3/8/2018

AIRWAY ASSESSMENT

UPPER AIRWAY ANATOMY AND PATHOLOGY

SMALL AIRWAY What Happened?

David C. Hatcher, DDS, MSc, MRCD ( C ) Oral and Maxillofacial Radiologist Airway Anatomy & Pathology

Sleep Disordered Breathing (SDB) Increasing Upper Airway Collapsibility Polysomnography (PSG) . Abnormal Respiratory Pattern During Sleep . Apnea Hypopnea Index (AHI) . Snoring  Apnea = Cessation of Airflow > 10 seconds

. Upper Airway Resistance Syndrome  Hypopnea = Decrease in Airflow by > 30% for > 10 . Obstructive Sleep Apnea Syndrome Seconds . Obesity‐Hypoventilation Syndrome  Associated with Drop SaO2 by > 3 %

 AHI = A+ H / Hour Sleep  > 5 Abnormal

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Obstructive Sleep Apnea Pathophysiology of OSA Role of Anatomy Awake: Small Airway + Neuromuscular Compensation

Sleep Onset . . Recurrent Collapse of Airway During Sleep Loss of Hyperventilate: Abnormal Upper Airway Anatomy Neuromuscualar Correct Hypoxia & Compensation Hypercapnia

. Abnormal AHI with Symptoms Pharyngeal Muscle . Increase Resistance Activity  Mild OSA‐ 5‐15 AHI Events/ Hour Airway Opens  Mod. OSA‐ 16‐30 AHI Events/ Hour Airway Collapse Pharyngeal Muscle . Turbulent Air Flow Activity Restored  Sev. OSA‐ > 30 AHI Events/ Hour Apnea

Hypoxia & Arousal From Sleep Hypercapnia . Increases Collapsibility

Ventilatory Effort

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

1 3/8/2018

OSA Airway Metric Analysis

. Related to Abnormal Timing of Upper Airway . Volume Dilator Muscle Contraction . Cross Sectional Area . Normally Dilator Muscles Contract BEFORE . Linear Distances Diaphragm & Accessory Inspiratory Muscles Move OR it will Create a Negative Pressure Leading to Airway Collapse

. Requires Good Neurological System

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Measurement Error Source Effect of Tongue Position on Airway Map Region of Interest (ROI)

. Soft Ware Accuracy . Head Position . Tongue Position . Tongue Motion

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Cross Sectional Area

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

2 3/8/2018

CSA v. Age Airway: Role of Imaging Upright Imaging

180 . Airway Imaging Can Not Confirm Or Exclude 160 (mm2) OSA 140 Area

120

. Imaging Can Help Understand Airway 100 Sectional Anatomy (Phenotype) 80 Medium OSA Risk

 Identify Potential Obstruction Sites Cross 50  Evaluate Airway Support Structures High OSA Risk

8 1012 14 16 20 40 >50 Age UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Airway Resistance and Flow Airway Dimensions and OSA 3d CBCT Trends . Poiseuille’s Law . Ohm’s Law 4 OSA Control  (R = 8nl / π r )  (V = Pmouth –Palveoli / R) . Retroglossal and Retropalatal Space  R = Reistance  V = Flow Predictive of RDI BMI 29.5 23.1  N = Viscosity  P = Pressure 3 3  Π = phi  R = Resistance Cross Sectional Area OSA Probability Volume 4868 mm 6051 mm  R = Radius 2 < 52 mm High Smallest Area 46 mm2 147 mm2 52 ‐ 110 mm2 Medium > 110 mm2 Low AP 4.6 mm 7.8 mm Radius = Resistance = Pressure Gradient Lateral 11.6 mm 16.2 mm •Li HY, Chen NH, Wang CR, Shu YH, Wang PC. “ Use of 3-dimensional computed tomography scan to evaluate upper airway patency for patients undergoing sleep-disordered breathing surgery.” Otolaryngol Respiratory Effort Head Neck Surg 2003;1294):336-42 Ogawa, T, Reyes Enciso, W Shintaku Glenn Clark, OOOOE Jan 2007

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Nasal Valves

. External Nasal Valve

. Internal Nasal Valve

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

3 3/8/2018

External Nasal Valve Internal Nasal valve

. Major Alar Cartilage:  Lateral Crus  Medial Crus

. Septal nasal cartilage . (Quadriangular cartilage)

Netter’s for Dentistry

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Pyriform aperture

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Nasal Septum boundaries

. Cribriform plate of the Ethmoid . Ethmoid air cells . Maxillary sinuses .

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

4 3/8/2018

Concha Bullosa Polyposis . Pneumatized Middle Turbinate . Etiology  Allergy + Inflammation ‐> Unstable Mucosa ‐> Epithelial Proliferation ‐> Morphological Changes

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Chronic RhinoSinusitis (CRS) . Group of Disorders Characterized by Inflammation of Nose & Sinuses >/= 12 Consecutive Weeks Duration

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

5 3/8/2018

Rhinolith Foreign Body

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

Sinonasal Tumor

Courtesy of Dr. Shikha Rathi

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

6 3/8/2018

Oral & Nasopharynx Nasal Resistance

Boundaries . Mouth Breathing  Inferior Tongue posture . Narrowing of Dental Arches

. Clockwise Facial Growth Pattern . Increase Anterior Face Height

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

7 3/8/2018

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

SCC of Palatine tonsils

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

8 3/8/2018

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

2 UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher 11.88 mm UOP Ortho Alumni Hatcher

9 3/8/2018

Support Structures for Airway

. Cervical Spine . Jaws

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

•Local Insult Facial Growth Patterns •Regional Adaptation

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

10 3/8/2018

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

11 3/8/2018

Conclusions

. Imaging provides a Support Role in SDB . Granular Dx. Leads to a Tailored Treatment . Accurate Dx. Leads to the Best Treatment Outcomes

. Consider Airway from External Nasal Valves to Trachea . Consider Support Structures for Airway  Jaws  Spine  Tongue  Soft Palate

UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher UOP Ortho Alumni Hatcher

12