RICKETTS ANALYSIS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

www.indiandenta...
In a reading at the Reunion meeting of the
Illinois Alumni, Chicago, March 1960, he stated
that he was often asked the que...
.

The purpose of the analysis is objective and
encompasses the 4 C’s of cephalometrics :
1.
To characterise or describe t...
AIM: To clarify the science of
cephalometrics and free it from some of the
confusion and misuse pervading the
discipline.
...
The Landmarks used were:

www.indiandentalacademy.com
CC= Center of craniumpointof intersection of the basion
Nasion plane and the facial axis.
DC=Point in the center of condy...
Ricketts(Angle 1960):
Superficial Analysis:
1.Facial Angle
2. Facial axis( x-y axis)
3.Facial Convexity( A- Pog)
4. Lower ...
Ricketts(Angle 1981):
I. Lateral Analysis
1.Facial Axis
2.Facial Angle
3.Mandibular Plane Angle
4.Mandibular arc( Mandibul...
II. Frontal Analysis
1. Nasal width
2.Mandibular width
3.Maxillary width
4.Molar width
5.Actual intermolar width
6.Intercu...
1. Facial axis (X-Y axis)
Angle between basion-Nasion
plane and Foramen rotundum –
Gnathion
Ricketts used Huxley’s Basion
...
Mean value in 9 years olds : 90° ± 3.5°
X-Y axis < 90° →long faces with
retropositioned chin
X-Y axis > 90°(+6 to +10) → M...
2.Facial( depth) Angle :
It is the angle formed between the
facial plane (N-Pog) and the
Frankfort Horizontal Plane.
It pr...
3. Mandibular Plane Angle
The mandibular plane:
(Go-Gn) to FHP
26° ± 4° at 9 years of
age, and reduces 1° every 3
years to...
4.Mandibular arc
(Mandibular Bend):
It measures the angulation
of the condylar process
to the body of the mandible.
It is ...
5. Facial convexity (point A to facial
plane).

Ricketts states that “A direct
measurement of point A to the
facial plane ...
High convexity (+ve readings)→
Convex-facial profile
class II skeletal pattern.
Low values (-ve readings →
Concave facial ...
6.Palatal Plane to F-H plane:
Angle between the F-Hplane
and the Palatal plane
( ANS- PNS)
The Objective in orthodontic
tr...
7.Denture Height/ Lower
Facial Height:
It is the angle made by
the ANS, Xi and Pm points
It describes the convergence /
Di...
8. Lower incisor position
and Angulation :
The A-Pog line/ denture
plane → To measure the
position of the lower anterior
t...
Mean value for 9 year olds (lower incisor
position) :
Ideally → 1.0 mm (± 2mm) ahead of the
A-Pog line.
It defines the ...
9. Upper Incisor
Position :(1960)
The distance between
the incisal edge of the
maxillary
central
incisor to the A-Pog
line...
10.Upper molar to Ptv(mm):
The distance from the
pterygoid vertical to the distal of
the upper molar
Average: Age of patie...
11.Inter incisal angle:
This angle give an idea of the interarch relationship
Ricketts did not agree with downs norm of 13...
12. Esthetic plane (E-plane) :
The Ricketts’ esthetic plane runs from the
tip of the nose to the soft-tissue pogonion.
In ...
www.indiandentalacademy.com
The lower lip ranges from +2 mm to -2 mm from the
E-line.
The normal value for the 9 year old is -2 mm
EN : Point on soft ...
DeepStructuresAnalysis(An
gle 1960)
1. Cranial Base Angle :
This is measured as the angle
N-S-Ba.
The average value = 129....
2. Cranial Base length :
The length of the anterior
cranial base SN was not
measured linearly but was
expressed as the unu...
3. Condyle or Fossa
Position :
A line S-Ba was bisected,
and this point was called
SOR (Spheno-occipital
Reference). The c...
4. Condyle Axis :
It is the DC-xi line.
The angle made by DC-xi
with the Basion-Nasion plane
hovers around the ideal of
90...
www.indiandentalacademy.com
Later new horizons have developed the need
for orthodontic criteria in terms of transverse
assessment such as
-Development...
Frontal Analysis:
1. Nasal width
2.Mandibular width
3.Maxillary width
4.Molar width
5.Actual intermolar width
6.Intercuspi...
1.Nasal cavity width
2.Mandibular width
3.Maxillary width
4.Symmetry
5.Intermolar width
6.Intercuspid width
7.Denture symm...
1.Nasal Width:
Measures the width of the Nasal cavity
because of the importance of attaining normal
respiration in the ort...
3.Maxillary width – two frontal lines, left and right, are
constructed from the medial margins of the
zygomaticofrontal su...
5.Intermolar width – measured from the
buccal surface of the first permanent molars
transversely.
Clinical norm B6 - B6= 5...
7.Denture symmetry – the relationship of the
midpoints of the upper and lower central incisor roots
to the midsagittal pla...
Peter Elbe, Valiathan Ashima, Suresh
M (J.P.F.A 2000)
Did a comparitive study among
south Indians and North Indians using
...
Results:

South
Indians

Facial axis
89.02º
Facial Angle
88.71º
Mandibular
18.9 º
Plane Angle
Convexity of point A
02.13
L...
Rakosi`s Analysis
presented by Thomas

Rakosi (1992)

Aims: To assist

the clinician in making diagnosis
and planning ther...
1.Accomplishment of growth increments and the direction
or vector of growth.
2. Assessment of the magnitude of growth chan...
3)Se:Midpoint of the
entrance to the sella
4)Sn-Subnasale,skin point
where nasal septum mergers
with upper lip
6) Apmax-To...
