periodontium
• Shows gentle curve of occlusal p...
Soft tissue images

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Air spaces

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Xeroradiography

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Xeroradiography


Xeroradiography is the recording of
radiologic images by a photoelectric process
rather than the photoc...
Advantages
Pronounced edge enhancement
A choice of positive and negative display
Good detail
Wide exposure latitude
N...
Types of Xeroradiographic systems
 Two types –
1. The Medical 125 system
– Used since 1970s.
– Used manly in Mammography ...
Medical Xeroradiography
Conventional X-ray source is needed.
Image is recorded on Selenium coated plate.
Before use, Se...
Processing of Xeroplate before exposure

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Exposure of Xeroplate

Latent image

Latent image is converted to visible image by
process called Development, in unit cal...
Development of Image

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Positive Image
 Darkest areas corresponds to most dense parts of anatomy.

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Negative image
 Darkest areas corresponds to least dense parts of anatomy
and dense objects appear white.

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Dental Xeroradiography
 Dental 110 xeroradiogrphic unit system is similar to
medical 125 system in concept but its design...
Dental xeroradiographic processor.

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Dental Xeroradiographic procedure.

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Radiologic exposure conditions and resultant skin doses
in application of Xeroradiography to Orthodontic
diagnosis. AJO-DO...
 The advantages were–

finer and clearer images due to edge effect and wider
latitude.

– Landmarks on cephlaogram such a...
A cephalometric appraisal of Xeroradiography
by Chate – AJO-DO 1980
Aim : To estimate the effect of xeroradiographic techn...
Clark’s technique

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Localization technique
 Two methods are used in dentistry to obtain
3-D information –
1. To employ two films projected at...
Clark’s technique
C.A Clark described it in 1910.
Its based on Parallax principle.
In this , 2 periapical films are tak...
The apparent movement of the object in this
radiograph will provide clue to its exact
location.
According to rule of thu...
Horizontal shift of central ray
Distal shift of cone

Cone shift

Cone shift

Standard
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Standa...
Vertical shift of central ray

Standard

Standard

Vertical shift
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Vertical shift
INDICES

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Index
According to Russell, an index is defined as
‘A numerical value describing the relative status
of the population on ...
Requirements of ideal orthodontic index are –
(Jamison H.D. and Mc Millan R.S )
1. Simple, reliable and reproducible.
2. O...
Types of Indices ( according to WHO)
 Occlusal Classification
– Angle’s classification by Angle in 1899
– Incisor classif...
 Treatment assessment
– Little’s irregularity index by Little 1975
– Peer Assessment rating by Richmond et al, 1992
 Cle...
Types Of Indices
According to Shaw , Richmond and O’Brien
 Diagnostic Classification
– Angle’s classification
– Incisor c...
 Treatment need ( Treatment priority) indices.
– Categorize malocclusion according to levels of treatment
needs.
– Eg 1. ...
Various indices of Occlusion
Master and Frankel (1951)
– Count the number of teeth displaced or
rotated
– Qualitative ass...
Handicapping Labio – Lingual deviation index
 Proposed to select subjects with severe or handicapping
malocclusions and d...
Conditions observed
1.
2.
3.
4.
5.
6.
7.
8.
9.

Cleft palate
Severe Traumatic deviations
Overjet in mm
Overbite in mm
Mand...
Handicapping Labio – Lingual deviation index
by Draker (1960)
 Modification of earlier used HLD index
 Main aim is to fi...
7 conditions of HLD index are 1.
2.
3.
4.
5.
6.
7.

Cleft palate
Traumatic deviations
Overjet
Overbite
Mandibular protrusi...
Occlusal index by Summers (1966)


Used to assess severity of malocclusion in population



Nine weighted and defined me...
 Seven malocclusion syndromes defined
1.
2.
3.
4.
5.
6.
7.



Overjet and open bite
Distal molar relation, overjet, over...
Treatment priority index by Grainger
(1967)
 The precursor of the TPI was the Malocclusion Severity
Estimate (MSE) develo...
Treatment priority index by Grainger (1967)

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.

11 weighted and defined measurements –
U...
Seven malocclusion syndromes were defined 1.
2.
3.
4.
5.
6.
7.

Prognathism
Retrognathism
Overbite
Openbite
Maxillary expa...
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 TPI is based on a scale of
1.
2.
3.
4.

0 (near ideal occlusion)
1 - 3 ( mild malocclusion)
4 – 6 ( Moderate malocclusio...
Handicapping malocclusion assessment
records by Salzmann (1968)


1.

The purpose of HMAR – To establish priority for
tr...
3. Six handicapping dento-facial deformities
1.
2.
3.
4.
5.
6.

Facial and oral clefts
Lower lip palatal to maxillary inci...
Instruction for Scoring

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Peer assessment rating Index (PAR index)
Index of orthodontic treatment outcome



Developed by 10 experienced British or...
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5 components-

Weighting
1. Upper & lower anterior segment - 1
2. Left and right buccal segments 1
3. Over jet
- 6
4. Ove...

