Oral Surgery and Orthodontic Interface

Question 1

What are the soft tissue surgeries that may be done to aid orthodontics?

Answer 1

Frenectomy
-> V to Y frenoplasty
-> Z-plasty

Impacted canines
-> Buccal apically repositioned flap
-> Palatal open exposure

Impacted premolar exposures (more often require only soft tissue procedure)

Question 2

What are the hard tissue surgeries that may be done to aid orthodontics?

Answer 2

Impacted canines
-> Buccal apically repositioned flap with bone removal
-> Palatal open exposure with bone removal
-> Buccal or palatal closed exposure with gold chain attachment
-> Extraction

Premolars
-> Extraction
-> Exposure of impacted premolars with bone removal

Other extractions

Submerged retained deciduous teeth

Implants

Mini-implants

Orthognatic surgery

Question 3

What are the treatment options for impacted canines?

Answer 3

 Leave- if tooth not damaging other teeth, if not affecting ortho tx, if reasonable aesthetics, patient not keen on surgery, if no associated pathology

 Extract- reasonable aesthetics without, poor position of canine (may allow easier tooth movement)

 Expose- encourage improvement in position

 Transplant- take it out and place into correct position (uncommon in UK)

Question 4

What are the risks of leaving impacted canines?

Answer 4

Infection

Future eruption

Dentigerous follicular cysts

Question 5

What can be done to the premolars if canines are impacted and left/extracted?

Answer 5

Can be moved into position of canine and made to look like canine

Question 6

What can happen to laterals and premolars if canines are impacted?

Answer 6

Drifting

Rotation

Question 7

What is the procedure for minimal exposure of an impacted canine if it is close to the surface?

Answer 7

 Remove primary tooth
 Excise soft tissue and follicle with 15 scalpel
 Remove bone with mongeurs
 Place dressing and suture with silk
 Provides environment for canine to erupt naturally (if it erupts into abnormal position- usually palatally, it can be fixed with ortho)

Question 8

When may autotransplantation of an impacted canine be considered?

Answer 8

 If it would damage teeth on way down
 If distance is too far

*Must be careful not to damage tooth in extraction phase

Question 9

What are the steps in autotransplantation?

Answer 9

 Raise flap
 Extract canine gently- try not to damage PDL
 Store in milk or saline- aim to have out mouth for least amount of time possible
 Remove deciduous tooth
 Trim bone to allow canine to fit (may require some trial and error)
 Fit canine- will be unstable so splint with titanium trauma splint or SS wire on one tooth either side (must be semi-rigid- to prevent risk of ankylosis etc)
 Lost bone may or may not regenerate
 Transplanted tooth will eventually ankylose- failure can be difficult to remove

Question 10

How can risk of ankylosis in autotransplantation be reduced?

Answer 10

Do 3d scan of patient
-> make 3d model of tooth and produce Co/cr replica as model used to prepare bone and produce custom socket for real tooth

EXPENSIVE- implant may be better option

Question 11

What are the issues with buccally placed canines?

Answer 11

 Easier access for OS (more difficult for ortho- poor aesthetics)
 Cannot cut hole like you would on palate as tooth would erupt through unattached mucosa (would lose attached mucosa)

Question 12

How is a buccally placed canine surgically exposed?

Answer 12

Apically repositioned flap- 3-sided full thickness flap with more parallel relieving incisions
-> Tissue is reflected and sutured apically at cervical margin, when canine erupts it brings attached mucosa
-> nice aesthetics and easier maintenance

Question 13

Why is it important to look at radiographs before carrying out surgery on impacted canines?

Answer 13

 We can look at space available to allow eruption of canines

 Can show us teeth which are not worth exposing- dilacerated etc

Question 14

What is the most common reason for impacted second premolars?

Answer 14

Premature loss of e
-> drift of 4 distally and 6 buccally, resulting in loss of space for 5 (may fail to erupt or erupt lingually/buccally)

Question 15

What are kissing canines?

Answer 15

One canine may come across midline and sit against opposite canine
-> seen on radiograph (require parallax to locate exact position)

Question 16

What are the treatment options for kissing canines?

Answer 16

Tooth crossing midline must be left, extracted or transplanted (ortho will not be possible)

Question 17

What are the steps in using a gold chain to align impacted canines?

Answer 17

 Lift flap of gum to expose canine- drilling may be required
 Acid etch and bond composite to palatally placed tooth (attach chain via button/mesh)
 Chain hangs down and can be attached to appliance and force applied to pull it into position

Closed exposure- put flap back

Open exposure- lift flap, drill away bone, cut hole in gum so you can see canine

Question 18

What are the issues with ankylosed deciduous teeth?

Answer 18

 Very difficult to remove- no space to extract normally

 Impedes eruption of other teeth

 Requires flap/sectioning (careful when drilling so not to damage unerupted tooth)

 Risk of pushing tooth into sinus

Question 19

What were frenectomies used for historically?

Answer 19

To remove thick fibrous frenums which were associated with midline diastema

Question 20

What were the steps in a frenectomy?

Answer 20

 Numb patient
 Hold with forceps and cut out with 15 blade
-> Creates large defect- place resorbable suture and dressing if required

Question 21

What is done in a V to Y frenoplasty?

Answer 21

 V shaped incision

 Close sutures on line parts of triangular defect

 Gives y shaped scar and less prominent frenum

Question 22

What is done in a Z-frenoplasty?

Answer 22

*Very uncommon

 Incision in shape of Z

 Switch places on points of z and suture in place to reduce prominence of frenum

Question 23

What are the ideal features of using implants for anchorage in orthodontics?

Answer 23

Patient compliance unnecessary

Absolute anchorage as there is no periodontal ligament

Easily used under a variety of treatment modalities

Easily placed

Removable, if necessary

Question 24

What are mini-implants? (TADs)

Answer 24

Screws made of SS
-> not titanium to prevent osteointegration

Placed by orthodontists for complex cases
-> allows for attachment of elastics to move teeth without compromising anchorage

Question 25

What are the steps in placing a mini-implant?

Answer 25

 Check radiograph to check where roots are (prevent damage)
 Punch hole into mucosa through papilla
 Tap screw into bone until only stud is showing
 Elastics are then used to move teeth

Question 26

What is different about a palatal mini-implant?

Answer 26

 Takes more surgical skill- palatal implant is attached to another screw
 Screws are longer- must be angled carefully to avoid structures
 Use lateral cephs to determine angle and amount of bone

Question 27

What are the advantages of palatal mini-implants?

Answer 27

 Stable as in firm bit of bone in midline of palate

 Prevents need for patient to wear head gear
-> attach screw to molars via SS bands (teeth can move back without compromising anchorage)

Question 28

Why may a corticotemy be carried out?

Answer 28

To speed up tooth movement through dense bone
-> if other methods have failed
-> can be helpful for intruded teeth which have occurred due to trauma

Question 29

What is done in a corticotemy?

Answer 29

Drill U-shaped gutter and small grooves into buccal and palatal bone to weaken bone in certain areas to encourage tooth eruption

*care not to damage erupting tooth itself