Dentoalveolar Surgery Flashcards
Order of impaction frequency
1-3rd molars
2-Max canines
3-Mandibular premolars
4-Max premolars
5-second molars
Rarely impacted teeth
1-Mandibular incisors
2-1st molarsf
Eruption pattern-Primary
Eruption pattern-permanent
Local vs systemic factors for tooth impaction
How to tell if a tooth is buccal or lingual from panoramic
If tooth is larger, out of focus, likely palatal.
If tooth is vertical, likely buccal
Describe cone beam computed tomography?
Conventional medial CT scanner uses fan-shaped beam to obtain individual image slices with each slice requiring a separate scan; slices stacked to get 3 dimensional rotation
Why does CBCT have less radiation
It is directed through middle of area and covers entire field of view, only one rotation needed; so less radiation
How does dose vary on CBCT
-slice thickness
field of view
mAs, kVP
Scan time
what is a gray or rad?
Absorption of 1 joule of radiation energy by 1 kg of matter
Sievert
Effective dose or quantification of potential radiologic detriment (cancer induction, genetic damage) from radiation
Bear in mind that 10,000 uSv single exposure = 1:1000 personal exposed will develop cancer.
What does it mean if an impacted canine/premolar is labial?
If palatal?
It means there is an arch-length deficiency.
If palatal, likely from extra space in the maxilla, excess growth, agenesis/peg lateral incisor, or stimulated eruption of lateral incisor or first premolar
How to help an impacted 2nd molar succeed?
In maxilla, remove and allow for the third molar to swing in.
That doesn’t always work in the mandible.
What is the ideal time to surgically uproot a canine?
2/3rd of root formation, with incomplete apical closure
What happens if you try and upright a 2nd molar too early?
tooth may move into wrong position.
If too late, pulpal necrosis/calcifcation maye occur leading to possible root fracture.
How to ensure appropriate surgical uprighting of a 2nd maxillary molar
1-Extract 3rd molar to posteriorly tip.
2-Need intact cortical plates for stability
3-Avoid damaging 2nd molar CEJ
4-Do not tip more than 90 degrees
5-Splint to first molar
6-Ensure tooth is out of occlusion
True or False? do you expose CEJ on an expose and bond?
False, do not expose CEJ –increased risk of root resorption, ankylosis, periodontal inflammation.
How to approach a mandibular premolar that is in the alveolar process?
Bond to the occlusal surface….apply vertical orthodontic forces until buccal surface exposed for new bracket placement.
Why is an apically positioned flap important
Allows erupting into attach mucosa and is less likely to have a periodontal defect with pocket formation.
What’s the normal eruption pattern of a 3rd molar
(6 stages)
What explains rotations of 3rd molars
1-Underdeveloped medial root-Under rotation = mesioangular impaction
2-Overdeveloped medial tooth with over rotation = distoangular impaction
3-Overdeveloped distal root (especially with medial curve) = severe mesioangular or horizontal impaction
By what age will tooth likely remain impacted if there is improper angulation or inadequate space?
18-20
Shorter arch or larger teeth leads to?
More impacted teeth
What is the Pell & Gregory Classification system?
Based on relation to occlusal plane and anterior border or ascending ramus
What is Winter classification
Baseront radiographic anatomical position of 3rd molar related to long axis of 2nd molar
What is the most commonly found impacted tooth?
Mesioangular at 45%
What three bacteria are often associated with pericoronitis?
Peptostreptococcus
Fusobacterium
Prophyromonas
What is the most common indication for extraction after 20
pericoronitis
What are symptoms of periocoronitis?
Associated with inflmmation of the operculum with pain, swelling, erythema, and purulence
What is the recommendation for removal of 3rds prior to surgery?
6-12 months to allow for adequate bony fill
What are periodontal considerations for wisdom toooth removal
1-Disrupted per ligament
2-Root resorption
3-Pocket Depths > 5 mm
T/F: Periodontal healing is best when…
3rd molars are extracted before exposure in the mouth and before bone resorption on the vital of the 2nd molar
Germectomy…
Perform when < 1/3rd root formation and radiographically discernible periodontal ligament.