23)FH-Rasc- Intersection of the F-H and the posterior margin
of the ascending ramus.
26) S`= Contructed point for assessin...
Rakosi`s Cephalometric Analysis:
I.Facial Skeleton
II.Jaw Bases
III.Dentoalveolar Relationships
I.Analysis Of the Facial S...
Saddle Angle(N-S- Ar):
Assesses the relationship
between anterior and postero
Lateral cranial bases
Large Saddle Angle = P...
Articular Angle(S-Ar_G0):
Angle between upper and
lower parts of the posterior
contours of the facial
skeleton.
Mean Value...
Influenced during orthopedic/orthodontic therapy,
Decreases during, a)Anterior positioning of
the mandible
b)Closing the b...
Children at 9years with horizontal growth pattern = 139.5º
Children at 9years with vertical growth pattern = 142.4º

www.i...
Gonial Angle (Ar- Go- Me):
angle between a)tangents
to the body of mandible
b)Posterior
border of the ramus
mean Value= 12...
It gives information on :
i)The form of mandible
ii)The mandibular growth direction
Acute/ small angle= Horizontal growth ...
Anterior and Posterior facial
height:
a)Posterior face height(S-Go)
of 9yr old with horizontal
growth pattern= 69.5mm
Grow...
b)A reverse ratio is seen,Anterior face height(NaMe) of 9 year old with
horizontal growth pattern= 103mm
Vertical growth p...
The assessment of growth direction is very
important in functional appliance therapy, for
determining
1.whether functional...
Anterior and posterior cranial base
length:
a)Anterior cranial base length(SeN):
. Superior entrance to sella turcica(Se)
...
b)Posterior (lateral) cranial base length (SAr).
A short posterior cranial base occurs in
vertical growth patterns or skel...
II.Analysis of the jaw bases
1.The angles between the vertical reference lines
represent the sagittal relationship (e.g., ...
S-N-A:
The angle S-N-A expresses the
sagittal relationship of the anterior
limit of the maxillary apical base
(point A) as...
Moderate decrease in SNA =>Activator therapy
Large decrease in SNA= Special activator(Clark
twin block)

www.indiandentala...
S-N-B the angle S-N-B expresses the
sagittal relationship between the
anterior extent of the mandibular apical
base and th...
Base plane angle (Pal-MP).
The base plane is the angle,
between the maxillary and
mandiblular jaw bases
Also used to deter...
Inclination angle:
The inclination angle gives
an assessment of the
inclination of the maxillary
base.
It is the angle for...
Small angle downward and backward tipping
of the anterior end of the palatal plane or
maxillary base.
This angle is not c...
Rotation of the Jaw bases:
can be evaluated by the base plane angle
and the Inclination angle.
These rotations are of spec...
b)The pattern of rotation of the maxillary base can be
observed by sequential measurements of the inclination
angle.
Envir...
c)Mutual relationship of the
rotating jaw bases. Rotation of
the mandible can be decisive in
establishing the vertical
pro...
3.Cranial rotation of both bases. In this
horizontal growth pattern there is a
relatively harmonious rotation of both jaws...
The therapeutic control of the vertical dimension is usually
more difficult than of the sagittal dimension. If a causal
th...
Linear measurement of the jaw bases.
If the mandible is retrognathic, the question arises
whether its size is relatively s...
Extent of the mandibular base.
Determined by measuring the distance
gonion-pogonion (projected
perpendicular to the mandib...
Extent of the maxillary base:
There are two “ideal” measurements for the
evaluation of this dimension:
1. Related to N-Se
...
Since the growth potential of the mandibular base is
greater than that of the maxillary base, the angle SN-B increases and...
Length of the ascending ramus.
This measurement is made by
calculating the distance between
gonion and condylion.
The leng...
Evaluation of the length of the jaw bases
Mandibular base. If the length of the mandibular
base corresponds to the distanc...
Maxillary base. There are two ideal values for
assessing the length of the maxillary base;
1)one related to the distance N...
Ascending ramus. If the ramus is too short in relation
to the other proportions, a large amount of growth
can be expected ...
Morphology of the mandible. The various facial
types
(orthognathic, retrognathic, prognathic) also reflect to
some degree ...
In the prognathic type the corpus is well
developed and is wide in the molar
region. The symphysis is wider in the
sagitta...
In the retrognathic facial type the
corpus is narrow, particularly in
the molar region. The symphysis is
narrow and long. ...
Analysis of the dentoalveolar relationships
I.Axial Inclination of the Incisors
Upper incisor axial
inclination: The long ...
Larger angles=Incisor Procumbany/ Incisor crown
tipping
Incisor protrusion requires lingual tipping, a therapeutic
objecti...
Lower incisors axial inclination: The posterior angle
between the long axis of the lower incisors and the
mandibular plane...
II.Position of the incisors. Linear
measurements serve best to assess
the position of the incisors with
respect to the pro...
The aim of orthodontic treatment is to achieve a
similar relationship to this normal guideline.
Uprighting of incisors tha...
Lower incisors
Tip of lower incisors to the N-Pog line
assists in determining the sagittal
discrepancy.
The lower incisors...
Summary: The salient points of the cephalometric analysis for
the use of functional appliance therapy as follows:
1.Cephal...
References:
1.Peter Elbe, Ashima Valiathan, Suresh M:
Cephalometric comparison of South Indians
and NorthIndians using Ric...
