**4.4 Hypoglossal nerve stimulation**

*Updates in Sleep Neurology and Obstructive Sleep Apnea*

Multiple techniques to improve lower pharyngeal airway by decreasing the

1.Radiofrequency tissue ablation: It is a minimal invasive procedure. Application of a temperature-controlled radiofrequency probe to multiple locations in the base of the tongue. It generates submucosal scar tissues that anticipated to reduce

2.Lingual tonsillectomy: Improves airway by removing obstructing lingual tonsil

3.Partial midline glossectomy: Resection of the midline tongue base tissue.

4.Submucosal lingualplasty: Resection of submucosal lingual tissue of the

Multiple procedures tend to improve lower pharyngeal airway by advance or

2.Genioglossus advancement: Advancing the genial tubercle of the anterior

3.Hyoid suspension: Suspend the hyoid bone to the thyroid cartilage or mandible by using permanent suture. It helps stabilize the base of the tongue and

Multiple studies showed the effectiveness of lower pharyngeal and laryngeal procedures. It demonstrates improvements in respiratory physiology during sleep, daytime somnolence and quality of life. Successful sleep study outcomes defined as a reduction in AHI of 50% or more and an AHI of less than 20, was achieved in

Adverse effects reported were based on the surgical techniques that been used. Pain, hemorrhage, tongue infection airway complications, taste change and dysphagia

Postoperative pain and submandibular edema were the two most common

The maxilla and the mandible are advanced together with both upper and lower teeth to widen the retrolingual and the retropalatal segments of the upper airway. It is beneficial mainly for patients with craniofacial issues, but it is not limited for patients with this problem. The maxilla is moved by a Le fort I osteotomy and the mandible by a sagittal split osteotomy. It is a major operation but showed a significant increase in the pharyngeal airway dimensions and decrease AHI score below

seen in partial glossectomy, lingualplasty and lingual tonsillectomy [25].

complications followed radiofrequency tissue ablation [26].

**4.3 Maxillomandibular advancement**

1.Tongue-base suspension: stabilize the tongue and prevent retrolingual collapse by placing a suture to the anterior mandible to create a tongue base sling.

**4.1 Tongue reduction procedures**

volume of the tongue tissues:

the tongue volume.

tissue.

tongue base.

**4.2 Tongue advancement**

lower pharynx.

35–62% of patients [24].

stabilize the tongue base and pharyngeal muscular:

mandible forward and create an osteotomy around it.

**180**

the threshold of 20.

New treatment for OSA by Implantable neurostimulator device was approved by US Food and Drug Administration in 2014. It keeps the lower pharyngeal airway open during sleep by activates the protrusion muscles of the tongue via the hypoglossal nerve.

Eligibility criteria include:


Hypoglossal Nerve Stimulation showed 68% decrease in AHI score, oxygen desaturation index score decreased by 70%, and improved quality of life [27].

Most common reported adverse outcomes are infection, hemorrhage, and tongue weakness. It is still unknown whether there are long term risks.