If age is greater than 25, what are the thoughts on 3rd molar extraction?
1-Only remove if pathology is present
2-30% chance of increased pocket depth associated with 3rd molar removal
3-Post-operative morbidity is 1.5 times higher.
4-After age 19, preoperative and postoperative defects are the same.
What is the leading cyst associated with 3rd molars
1-Dentigerous cyst (28%)
2-OKC (3%)
3-Odontoma (0.7%)
4-Ameloblastoma (0.3%)
5-Carcinoma-(0.23%)
6-Myxoma-0.04%
T/F: decreased risk of neoplastic changes in 3rd molar follicle in patient’s older than 40
True
What is the indication to extract a 3rd molar for an overlying prosthesis
If 1-2 mm of bone or only soft tissue is overlying the tooth, then the tooth should be extracted.
How much do 3rd molars increase the risk of an angle fracture?
2.8 x fold
Contraindications for 3rd molar extraction
1-Too young (no younger than 9)
2-Too old, >40 yrs
3-Med Compromise
4-Damage to nerves
What is the indication to leave a root behind?
If root is not infection ed and less than 2 mm long, okay to leave without complications.
requires close radiographic follow up
If root of tooth is displaced lingually and it cannot be retrieved, how long should you wait before retrieving it?
3-4 weeks.
What is the most common root dislodged into the sinus?
Maxillary palatal root
Local measures to retrieve a root from the sinus?
1-Close nostrils, blow through nose
2-Fine-Tip suction
3-lavage with saline
4-pack iodoform gauze
5-Caldwell Luk in canine fossa
What are the borders of the infra temporal fossa?
What to do if tooth is dislodged into infra temporal space?
1-Finger pressure in buccal vestibule near pterygoid plates to manipulate back into the socket.
2-Access with hemostat
3-Suction
4-Close up and go again after 3-4 weeks with abx.
3 dimensional imaging, right angled hemsotat to bring back into position.
How to stop bleeding vessels?
1-Burnish bone,
2-Crush surrounding bone
3-Apply wax
4-Cautery
5-Could be contaminant nerve injury.
What is gelfoarm?
reservable porcine skin gelatin sponge that promotes platelet disruption the forms fibrin framework then blood clot.
Can be hoisted in thrombin (which activates blood coagulation factor II and converts fibrinogen to fibrin
What is surgicel?
Oxidized cellulose plat polymer of polyanhydrogucoronic acid
More efficient than sponge, but delayed healing
-Forms matrix/scaffold then artificial blood clot
-Resorbed between 7-14 days
-Creates acidic environment and not the best for overlying the nerve.
What is a collaplug
A bovine collagen plug that is resorbed in 10-14 days
What is thrombin?
A bovine or recombinant human that activates blood coagulation factor IIa, then conveys fibrinogen into fibrin
What is amincaproic acid?
Antifibrinolytic that inhibits plasmin
What is transexamic acid
Inhibits conversion of plasminogen to plasmin
What can you do to work up coagulopathy?
-CBC
-PT/INR
-PTT
-Bleeding time
-Factor 8 levels
-Ristocetin cofactor levels
Where is the most common place of an oroantral communication
The first molar site
How to treat oroantral communication?
for 2 mm
3-6 mm
> 6 mm
1-If opening is greater than 2 mm, please suture over socket to support clot, no blowing nose for 1 week
2-3-6 mm, gelatin sponge pack, figure of eight suture over socket,
3-If opening > 6 mm, tension-free primary closure, excise fistula and invert into sinus.
What are options for closure/
1-Buccal advancement
2-Palatal island/finger flap. rotational flap
3-Pedicled buccal fat pad
4-Tongue flap-
What is the blood supply of the buccal fat pad
the internal maxillary artery
How long before you release a tongue flap?
