This journal club presentation summarizes a systematic review on unfavorable fracture patterns (known as "bad splits") that can occur during bilateral sagittal split osteotomy (BSSO) procedures. The review identified 33 studies from 1971-2015 reporting on 458 cases of bad splits among 19,527 BSSO procedures. The review developed a classification system for different types of bad splits and proposed salvage approaches for managing each type. Type 1 fractures involved the proximal segment, type 2 the distal segment, type 3 the coronoid process, and type 4 the condylar neck. The discussion analyzed factors that may contribute to different split types and emphasized the importance of proper fixation and positioning of segments. The conclusion was that most bad

1. JOURNAL CLUB #14
PRESENTED BY:
DR. BHAVIK MIYANI,
PG- 3RD YEAR, OMFS,
NPDCH, SPU, VISNAGAR.
GUIDED BY:
DR. ANIL MANAGUTTI,
DR. SHAILESH MENAT,
DR. RUSHIT PATEL,
DR. JIGAR PATEL,
DR. NIRAV PATEL.
1

2. Bad splits in bilateral sagittal
split osteotomy: systematic
review of fracture patterns
2
Title of article

3. 1. Title is an appropriate.
2. Type of study is mentioned in title.
3
Critics of Title

4. 1. About the Journal
2. About the Author
3. Abstract
4. Introduction
5. Material and Method
6. Results
7. Discussion
8. Review of Literature
9. Conclusion
10. References
4
Contents

5. 5
About the journal
• International Journal of Oral & Maxillofacial Surgery
• Peer reviewed journal
• Open access PubMed Indexed Journal
• Impact factor- 1.961(2016)
• Published By- Elsevier Inc.
• Volume- 45
• Issue- 2
• Year of Publication- February, 2016
• Page No.- 887-897.

6. 1. S. A. Steenen
2. A. G. Becking
 1. Department of Oral and Maxillofacial Surgery, Academic Medical Centre (AMC),
Amsterdam, Netherlands.
 2. Department of Oral and Maxillofacial Surgery, Spaarne Gasthuis Haarlem,
Academic Medical Centre (AMC), Amsterdam, and Academic Centre for Dentistry
(ACTA) in Amsterdam, Netherlands.
6
About the authors

7. 1. Qualification details of authors are not
mentioned.
7
Critics of author’s details

8.  An unfavourable and unanticipated pattern of the mandibular sagittal split osteotomy is
generally referred to as a ‘bad split’. Few restorative techniques to manage the situation
have been described. In this article, a classification of reported bad split pattern types is
proposed and appropriate salvage procedures to manage the different types of undesired
fracture are presented. A systematic review was undertaken, yielding a total of 33 studies
published between 1971 and 2015. These reported a total of 458 cases of bad splits among
19,527 sagittal ramus osteotomies in 10,271 patients. The total reported incidence of bad split
was 2.3% of sagittal splits. The most frequently encountered were buccal plate fractures of
the proximal segment (types 1A–F) and lingual fractures of the distal segment (types 2A and
2B). Coronoid fractures (type 3) and condylar neck fractures (type 4) have seldom been
reported. The various types of bad split may require different salvage approaches.
8Abstract
Key words: bad split; intraoperative complications; mandibular fracture; bilateral sagittal
split osteotomy; sagittal ramus osteotomy; orthognathic surgery; classification;
management.

9. 1. Type of study and aim of study is mentioned in
abstract.
2. Abstract is not well structured.
3. Keywords are mentioned in abstract.
9Critics of abstract

10.  Segmenting the mandible in an orthognathic procedure to reposition the
tooth bearing part is generally known as a bilateral sagittal split osteotomy
(BSSO). Historically, different ways of splitting the mandible have been
advocated.
 The Trauner and Obwegeser technique (1955), the Dal Pont modification
(1961), and the Hunsuck modification (1968) are the best documented.
 An unfavourable and unanticipated pattern of the mandibular osteotomy
fracture is generally referred to as a ‘bad split’.
 Bad splits may cause mechanical instability, a disturbance in bony union,
and lead to bone sequestration with subsequent infection.
10Introduction

11. The most common and best documented mandibular sagittal ramus splitting
techniques; from left to right: the Trauner and Obwegeser technique (1955), the
Dal Pont modification (1961), and the Hunsuck modification (1968).
11

12.  In addition, it has been proposed that temporomandibular joint (TMJ)
dysfunction and inferior alveolar nerve damage may arise due to excessive
intraoperative manipulation in an attempt to reposition the fractured segments,
and that subsequent difficulty in positioning the condyle in the glenoid fossa
may increase the risk of relapse.
 In order to reduce the risk of postoperative functional deficits, fractured split
segments are best fixated and reconsolidated. However, few restorative
techniques to manage the situation have been described.
12

13. 1. It is up to the point and explained to aims and objectives of
article.
2. It describes aim of study.
13Critics of introduction

