Learning to evaluate facial profiles can be very helpful when treatment planning both esthetic and occlusal issues. In this article I’ll focus on understanding how to evaluate profiles, and what the evaluation can teach us about possible treatment decisions.
Again, as in my most recent article, I’ll be using a photographic image to do my assessment since that is what most restorative dentists have at their disposal as opposed to a cephalometric radiograph.
Understanding the reference points is always the first step when making our assessments. The evaluation will consist of identifying each point and analyzing their relationships to each other.
Glabella: The prominent smooth area between the eyebrows as the forehead transitions down to the bridge of the nose.
Subnasale: The point at which the nasal septum merges with the upper lip.
Pogonion: The most anterior point on the contour of the chin.
After identifying each area on the photograph with a small dot, draw a line from glabella to subnasale, then draw a second line from subnasale to pogonion. The two lines will meet at subnasale and form an angle. A normal angle is typically 165° to 175°, as shown in the picture. Using a computer program, such as Keynote on a Mac or PowerPoint on a PC, to draw these lines makes it extremely easy to calculate the angle.
This can be extremely useful when treatment planning occlusal issues, such as managing excess or inadequate overjet. Assuming the patient had normal vertical facial proportion and a normal angle, it would be unlikely to consider correcting any existing overjet with orthognathic surgery since that could negatively affect the patient’s pleasing profile.
On the other hand, an angle that is significantly less than 165° most likely indicates a retrognathic mandible. A patient that presents this angle with excess overjet and a Class II dental occlusion, may have mandibular advancement in their treatment plan to solve the problem of excess overjet and create a more pleasing facial profile. The alternative to manage the excess overjet would be to consider the removal of maxillary first premolars and retraction of the maxillary anteriors. Doing this solves the overjet problem but could create an esthetic issue dentally in return, as well as leaving a less than ideal facial profile.
If the angle is greater than 180°, this is an indication of a deficient maxilla or a prognathic mandible. In this case if the patient had an end-to-end anterior occlusal relationship or a Class III anterior relationship, it would be likely to consider an orthognathic solution. Depending upon a more involved analysis, the surgery could involve a maxillary advancement, mandibular set back – or both. This approach would solve the occlusal relationship issues as well as create a more pleasing facial profile over a purely extractive and orthodontic approach.
The final possibility is the patient that has an ideal occlusal relationship, but a profile that is out of the range of normal. We have to recognize that normal is the middle of a Bell curve, and not necessary for acceptable and pleasing facial esthetics. However, there are instances where surgeries, such as genioplasty to reduce the chin prominence or chin augmentation to increase its prominence, can make significant improvements in facial esthetics while leaving the occlusion unchanged instead of using orthognathic surgery to make profile corrections.
I know for myself that learning to see profiles as a routine evaluation whenever I am contemplating esthetic or occlusal changes for a patient has helped me recognize when orthodontics or orthognathic surgery should be considered over restorative-only solutions. In my next article, we will start to consider the nose and its relationship to the lips and chin in evaluating facial esthetics.
(Click this link to read more dentistry articles by Dr. Frank Spear.)