2-3 weeks and the patient must be in MMF
What are the bacteria associated with sinus disease?
1-Streptococcus pneumonia
2-Haeomphilu sinflueze
3-Moraxella catarrhalis
What antihistamines and decongestants should be used for oroantral communications?
1-Amoxicillin, Augmentnin,
2-Antihstamines-Certirizine, diphenhydramine, fexofenadine, loratidine
3-Decongestants: Pseudorephedrine, tripolidine, oxymetazoline
Risk factors for a mandible fx with 3rds?
1-Pt older than 40 years
2-Male
3-Atrophic jaw
4-Associated cyst/tumor
5-osteoporosis
6-Inexperienced surgeon
Can occur 14 days after say, but can occur up to 6 weeks postoperatively
Where is the IAN often located?
buccal and apical to mandibular tooth roots?
What is the incidence of injury to IAN in 3rd molar surgery?
1-5%
What are the Rood criteria?
1-Loss of IAN canal wall–cortical (white) lines
2-3rd molar root darkening
3-Narrowing of IAN canal as it passes 3rd molar root
4-Diversion of IAN canal
5-Deflection of roots
6-Bifid root apex
Risk factors for nerve injury (7)
1-Age > 25 years
2-Female > Male
3-Tooth elevation stretching nerve
4-Instrumentation near nerve
5-Socket curettage
6-Socket medications
7-Articaine blocks
Indications for a coronectomy
1-No pathologic legion
2-No interference with future restorations or orthodontic treatment
How much reduction of the tooth must be performed for a coronectomy?
3 mm below crestal bone
Most common presentation of lingual nerve
2.5 mm medial and 2.5 mm inferior
How many lingual nerve occurs above the lingual plate?
10-15%
% of lingual nerves directly attached to lingual plate
25%
What often causes nerve damage?
Injection into epineurium can cause hematoma and transiet/permanent paresthesia.
Where does sensory innervation and taste of the lingual nerve come from?
Anterior 2/3 of tongue is supplied by CN VII carried along CN V
Nociceptor:
A receptor excited by injury/painful sensation
Wallerian degernation
Fatty degeneration of the nerve fiber
Layers of nerve fibers
Endo–>Surrounds gorupof fibers–>forms fasicle
Peri–>Surrounds group of fascicles
Epi:Outermost layer that surround the fascicle bundles and blood vessels–>protects against compressive forces.
What are the. 2 nerve injury classification systems?
1-Seddon
2-Sunderland
What is neuropraxia?
Seddon I and Sunderland I-Minor ompression/traction temporary conduction blockade
What is axontmesis?
Seddon II/Axontmesis. Minor crush/tration
What is neurotemesis?
Seddon III and Sunderland V - Complete transection
Describe the event, state of nerve sheathe, axons, Wallerian degeneration, treatment, and possible nerve recovery for both Seddon and Sunderland nerve injury systems
What is Level A nerve mapping consist of
Mechanoreceptor (A-alpha and A-bata fibers)
1-Brush stroke direction (+/-)
2-2 pt discrimination
4 mimes normal for IAN & 3 mm for lingual.
What is Level B of clinical nerve testing
Mechanoreceptors (A-beta fibers)
-Contact detection: static light tough and pressure perception
-Use cotton wisp or von Frey monofilaments
What is Level C clinical nerve testing?
Nociceptors
(A-Delta (myelinated)
C fibers (unmyelinated)
Pinprick nociception: Assess free net endings
Thermal Discrimation: Hot gutta percha or Endo ice
Dysthesia, diagnostic nerve blocks
Unusual sensations, if relief–>mincroneurosurgery
If no relief from diagnostic nerve block, what is the consideration?
Central pain process and need for pharmacologic treatment.
