This study looks at how jaw surgery called maxillomandibular advancement with counterclockwise rotation affects breathing during sleep in people with moderate to severe obstructive sleep apnea who cannot tolerate standard treatments such as Continous Positive Airway pressure treatment. The participants are followed over time to see whether the surgery improves sleep apnea symptoms, daytime sleepiness, and airway size, and whether these improvements last. Advanced three-dimensional imaging and airflow analysis are used to better understand how the surgery changes the airway and breathing. The goal is to evaluate the long-term effectiveness and safety of this surgical treatment.

Inclusion Criteria:

• Clinical diagnosis of obstructive sleep apnea with AHI ≥15 events/h.
• Residence and/or registration in Dalarna County
• Body mass index (BMI; kg/m^2) between 15 and 35
• Documented failure of CPAP or mandibular advancement therapy.

Exclusion Criteria:

• Medical conditions contraindicating general anesthesia.
• American Society of Anesthesiologists Physical Status (ASA) Class III-VI
• Central sleep apnea
• Narcolepsy
• Prior orthognathic surgery
• History of tumor disease or radiotherapy of the jaws. Participants with systemic conditions associated with an increased risk of OSA. Such risks include;
• Hypothyroidism
• Acromegaly
• Diabetes mellitus
• Active generalized rheumatoid arthritis
• Clinically manifest periodic limb movement disorder
• Restless legs syndrome.