1.
2.




Change expressed as:
Reduction in weighted PAR score : 22 point
reduction – Greatly improved
% reduction in ...
TheValidation of PAR for Malocclusion severity
and Treatment Difficulty
De Guzman,bahiraei, Vig, Weyant and O’Brien – AJO-...
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Index of Treatment Need (IOTN)
by Shaw
 Index has two components1.
2.



Dental Health component – derived from occlusio...
A special ruler summarizes the information
needed for dental health component.
 Assessed in order :
1. Missing teeth
2. ...
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www.indiandentalacademy.com
Esthetic Index
 Grades 8 – 10 =
definite need for
treatment.
 5 – 7 = moderate/
borderline need
 1 – 4 = No/ slight
nee...
Limitations
1.
2.
3.

In aesthetic component ,Class III not considered.
Facial profile not considered.
Class I bimaxillary...
Index of Complexity Outcome and Need
(ICON)


Based on expert opinions of 97 orthodontists from
various countries.



Fo...
 5 components taking about 1 min to measure.
1. Aesthetic component
 10 pictures

1. Upper arch Crowding/ Spacing
 Scor...
1. Aesthetic component

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ICON Scoring Method

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Limitations
1.
2.
3.

Overjet not considered.
Lower anterior crowding not considered.
Midline shift not taken in account.
...
A dental-facial attractiveness
scale
Tedesco, Albino, Cunat AJO-DO 1983
 The purpose of this study was to develop a valid...
Standard photographs of white males for points 1 (most
attractive) through 5 (least attractive) on the dental-facial
attra...
.
 Children were also assessed for severity of malocclusion
by means of the Treatment Priority Index
 Children seeking t...
Goslon yardstick :A new system of assessing
dental arch relationships in childeren with UCLP – Michael
Mars, Dennis A. Pli...

1.
2.
3.




Development of Yardstick – Clinical features
considered most important in characterizing
malocclusion in ...
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 Group 1 – excellent





Group 2 – good
Group 3 – fair
Group 4 – poor
Group 5 – very poor

 Group 1 or 2 - simple o...
References (Diagnostic set up)
1.
2.
3.
4.

Begg Orthodontics Theory & Technique – Kesling
Diagnosis and treatment plannin...
References (Radiology)
1.
2.
3.
4.
5.
6.

7.

Oral radiology – Goaz & White.
A Colour Atlas of Dental Radiology – Friedric...
References ( indices)
1.
2.
3.

Contemporary Orthodontics – Proffit
M Ortho Journal – Bristol University
Longitudinal eval...
7. Handicapping Malocclusion assessment to establish
treatment Priority J A Salzmann – AJO –1964
8. The use of Occlusal In...
Thank you
For more details please visit
www.indiandentalacademy.com

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Diagnostic setup. opg, xeroradiography,clarks technique /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
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Diagnostic setup. opg, xeroradiography,clarks technique /certified fixed orthodontic courses by Indian dental academy