Microneurosurgery repair indications
Indications (best results if <10 weeks
1-Complete anesthesia > 1-2 months
2-Profound hypothesia that does not improve > 3 months
3-Early dysesthesia-
4-Clinical observation of transection or foreign body
5-Progressive/worsening symptoms
6-Pt not able to tolerate hypoesthesia
Contraindications to nerve surgery
1-Centrally mediated pain, think meds like clonazepam or gabapentin, prcegablin
2-Improving sensory function
3-Symptoms are acceptable to present
4-Medically compromised patient
5-Patient age
6-Long duration since surgery
External neruolysis?
1-Free up Nerve
Internal neruolysis?
Open epineurium to decompress, evidence of fibrosis.
What is neurorrhaphy
the surgical suturing of a divided nerve
Tension free primary anastomosis – for IAN nerve and lingual nerve
> max IAN gap = 5 mm
Lingual nerve gap = 10 mm
What nerves are good options for autogenous nerve grafts?
1-Sural nerve
2-Great auricular nerve
Morbidity of a sural nerve harvest?
Up to 20 cm of harvest with a numb heel/lateral foot
Greater auricular nerve harvest?
Ascends on SCM to innervate skin behind auricle and parotid gland.
1-2 cm
Morbidity - Numb lateral neck, posterior mandible, ear
How much does a nerve grow a day?
Nerve grows about 1 mm/day within a conduit
Success rate of nerve repair?
50%
T/F: nerve repair can be delayed 6 months to a year
False, it should be taken care of in the first 1-2 months
When does alveolar osteitis occur?
Days 2-5 with throbbing, radiating pain, fetid odor, bad taste
Prevention of dry sockets
1-Copious Intraoperative and postoperative irrigation
2-Postopeartive Peridex rinse
3-Abx placement in extraction site
Etiology of dry sockets
1-Increased fibrinolytic activity from tissue, saliva, or bacteria from acceralted blood clot lysis before replacement by granulation tissue.
2-Anaerobic bacteria disturb wound healing: reducing bacterial load may decrease incidence of alveolar osteitis.
T/F: Eugenol has neurotoxic effects?
True
Do you give abx for dry sockets?
No, unless purulence or lymphadenopathy exists.
are dexamethasone and methylprednisolone glucocorticoids or mineralcorticoids
They are glucocortioids
What do steroids do?
Depressing on leukocyte chemotaxis
When are steroids contraindicated?
1-Peptic ulcer, active infection, psychosis
After 24 hrs, what should be used to eliminate swelling?
Heat
Subperiosteal abscess–Occurrence
2-6 weeks after surgery due to debris under mucoperiosteal flap
How to treat interstitial emphysema
1-Abx (cephalsporin, prevents secondary infection fro possible oral bacterial nidus)
2-Systemic corticosteroids
3-Resolves in 7-10 days
Edentulous mandible–> blood supply
Inferior alveolar nerve vessels string with age. Primary blood supply moves centripetally (center seeking) from periosteium
What is the supply in a dentate mandible?
Centrifugal supply meaning enter fleeing from inferior alveolar artery
Bone resorption patterns of the maxilla
-Inferior and lateral sides move posteriorly and superiorly from lack of attachments
Mandible resorbs and creates what type of pseudo relatioinship
Class III
Cawood and Howell classifications of edentulous ridge
I-VI
1-VI
What is the minimum distance required between the max tuberosity and mandibular retromolar pad?
10 mm
What must be excised during a frenectomy?
both the fibrous band and mucosa attachement otherwise a high recurrence rate.
What tissues are involved in a lingual frecectomy?
-Mucosa, ankyloglossia, connective tissue, and superficial genioglossus muscle
Why is a z pasty deformed for a lingual frenectomy
to increase tongue length and mobility
What is important to avoid chin sag in a vestibuloplasty procedure?
-maintain minimum of 10 mm of mentalist muscle attachment
If depth is inadequate or lip distortion occurs, what should be performed instead of a submucosal vestibuloplasty?
