The cephalometric tracing in orthodontics is a starting element to be able to make a correct diagnosis and a forecast of the effects of growth, a method of evaluation of the orthodontic mechanics to be used and a work base to link the diagnosis with the treatment.
The cephalometric tracing is obtained by means of a lateral skull x-ray or also called teleradiography.
The Steiner cephalometric analysis was prepared by Dr. Cecil C. Steiner in 1953 together with the publication of an article called Cephalometric for you and me. Steiner was the first to develop a treatment plan using cephalometry. Until then they were performed only with models and clinical examinations.
Thanks to cephalometry, information about the skeletal, dental and soft tissue structures of the patient can be obtained. From this information, the diagnosis can be made to know if the malocclusion or alteration that the patient presents is of skeletal origin, bone, dental origin or a combined origin. Based on the correct diagnosis, a treatment plan can be developed and the treatment options will be different depending on that diagnosis: orthopedics, orthodontics or orthognathic surgery.
Steiner’s cephalometric analysis is based on specific points of the lateral skull teleradiography, that from these points straight planes are made, angles are formed and values are obtained from which norms and deviations from the norm can be established for obtain a proper diagnosis and treatment plan.
Some of the points that are located in the teleradiography in Steiner’s analysis are:
- Nasion (N): is the most anterior point of the frontonasal suture.
- Point A: it is the deepest point of the anterior concavity of the maxilla.
- Point B: is the deepest point of the anterior border of the mandibular symphysis.
- Pogonion (Pg): is the most prominent point of the anterior border of the mandibular symphysis.
- Sella point (S): it is the geometric point located in the center of the sella turcica of the sphenoid bone.
From these points, among others, some of the blueprints shown below:
- Sella-Nasion Plane (SN): This is the reference plane for Steiner. Axis of the anterior area of the skull base.
- Nasion plane-point A (NA) that extends to the incisal edge of the upper incisors.
- Plane Nasion-Point B (NB) that extends to the lower edge of the symphysis.
The angles most prominent are the following:
- The SNA angle is the posteroinferior angle between the SN and NA planes. It places the upper jaw, sagittally, with respect to the base of the skull and establishes whether the maxilla is protruded or retruded.
- The SNB angle is the posteroinferior angle between the SN and NB planes. Locate the jaw and determine whether it is protruding or retruded.
- The ANB angle is the difference between the two anterior angles and establishes the relationship of the maxilla and mandible with each other in the anteroposterior direction. It is one of the indicators for the differential diagnosis of skeletal / dental class.
The Steiner analysis treatment plan sequence is based on:
- Problem, in the initial diagram the cephalometric values of the case are located, from which the prediction is made.
- Prediction, is based on the ANB and Pg angle values, using two diagrams.
- Solved or solution. Average of the two previous diagrams.
- Individualized treatment goal. The values obtained in resolution are adjusted using the data from the clinical examination, the patient’s musculature, the analysis of the models, among other values.
