Introduction
Apicectomy is always a
technique-sensitive procedure for oral surgeons and endodontists.1 They always desire to improve methodology of this procedure
by means of instrumentation, materials and different approaches to have better
success rates. The visibility of the area during the procedure is the key step
for an improved postoperative healing and to reduce the complications occurring
during surgery due to improper visibility. To attain this task, many surgical
flaps have been designed and practiced since decades.1 A review of these flap procedures resulted in gingival and subgingival flap designs. These are classified as:
1.
Gingival Flaps: Triangular and Trapezoidal
2.
Subgingival Flaps: Semilunar
and Ochsenbein – Luebke
(O-L) Flap.
These flaps have distinct
indications, advantages and disadvantages, but it is more the experience and
the choice of the operator according to the situation and need of the apicectomy case that determine the final outcome of the
procedure. Many studies have been done on selection of the appropriate flap
design,1-3 but since the
introduction of Ochsenbein-Luebke flap, some surgeons
prefer this design of flap.
The two most commonly used
Flap procedures currently in vogue are a) Trapezoidal Flap and b) Ochsenbein-Luebke Flap, because of their specific
advantages. However the Ochsenbein-Luebke procedure
offers additional advantages such as sparing of the marginal gingival,
non-exposure and minimal loss of crestal bone and
ease of reapproximation of the flap.2,3
The Trapezoidal technique
involves two vertical releasing incisions and one horizontal intra-sulcular (gingival) incision (Figure 1). This is a marginal
incision, as opposed to the O-L flap, which is a submarginal
incision.2,3
(a)
(b)
(c)
Figure 1: Diagrammatic representation of the
Trapezoidal flap: a) Outline
b) Exposure and c) Stitches
(a) (b)
(c) (d)
Figure 2: Diagrammatic representation of the O-L flap:
a) Outline. b) Incision Line. c)
Exposure and d) Stitches
Briefly the O-L technique
involves a scalloped horizontal incision in attached gingiva and two vertical
releasing incisions (Figure-2).2,3 Incisions
correspond to the contour of the gingival. There must be an adequate band of
gingiva present (3–5 mm). This requires an analysis of attachment level along
the entire length of the horizontal incision.
The
O-L technique is basically a modified semilunar or
trapezoidal flap in which a scalloped horizontal incision joins two vertical
incisions. The vertical incisions are made at least one tooth lateral to
surgery side. The horizontal incision is scalloped following the contour of
gingival margin 3-5 mm from gingival margin.2,3
Overall,
the O-L technique appears advantageous for both surgeons and patients. However,
very few studies have been done to compare the advantages of selecting one
technique over the other. There have been no studies in
MATERIAL
AND METHODS
The study was conducted at the Punjab Dental
Hospital Lahore
Patients were subjected to
detailed history, clinical examination, and investigations as needed. Patients
were selected for either the Trapezoidal or the O-L technique on a non-random
basis; surgery was performed according to standard
procedures. All the procedures were done under local anaesthesia in Minor Oral
Surgery Department, Punjab Dental Hospital Lahore. Equal numbers of patients
were assigned to the two groups (60 each).
Evaluation of technique(s)
involved assessment of intra-operative technical considerations as well as
postoperative morbidity, healing and cosmetic results.
Duration of surgery was noted by using a
stopwatch, timed from the first nick to the last reflection of the flap.
Technical problems related to the surgical
procedures of both groups were noted as tearing of the flap or damage to wound
edges.
Ease of operation and visibility were assessed
by the operator’s personal experience during holding of flap by assistant,
facilitation of visibility during bone and apex cutting and assistance in lip
retraction.
For stitching, 3-0 silk thread and half circle needle at cutting edge was used for both procedures. Comparison was done immediately, after 24 hours, after 3 days and after 5 days at the time of removal of stitches. The edges were noted after 14 days. Approximation was measured as:
1.
+ = Maximum approximation
2.
++ = Flap has defect in approximation in one to two
stitched areas of flap.
3. +++ = More than two areas of the flap have defective approximation in the stitched area.
Haemorrhage was assessed by the duration of
bleeding from the wound edges at the start of incision till the start of bony
procedure. Duration was recorded by use of a stopwatch.
Oedema/Swelling was
assessed on clinical basis as follows:
1.
+ = swelling confined to surgery flap.
2.
++ = Swelling involves upper lip as well.
3.
+++ = Swelling beyond
lip area or in canine fossa.
Findings were noted after 24 hours, 3 days, 5 days
and after 14 days.
Statistical analysis was
done using SPSS ver 8.0 computer software. The chi
square test was used to test for differences of frequencies and the Student’s T
test was used for differences of means. A p
value £ 0.05 was considered
significant.
