Final Flashcards
What is the incidence of cleft lip and palate?
1 in 700 live births
What gender has more cleft lips and palates?
Boys
Which side is more affected?
Left.
What are the most common problems affecting the orofacial region when you have clp?
Partial anodontia, supernumerary teeth, malocclusion, malformed teeth.
Who is on the cleft team?
Peds dentist, orthodontitis, OMXS, Plastic surgeon, pediatrician, speech pathologist, psychologist, social worker, geneticist.
When in fetal life does the formation of the nose lip and palate take place?
5th-10th weeks.
What forms the lip?
2 medial nasal swellings and 2 maxillary swellings. It is apart of the intermaxillary segment.
What forms the intermaxillary segment?
Labial component, alveolar segment and primary palate.
What is the cause of a cleft lip and palate?
Exact cause unknown, but is associated with other syndromes.
What is the most common malocclusion class for cleft lip and palate.
Class III. Retardation of MX growth.
Nasal deformity of a cleft lip
Alar cartilage is flared on side of cleft. Columella is pulled toward the non cleft side. Poor underlying bony support for base of nose.
What are ear problems associated with CLP
Predisposed to middle ear infections and poor drainage of the middle ear due to muscle dysfunction. These pts require myringotomy tubes.
Rule of 10’s for timing of surgical repair
10 weeks, 10 lbs, 10 g/dl hemoglobin.
What are the advantages of early closure?
Better palatal and pharyngeal muscle development, ease of feeding, better speech development, better auditory tube function, better hygiene, improved psychologic state of pt and parents.
Early closure disadvantages
More difficult in younger children, scar formation and resulting growth restriction.
At what age do you close a soft palate?
8-18 months.
At what age do you close a hard palate?
May be delayed to allow for growth. You wait until you at least have the eruption of deciduous teeth.
At what age do you close a cleft alveolus?
Usually performed between 6-10 years of age.
Why would you graft the alveolus?
Achieves stability of the arch, preventing collapse of alveolar segments, improves health of dentition, allowing for eruption of canine and lateral incisors, provides for continuity of the piriform rim (supports the ala of the nose), repairs residual oronasal fistula, improving hygiene and speech.
When would you do primary grafting?
Less than 2 years of age. The outcome is poor if it is at the time of lip repair due to abnormal MX development. You can also do it prior to palate repair but after lip repair. It provides reasonable results, but requires very specific protocol.
What is the protocol for primary grafting prior to palate repair but after lip repair?
Only rib graft performed with limited dissection, segments in very close proximity.
When is secondary grafting?
After 2 years of age. Early secondary (2-5 yr) is not supported by literature. Mixed dentition secondary is between ages 6-12 and can be considered early and late (6-8 and 9-12). Late secondary is after the age of 12. Ages 6-10 is the most common.
When is the ideal timing for mixed dentition grafting?
After the eruption of the central incisors and before the eruption of the canine. Less effect on facial growth as there is minimal maxillary growth after the age of 6-7. Generally better cooperation with perioperative and orthodontic care is acceptable. Donor sites have adequate bone for autogenous grafting, eruption of tooth may improve bone volume, enhances health of teeth in area of grafting.
What is the Ideal Patient for grafting?
8-12 years of age. MX canine root 1/2-2/3 developed. Some authors recommend 6-8 yrs so you preserve the lateral incisor, but this is controversial. There is a congenitally missing lateral in 35-60%, but if it is present you can consider it.
Should you use dental or chronologic age?
Use dental age for evaluation of grafting timing!
Factors affecting timing of grafting.
The presence and position of the lateral incisor is important. Degree of rotation or angulation of central incisor as the positioning is a result of the underlying bone and you may need grafting prior to ortho movement. Trauma and mobility of premax segment, social issues, pt. and cleft size, occlusion, need for adjunctive procedures, team dynamics.
Why is the iliac crest good for bone grafting?
Low morbidity and high volume of osteoblastic cells.
Calvarial Bone
Less successful than iliac crest. Less bone.
Mandibular symphysis
Less useful for earlier grafts due to tooth development
Tibia
Can’t be used in developing children.
Rib
Used in primary grafting. (less than 2 years of age)
Allogenic bone graft
Slower revascularization, less predictable in large or bilateral clefts, slower reformation of new bone.
