2B Flashcards
Clear aligners
● Esthetics highly valued in US more than other countries
○ Treatment is becoming more esthetic → colorful ties; shaped brackets; ceramic brackets/wires; clear braces (aligners)
● Adult vs. Child acceptability of orthodontic appliances:
○ Clear trays & ceramic were esthetically acceptable for both child & adult
○ Stainless steel was acceptable for child 70%, but only 50% for adults
Clear aligner advantages:
● Esthetics
● Hygiene (bc removable)
● Comfort
● Tooth movements (intrusion of posteriors; other movements more difficult)
Clear aligner Limitations:
● Tooth movements:
○ Translation →
difficult to put force & moment with plastic tray
Clear aligner Limitations:
● Tooth movements:
■ Tipping & uprighting
easier to achieve
Clear aligner Limitations:
● Tooth movements:
○ Rotation →
difficult; possible to rotate round teeth
Clear aligner Limitations:
● Tooth movements:
○ Extrusion →
very difficult; esp. for triangular shaped teeth like incisors (only a small area of undercut to grab onto)
Clear aligner Limitations:
● Speed ⇒
0.25mm/aligner
○ Often changed 2x month, so total 0.5mm/month
■ Speed disadvantage is overcome when you have
multiple movements going on at once, ie. intrusion on some teeth, extrusion & rotation on other teeth)
○ Conventional braces ⇒
1mm/month
Clear aligner
● Expense -
neutral
○ Added lab expense, but reduced treatment time & less frequent readjustments
Invisalign Process (submitting to company):
- PVS impression (or intra-oral digital scan) & bite registration
● PVS impression of uppers & lowers (even if only treating 1 arch)
○ Tray needs to reach distal of terminal molar
○ Don’t need to capture palate
○ Seat impression vertically without tilting (unlike seating alginate posterior to anterior to express excess) - Panoramic radiograph or full mouth series
- Extra & intra-oral photographs
- Prescription form (online submission)
Bit registration & panoramic/full mouth series no longer required
Invisalign treatment options:
● Express ⇒ maximum
10 stages with some clinical restrictions
○ Maximum extrusion of 0.5mm
○ Max. posterior extrusion of 0.5 mm
○ Max. interproximal reduction of 2mm per arch (treats 2 mm of crowding)
○ No sagittal (AP) corrections required
Invisalign treatment options:
● Full ⇒
unlimited stages; up to 3 refinements & mid-course corrections available
Invisalign treatment options:
● Teen ⇒
similar to full
○ Has compliance indicators & eruption tabs (maintains space for eruption)
Invisalign treatment options:
● Assist ⇒
reboot treatment or have more checkpoints
Invisalign:
● Choose where to place
attachments (composite buttons placed to facilitate movement of teeth
Invisalign:
○ Don’t place attachments on
implants, 3 unit bridges, or ceramic crowns (will have to repolish)
Invisalign:
● Treatment will affect
overbite/overjet & midline - program shows resulting changes after alignment
Invisalign:
○ Interproximal reduction may be necessary to maintain
initial position
Invisalign:
● For pts with spacing →
can close all spaces or maintain spaces (for implants, etc)
Invisalign:
● For pts with crowding → can correct
via lateral expansion of molars/premolars
Invisalign:
● Need to check how they plan to move
teeth (some movements are not easily done with invisalign)
Invisalign works like a
flexible archwire
● Amount of force determined by amount of distortion & tray material
● Attachments help direct the forces
Before choosing to procline teeth to correct crowding, make sure there’s no
recession
Normal physiology of sleep:
● Characterized by
decreased body temp, metabolic rate, sympathetics, but active brain
Sleep
○ Decreased sympathetics:
↓ HR, BP, RR
Sleep
● Not a ‘time out’ ⇒
increased parasympathetics & GH secretion
Non-REM sleep
● 3 stages ranging from light dozing to deep sleep
● 75% of sleep
REM (rapid eye movement) sleep
● 25% of sleep
● Dreaming occurs
● Characterized by eyelid fluttering, rapid eye movement, irregular breathing
○ Muscle paralysis (prevents moving during dreams)
○ ↓ body temp & changes in HR & BP
Sleep deprivation ⇒ leads to
excessive daytime sleepiness (falling asleep during day)
● Sleeping < 7 hours ⇒
increases risk of falling asleep during day, while driving, & snoring
● Sleep deprivation affects mood & performance
Sleep deprivation
● Causes:
○ Voluntary behavior (most common cause) ○ Medical: ■ Dyssomnias ⇒ ■ Parasomnias ⇒ ■ Medica/psychiatric ⇒
■ Dyssomnias ⇒
insomnia; narcolepsy, restless leg syndrome, sleep disordered breathing)
■ Parasomnias ⇒
sleepwalking; bruxism
■ Medica/psychiatric ⇒
anxiety; depression
Continuum of Sleep disordered breathing:
● Normal
● Non-sleepy snorer
● Sleepy snorer (Upper Airway Resistance Syndrome)
● Obstructive Sleep apnea (OSA)
● Non-sleepy snorer