1-Kazanjian or transpositional vestibuloplasty instead
What is a Kazanjian flap vestibulplasty
Peformed in maxilla or mandible when sub mucous vestibuloplasty is contraindicated due to inadequate labial vestibular depth
-Incision made at junction of attached and unattached gingiva; Create supraperioteal flap and suture down to greatest vestibular depth
-placed relined splint for 2-3 weeks
Epulis fissuratum: Treatment
Also known as fibrous inflammatory hyperplasia
Treatment:
-Surgical excision of cryosurgery (Co2 laser)
-Reline denture and use as a stint
-Better, new fitting denture.
Inflammatory Papillary hypoplasia etiology
Fungal infection (Candida, mechanical irritation, poor oral hygiene, smoking
Inflammatory Papillary hypoplasia: Treatment
Antifungicides (nystatin, clotrimazole), clean dentures in bleach
-Supraperiosteal excision but avoid palatal bone exposure
-Reline denture with tissue conditioner
-Need for better fitting denture
Odontogenic Infection: Induration
Odontogenic Infection: Cellulitis
Odontogenic Infection: Abscess
What do aerobes do to pave the way for anaerobic bacteria?
Aerobes start early and cause tissue hypos and acidosis, creates an environment for anaerobes
What do anaerobes do in an infection?
They destroy tissue and cause pus formation, takes about 48 hrs to culture
Gram Positive Cocci often found in odontogenic infections
Streptococcus Viridans
Gram Negative rod/bacilli found in odontogenic infections
Takes >48 hrs to culture, Bacteriodes (causes foul smell), Fusobacterium
Which spaces involve the masticator space?
pterygomandibular, masseteric, and temporal spaces
Lateral neck film, what are the distances from the anterior surface of the vertebrae to the posterior border of the airway to rule out retropharyngeal involvement
at C2- the distance should be 7 mm or less regardless of age.
At C6-The distance should be 14 more less (<15 yrs) or 22 mm (>15years)
What are indications for inpatient treatment of an infection (7) in mind
1-Compromised host defenses
2-Rapid, progressive infection
3-Secondary fascial space involvement
4-Temperature over 101 F
5-Severe trismus (<10 mm)
6-Toxic appearance
7-Difficulty swallowing or breathing
Where should a retropharyngeal space abscess be accessed?
2 cm vertical incision at the anterior border of the SCM (at the level of the hyoid bone) and use finger dissection
MOA for Penicillin, amoxicillin, and ampicillin
Inhibits bacterial cell-wall formation
MOA for Augmentin, zosyn, and Unasyn
Inhibits bacterial cell-wall formation,
Claavulonic acid, sulbactam, and tazobactam serve as beta-lactamase inhibitors.
Unasyn
Ampicillin and sulbactam
Augmentin
Amoxicillin and clavulonic acid
Cephalexic and cefazolin (ancef) MOA
First-generation cephalosporin
Inhibits bacterial cell-wall formation
*Contraindicated for penicillin-allergic patients.
Clindamycin MOA
Inhibits protein synthesis by binding to 50S ribosomal subunit
*excellent abscess penetration
Clindamycin-Hepatic/renal patients
No adjustment needed for both hepatic or renal-compromised patients.
Azithromycin and Clarithyromycin MOA
Inhibits protein synthesis by binding to 50S ribosomal subunit
Macrolide abx family
Which macrolide abx had good coverage against Haemophilus influenza (sinus infection)
Azithromycin and clarithromycin (Z-pak)
Ciprofloxacin, levofloxacin and moxifloxacin MOA
DNA gyrase inhibitor
Fluoroquinolone abx family
Ciprofloxacin limitation
Cipro has limited oral flora coverage (anaerobic organisms and streptococcus)
Fluoroquinolone has good coverage for…
Staphylococcus (skin infections)
Contraindicated in pediatric populations due to possible tendon rupture.
Metronidazole MOA
Not well udnerstood
-Forms cytotoxic particles that interact with bacterial DNA and eventually lead to DNA strand breakage.
Three facts about Metronidazole
1-Anaerobic coverage only
2-Excellent cerebrospinal fluid penetration
3-First line therapy against pseudomembranous colitis
Vancomycin MOA
Inhibits cell wall formation
What is Vancomycin typically reserved for?