RESULTS
A total of 120 patients were involved in the study, selected on the basis of involved teeth and inclusion criteria. The sex and age distribution of both groups is given in Table-1.
Table-1: Age and Sex
Distribution of both groups (n=60 each)
|
Age Groups (years) |
O-L Group |
Trapezoidal Group |
Total |
||
|
Male |
Female |
Male |
Female |
||
|
12 – 25 25 – 35 35 – 45 |
25 9 5 |
10 7 4 |
12 15 9 |
11 8 5 |
58 39 23 |
Total |
39 |
21 |
36 |
24 |
120 |
Most patients were in the age group of 12-25 years and the overall male to female ratio was 1.67:1.
Duration of surgery for both groups is given in Table-2. Differences in timings between the procedures were not significant, even though there were more patients with overall quick reflection time in the O-L group.
Table-2: Duration of surgery for the two groups
(n=60 each)
Groups
|
Time of Flap Reflection |
Total |
|
|
5–10 minutes |
>10 minutes |
||
|
O-L |
38 |
22 |
60 |
|
Trapezoidal |
29 |
31 |
60 |
Total
|
67 |
53 |
120 |
Technical problems related to the surgical procedures of both groups are seen in Table-3. The reflection procedure was more difficult with the Trapezoidal flap due to interdental papillae detachment as well as reflecting the attached gingiva.
Table-3: Damage to Flap in both groups (n=60 each)
Groups |
Damage to Flap |
Total |
||
|
|
During Reflection |
During Procedure |
During Stitching |
|
|
O-L |
4 |
3 |
3 |
10 |
|
Trapezoidal |
7 |
2 |
5 |
14 |
Total |
11 |
5 |
8 |
24 |
The same problem was noted during stitching where approximation of the interdental papillae was difficult.
Table-4: Visibility and Ease of Procedures (n=60 each)
|
Assessment |
O-L |
Trapezoidal |
Total |
|
Easy
flap retraction by assistant |
50 |
46 |
96 |
|
Visibility
during cutting of bone / apex |
48 |
46 |
94 |
Total |
98 |
92 |
190 |
Ease
of operation and visibility data are given in Table-4. It was observed that the
O-L procedure had both easy lip retraction and better visibility and ease during
cutting of bone.
The exact approximation of the flap edges was found most effective in the O-L procedure as compared to the Trapezoidal procedure (Table-5). There was overall better approximation with the O-L technique compared to the Trapezoidal technique.
Table-5: Wound approximation in both groups (n=60 each)
|
Post-operative Duration |
Procedure |
|||||
|
O-L |
Trapezoidal |
|||||
|
+ |
++ |
+++ |
+ |
++ |
+++ |
|
|
Day 1 Day 2 Day 3 Day 5 Day 14 |
42* 40 40 40 40 |
8 8 10 13 17 |
10 12 10 7 3** |
30 30 30 30 30 |
16 10 10 10 15 |
14 20 20 20 15 |
* p<0.05 as compared to trapezoidal group.
** p<0.001 as compared to the trapezoidal group.
+ = Maximum approximation
++ = Flap has defect in
approximation in one to two stitched areas of flap.
+++ = More than two areas of
the flap have defective approximation in the stitched area.
For the first day maximum approximation (+ category) was observed in the O-L group, which was statistically significant (p<0.05); the values remained constant till day 14. The same observation was noted for the ++ and +++ categories; however both flaps showed improvement in ++ categories as compared to the +++ categories. In the O-L group, difference in the +++ category at day 14 was statistically significant as compared to the Trapezoidal Group (p < 0.001).
The overall duration of bleeding was more in
the trapezoidal group (Table-6); it may have been due to more vascular supply
in the area of attached gingiva and dental papilla,
as well as more reflection of periosteum, but the
difference was not statistically significant.
Table-6: Duration of bleeding
for both groups (n=60 each)
|
Duration
(min.) |
Procedure |
Total |
|
|
O-L |
Trapezoidal |
||
|
Up to 5 5-10 >10 |
25 13 22 |
19 10 31 |
44 23 53 |
|
Total |
60 |
60 |
120 |
Swelling was observed in
both flaps in the first 24 hours up to 14 days (Table-7). The intensity of
swelling was maximal after 24 hours and reduced with the passage of time;
though more pronounced in the Trapezoidal group, the difference was not statistically
significant. After 3 days, however the difference became significant (p £ 0.05) and again after day 5
till day 14, it became not significant. The amount of swelling also depended on
the extent of the surgical procedure.