5. Ricketts RM: “Cephalometric Analysis and Synthesis”,
Angle ortho 1961, 31:3 page 141-156
6. Ricketts RM: A four step me...
9.Thomas Rakosi: An Atlas and Manuelof Cephalometric
Radiography, 1982 page 46- 76
10. Thomas M Graber, Thomas Rakosi, Ale...
13. Ruel W. Bench, Carl F. Gugino,
James J. Hilgers, Bioprogressive Part 3:Visualised
treatment Objective,1977, November, ...
Thank you
For more details please visit
www.indiandentalacademy.com

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Ricketts analysis /certified fixed orthodontic courses by Indian dental academy

  1. 1. RICKETTS ANALYSIS INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. In a reading at the Reunion meeting of the Illinois Alumni, Chicago, March 1960, he stated that he was often asked the question: “ What do you men get from cephalometric film that we don’t get from clinical examinations, models and photographs?” Ricketts produced his analysis with the intent of reviewing the purpose and usefulness of the cephalometric survey and to stress the use of this technique in treatment planning and estimating growth. www.indiandentalacademy.com
  3. 3. . The purpose of the analysis is objective and encompasses the 4 C’s of cephalometrics : 1. To characterise or describe the existing conditions. 2. To compare one individual with another or the same individual with himself at a later time. 3. To classify certain descriptions into various categories. 4. To communicate all these aspects to the clinician, to a fellow research worker, or to a parent. www.indiandentalacademy.com
  4. 4. AIM: To clarify the science of cephalometrics and free it from some of the confusion and misuse pervading the discipline. He also wanted to point out that the use of cephalometrics to describe and classify a malocclusion was one thing (Analysis) and the act of treatment planning as a result of this classification and description was another thing (synthesis). www.indiandentalacademy.com
  5. 5. The Landmarks used were: www.indiandentalacademy.com
  6. 6. CC= Center of craniumpointof intersection of the basion Nasion plane and the facial axis. DC=Point in the center of condylar neck along the Ba- Na Plane PM= Suprapogonion/ protrubrance mentiThe point at which the symphysis mentalis changes from convex to Concave Ptv= point of intersection of thedistal outline of ptm fissure and perpendicular to the F-Hplane. Xi= Geometric center of the ramus www.indiandentalacademy.com
  7. 7. Ricketts(Angle 1960): Superficial Analysis: 1.Facial Angle 2. Facial axis( x-y axis) 3.Facial Convexity( A- Pog) 4. Lower Incisor position and angulation. 5. Upper Incisor position 6. Esthetic Plane Deep Structure Analysis: 1. Cranial Base Angle 2. Cranial Base Length 3. Condyle or Fossa position 4. Condyle Axis 5. Mandibular Plane Angle www.indiandentalacademy.com
  8. 8. Ricketts(Angle 1981): I. Lateral Analysis 1.Facial Axis 2.Facial Angle 3.Mandibular Plane Angle 4.Mandibular arc( Mandibular Bend) 5.Point A to Facial plane 6.Palatal Plane to Frankfort horizotal plane 7.Denture Height /lowerfacial height/ Oral Gnomom 8.Lower incisor to Apog line(mm) and (Angulation) 9.Upper Incisor to Apog(1960) 10.Upper molar to Ptv 11.Interincisal Angle 12.Lower Lip to E Line www.indiandentalacademy.com
  9. 9. II. Frontal Analysis 1. Nasal width 2.Mandibular width 3.Maxillary width 4.Molar width 5.Actual intermolar width 6.Intercuspid width 7.Denture Symmetry 8. Upper to Lower Molar relation : www.indiandentalacademy.com
  10. 10. 1. Facial axis (X-Y axis) Angle between basion-Nasion plane and Foramen rotundum – Gnathion Ricketts used Huxley’s Basion – Nasion plane and measured its crossing of the Y axis as a means of describing the face height. He calls it the X-Y axis angle to distinguish it from the Y-axis of Downs. It seemed to be more useful in assessing facial height and prognosing the direction of www.indiandentalacademy.com growth of the face”.
  11. 11. Mean value in 9 years olds : 90° ± 3.5° X-Y axis < 90° →long faces with retropositioned chin X-Y axis > 90°(+6 to +10) → More Favourable X-Y axis > 90°( +10 to +12) → Closed bite tendencies with short facial vertical dimension Protrusive chin or forward growing chin Note: X-Yaxis does not measure the true length of the face. www.indiandentalacademy.com
  12. 12. 2.Facial( depth) Angle : It is the angle formed between the facial plane (N-Pog) and the Frankfort Horizontal Plane. It provides information of the horizontal position of the chin. Also suggest if a skeletal class II or III pattern is due to position of the mandible Mean value for 9 year olds : 87° ± 3.0° Age adjustment : +1° every 3 years www.indiandentalacademy.com
  13. 13. 3. Mandibular Plane Angle The mandibular plane: (Go-Gn) to FHP 26° ± 4° at 9 years of age, and reduces 1° every 3 years to adulthood. High mPA suggests : open bite Low mPA implies : deep bite www.indiandentalacademy.com
  14. 14. 4.Mandibular arc (Mandibular Bend): It measures the angulation of the condylar process to the body of the mandible. It is the angle between the Condyle axis(Xi through center of condyle neck) Posterior extent of the corpus axis(pm to Xi) Norm = 26º+/- 2º A total increase of 3º is seen every 5 years www.indiandentalacademy.com
  15. 15. 5. Facial convexity (point A to facial plane). Ricketts states that “A direct measurement of point A to the facial plane was a useful description of contour to the bony profile”. Clinical norm at 9 years of age : 2.0 mm. Age adjustment : -1 mm every 3 years, gradually decreases to 0 mm at adulthood. www.indiandentalacademy.com
  16. 16. High convexity (+ve readings)→ Convex-facial profile class II skeletal pattern. Low values (-ve readings → Concave facial profile Class III skeletal relationship However Convexity is also somewhat dependent on the facial type and is further a challenging orthodontic objectivity. The usual objectivity in almost all orthodontic www.indiandentalacademy.com practices is close to straight profile.