  1. 1. Seminar on, Diagnostic Set up Panoramic Radiography Xeroradiography Clark’s technique INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. DIAGNOSTIC SET UP  Practical aid in treatment planning and diagnosis.  Proposed by H.D. Kesling  It’s a procedure in which teeth are removed and replaced in positions they will occupy after experiencing mesial migration in an orthodontic environment. www.indiandentalacademy.com
  3. 3. Advantages – 1. To determine and visualise the resultant occlusion before the teeth have been extracted 2. Possible to change the treatment plan on the model by replacing some and removing other teeth so that one can thoroughly examine all possible occlusions. 3. Mainly useful in asymmetric extraction and combined surgical orthodontic treatment. www.indiandentalacademy.com
  4. 4. 4. Tooth size – arch length discrepancies can be visualised by means of set up. 5. Also a step in construction of tooth positioner. 6. Patient can be motivated . www.indiandentalacademy.com
  5. 5. Procedure A set of well trimmed models made of deep impressions of teeth and soft tissues. Lines are drawn through buccal groove on the mandibular first molars on to the soft tissue. This act as a reference point. A . 004 inch ribbon saw blade is used to cut through the contact areas and separate teeth. www.indiandentalacademy.com
  6. 6. www.indiandentalacademy.com
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  9. 9. www.indiandentalacademy.com
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  11. 11.  The lower first permanent molars are replaced to a new position they will occupy by mesial migration.  Deciding lower first molar position is the most important decision in constructing the set up.  Factors influencing position of first molar set up are – – Size of the teeth – Presence or absence of tooth crowding mesial to anchor molars. – Procumbency of anterior teeth. – Missing teeth – Age of the patient – Treatment plan – Tooth size related to jaw size. www.indiandentalacademy.com
  12. 12.  After all the above points have been considered, the orthodontist must anticipate the behaviour of anchor molar during treatment.  It again depends on – – – – – Technique employed The time requirement Orthodontist’s ability Patient’s cooperation  At this stage by studying the set up one can analyse that If anterior teeth – too far forward – Extraction – If already extracted – more extraction.  If anterior teeth – lingual – Eliminate planned extraction. www.indiandentalacademy.com
  13. 13.  Maxillary teeth are arranged according to mandibular teeth to obtain best possible occlusion.  In most cases, same no. and type of teeth are removed from maxillary arch as mandibular arch.  Exception – – Badly broken down teeth – Congenitally missing or deformed teeth. – Single tooth extraction in lower arch www.indiandentalacademy.com
  14. 14. ‘A Simplified wax set up technique’ by R.W. Knierim JCO- 1975 According to his procedure –  Plaster is filled to about 4 mm over gingival margin of impression.  As the plaster sets rough grooves are made in near set plaster to depth of 2mm.  When plaster is set it is removed and teeth are numbered. www.indiandentalacademy.com
  15. 15.  Teeth are then separated using discs on a lathe to slice root area, most teeth will now snap apart.  Root areas are then trimmed.  The impression are saved and kept moist. www.indiandentalacademy.com
  16. 16.  The trimmed dies are then reinserted in air dried alginate impression www.indiandentalacademy.com
  17. 17.  Melted wax is then poured in impression holding the dies, it should flow well in grooves. . www.indiandentalacademy.com
  18. 18.  Similar grooves are then placed in surface of wax as it hardens  Plaster is poured over wax surface to make base for model. www.indiandentalacademy.com
  19. 19. ‘A simplified Diagnostic set up technique.’ by Dr. Barry N. Resnick; 1979 JCO  According to his procedure –  The plaster is poured in impression only to the extent of clinical crown.  Soft wax of 5 mm thickness is poured over crown dies.  Remainder of impression is poured with plaster and allowed to set.  After separation from impression, the model consists of two plaster section connected by wax.  Teeth are marked and can be repositioned in desired way www.indiandentalacademy.com
  20. 20.  Original study model. www.indiandentalacademy.com
  21. 21.  Alginate impression with selected teeth poured up in stone to the extent of their clinical crowns. www.indiandentalacademy.com
  22. 22.  Dental units and model base connected by periphery wax. www.indiandentalacademy.com
  23. 23.  Diagnostic set up with mandibular left lateral incisor removed and remaining teeth aligned. www.indiandentalacademy.com
  24. 24. Panoramic Radiography www.indiandentalacademy.com
  25. 25. Panoramic Radiography  Also called as Ortho pantomograph (OPG)  Rotational Radiography.  It is a radiographic technique for producing single image of facial structures that includes both maxillary and mandibular arches and their supporting structures. www.indiandentalacademy.com
  26. 26. Advantages1. Broad anatomic coverage 2. Simple procedure 3. Better tolerated by pts with gagging problems 4. Low radiation dose 5. Convenience of the examination. 6. Useful in pts who are unable to open their mouth 7. Full mouth IOPA – 15 mins and OPG – 3-4 mins. www.indiandentalacademy.com
