Principles of MOS Flashcards
1
Q
What should tooth factors should you assess prior to undertaking minor oral surgery?
A
- amount and position of caries
- restorations in tooth or adjacent teeth
- any associated acute infection
2
Q
A radiographic assessment of a tooth prior to MOS should consider…
A
- root morphology and number
- bone density
- loss of lamina dura
- presence of cysts or pathology
- location of maxillary antrum/vital structures
3
Q
The loss of lamina dura is indicative of …
A
an infective process
4
Q
How can we manage cross infection during minor oral surgery?
A
- aseptic technique
- hand washing
- gloving
- gowning
- draping
5
Q
What is the purpose of draping? Outline a potential benefit of draping
A
- defines the operative field
- it provides a psychological barrier- aids the operator to seperae themselves
6
Q
Outline the components of the operative technique for MOS
A
- soft tissue management
- hard tissue management
- debridement
- closure
7
Q
Soft tissue management involves…
A
flap design e.g. full or partial thickness flap
8
Q
What is a full thickness flap?
A
this is where everything (to the level of the periosteum) is detached
9
Q
What is a flap?
A
it is a section of soft tissue
10
Q
What are the principles of a flap?
A
- they are outlined by a surgical incision
- they carry their own blood supply
- they allow surgical access to the underlying tissues
- they can be replaced in its original position
- they can be maintained by sutures and are expected to heal
11
Q
What is the main principle of flap design? What is the exception?
A
the base of the flap should be wider than the end
the base should be 2x the height
flaps used to close OACs are not wider at the base
12
Q
What kind of surgical incision is used in order to aid closure of an OAC? Suggest a reason why this is the chosen sugircal incision
A
parallel incision between the 5 and 7 (this is in reference to the removal of a 6 which is mostly likely to be in a position that will lead to OAC)
this is to prevent the flap from going over the teeth
13
Q
Give examples of full thickness, mucoperiosteal flaps
A
- envelope flap- one sided
- two sided flap- 3 cornered
- three sided flap- 4 cornered
14
Q
What is the reason for having a flap that is wider at the base?
A
ensures adequate blood supply to the margins of the incisions
15
Q
How many incisions are required to create an envelope flap/
A
one, semi lunar incision
16
Q
Briefly describe how an envelope flap is created
A
usually follows the gingival margins around the area of surgery
17
Q
When is an enevelop flap appropriate?
A
removal of roots
18
Q
____ incisions are required for a 2 sided flap. What are these incisions?
A
two
marginal incision and relieving incision
19
Q
How many incisions are required for a 3 sided flap? What are these incisions ?
A
three incisons
marginal incision and 2 relieving incisions
(as 2 sided flap but with an additional relieving incision)
20
Q
What are the indications of a 3 sided flap?
A
- root removal
- impacted tooth removal
- apicectomy
21
Q
What is the single use blade of choice when performing MOS?
A
blade No.15
22
Q
Give an example of an appropriate elevator of choice for root removal following decoronation
A
couplands elevator
(may also use 3 curve luxator if appropriately trained.
23
Q
Outline a summary of considerations to be made before surgical removal of a tooth
A
- decide which elevator + direction of removal
- decide where to take bone
- decide how to divide tooth
- decide if complications are envisaged
- design flap to accomodate
flap design is last and not first!
24
Q
Blood supply is essential for healing. What is the consequence of a compromised blood supply following oral surgery?
A
necrosis
25
Briefly describe the blood supply to the mandible and maxilla
it comes upwards and forwards
(so it comes from the carotid arteries!)
26
Margins of full thickness flaps should be on ____ bone
sound
27
Briefly describe how incisions for full thickness flaps should be made
the scalpel should be perpendicular to the mucosa, then incised down to the bone.
You should then start the reflection of the flap in the buccal sulcus
28
Where should you start reflection following the creation of a full thickness flap?
in the buccal sulcus
29
Two sided flaps are commonly used for ...
impacted 8s
30
What is the consequence of having flap where the base is less than the height?
compromised blood supply
31
When is a lunar incison acceptable?
for an apicectomy
32
When is a Y incision acceptable?
for removal of palatal tori
33
Give an example of an instrument that can be used to lift/ reflect full thickness flaps
howarths periosteal elevator
34
The choice of flap design depends on ...
