In this lecture, Bill Hang explains the facial contour angle—a measurement formed by a line from the glabella through subnasale extending to soft tissue pogonion—whose normative value is –11° ± 4°. He describes how most Class II malocclusion patients exhibit a significantly recessed mandible reflected in a more negative angle, and critiques traditional orthodontic approaches (headgear, tooth retraction) that may worsen facial balance and airway size. Hang advocates for treatment strategies that advance the mandible and maxilla to improve aesthetics and airway patency. He illustrates the concept with clinical case comparisons, showing both patients require forward movement of the maxilla and mandible, and with historical figures (Arthur Percival, Curtis LeMay, Don Shula) to demonstrate how chin projection influences perceived leadership. Finally, he presents an orthognathic surgery case achieving an almost perfect –11° angle and an airway exceeding 20 mm, underscoring the angle’s relevance to facial aesthetics and airway health.
Chapters
Welcome back. This segment is entitled Diagnostic Criteria: Facial Contour Angle. This is the facial contour angle constructed by drawing a line from glabella through subnasale and extending it, and then a line from subnasale to soft tissue pogonion. That number is -11 in a norm, and 2/3 of the population will have a number plus or minus 4 degrees from this number. Most Class II patients have a significant recessive lower jaw as measured by this angle. By pushing the upper teeth down and back in the face with a headgear, or traditional orthodontics with removal of teeth, or TADs, or any form of retraction, the lower jaw is probably going to either not go forward, or probably more likely will go down and back, as the face height will more likely lengthen and make this worse. Orthodontics which seeks to actively develop the lower jaw forward is therefore preferred to headgear wear if better facial balance is the goal, and it's certainly the case if getting a better airway is the goal, if getting a better airway involves getting the maxilla with the soft palate attached to it forward, and the mandible with the tongue attached to it forward to open the airway. Let's apply this number to an actual patient with a Class II occlusion. Again, we've been taught that these patients have the upper teeth stick out, and we would call this child buck-toothed. In reality, what The situation is, is that the mandible is massively recessed from where it ought to be. Look at another patient with about a similar overjet and a number that's even worse. How much good is a headgear going to do for a patient like this? This patient needs dramatic forward movement of the back maxilla and the mandible to get a better facial balance and a better airway. Let's look in the refereed literature at a case, however, or 2 cases, and And see what another person talks about with these 2 diagnostic criteria. Here we have 2 young orthodontic patients, each with a severe Class II Division I malocclusion, and the author states that the study casts may look almost identical, but it is apparent that the girl demonstrates a prognathic maxilla and a normal mandible, whereas the boy has a normal maxilla and a retrognathic mandible. Well, let's apply these diagnostic criteria. First of all, here's the nasolabial angle. In reality, both of these patients have a maxilla which is dramatically recessed from where they ought to be. Now, let's look at the facial contour angle. Both of them have a mandible which is severely recessed from where they ought to be. So, they're different, to be sure, but they're different in degree only. Both of them really need the maxilla and the mandible brought forward. If we're to give them better facial balance. Here you can see them with the Bolton Norm superimposed on their face. We're going to discuss that in another segment, but you can see that the drinking straw is superimposed on their face to basically let you know that their airways are not very good. So let's talk about facial aesthetics a little bit and how much— how important being a leader is. And let's apply that to an actual person. I like to use this person as an example. He's a British general by the name of Arthur Percival, also known as Rabbit for rather obvious reasons. But this is a description of him. He is the person, by the way, who surrendered the British forces in Singapore to the Japanese. He's over 6 feet in height and lanky, with a clipped mustache and 2 protruding teeth, and unphotogenic. Percival was an easy target for caricaturists, being described as tall, buck-toothed, and lightly built. There was no doubt his presentation lacked impact as his manner was low-key and he was a poor public speaker with a cusp of a lisp. Looking at him, you know that his maxilla is back dramatically from where it ought to be and his mandible is even further back. His upper teeth do not stick out in his face and he has a very weak chin. Let's contrast this to Curtis LeMay, who was a general also from World War II, an American general, and he flew bombers into Germany and leading his men on those missions. Notice how far forward his chin is. I don't have a facial contra-angle on him because I couldn't get a profile, but you can tell that his mandible is dramatically forward. He'll be perceived as far more of a leader. Why don't we now go to the NFL and look at a football coach, Don Shula, former football coach of the Miami Dolphins. If you apply the The facial contra-angle to him, you see that his chin is massively forward. A very strong person, a very strong personality, and we would perceive him as a very strong leader. In reality, his chin is forward, his tongue is likely to be dramatically forward as well, and his airway much more open than the average. Here then is another patient who has actually had orthognathic surgery and has a virtually perfect facial balance, and showing the facial contour angle at -11 degrees, nearly perfect position. Let's look at her airway now. And you can see that it is greater than 20 millimeters, and very, very few patients have an airway this big. But then we see very, very few patients whose faces are as ideally positioned as hers are. And you can see the metal from the fixation for the surgery that's gotten her there. The point is, facial contour angle is a very easy to, uh, number to understand, and it is intimately related and critically important to both facial aesthetics and to the size of the airway.
