Cephalometric Analysis
Definition
[edit]Cephalometric Analysis is a diagnostic procedure in Orthodontics that involves the measurement and interpretation of a lateral head radiograph (Cephalogram). It is used to analyze dental and skeletal relationships to determine the nature of a Malocclusion and to plan surgical or orthodontic treatment.
Landmarks and Planes
[edit]The analysis relies on identifying specific points (landmarks) on the radiograph:
Skeletal Landmarks
[edit]- Sella (S): Midpoint of the sella turcica.
- Nasion (N): The most anterior point of the suture between the frontal and nasal bones.
- A-Point: The deepest point on the curve of the maxilla between the anterior nasal spine and the dental arch.
- B-Point: The deepest point on the curve of the mandible.
- Menton (Me): The lowest point of the chin.
Reference Planes
[edit]- SN Plane: Represents the anterior cranial base.
- Frankfort Horizontal (FH): A line connecting the upper border of the external auditory meatus (Porion) and the lower border of the orbital rim (Orbitale).
- Mandibular Plane: A line representing the lower border of the mandible.
Clinical Interpretations
[edit]The measurements derived from these landmarks help classify the patient's skeletal profile:
| Measurement | Normative Value | Interpretation |
|---|---|---|
| SNA Angle | 82° ± 2° | Position of the Maxilla relative to the skull. |
| SNB Angle | 80° ± 2° | Position of the Mandible relative to the skull. |
| ANB Angle | 2° | 0-4° = Class I; >4° = Class II; <0° = Class III skeletal relationship. |
| IMPA | 90° | The inclination of the lower incisor relative to the mandibular plane. |
Digital Cephalometry
[edit]With the rise of Digital Dentistry, manual tracing of radiographs on acetate paper has been largely replaced by software (e.g., Dolphin Imaging, CephX). Modern systems utilize Artificial Intelligence to automatically detect landmarks, increasing speed and reducing inter-operator variability.
Applications
[edit]- Treatment Planning: Deciding whether a case requires extraction, surgery, or simple alignment.
- Growth Prediction: Assessing the remaining growth potential in adolescent patients.
- Research: Studying the long-term effects of orthodontic mechanics on the facial profile.