Bone Morphogenic Protein
Off label use, avoids donor site, shows similar results to iliac crest bone grafting, less dimensional support, costly.
Pre-surgical expansion
Controversial, but most authors support it. It is easier prior to grafting due to mobility of segments. There is improved access to the nasal floor and it eliminates traumatic occlusion. Improves post op hygiene.
Post-surgical expansion
Smaller tissue defect to close, improved bone consolidation when bone is put under dynamic load, narrower defect, bone heals more quickly.
Which approach to expansion would you use?
Both are appropriate, you must use clinical judgement.
Why is ortho movement of teeth next to the graft not typically desired?
It increases the chance of moving teeth into the cleft. Osseous cleft is usually larger than the soft tissue defect.
What are the goals of cleft surgery?
Closure of the nasal floor, closure of palatal and labial fistula, maintain keratinized tissue around teeth, closure without tension, avoid shortening of the vestibule.
What is the surgical technique?
Advancing buccal and palatal flaps
Post Graft Management
Monitor eruption of canine, occasionally needs surgical exposure. If laterals are missing, decide whether space maintenance or canine substitution is best. May need further grafting to facilitate implant placement.
What is the Bergland Scale?
The permanent canine must be erupted, there are 4 categories: Type I: 0-25% resorption. Type II: 25-50% resorption. Type III: 50-75% resorption. Type IV: 75-100% resorption with no residual bony bridge.
What is the Chelsea Scale?
Type A: Bone at CEJ with 75% of root covered.
Type B: Bone at CEJ with 25% of root covered.
Type C: 75% of roots covered with bone.
Type D: 50% of roots covered with bone.
Type E: Presence of bone tissue bridge.
Type F: 25% of roots covered with bone.
What is your initial assessment of a trauma patient? (Primary Survey)
Airway, breathing, circulation, disability (life threatening injuries and neurologic status), exposure. Basically ABC’s of CPR.
What is the secondary survey of a trauma pt.
Thorough examination. Most head and neck injuries are accomplished during this time. Systemic approach.
What type of radiographs do you need for dentoalveolar injuries?
PA films, pano, CT scan. May need to take at different angles and may need to take of soft tissues.
Crown Craze or Crack-Crown Infraction
Incomplete fracture of enamel with no loss of tooth structure.
Uncomplicated Crown Fracture
Confined to enamel or enamel with dentin. NO pulp
Complicated Crown Fracture
Enamel, dentin and exposed pulp.
Uncomplicated Crown/Root Fracture
Enamel, dentin, cementum. NO pulp
Complicated Crown/Root Fracture
Enamel, dentin, cementum, and pulp.
Horizontal Root Fracture
Dentin, cementum with pulp exposure.
Concussion
Sensitivity to percussion with no loosening of tooth.
Subluxation
Tooth is loosened, but not displaced.
Luxation
Dislocation or partial avulsion of the tooth. Tooth is displaced without accompaning communication or fracture of the socket.
Avulsion
Tooth lost from socket.
How do you manage an enamel fracture?
Smooth rough edges or repair with composite. Test vitality initially and again in 6-8 weeks.
How do you manage an uncomplicated crown fracture?
Composite restoration. Test vitality initially and then again in 6-8 weeks. Check for luxation. Better prognosis for tooth if it hasn’t been luxated due to blood supply.
How do you manage a complicated crown fracture?
If tooth is immature, attempt to save pulp. Mature teeth will most likely need RCT.
What does the prognosis of a complicated crown fracture depend upon?
Length of time since injury occurred (less than 2 hours if pulp is vital), size of pulp exposure (small pinpoint exposure), condition of pulp and stage of root development.
If there is an open apex and it has been less than 24 hours since the injury what do you do?
Pulp cap with calcium hydroxide!
If there is an open apex and a larger exposure that occurred more than 24 hours ago, what do you do?
Calcium hydroxide pulpotomies.
Calcium hydroxide pulpotomies
Allows for apex formation, usually requires root canal therapy.
If there is a closed apex and less than 24 hours since a small injury….
you do a pulp cap.
If there is a closed apex and a larger injury or it is more than 24 hours old….
RCT is needed.
How do you manage a crown-root fracture?
If it is more than 1/3 of the clinical root, extraction is recommended. If it is to or slightly below the cervical margin it can be restored, possibly using crown lengthening.
Where do most root fractures occur?
In apical or middle third, not always horizontal.
