Concepts of Growth and Dev. Pt 2 Flashcards
what is the most common reason to remove mand. 3rd molars?
To prevent incisor crowding
In class we covered 2 studies regarding 3rd molars as the cause of mandibular incisor arch crowding. What did each conclude?
1-the removal of third molars to reduce or prevent late incisor crowding cannot be justified
2- there was not enough evidence to incriminate third molars as being the only or even a major etiologic factor in the late lower dental arch crowding
One theory is that crowding develops as the mandibular incisors, and perhaps the entire mandibular dentition moves in what direction?
distally relative to the body of the mandible.
what other factors may be responsible for mandibular crowding?
1-posterior wear
2- stress, clenching, grinding
3-changes in muscular forces
**ultimately the cause is unknown
based on a study, who is more likely to recommend prophylactic removal of 3rd molars, surgeons or orthodontists?
Surgeons
*orthos are increasingly under the thought that 3rd molars do not cause incisal crowding
what is intrauterine molding?
distortions on the face or body due to pressure against the baby while in utero.
*baby’s arm pressed against his face can result in a facial depression because there is a decrease in amniotic fluid to that area
Pierre Robin Sequnce
-small jaw
tongue falls back in throat
difficulty breathing
-cleft palate
-acid reflux
-sox 9 gene
-AD
-Repeated ear infections
-Teeththat appearwhen the baby is born (natal teeth)
- congestive heart failure
-hypertensionPierre robin sequence TX
- break the jaw and use a device to move the jaw forward
- lip-tongue adhesion to tether tongue anteriorly
*fix cleft palate, may beed tracheotomy, tympanostomy tubes, monitor
what evidence is there that the mandibular condyle is not a growth center?
if the lateral pterygoid muscle rips the head of the condyle off, there is no growth impairment
if the condyle breaks off and resorbs what happens?
80% chance it will regenerate from the periosteum
5 late causes of TMJ injuries
1-Facial asymmetry,
2-Malocclusion,
3-Growth disturbance, 4- Osteoarthritis,
5- ankylosis (fusion across the joint so that motion is impaired
if TMJ trauma occurs, the px can experience what 5 things?
1-Limited opening and excursive movements
2-Deviation of opening
3-Malocclusion manifesting in cross-bites
4-Short ramus height
5-Hyper-eruption of the teeth on the opposite side, infra-eruption on the ankylosised side
what is the most common cause of facial asymmetry in regards to the condyle?
trauma–the condyle may fail to grow vertically
Cleft lip results from failure of what to fuse?
maxillary swelling to fuse with the intermaxillary process
*can be unilateral or bilateral
cleft palate results from what failing to fuse?
two palatine shelves
In patients with bilateral cleft lip, the _________ is situated too far forward beyond the tip of the nasal septum
primary palate
cleft lip may be caused by what 3 drugs?
1-phenytoin
2- vitamin A
3-Methotrexate
what 4 drugs can cause cleft palate
1- phenytoin
2- Vit. A
3- corticosteroids
4-cigarette smoke
How common is cleft lip
1 or 2 out of 1000
clefts are more common in ?
Asian, Latino, or Native American descent
what state has highest cleft incidence?
Utah at 2.2/1000
babies born with a cleft lip or palate will have trouble eating. what do you do?
make a good seal in oral cavity, make sure baby doesn’t choke, use obturator
Muscular derangments in cleft lip and palate patients cause the malformation of what muscles to worsen?
1-The superior pharyngeal constrictor muscle attaches to the posterior aspect of the maxillary palatal shelves.
2-orbicularis oris
before surgery what device is used as a orthopedic tx?
1-The nasoalveolar molding device or NAM is a very elaborate passive or active device
**made of acrylic and later in tx wires are added for protracting forces of nares and coumella
what is a Latham device
intraoral device to bring palate loser together
*will require an extra surgery
when should surgery for lip closure be done?
3-6 months of age and baby weighs at least 10 lbs
beyond lip repair, what 4 things will need to be improved?
1-hearing
2-speech
3-dental work
4-psychosocial integration issues
. Cleft lip surgery is usually done before age ___ months, and cleft palate surgery is done before ___months
12, 18
what is the goal of surgical tx for cleft palate?
to create a palate that works well for speech.
As kids grow older, they might need additional surgeries, such as an ____ ____ ___ which is used to close the gap in the bone or gums near the front teeth.
alveolar bone graft,
TX of Diagnostic examination, general counseling of parents, feeding instructions, palatal obturator (if necessary); genetic evaluation and specification of diagnosis; recommendation of a protocol for the prevention of a cleft recurrence in the family
is done when?
newborn
when is repair of cleft lip done?
3 months
at what age is Presurgical orthodontics (if necessary) part of tx; first speech evaluation
6 months
at what age does speech therapy begin?
9 months
at what age does repair of cleft palate happen?
9-12 months
at what age does ortho tx really begin?
1-7 yrs
at what age is a alveolar bone graft considered?
7-8 years
**used to close the gap in the bone or gums near the front teeth to provide stability for perm. teeth
at what age does ortho tx continue?
older than 8 yrs
what cause central sleep apnea?
your brain doesn’t send proper signals to the muscles that control your breathing.
what causes obstructive sleep apnea?
you can’t breathe normally because of upper airway obstruction
3 risk factors for sleep apnea
1- large tonsils
2- obesity
3-syndromic kids (Crouzon, Down Syndrome, Pierre Robins, etc)
besides sleep apnea, what other thing can cause kids to lose sleep?
food, exercise or emotions, electronics, bad night routine
sleep for 0-12?
14-15 h/day
sleep for 1-3yrs?
12-14 h
sleep for 3-6yrs?
10-12 h
sleep for 7-12 yrs?
10-11 h
sleep for 12-18 yrs
8-9 hs
what are physical signs of a px at risk for obstructive sleep apnea?
1-Small triangular chin 2-Retruded mandible 3-Flat alar cartilages of nose 4-Steep mandibular plane angle 5-High palatal vault 6-Long, oval-shaped face (adenoid facies) 7-Long soft palate 8-Large tonsils (3 or 4) 9-Anterior openbite 10-Posterior crossbite 11-Mouth breather
definition of sleep apnea
stoppage of breathing for 10+ seconds
what 2 imaging technologies may be used to evaluate airway obstruction?
cone beam and radiographs
should a dentist diagnose sleep apnea?
no
should dentists be aware of a px with sleep apnea?
yes, include in health history
If you think you px is at risk for sleep apnea, what do you do?
refer to ENT
what device can a dentist make to help with snoring?
class 2 correctors
what help can a maxillary expander offer for sleep apnea?
Increases the size of the maxilla and decreases nasal airway resistance.
how could an extraction for ortho purposes cause sleep apnea?
1-smaller arch forms
2-less space for tongue
3-tongue is forced posteriorly
4-sleep apnea
*extraction doens’t mean that apnea will occur
