· 7 min
Obstructive sleep apnea (OSA) is a systemic disease with documented consequences: arterial hypertension, cardiovascular risk, cognitive decline, metabolic disturbance, chronic fatigue, and reduced life expectancy. And most patients who have it don't know. In our practice we often suspect it before it is picked up in other clinical settings, because OSA leaves traces in the mouth that a trained dentist can read. This article explains what we can do as dentists, what is outside our role, and where the mandibular advancement device fits.
The mechanism is simple: during sleep, the upper airway muscles relax. In people with favorable anatomy, that causes no problem. In people with a narrow palate, a retracted jaw, a large tongue, enlarged tonsils, or excess weight, that relaxation partially or fully closes the airway. The result is a breathing pause (apnea) or a significant drop in airflow (hypopnea). The brain reacts with a microarousal to reopen the airway. The person falls back asleep without remembering it. The cycle repeats, sometimes dozens of times per hour.
Each of those microarousals fragments sleep, and each pause drops oxygen saturation. Added up night after night, they explain why someone who slept eight hours gets up as if they had not slept at all, and why untreated apnea is associated with elevated blood pressure and higher cardiovascular risk (prospective study).
Nobody looks inside a person's mouth as often, or under as much light, as their dentist. And apnea leaves signs there, even when the patient came in for something else:
None of these signs confirms apnea on its own. What we do is add them to the history (snoring, pauses a partner has noticed, daytime sleepiness) and, when the picture is consistent, say clearly that it needs to be studied.
The most frequent signals that lead to an evaluation are habitual snoring, waking with a choking sensation, daytime sleepiness despite sleeping enough, jaw pain or headache on waking, dry mouth, nighttime reflux, and bruxism. But there is one the patient almost never connects: sleep bruxism. Nocturnal masticatory hyperactivity can be the body's response to microarousals (study). When we see severe bruxism in the chair, we evaluate the airway systematically. We develop that relationship in bruxism and apnea: the connection.
There is one group where apnea is missed especially often: women. OSA was described mostly in men, and in many women it presents differently. Instead of the classic snoring, it shows up as insomnia, fatigue that will not lift, headache on waking, or low mood, symptoms often attributed to stress or hormones while nobody looks for the apnea. A sign almost no one connects is waking several times at night to urinate: in apnea, the breathing pauses favor greater nighttime urine production, so it is not always the bladder. These sex differences, and how they narrow after menopause, are described in the literature on menopause and sleep apnea. If you sleep the hours and still wake exhausted, it is worth looking into.
Let's be clear about it: a dentist does not diagnose sleep apnea. The diagnosis is medical and is made with a sleep study. Polysomnography is the gold standard and measures the apnea-hypopnea index (AHI), oxygen saturation, and sleep architecture. Respiratory polygraphy is a simpler alternative for cases with no suspicion of neurological disease. These studies are ordered and interpreted by a sleep medicine team.
Our role as dentists has three parts: recognizing the clinical signs, referring when appropriate, and taking part in treatment with oral appliances when the physician indicates them. We screen; the diagnosis stays with the physician. And the order matters: the study comes first, the device afterwards.
Some signs cannot wait and go straight to a physician: breathing pauses witnessed by a partner, severe daytime sleepiness (falling asleep while driving or mid-conversation), repeated awakenings with choking, or high blood pressure that does not respond to usual treatment. In those cases we design nothing until a diagnosis exists.
The first choice for severe OSA remains CPAP, a machine that delivers continuous positive airway pressure through the night. It works well and the clinical evidence is solid. The problem is adherence. Many patients abandon it within the first months because of discomfort, noise, nasal dryness, claustrophobia, or simply because nightly use wears on them. That is where the mandibular advancement device (MAD) comes in, and in selected cases it becomes the real alternative.
The MAD is a custom-made intraoral device worn at night. It advances the lower jaw a few millimeters, and that movement opens the upper airway. Clinical evidence supports its use in mild to moderate OSA as first-line therapy, in severe OSA when the patient cannot tolerate CPAP, and as combined therapy in selected cases. Adherence with a MAD tends to be higher than with CPAP, and its clinical efficacy is well documented (clinical trial). What the MAD does not do is replace CPAP in severe apnea: there, CPAP remains the standard.
Dr. Montserrat Ortega B., who leads temporomandibular disorders and orofacial pain at our clinic, covers when it is indicated, what to expect, and its limits in mandibular advancement device: the CPAP alternative. Before prescribing one we evaluate the temporomandibular joint, because advancing a jaw over a painful joint can make things worse.
