4. Schism
"I argue that it's a bit like the ancient Chinese practice of foot-binding," Jimmy continued. "The price for a debutante's beautiful smile could end up being a lifetime of pain and debilitation. You're not the only one with sleeping problems. What keeps me awake at night is wondering how many of them were my patients as children. And how often I might have made things worse. And why I treated them the way I did despite having all the information I needed to make better decisions. I remember reading an excellent paper in the early eighties that raised the alarm, but I ignored it because I wasn't ready to listen. Nobody was. That's the problem with a paradigm. Most subsequent studies have concluded that standard techniques are safe and effective. Reading them more carefully now, the obvious shortcoming is that very few consider long-term effects. The magnitude of the problem is becoming apparent only now that large numbers of patients are maturing."
"It must have made you a much better orthodontist, though?"
"I wish I knew. All I'm aiming for right now is to be more open-minded. I used to be such a big freaking Philly deal that I never had time to work through the literature, or any inclination to learn from anyone else." He toyed with the appliance he'd brought, and paged back to look at one of his sketches for a moment before setting it aside. "But we've still not answered that fundamental question about our young patient. I'd like to try to do that and apply what we learn to the possible consequences later in her life. There's one more learning point I want to wring out of our little balloon."
He picked it up. "We're still looking for a reason why her teeth didn't move apart with growth once they were no longer held in place by an orthodontic appliance." He squeezed and released the balloon a few times. "If the air pressure inside the balloon represents the tendency to grow, what opposes that? What does the elasticity of the latex represent?"
"After teeth and bone, there's only the soft tissues. Skin, fat, muscle ... and connective tissue I guess. Is it muscle?"
"They're likely all involved to some extent, but let's go with that. That's the myo- part of why we say we take a myofunctional approach. It's easy to forget how many muscles there are in and around the mouth. Please put your hands on the balloon where the cheeks would be ... right there." I did as he asked.
"Imagine our young lady at age eleven, before she wore any braces. Let's say for the sake of argument that her nasal airways weren't as wide open as they ought to be, for whatever reason. Humans are remarkably adaptable, so she very likely learned to breathe through her mouth to supplement the airflow. The way you still do." My mouth snapped shut. "So her lips would often be applying less force to her dental arches than her cheeks. It's not the whole story, and I'll come to the rest later. But if I hold the cranial vault like this to isolate the facial bones," he placed his hands behind and on top of the skull so that only the front remained free; "and you simulate the relatively greater force of those cheek muscles by squeezing the balloon -- what happens to the face?"
I squeezed.
"Do you see the maxilla projecting forward over the mandible? And that it may have more to do with angles than their relative sizes?"
I squeezed and released the pressure a few times.
"You see the paradox, don't you? We were trying to restrict the growth of the maxilla that we thought was already too small for all her adult teeth."
I felt as though I was drowning in a calculus class. I said "OK ..." without any clear understanding of the implications.
"Good. You're a very quick study. So then ..."
"No, please. Let's go over that again. You're saying that an overbite might be a kind of illusion, not because of a big upper jaw or a small lower one?"
"Overjet, but yes. Those prominent upper front teeth might not result from the relative sizes of the jaws. We agreed earlier that our patient's orthodontist very likely believed that her upper jaw was too small. Despite that, the headgear and elastics suggest that he was trying to slow its growth, or even pull the whole arch back a bit. That seems ludicrous looking at it from your and my current perspective this morning. But I would most likely also have missed the obvious and treated her in exactly the same way."
"I think I'm with you."
He released the balloon and referred to a sketch, pointing to the cheekbones. "We're so fixated on profile views that we often don't consider that the real problem might lie in the transverse plane. It could be that the facial structures didn't broaden as they should. A narrow face could lead to reduced nasal airway volumes. We've seen how that, in turn, could lead to prominent front teeth." He squeezed the balloon, not that I needed the reminder. "Trying to improve the profile with extractions and retraction misses the root cause and might actually make it worse." He referred back to his sketch with the facebow. "Small dental arches mean less space for the tongue in the mouth, forcing more of it back and down into the throat. And restricting the growth of maxillary structures might also prevent normal growth of the pharyngeal cavity, or even reduce its volume." He added a few heavy lines to his sketch. So heavy that he almost ripped the throat. "Are you still with me?"
The dawn sky reddened as I nodded in reluctant understanding.
"Might one reasonably conclude that constricting the pharynx could cause even more breathing difficulty? Even obstructive sleep apnoea?" I found myself quite unable to draw breath.
"So what's the solution?"
"It should have been to make better use of the structure that nature provided to maintain wide arches. Your natural retainer, if you will. That's what Peter's myofunctional therapist is likely to focus on."
"The bones of the palate?"
"Not quite. What structure protects them from the forces that compromised the maxilla and nasal airways in the first place?"
"I wish I'd paid more attention in my anatomy classes. Those little bones in the nose?"
"Remember that she's a myofunctional therapist. The cavity within your upper arch is almost exactly the same size and shape as what?"
"The tongue?"
"Exactly. It's a lump of very powerful muscle. If the tongue is where it's supposed to be in the mouth, it works much like the plate part of a retainer. The tongue's the key to developing and maintaining wide dental arches."
I tried to keep up as he spoke about environment rather than genetics. The work of a dentist who'd studied primitive populations. How much chewing was required by ancestral and modern diets. Of the relationships between posture, head carriage, narrow arches and facial development. How the structures of the head and neck worked as a dynamic system, and how any perturbation was likely to cascade into secondary problems. Colleagues who were trying to assemble a body of relevant knowledge, and their insights into poorly-developed faces, restricted airways, crooked teeth and even poor articulation of the temporomandibular joints.
I felt overwhelmed, but I did catch that last part. "Just go over that again please."
"It's a remarkable joint." He used several more pages in his notebook to illustrate the range of motion and the complexity of the structures that enabled this.
"What are the options for treatment?"
"Apart from what your orthodontist proposed, remodelling facial bones with functional appliances like this one may be a viable alternative. Peter thinks he may even be able to stimulate some growth, although most people argue that that's feasible only until the end of adolescence. There's remarkably little solid empirical evidence either way in adults, but I know him well enough to believe he'll want to try that first if he thinks it's possible. I'll have Mandy dig out his contact details for you."
"Thank you. You said there were some exercises ..."
He stressed the importance of lifting heavy things, good overall posture, adequate chewing, especially on firm foods, concentrating on breathing through the nose, and keeping the tongue up against the full length of the hard palate even though my narrow arch might make this difficult. "Google 'good oral posture exercises.' Or 'Mewing.' You'll find it interesting."