Cephalometrics Flashcards
Why are Lateral Cephalograms taken in Orthodontics
A high percentage of severe malocclusions is associated with discrepancies in jaw relationships
What are the TWO types of Skeletal Problems?
Vertical skeletal discrepancy attributed to an increased vertical growth pattern
Antero-posterior skeletal discrepancy attributed to a retrusive mandible
When is a cephalogram indicated?
Marked antero-posterior discrepancy e.g. Class II and III malocclusions
Class I bimaxillary protrusion
Marked vertical discrepancy e.g. AOB, deep overbites
What are the cranial base landmarks?
Sella
Nasion
Basion
Orbitale
Porion
Definition of Sella
The geometric centre of the sella turcica
Definition of Nasion
The most anterior portion of the frontal-nasal suture
Definition of Basion
The most inferior tip of the clivus
The most anterior part of the foramen magnum
Definition of Porion
The most superior point on the external auditory meatus
Definition of Orbitale
The most inferior point of lateral orbital margin
What is the Maxillary Outline?
Maxillary base and pterygo-maxillary fissure
What are the Maxillary Landmarks?
- Anterior nasal spine
- Posterior nasal spine
- A point (Subspinale)
- Is point (Incisor superius)
Definition of ANS
The most prominent point on the anterior maxilla in the mid-sagittal plane
Definition of A point
The deepest point in the concavity of anterior maxilla in the mid-sagittal plane
Definition of PNS
The distal most point on the hard palate in the mid-sagittal plane
Junction between hard and soft palate
What are the Mandibular Outlines?
Ramus
Condyle
Mandibular body
Symphysis
What are the Mandibular Landmarks?
Pogonion
Menton
Gonion
Point B (Supramentale)
Ii point (Incisor inferius)
Definition of Pogonion
The most anterior point on the mandibular symphysis
Definition of Menton
The most inferior point on the mandibular symphysis in the midline
Definition of B point
The point of the deepest concavity anteriorly on the mandibular symphysis
Definition of Gonion point
The most posterior, inferior point on the mandibular angle
A HYPOdivergent facial pattern means that the planes meet?
Very far behind skull
A HYPERdivergent facial pattern means that the planes meet?
Near or within skull
What does SNA measure?
The angle that measures the relationship of maxilla to cranial base
Patient’s SNA is ___ which is ___ , indicating that the patient has a protrusive, retrusive or maxilla in ideal AP position with reference to the cranial base
What does SNB measure?
The angle that measures the relationship of the mandible to cranial base
Patient’s SNB is ___ which is ___ , indicating that the patient has a prognathic, retrognathic or mandible in ideal AP position with reference to the cranial base
What does ANB measure?
The angle measures the relative position of maxilla to mandible
Patient’s ANB is ___ which is ___ , indicating that the patient has a Class I/Class II/Class III in ideal AP position with reference to the N point
What does WITS value mean?
Patient’s WITS is ___ which is ___ , indicating that the patient has a Class I/Class II/Class III in ideal AP position with reference to the FOP.
A point should be posterior B point (Class 1 = Negative value)
What does Frankfort-Mandibular plane angle mean?
Patient’s FMA is ___ which is ___ , indicating that the patient’s mandible is hyper/hypo/normodivergent with reference to the Frankfort plane.
This confirms/refutes the conclusion from the MMA value.
What does Maxillary-Mandibular plane angle mean?
Patient’s MMA is ___ which is ___ , indicating that the patient’s mandible is hyper/hypo/normodivergent with reference to the maxillary plane.
What does LAFH value mean?
Patient’s LAFH is ___ which is ___ , indicating that the patient has an increased/decreased/normal LAFH relative to TAFH
What does U1-Mx mean?
Patient’s U1-Mx is ___ which is ___ , indicating that the patient’s maxillary incisors are proclined/retroclined/ideally inclined with reference to the maxillary plane
What does L1-Apog mean?
Patient’s L1-Apog is ___ which is ___ , indicating that the incisal edges of the patient’s lower incisors are protrusive/retrusive/in ideal AP position with reference to A-pog line
What does L1-MP mean?
Patient’s L1-MP is ___ which is ___ , indicating that the patient’s lower incisors are protrusive/retrusive/in ideal AP position with reference to mandible plane
What does Patient’s Lower lip to E line value mean?
Patient’s Lower lip to E line is ___ which is ___ , indicating that the patient’s lower lip is protrusive/retrusive/in ideal AP position with reference to E line