MRSA
-Oral form is only used for pseudomembranous colitis
Pseudomembranous Colitis is caused by
Superinfection of clostridium deficit due to recent abx usage
-Can be any abx but most commonly associated with clindamycin, ampicillin, and cephalsporins
Clinical manifestations of C.Diff Pseudomembranous Colitis
-Profuse watery diarrhea
-Abdominal cramping
-Fever
-Elevated white blood cell count
C. Diff tested by
Stool sample, and toxin assay, sigmoidoscomy
What drug is used to treat Pseudomembranous colitis
-Metronidazole or vancomycin (oral form only)
Cavernous Sinus thrombosis
Vascular thrombosis in cavernous sinus secondary to contiguous spread of orofacial infections in retrograde fashion (dental abscess, sinusitis, nasal furuncle)
Cavernous sinus contents
CN III, IV, VI, V2, VI
Internal carotid artery
What is the route to the cavernous sinus?
Anterior facial vein to superior ophthalmic vein: Dangerous zones–upper lip, tip of nose and medial cheeks,
Deep facial vein through pterygoid plexus
Clinical manifestations of cavernous sinus thrombosis
-Unilateral periorbital edema
-Headache
-Photophobia
-Proptosis
-CN palsies (III, IV, V, & VI)
What is the first line of cavernous sinus thrombosis?
Abducens paresis (loss of CN VI–Lateral gaze)
MRI can show what regarding cavernous sinus thrombosis?
deformity of the internal carotid artery within the cavernous sinus
-Venus wall thickening as well
Cavernous sinus thrombosis treatment:
-Abx IV 6-8 weeks
-Surgical debridement or incision and drainage of source
-Anticoagulation and steroid use are contraversial
Cervicofacial necrotizing Fasciitis
Fulminant subcutaneous infection with spread and necrosis along fascial planes
What are the two types of Necrotizing Fasciiitis
Type I-Mixed arobic and anaerobic (most common)
Type II-Streptococcu pyogenes and S aureus (gas producing)
Risk factors for Necorizing Fascitiis
1-Diabetes
2-HTN
3-Obesity
4-Alcohol/drug use
Classic appearance of drainage in necrotizing fasciitis pateints
Dishwater drainage
Treatment: for open wound?
Surgical wound should be left open and packed with antimicrobial-soaked gauze.
Iodoform guaze
Iodoform gauze is a saturated gauze fabric that uses the antimicrobial and healing properties of iodoform. Iodoform gauze dressings are often used in clinical settings for patients who have infected wounds that may have build-up of necrotic or dead tissue. The gauze is also found in dentist or orthodontic office settings to pack tooth cavities, as an antiseptic and dry socket prevention measure. Iodoform dressing medicated wound dressings are usually packaged in long strips and sealed in a bottle container. They are absorbent and are made in strips so they can be packed into a wound with substantial depth, yet will still be loose and porous enough to allow a wound drain. Iodoform strips, although soaked in the antiseptic, are not moist to the touch. They are only slightly damp to maintain the mechanical function of gauze, yet will help prevent infection and necrotic tissue from forming.
Antiseptic
.
relating to or denoting substances that prevent the growth of disease-causing microorganisms.
Actinomyces
Disease characterized by the formation of multiple painful abscess which often contain sulfur-like granules
Can lead to fistula formation
Treatment for actiomyces
-Long-Term high-dose abx (oral penicillin for 6 weeks
-Surgery for debridement and removal of fistula tracts
What is the most common fungal infection in the mouth?
Candidiasis
What are the three clinical subtypes of candidiasis
1-Pseudomembranous (most common type)
2-Erythematous
3-Hyperplastic
What is the most common subtype of candidiasis?
pseudomembranous-it has a white coating that can be wiped off leaving a raw surface.
Asymptoamtic
Which is the most painful form of candidiasis?
