In this lecture Bill Hang introduces and explains John Mew’s theory of proper “restoral” (rest oral) posture, which he defines as light tooth contact, the tongue firmly pressed to the palate with its tip behind the upper incisors, and relaxed closed lips. Hang cites classic research—Egil Harvold’s 1960s monkey experiments that linked forced mouth‑breathing to malocclusion and increased facial height, and Prophet & Sellers’ rabbit study showing that limited tooth contact (4‑8 h/day) permits normal facial height while less contact leads to facial elongation. He illustrates how altered oral posture in mouth‑breathers causes the maxilla and mandible to fall back, the nose to appear larger, and the forehead to tilt, using longitudinal photographs of a boy who became a mouth‑breather after a gerbil allergy, and several clinical cases including a patient treated with extractions and orthognathic surgery, and a child named Mason who achieved normal forward facial growth through orthotropic appliances that enforce proper restoral posture. Hang emphasizes that modern industrialized societies foster chronic mouth‑breathing, leading to hyperdivergent skeletal patterns, and critiques dental education for omitting training on restoral posture. He concludes that the knowledge is teachable and that clinicians can adopt orthotropic principles to improve airway, facial growth, and aesthetics.
Chapters
Welcome back. This segment is entitled, What is Proper Restoral Posture? Proper restoral posture is a term that I never heard until 1990 when I heard John Mew from London, England speak. He's the author of both of these books. The one in the center was published in the 1980s, and the one on the right was published more recently. He talked about altered oral posture, usually secondary to airway issues, causing facial growth to fall short of the genetic potential for ideal growth. He developed what he called the Tropic Premise, in which he stated, if the teeth are together lightly, the tongue firmly to the palate with the tip behind the upper incisor teeth, and the lips closed without strain at rest, the face will grow forward according to its genetic potential. Back in the 1960s, Professor Egil Harvold did some studies on monkeys in which he Plug the nose of monkeys, which were normally nasally breathing, and then produced mouth breathing in these monkeys. What he developed was— what he showed is the monkeys developed malocclusions with increased face heights, just as we see in human beings. Another article out of the refereed literature was from Prophet and Sellers, talking about the effect of intermittent forces on the rabbit incisors. And how if the teeth are in contact for 4 to 8 hours per day, the face will stay about the same height. If they're in contact less than 4 to 8 hours per day, that will lengthen, which basically we get concerned about in the mouth breathing patients because these patients have their teeth rarely in contact. For the few that have their teeth in contact more than 4 to 8 hours per day, those would be the clenchers, the face height may actually shorten. But those people are a rarity. in dentistry, particularly compared to those whose faces lengthen a lot. Let's talk then about what really happens with some actual faces. Here's a boy who on the left is age 10, and he was a normal nasal breather. He bought a gerbil and kept it in his room and was allergic to the animal and became a mouth breather. And you can see what happens to his face over a period of approximately 6 or 7 years. You can see how his cheek gets to be flattened and his nose appears big. In reality, his nose is not big at all. But the maxilla has fallen back dramatically and the mandible has fallen back even more. He had a very nicely balanced face to begin with, but it's falling back dramatically, as you can see, just in those few years because of his altered restoral posture. Here then is another thing. This is from John Mew, a depiction of what happens to the face Starting at age 3, you can see what the face ought to be with a totally vertical forehead, as our foreheads should all be, and the face growing normally forward. By age 7, if the child has altered restoral posture, you can see the chin falling back, the face lengthening, and even the tip of the nose below the nasal bone, which is stable, will tend to fall back. Kids with profiles at age 7 like this are common all over the— Excuse me. By age 50, you can see how the nose is actually curved. The nasal bone portion hasn't changed at all. It's where it's supposed to be. But the cartilaginous portion of the nose has fallen back, as the entire maxilla and mandible have fallen back. You can see that the formerly vertical forehead is tilted back, and that's because the patient has to keep their chin forward, tilt their forehead back to keep the chin forward to maintain their airway. And that's why they have a double chin. So, this is a great depiction of what really happens to many of us in industrialized societies because we do not have proper restoral posture over time. Let's look at that in an actual patient. Here then is a patient that I treated many years ago, and I actually treated her with some extraction of some teeth, which really isn't the point here. You can see her pretreatment. With her lips apart. Post-treatment, her lips are apart. And about 15 years later, her lips are still apart. She was a chronic mouth breather, which I didn't recognize originally, and continued to be. And you can see how much her face fell back and how her nose curved in the process, just as the above, the previous pictures showed. And you can see the distance between her neck and her chin has dramatically decreased, which probably reduces her airway dramatically as well. Here then is a classic example of a child with lip-apart posture. This picture was taken in an SUV in New York State, and the person with the blonde hair is taking the picture of her son in the rearview mirror of her car. Notice that her son has his mouth hanging open. She has had orthodontics with 4 bicuspids taken out and has had orthognathic surgery to bring both of her jaws forward. She's highly motivated that her son not go down the same path, and that's why she was taking our Orthotropics Mini-Residency to help her son learn how to keep his lips together. She brought him to our course, and when they were flying back to New York afterwards, you see him here in the middle, along with his father right there on the aisle seat, and someone, a random person, And the window seat, both have their mouths open, both have their jaws recessed back. But if you look at her son, his face is in nice proportion, and he's learning to keep his lips together at rest because he's doing the orthotropic treatment with appliances in his mouth, which mandate that he keep his lips together and become a nasal breather. Fast forward to Long Island, New York, the next summer when he's at camp, and you notice all these boys with the yellow arrows pointing at them, all have their mouths hanging open. The one in the middle with the red shirt, you can see, with a very narrow jaw, very narrow nose, and a long face, which is going to get progressively worse over time. But this is not uncommon at all. But notice the yellow circle around her son, who's sitting there with his lips together. There's only one other boy in this picture, one with the glasses on, that has his lips together in this picture. All the others have their mouths open. And this is a classic example of what's going on in industrialized societies and why we need to be concerned about patients developing proper rest oral posture. A few years ago, before Thanksgiving, this woman sent me pictures of her son. His name is Mason. In this picture, you can see her husband in his football uniform with his mouth hanging open. At about the same time, or rather about the same age as Mason here, who has his lips together finally, and another picture of him smiling. One year later, here's another email from her, and she says, I guess I'll be sending you pictures for the rest of my life. Still can't believe we got this profile from where he started. Thank you, thank you. You can see Mason in the middle of the picture on the left with his lips nicely together and his face developing very nicely forward. She also noted that the other boy in this picture was not her patient, but it serves as a great example because here he has his forehead tipped back, he already has a curved nose, and his face is long, and his chin is recessed. These 2 kids form a great contrast. Mason, with his face going forward, with proper restoral posture achieved through orthotropic treatment, and the other boy, Growing like most of his classmates with a very hyperdivergent skeletal pattern that doesn't need to be this way. Why wasn't I and everyone else taught about proper restoral posture in dental school? Point is, it's not too late. You can learn about it now.
