Oral Surgery Exam 3

Obstructive Sleep Apnea Complications
-Hypoxemia/Hypercarbia
-Polycythemia
-Hypertension
-Depression
-Impotence
-CVA
-Arrhythmia
-Sudden death

Obstructive Apnea
-Most common type of apnea
-Airflow stops >10s due to closure of airway by obstruction
-Chest wall inspiratory effort is normal
– >2% drop in O2 sats
-Terminates with arousal

Obstructive Hypopnea
-Continuous but diminished airflow (<66%) -Ventilatory effort unchanged/increased -Partial obstruction - >2% drop in O2 sats
-Arousal from sleep

Polysomnography
-Sleep staging
-Respiratory effort and events
-Consequences of respiratory events
-Does NOT involve capnometry

Objectives of Sleep Apnea Treatment
-Decrease collapsibility of the pharyngeal airway
-Decrease the speed of airflow by increasing volume

Tele-gnathic Sugery
-May be curative
-Success rate is high
-More complicated than usual orthognathic surgeries
-Longer cases, older pts, bigger moves
-Maxillomandibular advancement to increase airway space

Physical Finding NOT Concerning for OSA
-Short soft palate

Skin Resurfacing
-Removes small rhytids
-Smooths deep rhytids
-May work w/acne scars
-Does NOT remove muscle creases
-Same as dermabrasion/chemical peel
-Does NOT replace facelift

Laser Skin Resurfacing
-Physical vaporization of epithelium and some dermis (flattens skin)
-Collagen contraction by 1/3 (tightens skin)
-Collagen welding

Advantages of Laser Skin Resurfacing
-Reduced swelling/scarring
-More consistent results
-Better depth control
-No systemic effects
-No aerosolization of blood

Rhytidectomy
-Facelift
-Reasons to do it:
–> Deep wrinkles
–> Muscle creases
–> Excess skin
–> Improves skeletal outline
–> Older pts

Rhytidectomy: Steps
-Incision
-Dissection
-SMAS plication
-Skin excision
-Closure
-Bandaging

Blepharoplasty: Indications
-Bulging fat (bags)
-Excess skin
-Visual disturbances
-Remove fat/skin/muscle

Blepharoplasty: Steps
-Incision
-Fat isolation
-Excision
-Hemostasis
-Closure

Endoscopic Midface Lift
-Pull of midface with forehead and brows
-Softens nasolabial fold
-Helps with lateral canthus and crows feet

Frontalis Muscle
-Transverse forehead wrinkle lines

Procerus Muscle
-Nose wrinkles/Between eyebrows

Corrugator Supercilli Muscle
-Vertical wrinkles between eyebrows and above nose

Obicularis Oculi
-Crow’s feet

Botulinum Toxin A Mechanism
-Prevents the release of ACh from pre-synaptic neurons

Laser used for Caries Removal
-Er:YAG (erbium-yag)
-Er:Cr:YSGG (erbium, chromium)
-Little lateral thermal effect
-No local anesthesia needed
-No drill sound

Advantages of CO2 Laser
-Inhibits fibroblastic proliferation (decreased scarring)
-Hemostasis (seals vessels)
-Less edema/post-op pain (seals nerve endings)
-Protective glaze resists bacteria/oral fluids

Disadvantages of CO2 Laser
-Laser plume may contain viral particles
-Will damage adjacent tissue
-Will damage teeth and bone

Zone of Necrosis: Laser
-0.5mm zone

Zone of Necrosis: Electrocautery
-3-6mm zone

Laser Safety
-No open source of O2 (combustible)
-No metal retractors
-Protect adjacent tissues w/wet gauze

Orthognathic Surgery Goals
-Restore occlusal and masticatory harmony
-Improve facial esthetics
-Maintain, restore or establish joint function
-Improve psych outlook
-Improve airway

Most Common Orthognathic Procedure in US
-BSSO

Distal Segment of BSSO
-More anterior
-Contains teeth
-Contains IAN

Proximal Segment of BSSO
-Condyle
-Coronoid process
-Lateral border of ramus
-Body of mandible

Ways to Fix BSSO
-Wire osteo-synthesis and IMF
-Position screw osteosynthesis
-Lag screw osteosynthesis
-Bone plate fixation

Reasons to do BSSO: Mandibular Advancement
-Overly convex face
-Retruded chin
-Procumbent lip
-Increased mentolabial fold
-Poor throat form
-Flat or high mandibular plane

Reasons to do BSSO: Mandibular Setback
-Class III

IVRO Advantage over BSSO
-Less likely to damage IAN
-Intraoral incisions

Indications for IVRO
-Mandibular setback only
-Esthetic concerns (internal incisions)
-Greater than ~10mm of setback needed

Distal Segment of IVRO
-More anterior
-Teeth
-IAN
-Coronoid process

Proximal Segment of IVRO
-Condyle
-Lateral border of ramus

Most Important Part of Tx Planning for Orthognathic Surgery
-Physical examination

“Rule of Tens” Repair of Cleft Lip
-10 weeks
-10g Hemoglobin
-10 lbs

Timing for Alveolar Cleft Grafting
-9-11 years old
-Prior to eruption of permanent canine
-After crossbite is fixed and incisors are rotated
-Canine root 2/3 formed
-Tooth not yet erupted

Drugs That Can Cause Clefts
-Corticosteroids
-Valium
-Dilantin
-1st 8 wks of pregnancy

Ethnicity/Gender and Cleft Incidence
-Asians (1:500)
-Caucasians (1:1000)
-African Americans (1:2000)
-Males 2x
-Worldwide (1:800)

Goals of Lip Surgery
-Preservation of Cupid’s bow
-Reapproximation of Obicularis Oris
-Minimize scarring/placement of scars in normal anatomic contours

Goals for Alveolar Cleft Grafting
-Stabilize dento-osseous segments
-Provide bone for eruption of teeth
-Improve alveolar continuity
-Closure of oronasal fistula
-Alar base support
-Prevent tooth loss

Cleft Pts & Orthognathic Surgery
-Hypoplastic maxilla/deficient midface
-Mandibular prognathism
-LeFort osteotomy w/advancement
-Mandibular setback (BSSO)

Velopharyngeal Dysfunction
-Repaired palate is too short
-Inadequate closure from oral to nasal pharynx (nasopharyngeal airway)
-Hypernasal speech
-Speech therapy
-Pharyngeal flap surgery
-Prosthetics

Medial Edge Epithelial Cells
-Do not disappear –> No fusion –> Cleft

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