  27. 27. Disadvantages 1. Magnification, Geometric distortion and overlapped images. 2. Resolution of fine anatomic details of peri-apical area and periodontal structures is less. 3. Poor image is obtained when sharp inclination of anterior teeth towards labial or lingual side. 4. The spinal cord superimpose on anterior region. 5. Common to have overlapped teeth images , particularly in premolar area. 6. Artifacts are common and may easily be misinterpreted. 7. Expensive www.indiandentalacademy.com
  28. 28. Indications 1. 2. 3. 4. 5. 6. To assess pattern and amount of root resorption of deciduous teeth. Useful in mixed dentition period to study the status of unerupted teeth. Presence or absence of permanent teeth: their size, shape, position and relative state of development. To view ankylosed and impacted teeth. To diagnose presence of supernumerary teeth or congenital absence of teeth. To study the character of alveolar bone and immediate lamina dura and periodontal membrane. www.indiandentalacademy.com
  29. 29. 7. To study morphology and angulations of roots of permanent teeth. 8. To study the path of eruption of teeth. 9. To diagnose fractures or pathologies of jaw. 10. To diagnose caries, periapical infections root fractures etc. 11. Useful aid in serial extraction to study status of eruption of teeth. 12. Can assess TMJ and Sinuses. 13. Assess shape, size and symmetry of condyles. www.indiandentalacademy.com
  30. 30.  To interpret OPG competently one must have a thorough understanding of the following : 1. Principles of Panoramic image formation. 2. Techniques for Patient positioning with head alignment and their rationale. 3. Radiographic appearance of normal anatomic structures. www.indiandentalacademy.com
  31. 31. Principles of Panoramic image formation  First described by Numata and independently by Paatero in late 1940s. Movement of the film and objects about 2 fixed centers of rotation. www.indiandentalacademy.com
  32. 32. Movement of film and X- ray source about one fixed center of rotation.  While disc 2 moves, the film on this disc rotates past the slit.  It is critical that speed of the film passing the collimator slit is maintained equal to the speed at which x-ray beam sweeps through the object of interest. www.indiandentalacademy.com
  33. 33. Movement of the film and x-ray source about the shifting center of rotation.  Structures near the film will be sharply imaged.  Structures which are near x-ray source get magnified and distorted and resultant image is not discrete. www.indiandentalacademy.com
  34. 34. Rotational Panaromic radiographic machines. www.indiandentalacademy.com
  35. 35. Focal Trough  It’s a 3-D curved zone or image layer in which structures are reasonably well defined on OPG.  The images seen on OPG consists largely of anatomic structures located within the focal trough.  Objects out of focal trough are blurred magnified/ reduced or distorted.  The shape of focal trough varies with brands of machines used. www.indiandentalacademy.com
  36. 36.  Ring at center of FT.  Ring 5mm anterior to FT  Ring 5 mm posterior to FT www.indiandentalacademy.com
  37. 37. Patient positioning and Head alignment.  Prepration of Patients. – Removal of earrings or any other metallic objects in head and neck region. – Instruct patients to remain still. – Drape with lead apron.  Patient Positioning – Place the pt so that dental arches are located in middle of focal trough. – A-P positioning – by biting at bite block. – Proper mid sagittal plane –proper head positioning – cephalostat. – Occlusal plane and chin must be properly positioned – FH plane parallel with floor.. – Back and spine be erect with neck extended. www.indiandentalacademy.com
  38. 38. www.indiandentalacademy.com
  39. 39. www.indiandentalacademy.com
  40. 40. If anterior teeth are located behind the FT - Blurred - Wide anterior teeth If anterior teeth are located infront of the FT -Blurred -Narrow anterior teeth www.indiandentalacademy.com
  41. 41. If skull tipped too far backward Position the skull according to FH plane and check for www.indiandentalacademy.com occlusal plane
  42. 42. Correct position using bite block www.indiandentalacademy.com
  43. 43. If skull tipped too far forward Position the skull according to FH plane and check for occlusal plane www.indiandentalacademy.com
  44. 44. Deviation in mid sagittal plane Asymmetric image www.indiandentalacademy.com
  45. 45. Positioning of the Tongue Pt should press tongue against palate www.indiandentalacademy.com
  46. 46. Radiation dose reduction  By using rare-earth intensifying screens.  Reduce the output by using filters infront of x-ray tube. Eg. Lanex screens. www.indiandentalacademy.com
  47. 47. Positioning in mixed dentition stage •The tooth buds should be in FT •If additional supernumerary teeth or impacted teeth has to be shown the pt must be positioned with occlusal plane steeply dorsally www.indiandentalacademy.com
  48. 48. Radiographic appearance of normal Anatomy www.indiandentalacademy.com
  49. 49. The four Diagnostic regions in OPG Dentoalveolar region Mandibular region TMJ,including retromaxillary www.indiandentalacademy.com and cervical region Maxillary region
  50. 50. Maxillary region www.indiandentalacademy.com
  51. 51. Mandibular region www.indiandentalacademy.com
  52. 52. Dentoalveolar region • Shape and angulation of roots. • Alveolar bone and periodontium • Shows gentle curve of occlusal plane • Missing 3rd molars and • Presence of metallic restorations. www.indiandentalacademy.com