14. The aim of this article is to review unfavourable split pattern
types reported in the literature, and to present appropriate
salvage procedures to manage the different types of undesired
fracture.
14Aim of the study

15.  Eligibility criteria
 All retrospective and prospective studies of unwanted splits in BSSO
procedures, with or without control groups, were included. There were
no restrictions.
 Trial selection
 After assessing the eligibility of the articles in a standardized manner
by reading the titles and abstracts, selected articles were retrieved and
the full-texts read to screen for eligibility.
15Material and Methods

16.  Data extraction and collection
 A data extraction sheet was developed. For each of the articles identified and included in this
study, the following data were extracted:
(1) Author and year of publication,
(2) Study design,
(3) Surgical technique,
(4) Number of patients who underwent BSSO,
(5) Number of patients who underwent concomitant third molar removal,
(6) Number of patients who had no third molars present at surgery,
(7) Patient age statistics,
(8) Number of split sites, number of bad splits, and the unwanted split pattern types per
patient and per split site.
 Summary outcome data were entered into Review Manager software (RevMan version 5.2;
Cochrane Collaboration, 2012). The development of the search strategy, study selection, and
data collection were performed by one author.
16

17. 1. Sample of review articles are sufficient.
2. Inclusion criteria are mentioned.
3. Data extraction and collection method is very well
described.
17Critics of material & methods

18.  The first study by Guernsey and De Champlain (1971) reported two
unanticipated proximal segment and three distal segment fractures among 22
patients who were operated on using the classical Obwegeser technique for
BSSO.
 Since then, several reports of bad splits occurring while using the different surgical
techniques have followed up until the present time.
18
Results

19.  A literature review for the period 1971– 2015 revealed a total of 458 cases of bad
splits among 19,527 sagittal ramus osteotomies performed in 10,271 patients (i.e.,
2.3% of sagittal splits reported).
 The most frequently reported bad splits were various unfavourable fracture
patterns of the buccal plate of the proximal segment (52.7%) and lingual fractures
of the posterior aspect of the distal segment (42.9%). Four cases of condyle
fracture and four cases of coronoid fracture were also reported.
19
Results

20. 1. Results in text match with the table.
2. Duration of study is also sufficient to
overcome a result.
20
Critics of results

21. Salvage surgical approaches
 In general, if a bad split occurs, emphasis should first be placed on a careful inspection
and if necessary dissection, in order to visualize the splitting pattern, followed by minimal
stripping of the periosteum to assure vascularization of the fractured segment.
 Second, a salvage surgical procedure needs to be designed to produce the desired
functional and aesthetic results.
 Lastly, and equally important, great care must be taken not to increase the morbidity
further, such as impairment of the neurovascular bundle. The various types of bad split
may require different salvage approaches.
21
Discussion

22. Type 1: Proximal segment (Buccal) fractures 22
Type 1: Proximal segment (buccal)
fractures
1A- Small anterior;
1B- Vertical;
1C- Angle;
1D- Horizontal ramal;
1E- Oblique ramal;
1F- Inferior border.

23.  The buccal cortical plate of the mandible in some patients is rather thin and susceptible to
fractures posterior to the second molar which may explain the frequently reported 1A, 1B,
and 1C fracture types.
 The difficulty of proximal segment fracture reduction depends on the fractured segment
size and anatomical location.
 Small segments that have been stripped from the periosteum (e.g., type 1A fractures) may
be removed to prevent sequestration.
 Larger fractured fragments (e.g., types 1B, 1C, 1E, and 1F) with an intact periosteum are
best secured immediately, and simply and quickly reduced with plate osteosynthesis, in
order to reduce stretching forces on the inferior alveolar nerve, which may occur if chisels
are used to finish the split.
23

24.  The split can be completed in the usual way with moderate force.
 If the fractured buccal fracture line runs above the lingula (type 1D), the condylar
segment is entirely free. Securing its position in the fossa requires securing the
condylar stump to the remaining buccal cortex.
 In this situation, additional removal of the coronoid process to eliminate traction of
the temporalis muscle may be necessary.
 The coronoid process may then instead be used as a free cortical graft.
24

25. Type 2: Distal segment (lingual)
fractures
2A- Vertical;
2B- Horizontal.
25Type 2: Distal segment (lingual) fractures

26.  In the early 1980s, the lingual split technique described by Hunsuck was still considered
to be a bad split by some.
 This fracture is most likely to occur in the third molar region where cortical bone is thin
and not easily stabilized, possibly resulting from excessive lateral inclination of the
osteotome.
 It has been proposed that surgical sectioning of the impacted third molar and removal in
segments may help to prevent this type of bad split from occurring.
 Repositioning the fractured segments and positioning the condyle in the glenoid fossa
may be difficult, but can be assessed during surgery if intermaxillary fixation (IMF) is
released.
26

