This document discusses principles of incisions and flap design for minor oral surgery. It describes five basic principles of incisions, including using a sharp blade, making firm continuous strokes, avoiding cutting vital structures, holding the blade perpendicular to epithelial surfaces, and properly placing incisions. It also outlines various types of mucoperiosteal flaps like envelope, three-corner, four-corner, semilunar, Y-incision, and pedicle flaps. Complications of flap design like necrosis, dehiscence, tearing, and injury are addressed. Considerations for flap design include ensuring an adequate blood supply, avoiding tension, and not crossing bony prominences.

1. Assist. Prof. Dr. Kareem M Alghanim
BDS , MSc (oral surg.) , PhD (oral med.)
Flap Design for Minor
Oral Surgery
4th Class Oral Surgery Lec.3

3. INCISIONS
An incision can be described as
a sharp wound produced by a
surgical scalpel.

4. Basic principles of incisions
1st principle: A sharp blade of
the proper size should be used.
Bone & ligamental tissues dull
blades more rapidly than dose
buccal mucosa.

5. Basic principles of incisions
2nd principle: is that a firm, continuous
stroke should be used when incising.
Long continuous strokes are
preferable to short interrupted ones.
Mucoperiosteal incision should be firm
that penetrates the mucosa &
periosteium with same stroke.

6. Basic principles of incisions
3rd principle: The surgeon should be
careful to avoid cutting vital structures
while incising.
No patient's microanatomy is exactly the
same. Therefore to avoid unintentionally
cutting large vessels or nerves.
For e.g., Incision in the mandibular buccal
sulcus & lingual area – prevent the
inadvertent cutting of facial & lingual
vessels.

7. Basic principles of incisions
4th principle: Incisions through
epithelial surfaces should be
made with blade held
perpendicular to the epithelial
surface.

8. Basic principles of incisions
5th principle: Incisions in
the oral cavity should be
properly placed.
E.g., Over healthy bone,
wound edges should be at
least 6-8mm away from
the defect.
Incision should lie at the
line angles of the teeth
and not at the facial
surfaces nor in the papilla.

9. Pen-grip holding of scalpel and incising by moving
hand and wrist not moving the entire forearm

10. INSTRUMENTR INCISING TISSUE
SCALPEL
1) Handle:-
 No.3, No.7
 Differently shaped.

11. INSTRUMENTR INCISING TISSUE
SCALPEL
2) Disposable, sterile sharp blade;
 1. No.15 blade:
Is most commonly used for oral surgery.
Relatively small.
Around teeth through mucoperiosteal.

12. INSTRUMENTR INCISING TISSUE
 2. No.10 blade:
Similar to No.15.
Large skin incisions.
 3. No.11 blade:
Sharp, pointed.
Small stab incisions.
Incising an abscess.
 4. No.12 blade:
Hooked.
Mucogingival procedures.
Posterior aspect of teeth
maxillary tuberosity.

13. Blade Loaded & Removed
Blade
Loaded
Blade
Removed

14. Remember..
• Pen Grasp: Allow maximal control
• Hold mobile tissue firmly
• Press down firmlye
• Single- patient use: dulled easily
• Several incisions: single operation- 2nd
blade
• Dull blades: no clean sharp incisons

15. FLAPS
Definition
Flap is a small incision made in mucosa &
periosteum under local anesthesia to gain
access to the area for raising the
mucoperiosteum to perform dentoalveolar
surgeries.

16. Rules of flap design
 Avoid severing large vessels
& nerves.
 Place margins far away
from surgical areas to
ensure wound margins over
sound bone, this also gives
room for any adjustments
and avoids collapse of flap
into the bony defect.
 Design the flap for
adequate visibility without
over exposure of bone.

17. Rules of flap design
 Base of flap should be the
widest portion.
 There should be no sharp
angles on the flap, sharp
corners tend to slough
due to poor circulation.
 Vertical or Oblique
incisions should not be
made over root
eminence, it is best to
incise in through between
adjacent teeth.

18. Rules of flap design
 Maintain integrity of
interdental papilla, the
papilla at incision line is
allowed to remain
whereas other papilla
should be included in
flap.

