Ortho - Lecture 10: Cephalometrics Flashcards
Standardized technique of studying the living skull by means of laterally oriented head radiographs. Allows for quantification of hard and soft tissue
dimensions/relationships and comparison to reference values
Cephalometry
Allow us to evaluate dento-facial proportions and clarify the anatomic basis for malocclusion
Cephalometric X-Rays
Sagittal and vertical planes
Lateral ceph
Transverse and vertical planes
PA ceph
Overlay drawing of specific anatomic features on a radiograph to allow superimpostion of structures to detect changes over time
Ceph tracing
What are the 5 functional units of the craniofacial complex?
Cranium + cranial base
Nasomaxillary complex
Maxilla
Dentoalveolar processes (maxillary + mandibular)
Mandible
Which landmark of the cranium + cranial base?
The posterior end of the anterior cranial base
Sella (S)
Which landmark of the cranium + cranial base?
Center of cavity of the sella turcica
Consistent throughout growth
Sella (S)
Which landmark of the cranium + cranial base?
Front end of anterior cranial base, located at anterior end of junction btwn nasal and frontal bones
Nasion (Na)
Which landmark of the cranium + cranial base?
Lowest point of bony orbit
Orbitale (Or)
Which landmark of the cranium + cranial base?
If R + L orbital rims overlap, the lowest point on the averaged outline is used
Orbitale (Or)
Which landmark of the cranium + cranial base?
Most superiorly positioned point of external auditory meatus; difficult to identify
Porion (Po)
Which landmark of the maxilla + nasomaxillary complex?
Front end of maxilla, at tip of anterior nasal spine
Anterior nasal spine (ANS)
Which landmark of the maxilla + nasomaxillary complex?
Associated w/ anterior maxilla, located at inntermost point of the contour of premaxilla btwn ANS and incisor
(junction btwn skeletal maxilla and maxillary dentoalveolar process)
A point (A)
Which landmark of the maxilla + nasomaxillary complex?
Posterior end of maxilla, located at tip of posterior spine of the palatal bone, at the junction of hard and soft palates
Posterior nasal spine (PNS)
Which landmark of the mandible?
Anterior part of the mandible, located in innermost point on contour of mandible btwn incisor and bony chin
B point (B)
Which landmark of the mandible?
Most anterior point on contour of chin (front of chin)
Pogonion (Pg)
Which landmark of the mandible?
Most inferior point on mandibular symphysis (bottom of chin)
Mention (Me)
Which landmark of the mandible?
Center of inferior contour of chin, halfway btwn Pg and Me
Gnathion (Gn)
Which landmark of the mandible?
Angle of mandible, located at center of inferior contour of mandibular angle
Gonion (Go)
Which landmark of the mandible?
Most superior point of condylar head
Condylion (Co)
Which landmark of the maxillary and mandibular dentoalveolar processes?
Tip of most anteriorly positioned maxillary incisor
Upper incisor tip (U1 tip)
Which landmark of the maxillary and mandibular dentoalveolar processes?
Apex of most anteriorly positioned maxillary incisor
Upper incisor apex (U1 apex)
Which landmark of the maxillary and mandibular dentoalveolar processes?
Tip of most anteriorly positioned mandibular incisor
Lower incisor tip (L1 tip)
Which landmark of the maxillary and mandibular dentoalveolar processes?
Apex of most anteriorly positioned mandibular incisor
Lower incisor apex (L1 apex)
Which landmark of the maxillary and mandibular dentoalveolar processes?
Bilateral structures - trace molar on L side
Slightly above and behind image of other side
Upper 1st molar (U6)
Lower 1st molar (L6)
What are the 5 key planes?
SN
Frankfort horizontal
Palatal
Occlusal
Mandibular
Line connecting Sella (S) to Nasion (Na)
SN plane
Line connecting Porion (Po) to Orbitale (Or)
Frankfort Horizontal plane
This is a commonly used reference plane and should be parallel to the floor
Frankfort Horizontal plane
Line connecting ANS and PNS
Palatal plane
Line intersecting overlapping cusps of 1st molars and incisal overbite
Occlusal plane
Line connecting Gonion (Go) and Gnathion (Gn)
Mandibular
Objective of ceph analysis is to establish the relationship of these units in the anteroposterior and vertical planes of space
slide 43
