Cephalometry in Orthodontics

Cephalometry in Orthodontics

Cephalometry has existed in the orthodontic field since 1922 when Paccini published the first paper about the cephalogram, a method of assessing the relationship of craniofacial and dental structures on radiograph which are taken and produced in a standardized manner.

 

However, the introduction and popularity into the field in the US didn’t take place until 1931 when Broadbent introduced an article titled “A new X-Ray technique and its application to orthodontia.” The first clinical application of the cephalogram, took place later in 1948 by Downs.

 

For Down’s clinical application the patient is placed in a cephalostat, this positions the patient so their head is oriented 90 degrees to the X-Ray beam 5 ft from the tube. The film is then placed 15 inches from the head. These are now standards under which all cephalometric radiographs are taken worldwide. This ensures the radiographs taken at different centers are easy to make comparisons.

 

Once the film is produced it’s then traced and the necessary standard landmarks, lines, and angles are measured and recorded. Now that you have the lines, landmarks, and angles for the patient it allows for an easier comparison with the normal values for a population and assessment of growth and the effects of treatment. In order to trace the image you need a light box and a dark room, without these conditions you won’t be able to properly make out all of the landmarks.

 

Main Aims

 

The main aims of cephalometric analysis in orthodontics is to enable the identification process of cephalometric points and planes that are typically used in orthodontic diagnosis and treatment planning, and to trace the lateral skull radiograph. The analysis attempts to evaluate relationships; both horizontal and vertical of 5 major functional components of the face. These components consist of the cranial base, the maxilla, the mandible, the maxillary, and the mandibular dentoalveolus.

 

Evaluation

 

The analysis utilizes cephalometric tracing by first describing the patient’s dentofacial morphology. This should include a quantitative description of the morphological deviations. Including both skeletal and dental horizontal and vertical measurements, and angles. These are then compared to the normal standard tracing to see any abnormalities from the ‘ideal.’

 

The analysis can also be utilized to make diagnostic and treatment planning decisions, and evaluate change over time. When you reconsider the tracings in a longitudinal setting you can reassure the effectiveness of treatment and keep an eye on growth processes.

 

The evaluation also consists of identifying anatomic landmarks along with the lines and angles of measurement. These anatomic landmarks are stable reference structures such as the maxillary, mandibular skeletal, and dental structures. Using angular or linear measurements orthodontists then use these landmarks graphically to relate the dento-facial elements to these reference structures.

Today, there’s a lot more technicalities involved and tools like CephX have innovated software platforms that stores all of your analyses and tracing in the cloud. Once you upload the ceph into your account it’s available within two days for you to upload, print, and trace on. With simple storage in the cloud you can easily track the progress and growth of all of your clients.

Jarabak Cephalometric Analysis

Jarabak Cephalometric Analysis

Dr. J.R. Jarabak was and is still considered to be a living legend. In the dentistry world Jarabak is known widely for his cephalometric analysis of Brazilian Black patients. The cephalometry practice is one of the best systems available for the diagnosis of dentomaxillofacial alterations. The craniometric points found in the analysis are then used to measure the skeletal structure.

Throughout history many successful doctors in orthodontic treatments have produced studies to analyze facial growth patterns amongst different populations of the world. The purpose of Jarabak’s cephalometric study was to analyze and define more precisely where in the complex craniofacial dysplasia or disharmony exactly causes abnormalities.

Jarabak’s study, originally based off of the works of Bjork, focused on the specific population of men and women of Piracicaba descent from the Piracicaba region inside Sao Paulo, Brazil. One of the fundamental problems in orthodontic treatment is how orthodontists can predict growth. Specifically, Jarabak worked with segments of the dentofacial complex to assess the relationship of these segments and how they increase the normal growth of an individual.

Determining the characteristics of growth

Jarabak’s analysis takes into consideration not only the dentofacial growth but also the anteroposterior relationship, vertical relationship, and jaw relation within reference to the original structure i.e. the skull base. When measuring such a variety of growth it makes it easier to attribute and diagnose the main contributing factors.

There are four aspects that should be heavily considered when determining the characteristics of growth.

morphological characteristics

These characteristics consist of all of your cranial complex measures including the surface area, height, width, and structure.

prediction of facial growth pattern

Skeletal age and maturation patterns can help to predict peak times of facial growth. Once these patterns are known you can better assess and attribute discrepancies.

possible reactions to different orthodontic approaches

For instance nickel has been found to be a common sensitivity in many female patients. The nickel found in many orthodontic tools can cause many negative side effects in allergic patients.

detection of possible tendencies to functional alterations

The earlier you can detect signs of alterations the better when it comes to measuring growth. Many of the patient’s characteristics will be skewed depending on their possible tendencies of functional alterations.

Race distinction in craniofacial treatment

It’s important to take note of the distinction amongst different races in the cephalometric analyses. Jarabak’s cephalometric analysis is able to predict results of different orthodontic approaches as well. The analysis is made up of a series of lines and angles that define each individual’s unique skeletal characteristics, and thereby identify the muscular pattern.

