Obstructive sleep apnoea has long been treated as a single condition with a single set of treatment options, ranked roughly from CPAP at the top to oral appliances further down the list. In practice, patients with the same severity score can respond very differently to the same treatment, and a growing body of sleep medicine research explains why. The answer lies in OSA phenotypes and OSA endotypes, and understanding both is changing how personalised treatment for sleep apnoea is approached.
The British Academy of Dental Sleep Medicine (BADSM) trains dentists to look beyond a single apnoea-hypopnoea index number and consider what is actually driving a patient’s condition. This article explains what OSA phenotypes and endotypes are, why sleep apnea phenotypes matter for treatment selection, and how dentists can bring this thinking into everyday practice.
What Are OSA Phenotypes?
OSA phenotypes describe the observable clinical patterns a patient presents with, rather than the underlying physiology causing them. Commonly recognised sleep apnea phenotypes include positional OSA, where apnoea events occur predominantly when sleeping on the back, REM-predominant OSA, where breathing events cluster during REM sleep, and obesity-related OSA, where excess soft tissue around the airway is the dominant factor. A craniofacial or anatomical phenotype is also common, particularly in patients with a narrow airway, retrognathic jaw position, or enlarged tonsils.
Recognising which phenotype a patient fits is useful because it points towards which interventions are more likely to help, long before more detailed testing is available.
What Are OSA Endotypes?
Where phenotypes describe what is observed, osa endotypes describe why it is happening at a physiological level. Sleep medicine research has identified several underlying traits that combine differently in each patient: how easily the airway collapses anatomically, how sensitive the patient is to waking up in response to breathing disturbances (arousal threshold), how effectively the airway dilator muscles respond during sleep, and how stable or unstable the patient’s breathing control system is (often described as loop gain).
Two patients with an identical apnoea-hypopnoea index can have very different endotype profiles. One might have a mainly anatomical problem, while another might have a low arousal threshold that causes them to wake before their airway muscles can properly compensate. These are functionally different conditions that happen to produce a similar severity score.
Why Sleep Apnea Phenotypes Matter for Treatment Selection
Treating every OSA patient the same way, regardless of phenotype or endotype, is one of the reasons treatment response can look inconsistent across a caseload. A patient whose apnoea is largely positional may do well with positional therapy alone. A patient with an anatomical phenotype driven by a retrognathic jaw is often a strong candidate for a mandibular advancement device, since it directly addresses the mechanical cause — a systematic review and meta-analysis of MAD responders found that responders were more likely to have a retruded maxilla and mandible, a narrower airway, and a shorter soft palate than non-responders. A patient with a low arousal threshold or high loop gain, however, may see limited benefit from a purely anatomical intervention, because the primary driver of their condition sits elsewhere in the breathing control system.
Matching treatment to the underlying phenotype and endotype, rather than applying the same pathway to every patient, is the basis of personalised treatment sleep apnea approaches now being explored across sleep medicine.
Personalised Treatment for Sleep Apnea in the Dental Setting
For dentists providing oral appliance therapy, phenotype-informed thinking has practical value. A patient with a clear anatomical component and mild to moderate severity is often a good fit for a mandibular advancement device. A patient whose case notes suggest a supine-dominant pattern may benefit from combining an appliance with positional guidance. Patients who do not respond as expected to a well-fitted device are worth reassessing with their endotype in mind rather than assuming the appliance has simply failed — a 2024 pilot study on phenotype-based MAD outcomes found that pathophysiological phenotyping helped explain differences in treatment response even among patients with similar baseline severity.
This is where personalised treatment sleep apnea principles genuinely change clinical decision-making in a dental setting, moving away from a single fixed protocol and towards an assessment of which mechanism is most likely driving each individual patient’s condition.
Precision Medicine and Sleep Apnea: Where the Field Is Heading
The broader shift towards precision medicine sleep apnea reflects a wider move in medicine away from one-size-fits-all treatment pathways. As phenotyping and endotyping become more accessible outside specialist sleep laboratories, dentists are increasingly positioned to use this information alongside their own clinical findings, rather than relying on it as a distant research concept. BADSM’s article on precision medicine for mild OSA explores this shift in more detail, particularly for patients at the milder end of the severity spectrum where treatment selection matters most.
Getting Trained to Apply Phenotype-Led Thinking
Applying phenotype and endotype awareness in practice takes more than reading about the concept. It requires structured training in how to recognise clinical patterns, when to suspect a particular endotype, and how to select or adjust oral appliance therapy accordingly. BADSM’s courses are designed to give dentists this practical framework, rather than leaving personalised treatment as a theoretical idea with no clear application in the surgery.
Frequently Asked Questions
What are OSA phenotypes?
OSA phenotypes are the observable clinical patterns of obstructive sleep apnoea, such as positional OSA, REM-predominant OSA, obesity-related OSA, and anatomical or craniofacial phenotypes.
What are OSA endotypes?
OSA endotypes are the underlying physiological mechanisms driving sleep apnoea, including airway collapsibility, arousal threshold, muscle responsiveness, and loop gain. They explain why patients with similar severity scores can respond differently to treatment.
Why do sleep apnea phenotypes matter for dentists?
Sleep apnea phenotypes help predict which patients are more likely to respond well to a mandibular advancement device compared with those who may need a combined or alternative approach.
What does personalised treatment for sleep apnea involve?
Personalised treatment sleep apnea approaches match therapy to a patient’s specific phenotype and endotype rather than applying the same protocol to every patient with a similar severity score.
Is precision medicine relevant to dental sleep medicine?
Yes. Precision medicine sleep apnea principles are increasingly relevant to dentists, since phenotype and endotype awareness can inform which patients are best suited to oral appliance therapy.
Want to bring phenotype and endotype thinking into your own practice? Join BADSM as a member and access training built around personalised sleep apnoea treatment.
Dr. Aditi Desai is the President and Founder of the British Academy of Dental Sleep Medicine, with over 20 years of experience in oral appliance therapy and a co-author of the Standards of Care for Mandibular Advancement Devices.*