  53. 53. Soft tissue images www.indiandentalacademy.com
  54. 54. Air spaces www.indiandentalacademy.com
  55. 55. Xeroradiography www.indiandentalacademy.com
  56. 56. Xeroradiography  Xeroradiography is the recording of radiologic images by a photoelectric process rather than the photochemical one used in conventional radiography. An electrostatic image of object is formed on a ‘ Xeroplate’ , a metallic plate coated with Selenium. An electrostatic image is printed on a paper in such a manner that xeroradiograph is obtained. www.indiandentalacademy.com
  57. 57. Advantages Pronounced edge enhancement A choice of positive and negative display Good detail Wide exposure latitude No need of silver halide coated films. Disadvantages High radiation exposure www.indiandentalacademy.com
  58. 58. Types of Xeroradiographic systems  Two types – 1. The Medical 125 system – Used since 1970s. – Used manly in Mammography and general radiography. – Also been used for Cephalometric radiography and Tomography of TMJ 1. The Dental 110 system  Designed for dental Xeroradiographs www.indiandentalacademy.com
  59. 59. Medical Xeroradiography Conventional X-ray source is needed. Image is recorded on Selenium coated plate. Before use, Selenium photoreceptors which are stored in a unit called conditioner are given a uniform electrostatic charge www.indiandentalacademy.com
  60. 60. Processing of Xeroplate before exposure www.indiandentalacademy.com
  61. 61. Exposure of Xeroplate Latent image Latent image is converted to visible image by process called Development, in unit called Processor www.indiandentalacademy.com
  62. 62. Development of Image www.indiandentalacademy.com
  63. 63. Positive Image  Darkest areas corresponds to most dense parts of anatomy. www.indiandentalacademy.com
  64. 64. Negative image  Darkest areas corresponds to least dense parts of anatomy and dense objects appear white. www.indiandentalacademy.com
  65. 65. Dental Xeroradiography  Dental 110 xeroradiogrphic unit system is similar to medical 125 system in concept but its design is physically different.  The image receptor plates are the size no. 1 and no. 2 films and fit well in oral cavity. www.indiandentalacademy.com
  66. 66. Dental xeroradiographic processor. www.indiandentalacademy.com
  67. 67. Dental Xeroradiographic procedure. www.indiandentalacademy.com
  68. 68. Radiologic exposure conditions and resultant skin doses in application of Xeroradiography to Orthodontic diagnosis. AJO-DO, 1980 by Akihiko Nakasima (Japan ) Minimum xeroradiologic exposure conditions for Skull projections, Schuller’s and TMJ projections and Hand projections were established by 13 examiners.  Relation b/w image production and radiation dose was discussed in comparison with conventional film techniques. www.indiandentalacademy.com
  69. 69.  The advantages were– finer and clearer images due to edge effect and wider latitude. – Landmarks on cephlaogram such as Sella, ANS,Basion, etc were more clear and exactly set. – Outline of condylar process and articular fossa, the trabecular pattern of mandible and interdental crestal bone edges were more clear and distinct.  The main hazard was unavoidable larger skin radiation dose . It was 2.4 to 16.2 times larger than conventional film techniques. www.indiandentalacademy.com
  70. 70. A cephalometric appraisal of Xeroradiography by Chate – AJO-DO 1980 Aim : To estimate the effect of xeroradiographic technique on the degree of inter and intra observer error in cephalometric landmarks identification. Method This study involved identification by four observers of 16 cephalometric landmarks on 12 xeroradiographs & on 12 radiographs, on 2 separate occasions. Conclusion  Neither technique provided a significant decrease in interobserver differences.  However, for 8 of 32 variables, xeroradiography produced a significant reduction in intraobserver error in comparison to radiography. www.indiandentalacademy.com
  71. 71. Clark’s technique www.indiandentalacademy.com
  72. 72. Localization technique  Two methods are used in dentistry to obtain 3-D information – 1. To employ two films projected at right angle to each other. 2. Tube shift/cone shift principle or Clark’s technique or buccal object rule or SLOB rule.  Mainly used in Orthodontia to locate position of impacted canine. www.indiandentalacademy.com
  73. 73. Clark’s technique C.A Clark described it in 1910. Its based on Parallax principle. In this , 2 periapical films are taken, – First, standard orthoradial projection, – Second, employs a vertical or horizontal change in central ray projection. www.indiandentalacademy.com
  74. 74. The apparent movement of the object in this radiograph will provide clue to its exact location. According to rule of thumb objects which moves with central ray movement are actually behind the reference object. Its basis of SLOB rule, that is Same side Lingual Opposite side Buccal www.indiandentalacademy.com
  75. 75. Horizontal shift of central ray Distal shift of cone Cone shift Cone shift Standard www.indiandentalacademy.com Standard
  76. 76. Vertical shift of central ray Standard Standard Vertical shift www.indiandentalacademy.com Vertical shift
  77. 77. INDICES www.indiandentalacademy.com