Since each individual has their own unique set of skeletal characteristics it’s easily studied according to racial and ethnic group. Several different studies have investigated unique heritage and cultural pools to understand the standard normality mean values for each particular group. It’s important that each group by evaluated separately and in depth according to their own characteristics.

For instance black subjects have a very strong distinction from other races, particularly caucasians. In the past cephalometric analyses have been routinely used for diagnosis and planning for treatment for caucasian patients. Caucasian cephalometric standards vary completely, this is why it’s important to determine Jarabak’s standards for cephalometric analysis for a wide variety of different ethnicities.

Normal Occlusion Growth

Growth as we discovered earlier is a determinant of many different factors. Growth is controlled by genetic, environmental, and many other contributing factors. Those with normal occlusion we typically see that patient’s jaws and other facial structures develop at the same rate with successive growth alterations expressed mainly in the sagittal and transversal directions. This is resulted in an adult matured face with normal proportions and adequate occlusal relationships.

Radiographic cephalometry has also been used to study facial form in normal occlusions. It’s also being used to assess and guide orthodontic diagnosis and treatment planning related to craniofacial growth, and predicting growth. When you combine the results from the radiographic cephalometry with those from the Jarabak analysis you can see the associated morphological characteristics of the lower jaw and the other structures of the craniofacial complex.

When comparing different ethnic groups it’s revealed that there are indeed differences in skeletal and dental framework. This presents the need to evaluate cephalometric patterns and characteristics of the whole dentofacial complex for each unique group.

In a study by Cotton three different ethnic groups were compared to the black analyses. It became prevalent in the study that when compared to caucasians, black individuals had a higher protrusion of maxilla, a convex profile, a steep mandibular plane and flared maxillary and mandibular incisors.

Bialveolar protrusion also known as bimaxillary protrusion is another common occurrence in some ethnic groups because of the forward positioning of their teeth and its effect on the facial profile. Since we have access to multiple different studies that show the ‘normal occlusion growth’ and measurements for various different ethnic and racial groups, we know that normal for one group is not necessarily normal for another.

It has also been found that while there are statistically significant results for different results among ethnicities, there has yet to be found statistically significant results among gender for any of the given ethnicities.

Jarabak gave us a lot of useful insights into the practices of cephalometric analyses. Without his great works we wouldn’t be nearly as developed and prospering as we are today. His studies and the tools he left us with will impact orthodontistry and cephalometric analyses in particular for a long time to come.

 

Cephalometric Analysis for Orthognathic Surgery

cephalometric analysis orthognathic surgery

The key for successful orthognathic surgery is the precise and careful diagnosis of facial, skeletal, and dental problems. The Cephalometric Analysis for Orthognathic Surgery (COGS) analysis is a specialized system that works with the hard tissue in the face. Orthognathic surgery works specifically to improve the imbalance between one’s upper and lower jaws. This will effectively enable the patient to bite together correctly; it also has been known to benefit and enhance one’s facial appearance.

 

The COGS analysis of hard tissue shows the orthodontists the horizontal and vertical positions of the facial bones by the use of a steady harmonized system. In the GOGS analysis the size of the bones are represented by direct linear measurements whereas the shapes are measured by angular measurements. When planning for the treatment for orthognathic surgery and for the diagnosis of orthognathic surgery the COGS analysis has been imperative.

 

The COGS analysis is so imperative to the evaluation of orthognathic surgical patients because it has certain characteristics which allow it to become particularly adaptable to the situation. The landmarks and measurements selected in the analysis can be altered by numerous surgical procedures. The rectilinear measurements can be transferred readily to a case study for mock surgery to learn further. And finally the comprehensive appraisal encompasses all of the facial bones and a cranial base for reference.

 

Patients who require orthognathic surgery are typically concerned not only with the fixation of the function of the jaw but also with the esthetics. The cephalometric analysis has been reduced to only the most relevant and significant measurements to provide patients with soft tissue evaluation to enable the clinician to achieve good facial esthetics for his or her patients.

 

To make it clinically practical, the analysis has been reduced to its most relevant and significant measurements. Used along with other diagnostic aids, this soft tissue evaluation will enable the clinician to achieve good facial esthetics for his or her patients. Because the measurements in cephalometric analyses are primarily linear, they may be eagerly applied to prediction overlays and serve as a basis for the assessment of other post treatment stability options.

 

Range of Normality

 

Like many other standards in orthodontistry, COGS analysis can differ quite vastly amongst different ethnicities and groups of people around the world. Perhaps the most challenging task in the entire diagnostic system is establishing what the range of normality is. Once you have a standard base of ‘what is normal’ it’s easier to detect changes in structure and evaluate abnormalities.

 

Cephalometric norms can be valuable to the clinician to determine a patients abnormalities. These norms are based upon a variety of ideal cephalometric measurements based upon the patient’s age, sex, size, and race. It has been found that perhaps the biggest differentiating factor in normality is the difference between ‘normal’ for different racial groups.

Hence much research has been done to trace individual ethnic groups own set of normal characteristics. The skeletal, dental, as well as soft tissue differs ing groups from varying populations around the world. The cephalometric parameters used for the COGS analysis can’t be applied from group to group. This is why it’s ever so important to determine the norms of cephalometrics for orthognathic surgery for different populations throughout the world.