In our practice the device starts with an intraoral scan, no uncomfortable impression trays. On that digital model we design a device in comfortable thermoplastic material with an adjustable advancement mechanism. The advancement is not set once and left alone: it is calibrated progressively over successive follow-up visits, looking for the point where snoring and symptoms subside with the least protrusion possible.
Follow-up is part of the treatment. With prolonged use there can be minor occlusal changes, joint or muscle discomfort on waking, or excess saliva during the first weeks. That is why we do periodic occlusal checks, prescribe morning repositioning exercises and, when the physician requests it, coordinate a repeat sleep study with the device in place to confirm it is actually working. You can see the full service at airway and sleep health.
The other scenario where the dentist is central is pediatric apnea. A child who snores chronically, breathes through the mouth, or has large tonsils may be developing an altered facial pattern: narrow palate, crossbite, retrognathia, low tongue posture. The window to intervene is between ages 4 and 9. What can be corrected in that period with maxillary expansion, functional orthopedics, and timely ENT referral when adenotonsillar hypertrophy is present is much harder to reverse in adolescence. Pediatric and adult apnea are different diseases, but they share the same logic: anatomy rules. How mouth breathing shapes the face and posture is explained in breathing, posture and oral health.
Patients who arrive with bruxism, snoring, or daytime sleepiness often do not connect those symptoms with an airway problem. Treating bruxism alone with a night guard, without investigating whether sleep-disordered breathing is behind it, is working the symptom and leaving the cause untouched. If you want to understand first what bruxism is and what triggers it, we explain it in what is bruxism.
Airway evaluation is part of the academic standard we apply as NYU College of Dentistry faculty, and it should be standard in any serious dental practice. If you snore, wake up tired, or have been told you stop breathing at night, talk to your physician and tell your dentist too. Both perspectives are needed.
If this article left you with questions, explore the related services or book an evaluation at AS Odontología Digital in Vitacura.
Book an evaluationNo. The diagnosis of sleep apnea is medical and requires a sleep study (polysomnography or respiratory polygraphy) ordered and interpreted by a sleep medicine team. What the dentist does is recognize the signs in the mouth and in the patient's history, refer when appropriate, and take part in treatment with oral appliances once a diagnosis exists.
Because the upper airway passes through structures the dentist examines at every visit: jaw, tongue, palate, occlusion. Signs such as tooth wear, a scalloped tongue, a narrow palate, dry mouth on waking, or little space between the tongue and the soft palate are visible in the dental exam. The mandibular advancement device is also a dental appliance that requires specific training to design and adjust.
The most frequent signs are habitual snoring, waking with choking, daytime sleepiness, jaw pain or headache on waking, dry mouth, nighttime reflux, and bruxism. In women it can present as insomnia, persistent fatigue, or getting up several times at night to urinate. The only way to confirm it is a sleep study. If your partner has seen you stop breathing or you fall asleep during the day, see your physician without waiting.
In mild to moderate obstructive apnea, where the evidence supports it as first-line therapy; in severe apnea when the patient cannot tolerate CPAP; and as combined therapy in selected cases. Always after a sleep study and with a prior evaluation of the temporomandibular joint, because advancing the jaw over a painful joint can make the condition worse.
Not in severe apnea: there CPAP remains the first-line treatment and the MAD is used as an alternative only when CPAP is not tolerated, in selected cases. In mild to moderate apnea the MAD can be the first option. The decision is made by the sleep medicine team together with the dentist, based on the apnea-hypopnea index, anatomy, and patient preference.
Minor occlusal changes can occur with prolonged use. That is why we calibrate the advancement progressively, do periodic occlusal checks, and prescribe morning repositioning exercises. Tooth movement is a real adverse effect of sustained use, and periodic follow-up is part of the treatment.
Chronic snoring in children always justifies evaluation. It can be associated with adenotonsillar hypertrophy, a narrow palate, or habitual mouth breathing. Pediatric apnea affects facial growth, cognitive development, and school performance. It is assessed together with ENT and, when appropriate, functional orthopedics or early maxillary expansion is indicated.
They can be. In some patients, nighttime muscle activity appears within the micro-arousal the body uses to reopen the airway. That is why, with marked bruxism, the airway becomes part of the evaluation. Treating only the bruxism with a conventional guard can leave the cause unaddressed.