  17. 17. 6.Palatal Plane to F-H plane: Angle between the F-Hplane and the Palatal plane ( ANS- PNS) The Objective in orthodontic treatment is that the Palatal plane should be parallel to the F-H plane The desired value shoud be 0º or 180º www.indiandentalacademy.com
  18. 18. 7.Denture Height/ Lower Facial Height: It is the angle made by the ANS, Xi and Pm points It describes the convergence / Divergence of the Oral cavity The norm= 47º +/ 4º High Values are seen in Skeletal openbite Low values= skeletal www.indiandentalacademy.com deepbite
  19. 19. 8. Lower incisor position and Angulation : The A-Pog line/ denture plane → To measure the position of the lower anterior teeth. Measuring the position of lower incisor w.r.t. the NB line in effect is relating the lower incisor to itself because the position of B is determined by the lower incisor in the first place. www.indiandentalacademy.com
  20. 20. Mean value for 9 year olds (lower incisor position) : Ideally → 1.0 mm (± 2mm) ahead of the A-Pog line. It defines the Protrusion of the lower arch. Mean value for 9 year(lower incisor angulations) : 22°±4°, www.indiandentalacademy.com
  21. 21. 9. Upper Incisor Position :(1960) The distance between the incisal edge of the maxillary central incisor to the A-Pog line was originally reported to be 5.7 ± 3 mm. This was later refined to a clinical norm of (3.5 ± 2.3) mm. www.indiandentalacademy.com
  22. 22. 10.Upper molar to Ptv(mm): The distance from the pterygoid vertical to the distal of the upper molar Average: Age of patient + 3mm Eg: In 11Years Patient it is 11+3= 14mm Helps to determine: 1. If the malocclusion is due to the upper or lower molar 2. In deciding whether extractions are necessary www.indiandentalacademy.com
  23. 23. 11.Inter incisal angle: This angle give an idea of the interarch relationship Ricketts did not agree with downs norm of 135º as he said that the sample were chosen with bias. So he suggested a lower angle= 125º- 126º as this lower angle will provide a good plateau on the upper incisor for articulation of the lower incisor and smooth incisal guidance www.indiandentalacademy.com
  24. 24. 12. Esthetic plane (E-plane) : The Ricketts’ esthetic plane runs from the tip of the nose to the soft-tissue pogonion. In adulthood the lips should be contained within the nose-chin line for esthetic purposes. Patterns in which lips protrude ahead of this line have been evaluated as disproportionate with facial disharmony. This line is employed for the purpose of describing the relationship of the mouth to the other structures.. www.indiandentalacademy.com
  25. 25. www.indiandentalacademy.com
  26. 26. The lower lip ranges from +2 mm to -2 mm from the E-line. The normal value for the 9 year old is -2 mm EN : Point on soft tissue nose tangent to E-line. DT : Point on anterior curve of soft tissue chin tangent to E-line (Lip normally lies 2 mm behind E-line). 1. This measurement is an indication of soft tissue balance between the lips and profile. 2. This line is useful in evaluating functional abnormalities of the lip. www.indiandentalacademy.com
  27. 27. DeepStructuresAnalysis(An gle 1960) 1. Cranial Base Angle : This is measured as the angle N-S-Ba. The average value = 129.6° ranges from 114° to 144°. www.indiandentalacademy.com
  28. 28. 2. Cranial Base length : The length of the anterior cranial base SN was not measured linearly but was expressed as the unusual angle formed by the intersection of lines S-Gn and N-Gn or the S-Gn-N angle. Mean value : 35° Range : 25° - 42° www.indiandentalacademy.com
  29. 29. 3. Condyle or Fossa Position : A line S-Ba was bisected, and this point was called SOR (Spheno-occipital Reference). The condylion was measured to that point. The average location of condylion was 1.3 mm upward and 1.9 mm backward from S.O.R. www.indiandentalacademy.com
  30. 30. 4. Condyle Axis : It is the DC-xi line. The angle made by DC-xi with the Basion-Nasion plane hovers around the ideal of 90° to the line N-Ba, but is expressed as plus or minus from the 90° ideal. (DC is the point in the center of the condyle neck along the Ba-N plane). 5. Mandibular plane angle www.indiandentalacademy.com
  31. 31. www.indiandentalacademy.com
  32. 32. Later new horizons have developed the need for orthodontic criteria in terms of transverse assessment such as -Development of palatal widening and maxillary orthopedics -Demonstration of mandibular posturing appliances( Frankel appliances) -Characteristic changes in the frontal view with extraoral traction. -There was an awakening awareness of the relationships between respiration and growth www.indiandentalacademy.com
  33. 33. Frontal Analysis: 1. Nasal width 2.Mandibular width 3.Maxillary width 4.Molar width 5.Actual intermolar width 6.Intercuspid width 7.Denture Symmetry 8. Upper to Lower Molar relation www.indiandentalacademy.com
  34. 34. 1.Nasal cavity width 2.Mandibular width 3.Maxillary width 4.Symmetry 5.Intermolar width 6.Intercuspid width 7.Denture symmetry 8.Upper to lower molar relation www.indiandentalacademy.com
  35. 35. 1.Nasal Width: Measures the width of the Nasal cavity because of the importance of attaining normal respiration in the orthodontic patient. Norm in adults = 29- 33mm 0.5 mm increase each year from 17 to 23years 2. Mandibular Width: Measured from antegonion to antegonion( trihedral eminences) Norm at 8 years =75mm Inscrease of 1.25 each year At 18 yrs =88.5mmwww.indiandentalacademy.com
  36. 36. 3.Maxillary width – two frontal lines, left and right, are constructed from the medial margins of the zygomaticofrontal sutures to antigonion points, and the maxillary width is evaluated on the left and right sides separately by relating ‘J’ point or point jugale to these lines.  10 mm distance is desirable 4.Symmetry: By measuring ANS and pogonion to the midsagittal plane Clinical norm = 0+/-2mm No change if symmetric Increases in Asymmetries www.indiandentalacademy.com