Erythematous (atrophic)
Burning mouth
-Angula chelitis
-Denture related stomatitis
-Median rhomboid glossitis
Describe hyperplstic oral candidiasis?
White coat that cannot be removed
Asymptomatic
Diagnosis by biopsy
What are the risk factors for candidiasis?
-Immunocompromised
-Recent abx use
-Poor denture hygiene
-Xerostomia
-Smoking
-Malnutrition
What is the treatment for candidiasis?
-Nystatin oral suspension 100,000 U/mL 5 mL, 4x/day 14 days
-Clotrimazole troches: 10 mg 4 x day for 14 days
Mucromycosis (zycomycosis)
Fungal infection that has tendency to invade into the vascular network, which results in thrombosis and necrosis of the surrounding tissues.
-Immunocompromised patients (HIV, diabetes)
What are the two types of mucormycosis?
Rhino-orbital-cerebral form (agressive)
Rhinomaxillary form (less aggressive)
How is Mucor diagnosed and treated?
Diagnosis by tissue biopsy: Large, broad, nonseptate hyphae with right-angle branching
-Multiple surgical debridements
-Intravenous amphotericin B
Noma?
Orofacail gangrene
-A rapidly progressive, polymicrobial, opportunitistc infeciton that can lead to painless tissue degradation and permanent disfigurment
Where is Noma often seen?
Orofacial gangrene
-Seen in Africa and Asia
-Affects kids less than 12 yrs old
-80% mortality rate
Commonly associated pathogens with Noma (orofacial gangrene)
Fusobacterium mecrophorum
Prevotella intermedia
Risk factors for Noma (orofacial gangrene)
1-Malnutrition
2-Poor oral hygeine
3-Immunodeficiency disease
Treatment for Noma (orofacial gangrene)
-Abx (intravenous ampicillin
-Debridement and I&D
-Nutritional improvement
-Reconstructive Surgery
TADs & Indications
Temporary anchorage devices
-Alternative to undesired tooth mobility/movmeemtn when teeth used for orthodontic anchorage
-Retraction, protraction, uprighting, intrusion
-Also used for mild to moderate skeletal discrepancies
-Since 2006, FDA cleared them for age ?12 yrs
Contraindications to TADs
-Allergy to titanium alloys
_heavy tobacco use
-Severe osteoporosis
-Uncontrolled immune/metabolic disorders (diabetes)
-Bisphosphonate use
Two types of TADs are?
-Miniplates
-Miniscrews
Describe Miniscrews TADs
-Placed in dense cortical bone-no osseointegration
-Disadvantage includes 15-30% failure rate
Miniplates TADs
Need to wait 10-14 days to load but must load before 3 weeks or else it can become loose.
Placement of TADS should have the following distances
away from tooth roots, incisive canal, and mid palatal suture, use paramedical placement
-Min 2 mm away from tooth roots and vital structures
-Min 1 cm away from incisive canal
-Avoid mid palatal suture
Excess torque in TADs
-Greater than >250 g decreases stability: higher risk of failure.
-Up to 30% relapse for intrusion of molars (depends on force amount, treatment period, degree of intrusion.
Indications for an apicoectomy (6)
1-Resection of undecided/unobsturated portion of root and apical curretage
-When conventional root canal retreatmetn unfeasible via coronal approach (calcification, severe root curvatures)
3-Restorative concerns, removal of post and core may cause root fracture.
4-Irretreivable material in canal (broken file, restorative material); need to remove with root apex
5-Iatrogenic failure (overfill, perforations
6-Large lesion that did not resolve after RCT
Filling materials for apicoectomy
1-Amalgam,
2-Trioxide aggregate;
3-Composite resin, can be used in shallow, concave preparations (Ie molar roots, but needs dry field
4-Reinforced zinc oxide cement
T/F: It is safe to use distilled water for irrigation
False, do not use because distilled water is hypotonic and can cause cells to die due to osmotic gradient which can cause cell lysis/rapid cell death.