* personal preference
* anatomical site
* access required
* bone removal required
* ability to suture
35
Hard tissue management for MOS may involve ...
* bone removal
* tooth sectioning
* debridement
36
What are the main objectives for bone removal (the transalveolar approach) ?
* achieve access
* establish a point of application of elevators/luxators
* removal of obstructions to tooth movement- this is important in the case of impacted 8s
37
What equipment is required for bone removal during MOS?
* surgical bur - in a surgical slow speed hand piece
* normal saline as coolant and irrigant
38
When a straight elevator is used as a shoehorn to luxate a broken root, what measure must be taken to prevent injurt to adjacent tissue?
* the hand must be securely supported on adjacent teeth to prevent inadvertent slippage of instrument and subsequent damage/injurt to adjacent tissue
39
Why should the mesiodistal width of bone removal be approximately the same as the mesiodistal dimension of the tooth itself?
to allow an unimpeded path of removal of the root in the buccal direction
40
Bone should be removed approximately ____________ the length of the tooth root
one half - one third of the length of the tooth root
41
After bone has been removed and tooth root luxated with straight elevator, ________ can be used to remove the root.
forceps
42
What is the purpose of tooth sectioning/division?
improve the path of withdrawal of the tooth
43
Briefly outline how you would go about sectioning a tooth
* envelope flap reflected
* small amount of crestal bone is removed to expose bifurcation
* drill is then used to section the tooth into mesial an distal halves
* lower universal forceprs are used to remove two crown and root portions seperately
44
Briefly describe how you would go about the removal of the remainder of a lower molar following the loss of the crown to fracture/caries
* reflect a small envelope flap
* remove a small amount of crestal bone
* bur is then used to section tooth into individual roots
* small elevator used to mobilise roots
* cryer elevator used to elevate distal root (the tip of the elevator is placed into the slot prepared by the bur and the elevator is used to deliver the root)
* opposite member of paired cryer elevators is then used to deliver the remaining tooth root with the same rotational movement
45
What is the active area of coupland elevators?
the concave areas which engage with the teeth
46
Outline the parts of an elevator
* blade
* shank
* handle
47
Outline the parts of a forcep
* blade/beaks
* hinge
* handles
48
The more steep the angle between the handle and the hinge of the forcep the more ________ it will be used
posteriorly
49
What kind of movement should be applied with a luxator?
rotation movement
50
What are the benefits of irrigation during MOS?
* flushes out debris
* improves field of view for evaluation of surgical site
51
What are the potential consequences of leaving sharp edges behind?
* poor wound apposition and tearing
* can lead to delayed wound healing
52
What is the consequence of excessive smoothing of sharp edges?
it can be traumatic
53
What kinds of needles are used for suturing following MOS?
semi-circular, reverse cutting needles
54
How should a needle enter the surface of the tissue?
at a right angle and it should be turned
55
What is the consequence of a needle entering at an acute angle and being pushed through the tissue?
tearing of mucosa with the needle or with suture
56
How can suturing a 3 cornered flap be made easier ?
(2 sided flap)
a periosteal elevator is used to elevate a small amount of fixed tissue so that the suture can be passed through the entire thickness of the mucoperiosteum
57
Where is the first suture placed when a 3 cornered flap is repositioned?
it should be placed on the occlusal end of the vertical relieving incision (slide 70)
58
Where are the 2nd and 3rd sutures placed folliwing the repositioning of the three cornered flap?
papillare are sutured sequentially
59
Where is the final suture following repositioning of the three cornered flap placed?
the superior aspect of the relieving incision
60
What are the benefits of using the horizontal mattress suture?
* decreaes the number of individual sutures that have to be placed
* compresses wound together slightly
* everts wound edge
61
What kind of suture can be placed when multiple sutures need to be placed?
running or continuous suture
62
What should be included in the case notes following MOS?
* description of operation
* POI-pain swelling; include out of hours contact number
* haemostasis achieved
* medications prescribed
* arrangements for review
* signature of staff
63
What are the classifications of wounds ?
