though there are many causes for sleep apnea .

some studies shows that  mandibular set back orthognathic surgery also has correlation with sleep apnea.

following are the references-

1. Upper airway changes after mandibular setback osteotomy. Concerns for obstructive sleep apnea

Paoli JR1, Lauwers F, Cances V, Tiberge M, Lacassagne L, Fossat W, Boutault F.Rev Stomatol Chir Maxillofac. 2000 Jun;101(3):129-34.

2.Effects of mandibular setback surgery on oropharyngeal airway and arterial oxygen saturation.

Kitagawara K1, Kobayashi T, Goto H, Yokobayashi T, Kitamura N, Saito C.

 Int J Oral Maxillofac Surg.2008 Apr;37(4):328-33. doi: 10.1016/j.ijom.2007.12.005. Epub 2008 Feb 12.

Thank you Dr. Zuber. It is really helpful.

Dear Dr. Zuber;

I was thinking with mandibular prognathism the airway is widely open. As this is used for MRA. so when you set the mandible back there should be enough opening. If there is development of OSAHS then may be the setting is more than required! What do you think

Up to Fernandez-Ferrer et.al. a decrease in the UA does take place but appears not to affect the patient's sleep quality. This study found no evidence to confirm that bimaxillary or mandibular orthognathic surgery predisposes to obstructive sleep apnoea development. 

Fernández-Ferrer, L., Montiel-Company, J. M., Pinho, T., Almerich-Silla, J. M., & Bellot-Arcís, C. (2015). Effects of mandibular setback surgery on upper airway dimensions and their influence on obstructive sleep apnoea – A systematic review. Journal of Cranio-Maxillofacial Surgery, 43(2), 248–253. http://doi.org/10.1016/j.jcms.2014.11.017

Kind regards

Ulrich Kritzler

Thank you Dr. Kritzler

I was thinking the same. Setting the mandible back in Class III will reduce the UA but to the ideal positioning, but if the mandible is moved back more than needed, will lead to occlusion of the UA. In this cases they may develop OSAHS!

I think that patients without pre-existing sleep-related breathing disorders who undergo orthognathic surgery with mandibular retropositioning can compromise the posterior airway space, alter the physiologic airflow through the upper airway, and can predispose patients to development of obstructive sleep apnea syndrome.

following is the reference:

Effects of Mandibular Retropositioning, With or Without Maxillary Advancement, on the Oro-Naso-Pharyngeal Airway and Development of Sleep-Related Breathing Disorders

Neophytos Demetriades, David Joey Chang, Constantinos Laskarides, Maria Papageorge

DOI: http://dx.doi.org/10.1016/j.joms.2010.02.033

Journal of Oral and Maxilofacial Surgery October 2010; 68(10):2431–2436.

Kind regards

Dr. Gladia Toledo

Personally I feel part of the diagnosis of these patients should be a CBCT to measure the initial Volume and Minimal Cross Sectional area (MCSA) and its location. If the MCSA is in the oropharynx and is below 150 mm2, I would concerned. Yes if the MCSA is large (>200mm2) then I may not be as concerned. Also acoustic pharyngometry or Drug Induced Sleep Endoscopy (DISE) could be used to document the initial airway size before surgery. 

Dear Adil! We test the hypothesis of the presence of patients with obstructive sleep apnea in addition to peripheral mechanisms (airway obstruction bony elements, tongue, uvula ...) and central mechanisms (violation of breath control and responsiveness to changes in respiratory homeostasis). Please see our work in this direction.

Thank you Dr. Kulchitsky. I will read the articles you have sent.

I feel the CBCT gives the volumeric actual size of the airway other than the 2 dimensions of the lateral ceph. So calculations could be more accurate. What do you think?

Three-dimensional voxels is better of course. But it depends very often on professionalism of staff.

The cone-beam 3-dimensional scan is a simple and effective method to accurately analyze the airway. ENT specialists question the validity of using conventional headfilms for evaluation of possible airway obstruction. (1, 2)

Abnoudara et al. compard imaging information about nasopharyngeal airway size between a lateral headfilm and a 3-dimensional (3D) cone-beam computed tomography (CBCT) scan in adolescent subjects.(3)

They found:

1) In adolescents, there is a significant positive relationship between nasopharyngeal airway size on a headfilm and its true volumetric size from a CBCT scan.

2) Accurate determination of airway volume for a patient from a headfilm is difficult because of the great variability in the 3D airway.

3) The inferior turbinates can protrude significantly into the nasopharyngeal airway space and cause severe airway restrictions for some patients.

Kind regards

Ulrich Kritzler

1) Vig P, Hall D. The inadequacy of cephalometric radiographs for airway assessment. Am J Orthod 1980;77:230-3.

2) Schwab RJ, Goldberg AN. Upper airway assessment: radiographic and other imaging techniques. Otolaryngol Clin North Am 1998;31:931-68.

3) Aboudara, C., Nielsen, I., Huang, J. C., Maki, K., Miller, A. J., & Hatcher, D. (2009). Comparison of airway space with conventional lateral headfilms and 3-dimensional reconstruction from cone-beam computed tomography. American Journal of Orthodontics and Dentofacial Orthopedics : Official Publication of the American Association of Orthodontists, Its Constituent Societies, and the American Board of Orthodontics, 135(4), 468–79. http://doi.org/10.1016/j.ajodo.2007.04.043

Dear Adil Osman,

I just saw the question today and love it.

Sassouni plus cephalometric analysis

CBCT is not a standard of care in diagnosis of OSA.

The volumetric Airway study is just a screening tool.

By today standard of care the SPG is the only Diagnosis of OSA before and after the BSSO mandibular set back orthognatic surgery.

Evidence of TMJ Internal Derangement happened or worsened following BSSO surgery was proven by several published research papers.

When we push the condyles backward we Cause or Aggravate TMD.

TMD and OSA are happening most of the time together.

We can prove to ourselves just by collecting SPG and MRI of TMJ before and after BSSO surgery.

In 1997 I discovered the 2 unpublished cephalometric factors used in the screening and diagnosis of TMD and OSA.

This is a clinical discovery that proves to have extremely high Sensitivity and Specificity of above 95%.

All other proposed methods of OSA screening can not even have Specificity above 40%.

We look at the relationship of Atlas, the first cervical vertebrae, Posterior Border of Ramus and Posterior Pharyngeal Wall on the Head xray or Lateral Cephalometric x-ray taken at the upright position of the patient.

We presented the findings at the AAMS first International Congress in Los Angeles in 2015.

We taught these findings together with the Sassouni Plus cephalometric analysis in study clubs, dental meetings and United States Dental Institute.

We welcome all collaboration in a structured research project to prove the concept.

Please find here the poster we recently uploaded in Research Gate.

Please try it and give us feedback.

Thank you very much.

Viet Nghiem DDS

The answer is actually

in the question

I know you already knows Adil, my Dear Colleague

Thank you, Dr Viet.

Dear Adill,

Please call me Viet

Just like I call you Adill

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