Can you visualize root fractures radiographically?
Not always. It may not show immediately. Later radiographs (1-2 weeks) may show separation due to inflammation, hemorrhage or resorption.
How do you treat a root fracture?
Apical or middle 1/3 are not splinted unless there is mobility. With mobility, you splint them for 2 weeks. The fracture is bridged with calcified tissue, and teeth often remain vital. If its in the cervical 1/3, much more difficult to save, usually requires extraction.
Abrasion
An abrasion is a wound caused by friction between an object and the surface of the soft tissue. This wound is usually superficial, denudes the epithelium, and occasionally involves deeper layers.
Contusion
A contusion is more commonly called a bruise and indicates that some amount of tissue disruption has occurred within the tissues, which resulted in subcutaneous or submucosal hemorrhage without a break in the soft tissue surface.
Laceration
A laceration is a tear in the epithelial and subepithelial tissues.
Which periodontal injury has the worst prognosis?
Intrusion
What is the treatment for intrusion?
Do nothing. Surgically reposition and splint in place (worst prognosis). Ortho extrusion over 3-4 weeks, then splinted for 2-3 months (needs to happen immediately to prevent ankylosis). If it is a deciduous tooth, extract atraumatically.
Management of extrusion
Manually reseat it and splint it into place for 1-3 weeks. Will most likely need endo.
Management of lateral displacement
Usually have a fractured alveolus and gingival lacerations. Minimal can be replaced by splinting for 2-3 weeks.
What are the factors affecting success of an avulsed tooth?
Length of time out of socket, health of bone and periodontal tissues, preservation before implantation.
What has the best prognosis for avulsion for length of time out of socket?
More than 2 hours is poor. Less than 30 min is excellent.
What should you keep an avulsed tooth in?
Balance salt solution for 30 min and doxycycline for 5 min, if it has been out of the mouth for more than 20 min. Hanks Balanced Salt Solution is best, milk is an alright alternative. Rinse with saliva, water or saline and reimplant if possible.
When should you initiate RCT?
After 2 weeks, especially with closed apices. The inflammatory reaction associated with degenerating pulp can lead to resorption and ankylosis.
Greenstick
Incomplete fractures with flexible bone. Greenstick fractures generally exhibit minimal mobility when palpated and the fracture is incomplete.
Simple
Complete transection of the bone with minimal fragmentation at the fracture site.
Comminuted
The fractured bone is left in multiple segments.
Compound
Communication of the fractured segments with the external environment. Also called open fractures. Any fracture through a tooth socket is a compound fracture.
How are alveolar fractures treated?
Similar to other fractures. Usually closed with stabilization. May need a composite/wire spline to help stablize teeth.
Lefort Fracture
A type of midface fracturef
Closed Reduction
No exposure of the fracture or plate placement
Open Reduction
Fracture exposed, and then you can treat it without fixation once repositioned or you can apply internal fixation through titanium plates and screws or stainless steel wires.
Closed reduction with external fixation
May be requred in seerely comminuted fractures, and can be utilized with open reduction.
Edentulous MN Fractures
Need rigid fixation and possibly bone grafting to aid in healing.
Laceration repair
Thoroughly clean and inspect wound. Close from inside out, closing oral communications first. Re-approximate important esthetic structures, such as vermillion border and eye brow. Re-approximate like tissues: muscles, dermis, epidermis. Use resorbing sutures in deep tissue (vicryl, monocryl)
Why do you place deep sutures?
Takes tension off of the superficial layers, allowing epithelium to heal well without pulling open.
What type of fractures do you normally see with gunshot wounds?
Comminuted. Immediate intervention is important.
Anterior disk displacement with reduction
Disk is located anteriorly in close position, slips into position with opening.
Anterior disk displacement without reduction
Prevents full range of motion of joint. Deviation of condyle with opening.
Chondromalacia
Softening of cartilage
What are the degenerative changes you see in bone or cartilage?
Osteophytes seen. Damaged/perforated disks. Articular surface flattening, bony erosions, sub cortical cyst.
What is an example of a crystal deposition disorder?
Gout and pseudogout
Wilkes Classification
1: Early reducing disk
2: Late reducing disk
3: Nonreducing disk-acute/subacute
4: Nonreducing disk-chronic
5: Nonreducing disk with osteoarthritis
Anabolic Cytokines
Insulin like growth factor 1, transforming growth factor beta. Important for formation of extracellular joint matrix molecules.