* clean
* clean- contaminated
* contaminated
* dirty
64
What is a clean wound?
no inflammation
65
What is a clean, contaminated wound?
infected clean wound, respiratory, GI, UG system is opened under aseptic conditions antibiotic prophylaxis is given in high risk patients
66
What is a contaminated wound?
microorganisms involved in the infection were in the operation site before operation
67
Give examples of contaminated wounds
* acute accidental wounds
* perforation
* fistula
* abscess
68
What is a dirty wound ?
long time contact between contamination and the wound care
69
Give examples of dirty wounds
* war wounds
* gangrene
* tissue necrosis
* abscess
* organ necrosis
70
What are the stages of wound healing ?
* Coagulation
* Inflammation
* Fibroplastic/ proliferative (fibroblasts)
* remodelling (collagen)
Haemostasis- inflammation Granulation- proliferation
Remodelling
71
What occurs at the start of remodelling?
granulation- proliferation
72
What occurs at the granulation- proliferation stage?
* fibroblast migration
* collagen deposition
* angiogenesis
* granulation tissue formation
* epithelisation
* contraction (loss of tissue)
73
What occurs at the remodelling stage?
* regression of many capillaries
* physical contraction - myofibroblasts
* collagen degeneration and synthetisation
* new epithelium
74
What is the tensile strength of remodelled tissue?
it is a maximum of 80% of the original tensile strength
75
What are the types of wound healing?
* primary intention
* secondary intention
76
How does primary intention occur?
fibrin fibres cover the wound and offer protection
linear wound healing
77
Outline some causes of secondary intention
* infection
* dehiscence (marginal bone loss)
* crush wound
* surgical fault
78
Outline local factors that can affect healing
* wound sepsis
* poor blood supply
* wound tension
* foreign bodies
* previous irradiation
* poor technique
79
Outline systemic factors that can affect healing
* nutritional deficiencies
* systemic disease
* therapeutic agents
80
Give examples of complications of healing
* infection
* dehiscence - loss of tissue unnecesarily
* hypertonic scarring- more in skin, less so in mucosa
* keloid scarring
* contractures
81
When does a primary haemorrhage occur ?
occurs intraoperatively or is immediately post operative
82
When does reactionary haemorrhage occur?
within 4-6 hours
83
How can reactionary haemorrhages be managed ?
sutures
haemostatic agents
84
When does a secondary haemorrhage occur?
after 24 hours
85
What is the approximate volume of blood loss in class I haemorrhagic shock?
up to 750 ml
86
What is the approximate volume of blood loss in class II haemorrhagic shock?
750-1500ml
87
What is the approximate volume of blood loss in class III haemorrhagic shock?
1500 -2000ml
88
What is the approximate volume of blood loss in class IV haemorrhagic shock?
>2000ml
89
Outline mechanical methods that can be used to achieve haemostasis
* digital/direct pressure
* tourniquet
* ligation
* suturing
* preventive haemostasis
* clips
* bone wax
90
Give an example of low temperature thermal methods used to achieve haemostasis
* cryosurgery
* hypothermia (e.g. for stomach bleeding?)
91
How can low temperatures help control bleeding ?
* dehydration and denaturation of fatty tissue
* decreases the cell metabolism
* vasoconstriction
92
Give examples of high temperature thermal methods used to achieve haemostasis
* electrosurgery- electrocauterisation
* monopolar diathermy
* bipolar diathermy
* laser surgery- coagulation and vaporisation for fine tissues
93
Give examples of haemostatic agents
* cotton/gauze +/- vasoconstrictor
* surgicel (oxycellulose)
* bone wax
* calcium alginate (kaltrostrat)- periodontal surgery
* calcium sulphate
* ferric sulphate - astringent ?
* gelofoam- gelatin
* collagen- collaplug
* tranexamic acid - antifibrinolytic agent
94
Extracellular fluid (outside of the cell) includes ...
* interstitial fluid
* intravascular fluid
95
What solutions can you use to resolve hypovolemic shock?
* 5% glucose
* hypertonic normal saline
* ringers lactate/hartmanns solution
* colloids
* blood
