IN THE NAME OF GOD LATERAL CEPHALOMETERY BY

IN THE NAME OF GOD

LATERAL CEPHALOMETERY BY: Dr. Sepideh Arab

Objectives

STEINER ANALYSIS

Reference line: SN SNA ANB 1/ /1 to NA, NB SN-Go. Gn Holdaway Ratio

In the Steiner analysis, the ideal relationship of the incisors is expected when the ANB angle is 2 degrees, as indicated in the third diagram from the left. The inclination of the upper incisor to the NA line in degrees and its prominence in millimeters are shown on the second vertical line (22 degrees and 4 mm for an ANB of 2 degrees). The inclination of the lower incisor to the N B line and its prominence in millimeters are shown on the third line (25 degrees and 4 mm for an AN B of 2 degrees). If the AN B angle is different from 2 degrees, the different positioning of the incisors given by the inclination and protrusion figures will produce a dental compromise that leads to correct occlusion despite the jaw discrepancy. The fact that this degree of compensation in tooth position for jaw discrepancy can be produced by orthodontic treatment does not, of course, indicate that these compromises are necessarily the best possible treatment results.

Reference line: SN SNA ANB 1/ /1 to NA, NB SN-Go. Gn Holdaway Ratio

آﻨﺎﻟیﺰ ﺳﺎﺳﻮﻧی SASSOUNI ANALYSIS 19

The inclination of these planes to each other reflects the vertical proportionality of the face: � skeletal open bite � skeletal deep bite.

ARCIAL ANALYSIS �Sassouni evaluated the anteroposterior position of the face and dentition by noting the relationship of various points to arcs drawn from the area of intersection of the planes. 1. 2. 3. The anterior nasal spine, The maxillary incisor The bony chin should be located along the same arc.

Unfortunately, as a face becomes more disproportionate, � it is more and more difficult to establish the center for the arc, and � the anteroposterior evaluation becomes more and more arbitrary.

: ﻫﺪﻑ ﺍﺯ آﻨﺎﻟیﺰ ﻫﺎﺭﻭﻟﺪ . ﻧﺸﺎﻥ ﺩﺍﺩﻥ ﺷﺪﺕ ﻭ ﻣﻘﺪﺍﺭ ﻧﺎﻫﻤﺎﻫﻨگی ﻓک ﻫﺎﺳﺖ ﻃﻮﻝ ﻓک ﺑﺎﻻ ﻃﻮﻝ ﻓک پﺎییﻦ ﺗﻔﺎﺿﻞ ﺍیﻦ ﺩﻭ Lower facial height TMJ, the posterior wall of the glenoid fossa, to prognathion ANS, defined as the point on the lower shadow of the anterior nasal spine where the projecting spine is 3 mm thick. 25

THE EFFECT OF SHORT AND LONG CRANIAL BASE

THE EFFECT OF ROTATION OF THE JAWS RELATIVE TO THE ANTERIOR CRANIAL BASE ON THE ANB ANGLE.

The ANB angle can be misleading when nasion is displaced anteriorly, as in this individual. Note that the ANB angle is only 7 degrees, but the A-B difference projected to the true horizontal is ‘ 14 mm. ANB, at best, is an indirect measurement of the A-B difference, and must be used with full awareness of its limitations.

ﺑﺮ پﻠﻦ ﺍکﻠﻮﺯﺍﻝ ﻓﺎﻧکﺸﻨﺎﻝ A ﻭ B ﻋﻤﻮﺩ ﺍﺯ ﻧﻘﺎﻁ The functional occlusal plane, drawn along the maximum intercuspation of the posterior teeth, be used rather than an occlusal plane influenced by the vertical position of the incisors. Therefore, the average jaw relationship according to the Wits reading is 1. 0 mm for men and 0 mm for women. 33

� In skeletal Class II jaw dysplasia, point BO would be located well behind point AO (a positive reading). � In skeletal Class III jaw disharmonies, the Wits reading would be negative (ie, point BO being forward to point AO).

The Mc. Namara analysis combines elements of : Previous approaches (Ricketts and Harvold)

آﻨﺎﻟیﺰ ﻣک ﻧﺎﻣﺎﺭﺍ The reference planes: � The Frankfort plane � The basion-nasion line

The anteroposterior position of the maxilla is evaluated with regard to its position relative to the "nasion perpendicular”, � a vertical line extending downward from nasion perpendicular to the Frankfort plane. The maxilla should be on or slightly ahead of this line.

Maxillary & mandiblar length and LAFH A- N-perp Pog- N-perp 1/ to A-perp /1 to A-Pog 41

آﻨﺎﻟیﺰ ﻣک ﻧﺎﻣﺎﺭﺍ The second step in the procedure is a comparison of maxillary and mandibular length, using Harvold's approach. The mandible is positioned in space utilizing the lower anterior face height (ANS-menton).

آﻨﺎﻟیﺰ ﻣک ﻧﺎﻣﺎﺭﺍ THE UPPER INCISOR IS RELATED TO THE MAXILLA using a line through point A perpendicular to the Frankfort plane, � similar to but slightly different from Steiner's relationship of the incisor to the NA line.

آﻨﺎﻟیﺰ ﻣک ﻧﺎﻣﺎﺭﺍ The lower incisor is related as in the Ricketts analysis, primarily using the A-pogonion line.

آﻨﺎﻟیﺰ ﻣک ﻧﺎﻣﺎﺭﺍ THE MCNAMARA ANALYSIS HAS TWO MAJOR STRENGTHS: ﻓﺎﺻﻠﻪ ﻗﺪﺍﻣی ﺧﻠﻔی ﻓک ﻫﺎ ﺭﺍ ﻧﺴﺒﺖ ﺑﻪ ﺧﻄی کﻪ ﺗﻘﺮیﺒﺎ ﺷﺒیﻪ ﺧﻂ. 1. ﻋﻤﻮﺩ ﻭﺍﻗﻌی ﺍﺳﺖ ﻣی ﺳﻨﺠﺪ (Using a true vertical line, perpendicular to the true horizontal rather than anatomic Frankfort, would be better yet; � the major reason for not doing so in constructing the analysis is that the cephalometric radiographs from which the normative data were derived were not taken in NHP. ) � . ﻧﺮﻡ ﻫﺎی ﻣک ﻧﺎﻣﺎﺭﺍ ﻣﻄﺎﺑﻘﺖ ﺯیﺎﺩی ﺑﺎ ﺗﻤپﻠﺖ ﺑﻮﻟﺘﻮﻥ ﺩﺍﺭﺩ. 2

What is a compensation? Examples about useful compensations Vertical dimention Anteroposterior dimention

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SUPER IMPOSITIONS SELECTION OF APPROPRIATE TEMPLATE

TEMPLATES Schematic anatomic

INTERPRETATION, REPRESENTATION