19. Rules of flap design
 Be gentle with the flap, the
retractor should be broad and
designed to contact bone so
the flap rests on it passively.
 Do not incise close to gingival
sulcus when using a horizontal
or semilunar incision. 2-3mm of
attached gingiva should be left
around each tooth.
 To avoid tearing the
mucoperiosteum, incision
should be made in one pass
bone deep & with firm &
continuous stroke.

20. Rules of flap design
 Elevate the flap away from the line of
vision to provide adequate exposure of
the surgical area.

21. 1. Envelope/sulcular incision.
2. Envelope with one releasing incision (three-
corner flap).
3. Envelope with two releasing incisions (four-
corner flap).
4. Semilunar incision.
5. Y-incision.
6. Pedicle flap.
7- Submarginal Flap. Full-thickness
mucoperiosteal
flap
Types of Mucoperiosteal Flaps

22. Types
of
Mucoperiosteal
Flaps
1. Envelope/sulcular incision.
2. Envelope with one releasing
incision (three-corner flap).
3. Envelope with two releasing
incisions (four-corner flap).
4. Semilunar incision.
5. Y-incision.
6. Pedicle flap.
7- Submarginal Flap.
Types of Mucoperiosteal Flaps

23. 2 teeth anterior
1 tooth posterior
Edentulous: at the
crest of the ridge 
removal of a
mandibular torus.
1. Envelope/sulcular incision

24. This type of flap is the result of an extended
horizontal incision in the gingival sulcus along the
cervical lines of the teeth.
Indications:
- Surgical procedure involves the cervical lines of the
teeth labial or buccal and palatal or lingual.
- Cases of removal of impacted teeth.
- Apicoectomies (palatal root of molar).
1. Envelope/sulcular incision

25. 1. Envelope/sulcular incision

26. 1. Envelope/sulcular incision
Advantages:
- Avoidance of vertical incision.
- Eeasy reapproximation to original position.
Disadvantages:
- Difficult reflection (mainly palatally).
- Great tension with a risk of the ends tearing.
- Limited visualization in apicoectomies.
- Limited access.
- Possibility of injury of palatal vessels and nerves.
- Defect of attached gingiva.

27. 1 tooth anterior
1 tooth posterior
Greater access in an apical
direction, especially in the
posterior aspect of the
mouth.
2. Three-corner flap

28. This flap is the result of an L-
shaped incision, with a horizontal
incision made along the gingival
sulcus and a vertical or oblique
incision.
 The vertical incision begins
approximately at the
vestibular fold and extends to
the interdental papilla of the
gingiva.
 The triangular flap is
performed labially or buccally
on both jaws.
 Indications: Surgical removal
of root tips, small cysts, and
apicoectomies.
2. Three-corner flap

29. Advantages:
 - Ensures an adequate blood supply.
 - Satisfactory visualization.
 - Very good stability and reapproximation.
 - Easily modified with a small releasing incision, or an
additional vertical incision, or even lengthening of the
horizontal incision.
Disadvantages:
 - Limited access to long roots.
 - Tension is created when the flap is held with a retractor.
 - It causes a defect in the attached gingiva.
2. Three-corner flap

30. 3. Four-corner flap
(Envelope with two releasing
incisions / Trapezoidal flap / Three
sided flap).
1 tooth anterior
1 tooth posterior
Rarely indicated

31. It is formed by giving an second vertical incision
to the horizontal incision for better access. (Two
oblique vertical releasing incisions extending to
the buccal vestibule).
The oblique vertical releasing incisions always
extend to the interdental papilla. This ensures the
integrity of the gingiva.
Indications: Extensive surgical procedures,
especially when the triangular flap would not
provide adequate acces.
3. Four-corner flap

32. Advantages:
Provides excellent access, allows surgery to be
performed on more than one or two teeth,
produces no tension in the tissues, allows easy
reapproximation of the flap to its original position
and hastens the healing process.
Disadvantages:
Produces a defect in the attached gingiva
(recession of gingiva).
3. Four-corner flap

33. In case of missing teeth and edentulous arches,
horizontal incision is made over the alveolar crest
whereas vertical incision is carried out in the same
way
3. Four-corner flap

34. * To approach the root apex.
* Avoids trauma to the papillae and gingival margin.
* Useful for periapical surgery of a limited extent.
* Should not cross major prominences, ex: canine
eminence.
4. Semilunar incision

