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

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

nasion and sella

S NS

N

S

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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.

Cephalometric analysisLines- Plans- Angles

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

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• Palatal Plane PP = ANS PNS

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• Occlusal Plane

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• Mandibular plane MP=Go-Me

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

Cephalometric analysisLines- Plans- Angles

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

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

Cephalometric analysisLines- Plans- Angles

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

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

Cephalometric analysisLines- Plans- Angles

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°

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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

Cephalometric analysisLines- Plans- Angles

SN

A

82

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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

Cephalometric analysisLines- Plans- Angles

S

N

B

79

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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.

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

• < 86 ° Deficient or retrognathic maxilla.

Cephalometric analysisLines- Plans- Angles

A

Na

FH Po Or

90 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

90

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• MANDIBLE to CRANIAL BASE = 80 ° ± 3

• SN-Pg (Sella-Nasion-Pogonion).

• > 83 ° prognatic mandible

• < 77 ° retrognathic mandible

SNa

Pog

Cephalometric analysisLines- Plans- Angles

80

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• Inter incisal amgle = 135 °

• > 135 ° retroclination of the anterior teeth

• < 135 ° proclination of the anterior teeth

Cephalometric analysisLines- Plans- Angles

135 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• Palatal plan to Mandibular plane PM 32 °

• Skeletal Open 33 °

• Skeletal Closed 24 °

Cephalometric analysisLines- Plans- Angles

32 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

• Norm 129 ° ± 5

S

Na

Ba

129 °

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

S Na Longeur base du crane = 72mm -Court

-Long

Utlise en correlation avec SBA , SNBS

Na72mm

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

Cephalometric analysisLines- Plans- Angles

8 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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)

Cephalometric analysisLines- Plans- Angles

NS

Me

Go

32 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• Frankfurt Mandibular plane Angle• Skeletal open > 28 adult

• > 30 children

• Skeletal average

• 19-27 adult

• Skeletal Closed < 20 Children

• < 18 adult

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

• Skeletal Average 25 ° to 32 °

• Skeletal Closed < 24 °

Cephalometric analysisLines- Plans- Angles

25 ° to 32 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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

Cephalometric analysisLines- Plans- Angles

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

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

Or

Cephalometric analysisLines- Plans- Angles

59 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR

• 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

Cephalometric analysisLines- Plans- Angles

116 °

Oussama SANDID - Mohamad ABOUALNASER- Awatef SHAAR