Endoscopically Assisted



Endoscopically-Assisted Surgical Expansion (EASE)


In 2004, Dr. Kasey Li and Dr. Christian Guilleminault reported their results of maxillomandibular expansion improving obstructive sleep apnea (OSA). The rationale of the operation is based on the findings that patients with OSA often have narrow jaws, which result in constricted nasal airways and posterior tongue displacement with resultant airway obstruction. By widening the upper and lower jaws, maxillomandibular expansion enlarges the nasal and retropalatal airway, stiffens the soft palate, and thus creates more intraoral space.

Over the past 15 years, Dr. Li has made numerous modifications to reduce the invasiveness and improve the outcomes of maxillomandibular expansion; the resultant current approach developed by Dr. Li is known as endoscopically-assisted surgical expansion (EASE). In EASE, widening of the upper jaw is achieved in a minimally-invasive fashion. The upper jaw is widened by inserting a distractor on the palate. With endoscopic assistance, very conservative bone scoring is then performed to facilitate expansion of the upper jaw. The procedure is conducted using under sedation or general anesthesia and is completed in under 1 hour. No hospitalization is necessary, and patients usually return to work in 1-2 days without any dietary or activity restrictions. Once the upper jaw widening is complete, the lower jaw is widened orthodontically.

EASE has numerous advantages compared to that of other surgical widening techniques:

  1. EASE is dramatically less invasive compared to other surgical jaw-widening techniques. Instead of making lengthy incisions inside the mouth as is done in other jaw-widening surgeries, EASE involves making a very small pinhole incision. Since no saw is used, EASE minimizes patient trauma, pain and swelling. Most patients do not need pain medications beyond 1-2 days.
  2. EASE is a single-stage operation in which the distractor is placed at the same time as the bone operation. This is in contrast to other jaw-widening surgeries that are two-step procedures.
  3. EASE does not require an incision at the front part of the mouth and thus avoids any long-term distortion of the nose and/or upper lip that may have otherwise resulted from muscle stripping and trauma that can occur in other surgical jaw-widening procedures.
  4. EASE results in a small gap between the front teeth (usually 2-3 mm) that can be eliminated easily using orthodontics (possibly with Invisalign). Other widening procedures result in a very large (8-10 mm) and unsightly gap. Such a large gap leads to prolonged orthodontics and can compromise the health of front teeth due to the distance of teeth movement needed to close the gap.
  5. EASE achieves opening of the entire nasal airway, especially the back of the nose and palate, and thus achieving superior results compared to other techniques.

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Guilleminault C, Li KK.  Maxillomandibular Expansion by Distraction Osteogenesis for the Treatment of Sleep-Disordered Breathing: Preliminary Results.  Laryngoscope; 114:893-896, 2004.

Li KK.  Surgical Therapy for Obstructive Sleep Apnea Syndrome.  Seminars in Respiratory and Critical Care Medicine; 26:80-88, 2005.

Li KK, Quo S, Guilleminault C.  Endoscopically-Assisted Surgical Expansion (EASE) for the Treatment of Obstructive Sleep Apnea Syndrome.  Sleep Med. 2018 Sep 29. pii: S1389-9457(18)30391-5. doi: 10.1016/j.sleep.2018.09.008.