3. A method of cephalometric analysis that is sensitive
not only to the position of the teeth within a given
bone but also to the relationship of the jaw elements
and cranial base structures one to another.
In short, the method of analysis described here
represents an effort to relate teeth to teeth, teeth to
jaws, each jaw to the other, and the jaws to the cranial
base.
7.
The method of analysis described here
represents an effort to relate
teeth to teeth,
teeth to jaws,
each jaw to the other, and
the jaws to the cranial base.
8. THE COMPOSITE NORMATIVE STANDARDS DERIVED FROM 3
SAMPLES
1
2
3
• Lateral cephalograms of the children
comprising the Bolton standards
• Selected values from a group of
untreated children from the Burlington
Research Centre
• A sample of 111young adults from
Ann Arbor, having good to excellent
facial and dental configurations and
good skeletal balance with an
orthognathic facial profile
20. Maxilla To Mandible
Anteroposterior relationship
Midfacial length
Effective mandibular length
Maxillomandibular differential
Any effective midfacial length corresponds
to an effective mandibular length .
21. MID-FACIAL LENGTH
measuring a line from Condylion to point A.
Condylion- most posterosuperior point
on the outline of mandibular condyle
MANDIBULAR LENGTH
-measuring a line from Condylion to
anatomic Gnathion
Gnathion – most anteroinferior aspect of the
mandibular symphysis.
23. The effective lengths of max & mand are related to
the size of the component parts .
Thus termed:
small for mixed dentition
medium for adult female
large for adult male
The Maxillomandibular Difference :
In small individuals: 20-24 mm,
In medium sized individuals: 25-28 mm
In large individual : 29-33 mm
28. measured from).
anterior nasal
spine(ANS) to
Menton(Me
Increases with
age.
If LAFH
retrognathic
mandible.
Correlated to the
effective length
of the midface.
If LAFH
prognathic
mandible
29.
30.
31.
32.
33.
It is the angle between anatomic FH and the
line drawn along the lower border of the
mandible through constructed Gonion(Go)
and Menton(Me).
Average is 22 ± 4 degrees.
- Excessive lower facial height
- Deficiency in lower facial height.
34.
35.
It is formed by a line constructed from the
posterosuperior aspect of the pterygomaxillary
fissure (PTM) to gnathion(Gn) and a line
perpendicular to cranial base (ie a line from
basion(Ba) to nasion(N).
An ideal relationship is when PTM-Gn lies on
the perpendicular(0 degrees).
If PTM-Gn lies anterior to the perpendicular,
the angle is positive, suggesting deficient
vertical development of face and vice versa.
39.
Is determined by measuring distance from
pogonion to nasion perpendicular.
In mixed dentition 6-8 mm (behind N per)
In adult female
0-4 mm (behind N per)
In adult male
2 mm(behind to 5 mm
fwd of N per)
44. In vertical position mandibular incisors are
related to functional occlusal plane.
If curve of Spee is excessive
incisors intruded or molars
Extruded
LAFH is the determining factor
46.
Two measurements are used to
examine the possibility of airway
impairment.
Upper pharynx
Lower pharynx
47. It is measured from a point on the posterior
outline of the soft palate to the closest point
on the posterior pharyngeal wall.
Normal(adults) - 17.4 mm
Increases with age
48. It is measured from the intersection of the
posterior border of the tongue and the inferior
border of the mandible to the closest point on
the posterior pharyngeal wall.
Normal – 10 – 12mm
Does not change with age
49. SIGNIFICANCE
Adenoid obstruction of upper airway –
upper pharyngeal width decreases.
Lower pharyngeal width –greater than
15 mm
-anterior positioning of tongue –
habitual or
enlargement of tonsils .
50.
51. McNamara Analysis
1. Maxilla to cranial base
Normal
Patient
Inference
Nasolabial Angle
102±8˚
110˚
Normal upper lip
Cant of upper lip
14±8˚
8˚
Normal upper lip
Point A to Nperpendicular
0-1mm
-9mm
retrusive maxilla
52. 2.Maxilla to mandible
Normal
Patient
value
Inference
Maxillary Length
100.9
103mm
Maxillary length normal
Mandibular
Length
131mm
127mm
decreased mandibular length
(136-139)
Anteroposterior
Maxillomandibula 30mm
r differential
24mm
decreased
Vertical
LAFH(ANS-Me)
71.6mm
67mm
Reduced
Mandibular Plane
Angle(FH-Go-Me)
22± 4˚
34˚
VGP
Facial Axis Angle
0±3.5˚
-7˚
VGP
53. Normal
Patient
Value
Inference
0-4mm
-13mm
Backwardly placed chin
Maxillary incisor
to point A
4-6mm
7mm
Protrusive upper incisor
Mandibular
incisor to A-p0g
1-3mm
5mm
Protrusive lower incisor
3.Mandible to
cranial base
Pog to Nperpendicular
4.Dentition
5.Airway
Upper pharynx
15-20mm 17mm
Normal upper pharyngeal width
L0wer pharynx
11-14mm
Normal lower pharyngeal width
12mm