35.  This flap is the result of a curved incision, which begins
from the vestibular fold and has a bow-shaped course
with the convex part towards the attached gingiva.
 The lowest point of the incision must be at least 0.5 cm
from the gingival margin, so that the blood supply is not
compromised.
 Each end of the incision must extend at least one tooth
over on each side of the area of bone removal.
 Indications: surgeries requiring periapical exposure,
apicoectomies, removal of small cysts and root tips.
4. Semilunar incision

36.  Advantages:
 Small incision and easy reflection, no recession of
gingivae, no intervention at the periodontium, easier oral
hygiene compared to other types of flaps.
 Disadvantages:
 Possibility of the incision being performed right over the
bone lesion due to miscalculation, scarring mainly in the
anterior area, difficulty of reapproximation and suturing
due to absence of specific reference points, limited
access and visualization, tendency to tear.
4. Semilunar incision

37. An incision is made along
the midline of the palate,
as well as two
anterolateral incisions,
which are anterior to the
canines
 Indication: in surgical
procedures involving
the removal of a
maxillary palatal torus.
5. Y-incision

38.  * Mobilizes from
one area and
then rotates to fill
a soft tissue defect
in another area.

* The three main
types of pedicle
flaps used for
closure of an
oroantral
communication
are:

1) buccal flap.

2) palatal flap.

3) bridge flap.
6. Pedicle flap

39.  This type of flap is
based on and along
a particular blood
vessel like Greater
Palatine Artery in the
palate.
 Indication: Mainly
used for closure
of an oroantral
communication,
Reconstruction
for malignant
defects.
6. Pedicle flap

40. Pedicle bridge flap, used
for closure of oroantral
communication

41.  It is a combination of both vertical & semilunar incisions.
The flap is scalloped to follow gingival architecture.
 Indications: For those cases where there is a
fear that elevation of attached gingiva will
lead to shrinkage & exposure of margins of
restoration.
7- Submarginal Flap

42. Examples

43. Examples

44. Complications:
 A. Flap necrosis.
 B. Flap Dehiscence.
 C. Flap Tearing.
 D. Injury to Local Structures.
Principles of Flap Design

45. A. Flap necrosis
 Base > Free margin
* to preserve an adequate blood supply
* unless a major artery is present in the base.
 Width of Base > Length of Flap
* less critical in oral cavity, but length < width.
* a long, straight incision with adequate flap
reflection heals more rapidly than a short, torn
incision.
 An axial blood supply in the base.
 Hold the flap with a retractor resting on
intact bone to prevent tension.

46. A. Flap necrosis

47. B. Flap Dehiscence
 * The incisions must be made over
intact bone.
 * If the pathologic condition has
eroded the buccocortical plate,
the incision must be at least 6 or 8
mm away from it.
 * The incision is 6 to 8 mm away
from the bony defect created by
surgery.
 * Gently handle the flap's edges.
 * Do not place the flap under
tension.
 * Do not cross bony prominences,
ex: canine eminence.

48. B. Flap Dehiscence

49. C. Flap Tearing
Envelope flaps: an incision around the necks of several
teeth extends 2 teeth anterior and 1 tooth posterior
 If not provide sufficient access.
Vertical (oblique) releasing incisions:
 Extends 1 tooth anterior and 1 tooth posterior
 Started at the line angle of a tooth
 Carried obliquely apically into the unattached gingiva
 If cross the papilla  localized periodontal problems

50. C. Flap Tearing

51. D. Injury to Local Structures
 Mandible: lingual n. & mental n.

52. D. Injury to Local Structures
 Maxilla: greater palatine a. & nasopalatine
n./a.

53. Table: Flap Design Considerations
Summary

54.  Reflection is performed to separate the mucoperiosteal
flap from the underlying bone.
 The elevator is in direct contact with bone and reflection
starts at the incision, usually at an angle, and is
completed with gentle, steady strokes towards the labial
or buccal vestibule, without damaging the tissues. When
the attachment between bone and periosteumis strong
or if symphysis occurs, then scissors or surgical blades
may be used.
Reflection of the
Mucoperiosteum

55. THANK
YOU