  78. 78. Index According to Russell, an index is defined as ‘A numerical value describing the relative status of the population on a graduated scale with definite upper and lower limits which is designed to permit and facilitate comparison with other population classified with the same criteria and the method.’ In the orthodontic context index is described as – ‘A rating or categorizing system that assigns a numeric score or alpha numeric label to a person’s occlusion.’ www.indiandentalacademy.com
  79. 79. Requirements of ideal orthodontic index are – (Jamison H.D. and Mc Millan R.S ) 1. Simple, reliable and reproducible. 2. Objective and yield quantitative data. 3. Differentiate b/w handicapping and non handicapping malocclusions. 4. Measure degree of handicap. 5. Quick examination. 6. Amenable to modifications. 7. Usable either on patient or on study model. www.indiandentalacademy.com
  80. 80. Types of Indices ( according to WHO)  Occlusal Classification – Angle’s classification by Angle in 1899 – Incisor classification by Ballard and Wayman, 1964  Skeletal classification by Houston et al, 1993  Malocclusion – Occlusal index by Summers 1966 – Handicapping Malocclusion Assessment Record (HMAR) by Salzmann, 1968 – Index of Treatment Need by Evans and Shaw 1987 www.indiandentalacademy.com
  81. 81.  Treatment assessment – Little’s irregularity index by Little 1975 – Peer Assessment rating by Richmond et al, 1992  Cleft Outcome – Goslon Yardstick by Mars et al, 1987 – 5Year olds’ Index by Atack et al ,1997  Periodontal – Plaque Index by Stilness & Loe , 1964 – Gingival Index. by Loe & Stilness, 1963 www.indiandentalacademy.com
  82. 82. Types Of Indices According to Shaw , Richmond and O’Brien  Diagnostic Classification – Angle’s classification – Incisor classification  Epidemiologic indices – Study prevalence of malocclusion in population. – Eg 1.Summer’s occlusal index. 2. Registration of malocclusion described by Bjork, Krebs and Solow www.indiandentalacademy.com
  83. 83.  Treatment need ( Treatment priority) indices. – Categorize malocclusion according to levels of treatment needs. – Eg 1. Index Of Treatment Need (IOTN) 2. Draker’s Handicapping Labio – Lingual Deviation index (HLD) 3. Grainger’s Treatment Priority Index.(TPI) 4. Salzmann’s Handicapping Malocclusion Index  Treatment outcome indices. – Assesssment of changes resulting from treatment – Eg 1. Peer Assessment Rating index 2. Summer’s index  Treatment complexity index – Index of Complexity Outcome and Need (ICON) www.indiandentalacademy.com
  84. 84. Various indices of Occlusion Master and Frankel (1951) – Count the number of teeth displaced or rotated – Qualitative assessment Malalignment Index byVankrik and Pennel (1959) – Tooth displacement and rotations were measured. www.indiandentalacademy.com
  85. 85. Handicapping Labio – Lingual deviation index  Proposed to select subjects with severe or handicapping malocclusions and dentofacial anomalies.  Applicable only to permanent dentition  First Orthodontic index to meet administrative needs of programme planners.  Made use of weighting factors developed by trial and error.  Had 9 components www.indiandentalacademy.com
  86. 86. Conditions observed 1. 2. 3. 4. 5. 6. 7. 8. 9. Cleft palate Severe Traumatic deviations Overjet in mm Overbite in mm Mandibular protrusion in mm Open bite in mm Ectopic eruption ,Anteriors only Anterior crowding : Maxilla Anterior crowding : Mandible TOTAL www.indiandentalacademy.com HLD score Score 15 Score 15 x5 x4 x3
  87. 87. Handicapping Labio – Lingual deviation index by Draker (1960)  Modification of earlier used HLD index  Main aim is to find presence or absence and degree of handicap caused by components of index.  Has 7 components.  All measurements are made with Boley gauge scaled in mm.  A score of 13 and over constitutes physical handicap www.indiandentalacademy.com
  88. 88. 7 conditions of HLD index are 1. 2. 3. 4. 5. 6. 7. Cleft palate Traumatic deviations Overjet Overbite Mandibular protrusion Open bite Labio Lingual spread Following codes are used –  ‘O’ = condition present  ‘X’ = condition absent  ‘M’= mixed dentition  ‘A’= Clinical approval  ‘D’=Clinical disapproval www.indiandentalacademy.com
  89. 89. Occlusal index by Summers (1966)  Used to assess severity of malocclusion in population  Nine weighted and defined measurements – Molar relation Over jet Overbite Posterior cross bite Posterior open bite Tooth displacement Midline relation Maxillary median diastema Congenitally missing maxillary incisors. 1. 2. 3. 4. 5. 6. 7. 8. 9. www.indiandentalacademy.com
  90. 90.  Seven malocclusion syndromes defined 1. 2. 3. 4. 5. 6. 7.  Overjet and open bite Distal molar relation, overjet, overbite, posterior crossbite, midline diastema and mid line deviation. Congenitally missing maxillary incisors. Tooth displacement. Posterior open bite. Mesial molar relation, overjet, overbite, posterior crossbite, midline diastema and mid line deviation. Mesial molar relation, mixed dentition analysis (potential tooth displacement) and tooth displacement. Different scoring schemes and forms for different stages of dental development: Deciduous, Mixed & Permanent dentition. www.indiandentalacademy.com
  91. 91. Treatment priority index by Grainger (1967)  The precursor of the TPI was the Malocclusion Severity Estimate (MSE) developed by Grainger at the Burlington Orthodontic Research Center in 1960-61  Unlike the TPI, the MSE score was that of the syndrome with the largest value, regardless of the scores of the other syndromes.  The TPI also differed from the MSE by deleting potential tooth displacement (mixed-dentition space analysis) and by rating distoclusion and mesioclusion equally. www.indiandentalacademy.com