  37. 37. 5.Intermolar width – measured from the buccal surface of the first permanent molars transversely. Clinical norm B6 - B6= 56+/- 2mm May narrow with mesial drift,but essentially no change 6. Intercuspid width – the width between the tips of the lower cuspids Clinical norm B3- B3= 22.5+/-2mm at 8 years 26mm+/-1.5mm at 13years Crowns converge, then diverge in eruption www.indiandentalacademy.com
  38. 38. 7.Denture symmetry – the relationship of the midpoints of the upper and lower central incisor roots to the midsagittal plane. Ideally the midsagittal plane should fall on all the midpoints. 8.Upper to Lower Molar relation It is an indicator of the Molar crossbite,as it describes the width difference between the buccal surface of upper and lower molars The average value= 1mm+/- 1mm www.indiandentalacademy.com
  39. 39. Peter Elbe, Valiathan Ashima, Suresh M (J.P.F.A 2000) Did a comparitive study among south Indians and North Indians using Ricketts Lateral cephalometric analysis The sample consisted of 100 subjects( 18- 25years) 50 North Indians (25M 25 F) 50 South Indians (25M 25 F) www.indiandentalacademy.com
  40. 40. Results: South Indians Facial axis 89.02º Facial Angle 88.71º Mandibular 18.9 º Plane Angle Convexity of point A 02.13 Lower Incisor to Apog 03.63 Upper Molar to Ptv(mm) 23.66 Lip to E- Line(mm) -0.42 Mandibular Arc 39.12º Lower Facial Height 39.20º Palatal plane angle 01.33º www.indiandentalacademy.com Inter incisal Angle 120.12º North Indians Norms 87.76º 90º+/-3 87.89º 87+/-3 19.00º 26+/-4 01.64 2+/-2 03.26 1+/- 2 21.78 21yrs +3 -1.73 -2+/-2mm 38.74 22+/- 4 39.86 47 01.12 0º/180º+/-3 123.14º 126º
  41. 41. Rakosi`s Analysis presented by Thomas Rakosi (1992) Aims: To assist the clinician in making diagnosis and planning therapy with functional appliances. Four major areas of emphasis in cephalometric diagnostic assessment for patients treated with functional appliances were www.indiandentalacademy.com
  42. 42. 1.Accomplishment of growth increments and the direction or vector of growth. 2. Assessment of the magnitude of growth change 3.Inclination and position of the upper and lower incisors, as it helps to forecast the reciprocal growth increment of the jaw bases. 4. To differentiate between skeletal and dentoalveolar malocclusion and provide information on a combination of factors a) etiology of malocclusion b) The therapeutic possibilities for treatment www.indiandentalacademy.com
  43. 43. 3)Se:Midpoint of the entrance to the sella 4)Sn-Subnasale,skin point where nasal septum mergers with upper lip 6) Apmax-To determine the length of the maxilla->By drawing aperpendicular from point A to the palatal plane. 18) Apman-To determine the length of the mandible->By drawing a perpendicular from Pog to the Mandibular plane www.indiandentalacademy.com
  44. 44. 23)FH-Rasc- Intersection of the F-H and the posterior margin of the ascending ramus. 26) S`= Contructed point for assessing length of maxillary basea perpendicular line from se to the palatal plane. 27) APOcc= Anterioorly drived point for determining occlusal planeMiddle of incisor overbite in occlusion 28)PPOcc= Posteror point for determining occlusal plane most distal contact between the most posterior molars in occlusion www.indiandentalacademy.com
  45. 45. Rakosi`s Cephalometric Analysis: I.Facial Skeleton II.Jaw Bases III.Dentoalveolar Relationships I.Analysis Of the Facial Skeleton 1. Three Angular Measurements Saddle angle, Articular angle, Gonial angle 2. Four Linear Measurements Anterior and posterior face height Anterior and Posterior cranial base length www.indiandentalacademy.com
  46. 46. Saddle Angle(N-S- Ar): Assesses the relationship between anterior and postero Lateral cranial bases Large Saddle Angle = Posterior condylar Position when mandible is posteriorly located relative to the cranial base and maxilla Difficult to influence with Functional appliance www.indiandentalacademy.com therapy
  47. 47. Articular Angle(S-Ar_G0): Angle between upper and lower parts of the posterior contours of the facial skeleton. Mean Value= 143+/- 6º Its size depends on the position of the mandible Large = Mandible is Retrognathic Small= Mandible is prognathic www.indiandentalacademy.com
  48. 48. Influenced during orthopedic/orthodontic therapy, Decreases during, a)Anterior positioning of the mandible b)Closing the bite c)Mesial migration of the posterior segment Increases, a)Posterior relocation of the mandible b)opening the bite c)Distal driving of the posterior teeth www.indiandentalacademy.com
  49. 49. Children at 9years with horizontal growth pattern = 139.5º Children at 9years with vertical growth pattern = 142.4º www.indiandentalacademy.com
  50. 50. Gonial Angle (Ar- Go- Me): angle between a)tangents to the body of mandible b)Posterior border of the ramus mean Value= 128+/- 7º 9 yr old child with horizontal growth pattern= 125.5º avg 9 yr old child with vertical growth pattern= 133.4º avg www.indiandentalacademy.com
  51. 51. It gives information on : i)The form of mandible ii)The mandibular growth direction Acute/ small angle= Horizontal growth of the mandible It is favourable for anterior positioning of mandible with an activator In case of Large angle= Activator treatment is contraindicated www.indiandentalacademy.com
  52. 52. Anterior and Posterior facial height: a)Posterior face height(S-Go) of 9yr old with horizontal growth pattern= 69.5mm Growth increment( 915yrs)=11.05 vertical growth pattern at 9yrs= 64.1mm Growth increment( 915yrs)=10.8mm www.indiandentalacademy.com
