The Vancouver Sleep and Breathing Centre

 

STANFORD METHOD

 

The Stanford Method predicts which patients will have Obstructive Sleep Apnea.

BMI = Body Mass Index = (Weight in Kilograms) / (Height in meters)2

NC = Neck circumference measured at a point 2 cm below the Adam's apple

Diagram of Measurements  

Craniofacial Measurements

 

Palatal Height (distance D - F): mm = P

Maxillary Intermolar Distance: mm = Mx

Mandibular Intermolar Distance: mm = Mn

Overjet: mm = OJ

 

(Angle AC is 20 degrees)

  1. Kushida CA, Efron B, Guilleminault C. A Predictive Morphometric Model for the Obstructive Sleep Apnea Syndrome Ann Intern Med 1997; 127:581 - 587.

= {Craniofacial Score} + {Obesity Score}

If > 70 patient has OSA; and if < 70, there is a 10% chance of OSA

What this equation says is the following:

  1. If the jaw is too small, there will not be enough room for the tongue. This is reflected in the Craniofacial Score.
  2. If the person is obese and/or has a very thick neck (such as a weightlifter or bodybuilder), thickening of the muscles around the spine and the weight of the jaw on the throat can lead to collapse of the throat during sleep. This is reflected in the Obesity Score.

This equation does not fully account for individuals who have a large and heavy lower jaw who are also at increased risk for breathing problems during asleep. This may explain the 10 % chance of having OSA when the score is less than 70.

These measurements are very simple to make using calipers and a tape measure. This can be done by a family doctor or by a dentist. In a full - grown individual, the mouth measurements only need to be made every 5 - 10 years. When the score is less than 70, tracking the BMI and NC on an annual basis will allow for the early detection and treatment of OSA before it can lead to serious health problems.

 

Dynamic Nasopharyngoscopy
Epworth Sleepiness Scale
Calculated Probability of Having OSA
Sleep Study
Stanford Method for Predicting OSA

 

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