Collagen, proteoglycans, and glycoproteins. Important for load bearing joints.
Catabolic cytokines
IL-1, IL-6, TNF-alpha
Contribute to formation of proteases. Work at low or normal pH
Oxidative stress
Free radical formation, amplifying cytokines response.
Most common type of joint infection?
GONORRHOEAE
Synovial Chondromatosis
Most common tumor. Older population. Swelling and pain. Superior joint space. Rule out chondrosarcoma
Ganglion cyst
Arise subcutaneously. Limits movement.
Where does a malignant tumor in the TMJ most likely metastasize from?
Breast, kidney or lung.
NSAIDS and TMJ
Analgesic and antiinflammatory. COX-2 is potent mediator.
Corticosteroids and TMJ
Block arachadonic acid pathway. Short term therapy indicated, but not long term use. Can be injected into joint directly.
Stabilization/flat plane splint vs. Anterior Repositioning appliance
Relaxes muscles, stables joints, protects teeth.
Guide MN into a more anterior position to alter condyle/disk relationship.
Arthrocentesis
Places needle into TMJ space and flushing fluid through the joint, expanding the joint, aiding in lysis of adhesions, removing inflammatory mediators.
Arthroscopy
Visualization of joint space for diagnosis. Lysis and lavage. Biopsy, disk repair and repositioning
Disk repositioning
Goal is to reestablish condyle/disk relationship. Used for disk displacement not responding to treatment, and both non-reducing and reducing disks causing pain.
What size disk perforations are treated with primary repair?
1-3 mm
After disk removal what are the options?
NO replacement. Free grafts, pedicle flaps.
Condylotomy
Produces more joint space.
Ankylosis
Severe limitation of joint movement.
Extracapsular ankylosis
Muscle contracture, coronoid process fusion, fibrous ankylosis
Intracapsular ankylosis
Fibrous or bony. See irregular joint surfaces radiographically.
LeClerc procedure
Provides blockage by down fracturing the zygomatic arch
pKa and local anesthesia
Affects onset
lipid solubility and local anesthesia
Affects potency
Protein binding and local
Affects duration of action. Increased binding means longer duration.
Vasoconstrictor and local
Duration and potency. Slows bloodflow
Where are amides metabolized?
Liver
Prilocaine and methemoglobinemia
Orthotoluidine is a matabolite of prilocaine and induces the formation of methemoglobin
Lidocaine and sedation
Metabolites can produce mild sedation
Where are esters metabolized?
Urine
High overdose of anesthesia
Tonic clonic seizure, CNS depression, hypotension, bradycardia, bradypnea, cardiac arrest
Moderate Sedation
Minimally depressed. Independent airway. Respond to physical stimulation and verbal command.
Deep sedation
Partial loss of protective reflexes. No airway. No verbal response.
General anesthesia
complete loss of reflexes. No airway. No responses.
Where does benzodiazepine bind?
On the GABAa Receptor
What are the effects of benzodiazepines?
Anxiolysis, anticonvulsant, sedation, amnesia, hypnosis, muscle relaxation
Where are benzos metabolized?
Liver
What are the two benzos used in iv sedation?
Midazolam and diazepam
Midazolam
Onset is 2-8 min. Lasts 20-35 min. Greater amnesia, but slower onset than diazepam. More water soluble, meaning less pain.
Diazepam
1-3 min. Duration is 35-60 min. More post op sedation than midazolam. More lipid soluble. More pain on injection
Lorazepam
Peak effect in 30-60 min. Amnesia lasts 4-6 hours. Slow onset and prolonged duration of action.
Opiod receptors
Mu receptors. euphoria, sedation, decreased respiration, dependence.
Diazepam and ketamine interaction.
D increases plasma levels of ketamine and decreases clearance rate.
N20 and ketamine
Nitrous decreases amount of ketamine needed for surgical anesthesia and shortens the recovery period.
Contraindications for ketamine
Open globe, hypertension, coronary artery disease, illicit drug use, psychiatric disorders
Neuropraxia
No nerve degeneration. From traction or compression. Recovery expected.
Axonotmesis
Isolated axonal loss. Recovery, may not be complete.
Neurotmesis
Complete or near complete transection of the nerve. Requires microneurosurgery