  53. 53. b)A reverse ratio is seen,Anterior face height(NaMe) of 9 year old with horizontal growth pattern= 103mm Vertical growth pattern= 106.6mm So Jarabak in 1972 setup a ratio to determine the growth direction; Posterior face height X 100 ----------------------------------Anterior face height Ratio 0f <62ºVertcal growth pattern >62ºHorizontal growth pattern www.indiandentalacademy.com
  54. 54. The assessment of growth direction is very important in functional appliance therapy, for determining 1.whether functional appliance therapy should be used . 2.The construction details, type of construction bite, etc.(high/ low) www.indiandentalacademy.com
  55. 55. Anterior and posterior cranial base length: a)Anterior cranial base length(SeN): . Superior entrance to sella turcica(Se) to Nasion In 9-year-old average length of anterior cranial base is 68.8mm horizontal growth patterns a 63.8 mm with a vertical growth vector. The incremental change between 9 and 15 years = 4.46 mm in the horizontal pattern 3.52mm in the vertical pattern. www.indiandentalacademy.com
  56. 56. b)Posterior (lateral) cranial base length (SAr). A short posterior cranial base occurs in vertical growth patterns or skeletal open bites, which gives a poor prognosis for functional appliance therapy. In 9-year-old children with a horizontal growth pattern the average length was 32.2mm, with an increment of 9.16mm in the following 6 years, As opposed to 30mm with an increment of 4.47mm in the vertical pattern. www.indiandentalacademy.com
  57. 57. II.Analysis of the jaw bases 1.The angles between the vertical reference lines represent the sagittal relationship (e.g., S-N-A, S-N-B) 2.whereas those between the horizontal lines assist in evaluating the vertical relationship (e.g., base plane angle, inclination angle). 3.The linear measurements give an indication of the length of the maxillary and mandibular bases as well as the ascending ramus. 4.A morphologic assessment, particularly of the mandible, is also important in forecasting the growth direction. www.indiandentalacademy.com
  58. 58. S-N-A: The angle S-N-A expresses the sagittal relationship of the anterior limit of the maxillary apical base (point A) as related to the anterior cranial base It is large in prognathic maxilla Small in Retruded maxilla Growth direction Mean Horizontal Vertical 9yrs 15yrs 79.5 81.28 79.73 81.57 79.0 80.57 www.indiandentalacademy.com
  59. 59. Moderate decrease in SNA =>Activator therapy Large decrease in SNA= Special activator(Clark twin block) www.indiandentalacademy.com
  60. 60. S-N-B the angle S-N-B expresses the sagittal relationship between the anterior extent of the mandibular apical base and the anterior cranial base. It is large in Prognathic mandible Small in Retrognathic mandible Growth direction 9yrs 15yrs Horizontal 77.2 80.5 Vertical 74.3 75.9 .Again based on the growth pattern myofunctional appliances can be used for sucessful treatment by anteriorly positioning the mandible www.indiandentalacademy.com
  61. 61. Base plane angle (Pal-MP). The base plane is the angle, between the maxillary and mandiblular jaw bases Also used to determine the inclination of the mandibular plane. Growth direction 9yrs 15yrs Horizontal 23.4 20.5 Vertical 32.9 30.9 The age dependent decrease in this angle corresponds to the general trend toward a more horizontal growth pattern (Moss,graber 1970) www.indiandentalacademy.com
  62. 62. Inclination angle: The inclination angle gives an assessment of the inclination of the maxillary base. It is the angle formed by the Pn line(perpendicular dropped from N-Se at N`) and the palatal plane. A large angle upward and forward inclination www.indiandentalacademy.com
  63. 63. Small angle downward and backward tipping of the anterior end of the palatal plane or maxillary base. This angle is not correlated with the growth pattern or facial type. However Functional or therapeutic influences can alter the inclination of the maxillary base.Hence there is need for periodic assessment during active treatment. www.indiandentalacademy.com
  64. 64. Rotation of the Jaw bases: can be evaluated by the base plane angle and the Inclination angle. These rotations are of special interest in treatment with functional appliances since they show whether such appliance are indicated and provide the criteria in appliance construction. a)Rotation of the mandible is due to both growth dependent and functional influences.. For this reason it is possible to influence therapeutically to a moderate degree the rotation of the mandible. www.indiandentalacademy.com
  65. 65. b)The pattern of rotation of the maxillary base can be observed by sequential measurements of the inclination angle. Environmental influences such as neuromuscular dysfunction, occlusal forces, gravity, and nasorespiratory malfunction (according to LinderAronson) can modify this inclination. An upward and forward tipping of the anterior part of the maxilla is often seen in confirmed mouthbreathers. A downward and backward tipping of the anterior part of the maxillary base is seen as a natural compensation in patient with vertically growing faces. www.indiandentalacademy.com
  66. 66. c)Mutual relationship of the rotating jaw bases. Rotation of the mandible can be decisive in establishing the vertical proportions of the facial skeleton. 1) Convergent rotation of the jaw bases: creates a severely deep overbite Is difficult to manage using functional methods. 2)Divergent rotation of the jaw bases: causes marked open bite problems. In severe cases or thognathic surgery is required for the correction. www.indiandentalacademy.com
