155 interpretation of cephalometric data-cepahalometric analysis-analyses...

155-Cephalometric analysis

InterpretationPart 2: Lines- Plans- Angles

2010

Oussama SANDID- Orthodontist,.

Awatef SHAAR (BAU-LB), Orthodontist.Mohamad ABOULNASER- Orthodontist, BAU, Connecticut, USA.

Cephalometric analysis

Part 2: Lines- Plans- Angles

• Lines- Plans- Angles

• SN line

• Frankfort Plane

• Mandibular Plane

• Maxillary Plane

• SNA

• SNB

• ANB

Cephalometric analysis Anatomic pointsOussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

SN line The plane demonstrated by a line through the nasion and sellaFrankfort Plane The plane demonstrated by a line through the orbitale and porionMandibular Plane (MnPl) The plane demonstrated by a line through the gonion and menton. The definition varies slightly, but the plane is used to show the plane of the lower border of the mandibleMaxillary Plane (MxPl) The plane demonstrated by a line through the anterior and posterior nasal spines

Cephalometric analysisLines- Plans- Angles

S

N

Po

Or

PNS

ANS

Go

M e

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

SN line The plane demonstrated by a line through the nasion and sellaFrankfort Plane The plane demonstrated by a line through the orbitale and porionMandibular Plane (MnPl) The plane demonstrated by a line through the gonion and menton. The definition varies slightly, but the plane is used to show the plane of the lower border of the mandibleMaxillary Plane (MxPl) The plane demonstrated by a line through the anterior and posterior nasal spines



• SN Plane =S N, The plane demonstrated by a line through the

nasion and sella

S NS

N

S



• Frankfort Plane 1) A plane passing through three points of the right and left porion and the left orbitale.2) First proposed at the Craniometric Congress held in Munich, Germany, 1877.3) An orientation of skull in a consistent and reproducible position.4) Comparisons: natural head position; horizontal visual axis; and horizontal plane.


http://www.columbia.edu/itc/hs/medical/humanAnatomy/yuan/craniologyISlides_files/slide0062.html


• Palatal Plane PP = ANS PNS



• Occlusal Plane



• Mandibular plane MP=Go-Me



Oussama SANDID (France)- Mohamad ABOUALNASER (USA)- ORTHODONTISTS- DENTISTS LEBANON- FRANCE -USA-pediatric dentistry lebanon-dentistry lebanon-


SNA (82 °) ± 3° : Represents the antero-posterior relation between the maxilla and the craniumMaxilla is Retrusive < 76 ------- Or Deficient Retrognathic Maxilla Maxilla is Average 77-82Maxilla is Protrusive > 83 ----- Or Prognathic Maxilla

82 °

82 °

S N

A



SNB (80°) ± 3° Represents the antero -posterior relation betwwen mandible and craniumMandible is protrusive if > 83------ Or Prognathic MandibleMandible is average 76-82Mandible is retrusive < if 75-------- Or Retrognathic mandible

80°

80°S N

B



ANB = SNA -SNB + 2° Represents Angle’s class (I,II,III) 0 - 4 Normal Class I> 4 Class II Skeletal< 0 Class III Skeletal

2°

2°


• SNA = Sella - Nasion - A point 82 3 MAXILLA to CRANIAL BASE

• This angle indicates the horizontal position of the maxilla relative to the cranial base.

• > 85 - protrusive or prognathic maxilla

• < 79 - deficient or retrognathic maxilla


SN

A

82


• SNB Sella - Nasion - B point 79 3 MANDIBLE to CRANIAL BASE

• B-point is the most anterior measure point of the mandibular apical base. This angle expresses the horizontal position of the mandible relative to the cranial base using B-point as a cephalometric landmark.

• > 82 - prognathic mandible

• <76 - retrognathic mandible


S

N

B

79


• ANB A point - Nasion - B point 3 2 MAXILLA to MANDIBLE

The ANB angle measures the relative position of the maxilla to mandible. The ANB angle can be measured or calculated from the formula: ANB = SNA - SNB.A positive ANB angle indicates that the maxilla is positioned anteriorly relatively to the mandible (Class I or Class II malocclusion cases). A negative ANB angle indicates that the maxilla is positioned posteriorly relative to the mandible (Class III malocclusion cases).The normal range is 1-5. >5 indicates a Class II skeletal jaw relationship, protrusive maxilla or retrognathic mandible.<1 indicates a Class III skeletal jaw relationship, deficient maxilla or prognathicmandible.



• MAXILLA TO CRANIAL BASE Na-A point to FH = 90 ° ± 4• > 94 ° Protrusive or prognathic maxilla.

• < 86 ° Deficient or retrognathic maxilla.


A

Na

FH Po Or

90 °


• Lower 1 to Mandibular plane- L1 MP-- Me Go- iThe lower incisor inclinationRetroclined < 90 °Average 90 ± 3 °ProclIned > 93 °

90



• MANDIBLE to CRANIAL BASE = 80 ° ± 3

• SN-Pg (Sella-Nasion-Pogonion).

• > 83 ° prognatic mandible

• < 77 ° retrognathic mandible

SNa

Pog


80


• Inter incisal amgle = 135 °

• > 135 ° retroclination of the anterior teeth

• < 135 ° proclination of the anterior teeth


135 °


• Palatal plan to Mandibular plane PM 32 °

• Skeletal Open 33 °

• Skeletal Closed 24 °


32 °


• CRANIAL BASE DEFLEXION Basion Sella Nasion -SNa / BA = 129 °• Used describe the cranial base.

• Norm 129 ° ± 5

S

Na

Ba

129 °



S Na Longeur base du crane = 72mm -Court

-Long

Utlise en correlation avec SBA , SNBS

Na72mm



• SN-H = 8 ° Angulation Base du crane avec plan horizontal


8 °


• Mandibular plane angle 32 ° SN-MP It represents vertical relation> 32 open bite (downward and backwards rotation of the mandible)< 32 deep bite (upward and forword rotation of the mandible)


NS

Me

Go

32 °


• Frankfurt Mandibular plane Angle• Skeletal open > 28 adult

• > 30 children

• Skeletal average

• 19-27 adult

• Skeletal Closed < 20 Children

• < 18 adult



• Palatal plan to mandibular plan• Skeletal open > 33 °

• Skeletal Average 25 ° to 32 °

• Skeletal Closed < 24 °


25 ° to 32 °


• Upper 1 to A Vertical

• Perpendicular from Frankfurt Horizontal that passes through A point + Reference line

• Measure in millimeters from the reference line to the incisal edge of the upper incisor

• Protruded > + 6

• Average + 3 to + + 5

• Retruded < + 2



• Y axis:FH-S Gn=59 °• It indicated the growth pattern (vertical horizontal or normal

Or


59 °


• U1/SN =116 °• Inclination of the upper incisor in relation to cranial base

• More than 116 °:proclination upper anterior teeth

• Less than 116 °:retroclination of the upper anterior teeth

S N


116 °


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