○ Snoring bc windpipe closes slightly during sleep when muscles relax
● Sleepy snorer (Upper Airway Resistance Syndrome)
○ Smaller windpipe causes inflammation - airway size disturbs sleep
Apnea ⇒ cessation of breathing
> 10sec
Hypoapnea ⇒
decreased airflow (30 or 50%) ass. with O2 desaturation of 3-4%
Apnea-Hypopnea Index (AHI) =
total # of apnea + hypopnea / hours of sleep
● Severity of sleep apnea:
○ Normal < 5
○ Mild 5-14; Moderate 15-30
○ Severe > 30
Normal sleep O2 saturation =
94-98%
All O2 desaturations
90% medically significant
OSA ⇒ AHI at least
5 + daytime somnolence
OSA:
● Prevalence:
○ More common in males
○ Worsens with age & increasing weight
Obstructive Sleep Apnea:
● Breathing disorder with
intermittent hypoxemia & sleep arousals
Obstructive Sleep Apnea
○ Apnea →
Hypoxia/hypercapnia stimulates sympathetic response → increases ventilatory effort & causes arousal from sleep
Obstructive Sleep Apnea
○ Increased sympathetics →
cardiovascular complications
Obstructive Sleep Apnea
Causes:
○ Anatomic airway narrowing
■ Obstruction can be in nasopharynx; oropharynx (70%), hypopharynx
○ Sleep induced loss of muscle tone
■ Neuromuscular compensatory mechanisms keep airway open when awake
○ Insufficient dilator muscle contraction
Obstructive Sleep Apnea
● Clinical consequences:
○ Excessive daytime sleepiness (affects mood & 2x likely for car accident)
○ Increased sympathetic tone → increases risk for HTN, coronary artery disease, CHF
Obstructive Sleep Apnea
■ Treatment of OSA with CPAP reduces
HTN
Obstructive Sleep Apnea
Comorbidities ass. with OSA:
○ Drug resistant HTN (83%) - uncontrolled by 2+ antihypertensives ○ Obesity (77%) ○ Congestive heart failure (76%) ○ Diabetes (50%) ○ Benign HTN (37%)
Obstructive Sleep Apnea
● Risk factors for sleep apnea:
○ Obesity
■ Neck size better predictor than BMI
● 17+ inches in males & 16+ inches in females increases likelihood of OSA
■ Biggest risk factor for adults, but NOT elderly ( ↓ muscle tone) or children (tonsillar hypertrophy)
○ Increasing age
○ Family history - bc heritable skeletal relationships
○ Smoking & alcohol use (depresses CNS)
Obstructive Sleep Apnea
● Findings in clinical examination:
○ Retrognathia (increased overjet bc small mandible)
○ Macroglossia
○ Lateral peritonsillar narrowing
Metabolic syndrome ⇒
group of risk factors that occur together & ↑ risk of CAD, stroke, DM Type II
Metabolic syndrome
● Diabetes, impaired glucose tolerance, insulin resistance AND 2 of the following:
○ HTN
○ Dyslipidemia
○ Central obesity
○ Microalbuminuria
Pediatric sleep apnea ⇒
AHI 1 or greater considered OSA; (fussy rather than sleepy throughout day)
STOP-BANG model questionnaire:
● Snoring loudly? ● Tired during day? ● Has anyone Observed you stop breathing during sleep? ● High blood Pressure ● BMI > 35? ● Age > 50? ● Neck circumference greater than 40 cm (16 in)? ● Gender
High risk of OSA if
AHI >5 with 3+ above items
● Note: signs & symptoms poorly predict disease severity
Diagnosis with Polysomnography
● EGG ⇒
monitors brain activity to document sleeps stages
Diagnosis with Polysomnography
● EOG ⇒
eye movements - determines REM vs. non-REM sleep
Diagnosis with Polysomnography
● Nasal/oral capnography ⇒
measures air flow from nose & mouth
Diagnosis with Polysomnography
● EMG ⇒
muscle activity; bruxism & restless leg syndrome
Diagnosis with Polysomnography
● EMG ⇒
muscle activity; bruxism & restless leg syndrome
● Lingual constriction has highest accuracy for
invisalign
OSA treatment:
● Oral appliance - Mandibular advancement devices
○ Advances lower jaw, pulling tongue forward & stretching dilators of pharynx
○ Alternative for patients who won’t tolerate CPAP
○ Indicated for snoring & non-severe apnea
OSA treatment:
Mand advancement devices
■ Effective for
mild-moderate sleep apnea (less effective for severe)
OSA treatment:
Mand advancement devices
■ Improves
AHI & EDS, but no effect on blood pressure
OSA treatment:
Mand advancement devices
○ Side effects ⇒
TMJ/tooth discomfort; changes in occlusion
OSA treatment:
Mand advancement devices
○ Contraindications:
■ <5 teeth per quadrant (excluding 3rd molars & fixed bridges)
■ Periodontal disease or dental caries
■ TMJ disorder; Inadequate jaw opening for fitting
■ <3 mm of voluntary jaw protrusion
■ < 6-10 teeth per arch
■ Bruxism? - may be indicator
OSA treatment:
Mand advancement devices
○ Treatment end point:
■ At least 7mm or 75% protrusion
■ Continue advancing till snoring & apnea subjectively resolves
OSA treatment:
● Upper airway surgery
○ Uvulopalatopharyngoplasty (UPPP)
■ Limited success ~40%
■ Unsuccessful for Type 2 or 3 obstruction (retropalatal / retrolingual)
OSA treatment:● Nasal CPAP
○
Gold standard, but poor compliance unless severe