  67. 67. 3.Cranial rotation of both bases. In this horizontal growth pattern there is a relatively harmonious rotation of both jaws in an upward and forward direction. The upward and forward rotation of the maxilla compensates for the upward and forward mandibular rotation, offsetting what could be a deep bite. The result is a normal overbite. 4.Caudal or downward and backward rotation of both bases in a relatively harmonious manner. The downward and backward maxillary rotation offsets what could be an open bite created by the downward and backward mandibular rotation. www.indiandentalacademy.com
  68. 68. The therapeutic control of the vertical dimension is usually more difficult than of the sagittal dimension. If a causal therapeutic skeletal reconstruction is not possible, some compensatory form of treatment is indicated. (functional appliance therapy) This means, for example, that if the vertical morphogenetic pattern cannot be altered an occlusal adjustment must be achieved by retroclination of the maxillary base, often with tooth sacrifice. ( orthodontically) Again, orthognathic surgery is the ultimate corrective procedure if the magnitude of the malrelationship transcends orthodontic or orthopedic growth guidance procedures. www.indiandentalacademy.com
  69. 69. Linear measurement of the jaw bases. If the mandible is retrognathic, the question arises whether its size is relatively small or large. This is important in considering the etiology and therapy for each patient. The length of the maxillary and mandibular bases, and of the ascending ramus, is measured relative to Se-N. (schwarz 1958 ) in his “roentgenostatic analysis” The ideal dimension relative to Se-N is calculated by using the following formula: N-Se: ManBase 20:21 Ascending ramus: ManBase 5:7 MaxBase: ManBasewww.indiandentalacademy.com 2:3
  70. 70. Extent of the mandibular base. Determined by measuring the distance gonion-pogonion (projected perpendicular to the mandibular plane). Ideally the mandibular base should be 3mm longer than Se-N up to the twelfth year and 3.5mm longer after the twelfth year. Growth direction Horizontal Vertical 9yrs(mm) 15yrs 67.59 77.35 65.23 73.5 www.indiandentalacademy.com
  71. 71. Extent of the maxillary base: There are two “ideal” measurements for the evaluation of this dimension: 1. Related to N-Se 2. The other to the length of the mandibular base. As Johnston(1976) points out, the mandible outgrows the maxilla. Growth direction Horizontal Vertical 9yrs(mm) 15yrs 44.56 48.6 44.0 47.16 www.indiandentalacademy.com
  72. 72. Since the growth potential of the mandibular base is greater than that of the maxillary base, the angle SN-B increases and A-N-B thus decreases. This corroborates the impression of many clinicians that the mandible is less retrognathic after 12 years of age. The growth advantage, with the mandible outgrowing the maxilla by as much as 5mm, is of special value to functional appliance proponents and, of course, to the Class II patients being treated. www.indiandentalacademy.com
  73. 73. Length of the ascending ramus. This measurement is made by calculating the distance between gonion and condylion. The length of the ramus is important in determining posterior face height and subsequent relation to anterior face height. Growth direction Horizontal Vertical 9yrs(mm) 15yrs 48.9 58.67 44.47 51.7 www.indiandentalacademy.com
  74. 74. Evaluation of the length of the jaw bases Mandibular base. If the length of the mandibular base corresponds to the distance N-Se (ManBase: N-Se +3mm) then this expresses an age-related normal mandibular length and we can expect an average growth increment. If the base is shorter, the growth increment will probably be larger. I f it is longer, the growth increment may will be smaller. This forecasting can be made more exact by using two additional measurements, the lengths of both the maxillary base and ascending ramus. www.indiandentalacademy.com
  75. 75. Maxillary base. There are two ideal values for assessing the length of the maxillary base; 1)one related to the distance N-Se, the other to the length of the mandibular base. A deviation from the mandibular base-related norm means that the maxillary base is too long or too short. If the maxillary base corresponds to the mandibular base-related norm, then the facial skeleton is proportionally developed, particularly if the ramus length also corresponds to these values. If the N-Se length does not relate to these three proportionate measurements, then the facial skeleton is proportionate but either too large or too small. www.indiandentalacademy.com
  76. 76. Ascending ramus. If the ramus is too short in relation to the other proportions, a large amount of growth can be expected under the supposition that the growth pattern is not vertical. In the vertical type the ramus remains short. To enhance the differential diagnosis, the morphologic characteristics of the mandible should also be studied. www.indiandentalacademy.com
  77. 77. Morphology of the mandible. The various facial types (orthognathic, retrognathic, prognathic) also reflect to some degree the morphology of the mandible. In the orthognathic type of face the ramus and body of the mandible are fully developed and the width of the ascending ramus is equal to the height of the body of the mandible, including the height of the alveolar process and the incisors. The condylar and coronoid processes are almost on the same plane, and the symphysis is well developed. www.indiandentalacademy.com
  78. 78. In the prognathic type the corpus is well developed and is wide in the molar region. The symphysis is wider in the sagittal plane. The ramus is wide and long, and the gonial is acute or small. The prognathic type of mandible grows horizontally. Even if there is an average or slightly vertical growth direction in the mixed dentition, shift of the mandible to a horizontal growth direction can be expected in the prognathic type of mandible in the following years www.indiandentalacademy.com