27.  Restoring the anatomy in this type of bad split requires securing the condyle in the fossa
by whatever means possible, followed by careful dissection to visualize the fracture.
 In the case of a vertical fracture (type 2A), the split can be completed and the lingual
plate will remain unattached; fixation can only be accomplished with buccal plating and
monocortical screws.
 If desired, the lingual fragment can be fixed with one or two bicortical screws.
 In the case of a horizontal fracture (type 2B), the situation does not hamper the surgery,
and fixation can still be accomplished within the same surgical session with plate
osteosynthesis or upper border bicortical screws.
27

28. 28Type 3: Coronoid process fractures
 Only four cases of coronoid fracture were
identified.
 These fractures probably result from
incorrect positioning of the bone cuts.
 In this type of fracture, the free coronoid
may be left in place without consequences.

29.  This type of bad split may be the most difficult to
reduce, especially if the condyle remains attached to
the distal tooth-bearing segment.
 This type of fracture is best managed by aligning the
bony fragments and semi-rigid plating.
 This may be a difficult procedure, necessitating
routines in open reduction and internal fixation in
condylar fracture treatment and transcutaneous
access.
 Discontinuing the procedure and a secondary
attempt after consolidation may be the best choice.
29Type 4: Condylar neck fractures

30.  If both splits occur in undesired patterns, bilateral salvage may be
attempted.
 However it may be best to discontinue the surgery, especially if
operator experience is limited. After consolidation for 6 months,
re-operation may be considered.
30
Bilateral bad splits

31.  When repositioning the split segments; proper positioning of the
mandibular condyle in the fossa is of great importance to reduce the
risk of TMJ dysfunction, inferior alveolar nerve injury, and relapse.
 It appears that in most cases, bad splits can be repaired with additional
osteosynthesis measures without having a negative influence on the
postoperative course or end results.
31
Additional recommendations

32. 1. The points mentioned in material & method and results are justified by
discussion.
2. All the possible splits in BSSO are well described in terms of
classification with treatment plan.
3. Possible complications are also described in the discussion.
32
Critics of discussion

33. 33
Review of literature

34. Two similar "bad splits" and how
they were treated-M. Y. Mommaerts. Int. J. Oral Maxillofac. Surg. 1992;
21: 331-332. © Munksgaard 1992
 Two high fractures of the proximal segments during separate sagittal split osteotomies were treated by a
modification of the "Obwegeser II" technique and screw osteosynthesis.
 A technique has been described that had to be adopted "on the spot" to overcome the problem; it is an
alternative to miniplate osteosynthesis.
 Careful wedging of the large spreading osteotome in a more superior position while splitting up to the
posterior border will probably prevent such complications.
 CONCLUSION- As the author wedge the large osteotome with its upper edge superior to the lingual
osteotomy line, before tapping and, especially, before torqueing.
 With this small modification of the Obwegeser technique, the author has not encountered any "bad splits" in
a series of 94 consecutive bilateral sagittal split osteotomies.
34

35. Bad split during bilateral sagittal split osteotomy of the mandible with
separators: a retrospective study of 427 patients
Gertjan Mensink ,Jop P. Verweij,Michael D. Frank, J. Eelco
Bergsma,J.P. Richard van Merkesteyn
 An unfavourable fracture, known as a bad split, is a common operative complication in bilateral sagittal split
osteotomy (BSSO). The reported incidence ranges from 0.5 to 5.5%/site. Since 1994 we have used sagittal
splitters and separators instead of chisels for BSSO in our clinic in an attempt to prevent postoperative
hypoaesthesia. Theoretically an increased percentage of bad splits could be expected with this technique. In
this retrospective study we aimed to find out the incidence of bad splits associated with BSSO done with
splitters and separators. We also assessed the risk factors for bad splits. The study group comprised 427
consecutive patients among whom the incidence of bad splits was 2.0%/site, which is well within the
reported range. The only predictive factor for a bad split was the removal of third molars at the same time
as BSSO. There was no significant association between bad splits and age, sex, class of occlusion, or the
experience of the surgeon. We think that doing a BSSO with splitters and separators instead of chisels does
not increase the risk of a bad split, and is therefore safe with predictable results.
35

36.  Often, the proximal and distal segments may be separated adequately. However, subsequent
efforts to install semi-rigid fixation in order to refrain from IMF may be challenging.
 If IMF is necessary, it will be used as an adequate but inconvenient salvage method for a 6-
week consolidation period.
 If IMF is used, there is no certainty that the final occlusion will be correct, because
intraoperative information on condylar seating is absent.
 In some cases, however, after extraoral approaches have already been attempted, an
acceptable sagittal split pattern might not be achievable. In such cases, the surgery may best
be discontinued and revisited using a different osteotomy design after consolidation.
36
Conclusion

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