  92. 92. Treatment priority index by Grainger (1967)  1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 11 weighted and defined measurements – Upper anterior segment overjet. Lower anterior segment overjet. Overbite Anterior openbite. Congenital absence of incisors. Distal molar relation Mesial molar relation Posterior cross bite (max. teeth buccal to normal). Posterior cross bite (max. teeth lingual to normal). Tooth displacement Gross anomalies. www.indiandentalacademy.com
  93. 93. Seven malocclusion syndromes were defined 1. 2. 3. 4. 5. 6. 7. Prognathism Retrognathism Overbite Openbite Maxillary expansion syndrome Maxillary collapse syndrome Congenitally missing incisors www.indiandentalacademy.com
  94. 94. www.indiandentalacademy.com
  95. 95.  TPI is based on a scale of 1. 2. 3. 4. 0 (near ideal occlusion) 1 - 3 ( mild malocclusion) 4 – 6 ( Moderate malocclusion) Over 6 ( severe malocclusion)  TPI scores only occlusal characteristics, excluding skeletal and facial components.  TPI is used in national studies of orthodontic needs for children. Eg. USPHS study in USA of childeren aged b/w 6-11 yrs in year 1967 www.indiandentalacademy.com
  96. 96. Handicapping malocclusion assessment records by Salzmann (1968)   1. The purpose of HMAR – To establish priority for treatment according to severity as shown by score. Weighted measurements consists of 3 parts – Intra arch deviations Missing teeth Crowding Rotation Spacing 1. Interarch deviations Overjet Overbite Crossbite Openbite www.indiandentalacademy.com Mesiodistal deviations
  97. 97. 3. Six handicapping dento-facial deformities 1. 2. 3. 4. 5. 6. Facial and oral clefts Lower lip palatal to maxillary incisors. Occlusal interferences Functional jaw limitations Facial asymmetry Speech impairment.  Score 8 points for each deviation. www.indiandentalacademy.com
  98. 98. Instruction for Scoring www.indiandentalacademy.com
  99. 99. www.indiandentalacademy.com
  100. 100. Peer assessment rating Index (PAR index) Index of orthodontic treatment outcome  Developed by 10 experienced British orthodontists.  Its developed mainly to assess effectiveness of Orthodontic treatment .  Assigns scores to different occlusal traits.  Study models used.  A scoring system was developed and a ruler designed to allow analysis of a set of study casts in 2 minutes. www.indiandentalacademy.com
  101. 101. www.indiandentalacademy.com
  102. 102. 5 components- Weighting 1. Upper & lower anterior segment - 1 2. Left and right buccal segments 1 3. Over jet - 6 4. Overbite - 2 5. Centerlines - 4  Individual scores are summed to get a final score..  Index is applied to both the start and end of treatment study casts, and change in total score reflects the success of treatment. www.indiandentalacademy.com
  103. 103.  1. 2.   Change expressed as: Reduction in weighted PAR score : 22 point reduction – Greatly improved % reduction in weighted PAR score: < 30% reduction – worse/ no better > 30% reduction – Improved. Indicator of clinical performance. Limitations of PAR 1. Generic weightings of Over jet and overbite. 2. Sensitive to malocclusion with high over jet. 3. Overbite low weighting. 4. Zero weighting for displacements. 5. Facial profiles not considered Eg. Bimaxillary protrusion www.indiandentalacademy.com
  104. 104. TheValidation of PAR for Malocclusion severity and Treatment Difficulty De Guzman,bahiraei, Vig, Weyant and O’Brien – AJO-DO 1995  11 American Orthodontists examined a sample of 200 sets of study casts and rated them for malocclusion severity and perceived treatment difficulty.  The results of this study made it possible to derive a set of weightings for the PAR index that would represent groupings of malocclusion severity and treatment difficulty, according to perceptions of panel of Orthodontists. www.indiandentalacademy.com
  105. 105. www.indiandentalacademy.com
  106. 106. Index of Treatment Need (IOTN) by Shaw  Index has two components1. 2.  Dental Health component – derived from occlusion and alignment. Aesthetic component – Derived from comparison of dental appearance to standard photographs. Aesthetic component is calculated by direct examination, but dental health component can be studied by dental casts. www.indiandentalacademy.com
  107. 107. A special ruler summarizes the information needed for dental health component.  Assessed in order : 1. Missing teeth 2. Overjet 3. Crossbites 4. Displacements (Contact point) 5. Overbite www.indiandentalacademy.com
  108. 108. www.indiandentalacademy.com
  109. 109. www.indiandentalacademy.com
  110. 110. Esthetic Index  Grades 8 – 10 = definite need for treatment.  5 – 7 = moderate/ borderline need  1 – 4 = No/ slight need www.indiandentalacademy.com
  111. 111. Limitations 1. 2. 3. In aesthetic component ,Class III not considered. Facial profile not considered. Class I bimaxillary protrusion not considered. www.indiandentalacademy.com
  112. 112. Index of Complexity Outcome and Need (ICON)  Based on expert opinions of 97 orthodontists from various countries.  For use on patients and Dental casts.  A single assessment method to record complexity, outcome and need. www.indiandentalacademy.com