  79. 79. In the retrognathic facial type the corpus is narrow, particularly in the molar region. The symphysis is narrow and long. The ramus is narrow and short. The coronoid process is shorter than the condylar process, and the gonial angle is obtuse or large. . In a retrognathic type of mandible, shift of the growth pattern in the opposite direction is less likely and with much less expressivity. www.indiandentalacademy.com
  80. 80. Analysis of the dentoalveolar relationships I.Axial Inclination of the Incisors Upper incisor axial inclination: The long axis of the maxillary incisors, as viewed on the lateral cephalogram, is extended to intersect the S-N line and the posterior angle is measured Upto 7 years this angle = 94 ° - 100 ° 1 or 2 years after eruption the inclination increases to an average 102° www.indiandentalacademy.com
  81. 81. Larger angles=Incisor Procumbany/ Incisor crown tipping Incisor protrusion requires lingual tipping, a therapeutic objective that can be performed quite successfully with removable appliances, if there is adequate space. However, before a decision on the mode of movement of these teeth can be made, an assessment of their position is necessary. www.indiandentalacademy.com
  82. 82. Lower incisors axial inclination: The posterior angle between the long axis of the lower incisors and the mandibular plane is the classic method of assessing axial inclination of these teeth. Average value often given is 90° Between the sixth and twelfth years of life it increases from 88° for the relatively upright deciduous incisors to 94° A smaller angle may be indicative of lingual tipping of the incisors, which is advantageous for functional appliance treatment as it tips the lower incisors labially www.indiandentalacademy.com
  83. 83. II.Position of the incisors. Linear measurements serve best to assess the position of the incisors with respect to the profile Upper Incisors:The most common method is to measure the distance of the incisal edges to the line N-Pog Average position of the maxillary incisors is 2 to 4mm anterior to the N-Pog line. The lower incisors vary from 2mm posterior to 2mm anterior to this line. www.indiandentalacademy.com
  84. 84. The aim of orthodontic treatment is to achieve a similar relationship to this normal guideline. Uprighting of incisors that are tipped too far labially with respect to the N-Pog line is possible with removable appliances. But if labially malpositioned incisors have a good axial inclination already, then bodily movement is required, and this is possible only with fixed appliances and root torque. www.indiandentalacademy.com
  85. 85. Lower incisors Tip of lower incisors to the N-Pog line assists in determining the sagittal discrepancy. The lower incisors vary from 2mm posterior to 2mm anterior to this line. Incisors that are behind this line can be moved labially, since space is available. Incisors anterior to the facial plane that must be moved lingually need space, which may be obtained only by extraction procedures. www.indiandentalacademy.com
  86. 86. Summary: The salient points of the cephalometric analysis for the use of functional appliance therapy as follows: 1.Cephalometrics enables the anomaly to be located and a differentiation made between skeletal and dentoalveolar malocclusions., 2.The cephalometric assessment helps determine the primary and secondary dysplastic structures and possible autonomous compensatory response before treatment. 3.It is possible to determine whether the jaw bases are anteriorly or posteriorly positioned and whether short or long. 4.In the vertical plane the possible rotations of the maxillary and mandibular bases can be observed and the growth pattern delineated. 5.The position and inclination of the upper and lower incisors are important from both a functional and an esthetic point of view. 6.Cephalometrics enhances the assessment of the influences of neuromuscular dysfunction on the dentition. This is vital for www.indiandentalacademy.com diagnosis and treatment planing with functional appliances.
  87. 87. References: 1.Peter Elbe, Ashima Valiathan, Suresh M: Cephalometric comparison of South Indians and NorthIndians using Ricketts Lateral Cephalometric Analysis, JPFA Vol 14 December 2000page 113-117 2. Ricketts RM:Perspectives in the clinical application of cephalometrics. Angle ortho 1981:51:page115-150 3.Ricketts RM:A foundation for cephalometric communication,AJO 1960, 46: 330-57 4.Ricketts RM: “Cephalometric Synthesis”AJO1960 46:9 page 647-673 www.indiandentalacademy.com
  88. 88. 5. Ricketts RM: “Cephalometric Analysis and Synthesis”, Angle ortho 1961, 31:3 page 141-156 6. Ricketts RM: A four step method to distinguish orthodontic changes from natural growth” JCO 1975,April ,page 208- 228 7. Ricketts RM,Bench RW, Gugino CF, Hilgers jj, schulhof R:Bioprogressive Therapy.(Rocky Mountain Orthodontics: Denver) 1979 page 55-70 8.Jacobson A, Sadowsky PL. A Visualised treatment objective. JCO 1977: 14:page 554 www.indiandentalacademy.com
  89. 89. 9.Thomas Rakosi: An Atlas and Manuelof Cephalometric Radiography, 1982 page 46- 76 10. Thomas M Graber, Thomas Rakosi, Alexandre G Petrovic: Dentofacial Orthopedics with Functional Appliances, 2nd edition page 107- 124 11.Athanasios E Athanasiou: Orthodontic Cephalometry, 1995 page 271 12.Alexandre Jacobson: Radiographic Cephalometry,1995 Page 87- 95 www.indiandentalacademy.com
  90. 90. 13. Ruel W. Bench, Carl F. Gugino, James J. Hilgers, Bioprogressive Part 3:Visualised treatment Objective,1977, November, page 744-763 14.Ruel W. Bench, Carl F. Gugino, James J. Hilgers, Bioprogressive Part 4: The use of superimposition areas to establish treatment design, 1977, December page 820- 834 www.indiandentalacademy.com
  91. 91. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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