Table-7: Presence of Oedema/Swelling in both groups
(n=60 each)
|
Post operative Duration |
Procedure |
|||||
|
O-L |
Trapezoidal |
|||||
|
+ |
++ |
+++ |
+ |
++ |
+++ |
|
|
After
24 hrs. Day
3 Day
5 Day
14 |
40 45 48 59 |
14 10* 9 1 |
6 5 3 Nil |
32 34 40 57 |
18 20 17 3 |
10 6 3 Nil |
*p significant (£ 0.05) as compared to the
trapezoidal group.
+ = swelling confined to
surgery flap.
++ = Swelling involves upper lip
as well.
+++ = Swelling beyond lip area or in canine fossa.
Marginal
recession was observed only in the trapezoidal flaps. A total of 20 cases
reported with gingival recession, including 6 patients with restoration in
anterior segment. Two patients underwent new restoration for aesthetic reasons.
Postoperative pain related to
flap only could not be assessed as the nature of endodontic
surgery, bone resection and manipulation were also
contributory factors to pain.
DISCUSSION
Success in surgical endodontics depends upon the
correct selection of case, proper endodontic procedure,
obturation and proper surgical endodontic
procedure.1 The initiation of surgery
should be based purely on the selection of flap design, considering exposure of
field, ease in surgery, assistance and finally good closure resulting in good
healing and aesthetic scar. Many flaps have been introduced, but in gingival
flaps, trapezoidal flap is favoured a lot due to its good visibility, easy
stitching and handling. But since the introduction of this flap, the
approximation of flap back in its original position, maintaining the interdental attachment and prevention of recession of
gingiva after healing has not been accomplished. Now other flaps, like Semi
lunar or Triangular flaps are considered as good as trapezoid.
Since the introduction of
the O-L flap, oral surgeons tried this flap and found it better in many ways,
such as ease in reflection of flap (as you have not to reflect the attached
gingiva), no recession of gingiva and no fear of exposure of restorative
margins,2,3 ease of stitching4
and good cosmetic results.5 In fact both flaps are being practiced
in surgical endodontics but no direct comparative study has been conducted.
This comparative study
conducted on 120 patients at the Punjab Dental Hospital Lahore
Selection of an appropriate
surgical procedure by a surgeon involves issues of ease of operation and
visibility of the field. Both these criteria favoured the O-L flap procedure
over the Trapezoidal one (Table-4) in our study; however the difference found
was not significant but the handling of flap during stitches revealed a
significant difference (Table-5). It was observed that the adaptation of interdental papilla in trapezoidal flap is difficult, more
time consuming, with more tearing of flap and improper cosmetic results. The
duration of haemorrhage (Table-6) was more in Trapezoidal flap (31/60 or 51.7%
patients with bleeding > 10 minutes) compared to the O-L flap (22/60 or
36.7% patients with bleeding > 10 minutes); this is related to increased
duration of operation due to more reflection of periosteum in the Trapezoidal
flap as compared to the O-L flap. Oedema was present in both the modalities but
was more in Trapezoidal group (Table-7) and the difference between the groups
became statistically significant after the third postoperative day. It may be
due to involvement of interdental papilla and
reflection of more periosteum.
The most annoying aspect
observed in trapezoidal flap in our study was the recession of gingival margin
in 20 cases (33.33%). Two patients even underwent new anterior crown
replacement due to bad aesthetic effect in gingival area as an end result of
surgery. No such complaint was received for any of the patients operated by O-L
flap.
Pain could not be assessed
due to contribution from other bony procedures as well, thus could not be
related to flap procedures alone.
CONCLUSION
O-L flap has distinct advantages over the
Trapezoidal flap as it is easy to reflect, has good visibility, less bleeding
duration and is easy to handle during surgery. Stitches are less time
consuming, there is less tearing, better cosmetic result and no recession of
gingiva. However it is recommended that future studies should be done in more
numbers of patients. to demonstrate its superiority.
Acknowledgment
I wish to extend my thanks to Dr. Adnan Ali Shah, Associate Professor of Oral and
Maxillofacial Surgery at
REFERENCES
1.
Gerstein H. Surgical Endodontics. In: Laskin DM.
Oral and Maxillofacial Surgery, vol. 2, Indian edition, 1999 New Delhi C.V. Mosby Co., St. Louis Missouri USA, pp. 143-71.
2.
Endodontic Surgery Handout. Online
Webpage. Accessed
3.
Allemang JD. Endodontic
Surgery. Online Webpage. Accessed
4.
Kleier DJ. The continuous locking
suture technique. J Endod 2001; 27(10):624-6.
5.
Kramper BJ, Kaminski EJ, Osetek EM, Heuer MA. A
comparative study of the wound healing of three types of flap design used in periapical surgery. J Endodon
1984;