  113. 113.  5 components taking about 1 min to measure. 1. Aesthetic component  10 pictures 1. Upper arch Crowding/ Spacing  Score according to amount of crowding or spacing  Impacted teeth in either arch immediately scored 5  Spacing in one part can cancel out crowding elsewhere. 1. Crossbite 2. Incisor open bite/ overbite  Open bite measured at mid incisal edges  Deep bite is measured at deepest part of overbite. 1. Buccal segment Antero posterior  Quality of buccal segment interdigitation is measured (not Angles Classification) www.indiandentalacademy.com
  114. 114. 1. Aesthetic component www.indiandentalacademy.com
  115. 115. ICON Scoring Method www.indiandentalacademy.com
  116. 116. www.indiandentalacademy.com
  117. 117. Limitations 1. 2. 3. Overjet not considered. Lower anterior crowding not considered. Midline shift not taken in account. www.indiandentalacademy.com
  118. 118. A dental-facial attractiveness scale Tedesco, Albino, Cunat AJO-DO 1983  The purpose of this study was to develop a valid and reliable index that provides relatively objective judgments of dental-facial attractiveness.  The subjects in this study were eighth- and ninth-grade children. Few were seeking orthodontic treatment and few were not seeking treatment.  Photographs of the children were rated for dental-facial attractiveness by lay and dental judges. www.indiandentalacademy.com
  119. 119. Standard photographs of white males for points 1 (most attractive) through 5 (least attractive) on the dental-facial attractiveness scale. Point 2 Point 1 Point 3 Point 4 www.indiandentalacademy.com Point 5
  120. 120. .  Children were also assessed for severity of malocclusion by means of the Treatment Priority Index  Children seeking treatment were perceived as significantly less attractive than children not seeking treatment.  The relationship between dental-facial attractiveness and overall severity of malocclusion is also established as proved by TPI scores. www.indiandentalacademy.com
  121. 121. Goslon yardstick :A new system of assessing dental arch relationships in childeren with UCLP – Michael Mars, Dennis A. Plint : 1987 A cleft Palate journal  The Goslon Yardstick is a clinical tool that allows categorization of the dental relationships in the late mixed and or early permanent dentition in to 5 discrete categories.  Objective : 1. To categorize malocclusions in patients with UCLP to represent severity of malocclusion and the difficulty of correcting it. 2. To compare long term results of different approaches to the early treatment of children with UCLP. www.indiandentalacademy.com
  122. 122.  1. 2. 3.   Development of Yardstick – Clinical features considered most important in characterizing malocclusion in children with UCLP are – A- P arch relationship –Class III incisor relationship> class II div I Vertical labial segment relationship – Open bite> Reduced overbite > deep overbite. Transverse relationship – Canine crossbites > molar crossbites. To test the application of these subjective criteria study models of 30 cases were taken. These models were ranked by 4 orthodontists and separated in 5 groups , which then formed basis for yardstick. www.indiandentalacademy.com
  123. 123. www.indiandentalacademy.com
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  125. 125. www.indiandentalacademy.com
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  127. 127. www.indiandentalacademy.com
  128. 128.  Group 1 – excellent     Group 2 – good Group 3 – fair Group 4 – poor Group 5 – very poor  Group 1 or 2 - simple orthodontic treatment/ no treatment  Group 3 – complex orthodontic treatment  Group 4 – limit of orthodontic treatment without orthognathic surgery  Group 5 – Orthognathic surgery www.indiandentalacademy.com
  129. 129. References (Diagnostic set up) 1. 2. 3. 4. Begg Orthodontics Theory & Technique – Kesling Diagnosis and treatment planning in Orthodontics – Van der Linden A Simplified wax set up technique by Dr. R.W. Knierim JCO-1975. A simplified Diagnostic set up technique by Dr. Barry N. Resnick; 1979 JCO. www.indiandentalacademy.com
  130. 130. References (Radiology) 1. 2. 3. 4. 5. 6. 7. Oral radiology – Goaz & White. A Colour Atlas of Dental Radiology – Friedrich A Pasler. Essentials of Dental Radiography – Orien N Johnson. Principles of Dental Imaging – Langland. Orthodontics - T. M .Graber. Radiologic exposure conditions and resultant skin doses in application of xeroradiography to Orthodontic diagnosis by Akihiko Nakasima AJODO, 1980 . A cephalometric appraisal of Xeroradiography by Chate AJO-DO 1980. www.indiandentalacademy.com
  131. 131. References ( indices) 1. 2. 3. Contemporary Orthodontics – Proffit M Ortho Journal – Bristol University Longitudinal evaluation of the Treatment Priority Index (TPI) AJO-DO 1989 : 4. Goslon yardstick A new system of assessing dental arch relationships in childeren with UCLP – Michael Mars, Dennis A. Plint : 1987 A cleft Palate journal 5. A dental-facial attractiveness scale Tedesco , Albino, Cunate AJO-DO 1983 The Development of PAR Index – S. Richmond 6. www.indiandentalacademy.com
  132. 132. 7. Handicapping Malocclusion assessment to establish treatment Priority J A Salzmann – AJO –1964 8. The use of Occlusal Indices : A European prospective – AJO-DO 1995 9. The validation of PAR for malocclusion severity and treatment difficulty AJO-DO 1995 10. The effectiveness of ClassII div I treatment – AJO-DO 1995 www.indiandentalacademy.com
  133. 133. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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