INTRODUCTION
Maxillofacial trauma is a common emergency in everyday life, increases
significantly in recent years and tends to be more serious and complicated
about amount of fracture line, more displaced, combines with soft tissue,
blood vessel - nerve, brain injury or coordinate with trauma of other parts
of the body, is mainly due to traffic accidents, specially motorcycle
accident.
In these traumas, mandibular fracture has the highest percentage, is being a
heed matter, particularly in developing countries (Vietnam, Turkey,
Africa ). According to Balwant Rai et al (2007), this kind of fracture
occupied 61% in kinds of maxillofacial fracture. In Vietnam, a research of
Tran Van Truong and Truong Manh Dung in National Hospital of Odonto-
Stomatology (1988 - 1998), with 2149 cases of maxillofacial trauma,
mandibular fractures was the most common (63.66%) and was mainly due
to traffic accidents (82.5%).
The lower jaw is a main bone, to form the structures of middle face, and is
the only moveable bone of the skull blocks. On this, there are teeth and
muscles attached to make chewing function, expressing emotion,
particularly this bone has a curved body with several weaknesses, such as
the angle of the jaw, middle lines, neck of condyle, so it is easy to be
broken. The purpose of treatment is not only maintaining chewing function
but also aesthetics. The choice of methods and materials for surgery is very
important, determines the result of the surgery. In recent years, there are so
many plate and screw system are used in combination lower jaw, achieves
good results, the rigid fixed after surgery to help healing process faster,
avoid secondary displacement, fixed time is shortened.
In the world, absorbable material (plates and screws) first appeared in the
United States since the early 90
th
decade of the twentieth century, is a good
technical solution cause it has inherited the advantages of conventional

has 38 pages, chapters 2 about subjects and methods has 14 pages, chapter
2
3 about research result has 20 pages, chapter 4 about discussions has 24
pages. There are 36 tables, 6 charts and 20 figure, 102 book references: 32
Vietnamese ones, 66 English ones, 4 French ones. The appendix includes
illustrations of patients, medical records, patient list.
* Meaning and new contributions of the thesis
This method brings the results which is not different from the usage of
Titanium material when having accurate indication.
During doing a research, we found that the application of this method has
some advantages:
- The biggest advantage is that the patient does not have to proceed to the
second surgery to remove the plates and screws, this is significant for
female patients, thereby helping patients quickly regain confidence, do not
have to worry about having to remove the material.
- The material is absolutely preserved in a sterilization condition, in the
process of studying, we have not seen any complications of patients wound
like infection or osteitis.
- This is biomaterials, does not affect the diagnostic imaging (X-ray, MRI).
- About aesthetics: No difference from the usage of Titanium because the
absorbable material does not occupy more volume than the maxi Titanium
plate.
CHAPTER 1. LITERATURE REVIEW
1.1. ANATOMICAL FEATURES OF MANDIBLE RELATE TO
TRAUMA
Mandibular region is formed by two bones, stick together at the centre and
the soft tissues around.
Border: The zygoma and maxillary above, inframandibular edge beneath,
the mental area is ahead, the back of ramus behind.
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g) Mandibular movement disorder, including limitation of mouth opening
and deviation to the contralateral.
h) Paraesthesia
i) Subcutaneous emphysema: rare.
1.2.2. X-ray fracture
1.2.2.1. Survey the entire mandible
a) Panoramic films
- The vertical displacement on the bottom can be assessed very good on panoramic
films, in the fracture of neck’s condyle shows the displacement between ahead and
behind, the relationship between condyle and mandibular fossa.
b) Facial X-ray:
- Assess of the horizontal displacement of the fracture, compare with the
proportions of the whole mandible.
1.2.2.2. Films examined the region of the mandible (Oblique jaw film)
1.2.2.3. CT Scanner (CT: Computerized tomography)
To get clarity, accuracy of lesion and location (both bones and soft tissues)
of most mandibular fracture. 3 dimensional images show clearer about
displacement pattern and degree of fracture displacement.
1.3. COORDINATE INJURIES
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Brain injury has the highest percentage (9.5%), the second is coordinated
with maxillary fracture (5.2%), then zygomatic fractures (2.2%). Injuries
coordinated with other parts such as limbs, chest, abdomen, spine appear
with lower rates.
1.4. TREATMENT
1.4.1. The goal of treatment
- Recovery of anatomy
- Recovery of function
- Recovery aesthetics
1.4.2. Requirements

- Advantages of absorbable material
It is created from the natural compounds. Not only meets the treatment,
inherits the advantages of the metal plate and screw, but also overcome the
disadvantages of metallic material.
- Indication:
+ Facial and skull fractures.
+ Nasal fracture, anterior walls of sinuses, lateral orbital wall, the floor of
orbital.
+ Replicate the facial bones and skull.
+ Replicate the jaw bone (bone graft).
- Contraindications
+ Acute infection.
7
+ Poor blood supplying in the position which plates are put on, bone
defects, high risk of infection.
+ Not use for high pressure position
+ Temporomandibular joint surgery.
In my research, we use the products of Bio Tech One.
CHAPTER 2
SUBJECTS AND METHODS
2.1. SUBJECTS
The patients have mandibular fracture, are indicated for surgery at the
Department of Orthopedic Surgery in National Hospital of Odonto
Stomatology and Department of Odonto Stomatology, E hospital from
January 2008 to August 2012.
2.1.1. Requirement
- Being diagnosed mandibular fractures with 1 or 2 lines, very little
displaced.
- Combine mandible by absorbable and Titanium material.
- Be volunteer to participate in research.

- Correct border
- Correct occlusion in the central
occlusion
- No swelling, no deformation
- Incision is dried
- No having the feeling of unpleasant
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Medium
- A little deviated border
(≤1mm)
- Open bite ≤1mm at the
fracture position
- A little swelling and deformed
- Incision is dried
- A little stimulant at which the plate
was put on, patient feel acceptable
Bad
- Much deviated border (>1mm)
- Open bite >1mm
- Much deformed, need surgery
- Very unpleasant, patients complain
* Review the results after 6 weeks and 3 to 6 months:
Table 2.3. Evaluation based on the standard of anatomy, function and aesthetics.
Degree Anatomy Function Aesthetics
Good
- Good healing
- Good in contact
between two fragments
(displacement < 1mm)
- No pain, eat well

mouth ≤ 20mm
- Incorrect occlusion
- Need reoperation
- Unproportional face,
deformation of bone and
soft tissue.
- Need reoperation
2.4. ANALYSE THE DATA: Collecting, summarizing data by
biostatistics algorithmic, SPSS 16.0 software.
CHAPTER 3: RESULTS
3.1. CHARACTERISTICS OF SUBJECTS
3.1.1. Gender
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Regarding gender, men were major, accounted for 81.7% (80% absorbable
group, 83.3% Titanium group), 18.3% of women. Ratio M / F was 4.5.
3.1.2. Cause of injury
The most common injuries were traffic accidents, with a rate of 73.3%
(66.6% in the absorbable group and 80% in Titanium group). In particular,
the traffic accidents group was dominated with motorcycles reason with a
ratio 68.3% (63.3% and 73.3% respectively).
3.1.6. Injured position
Table 3.9. Classification of mandibular fractures by injured position
Group

Position
Absorbable Titanium Total
Amount
Ratio
(%)
Amount

2 11 36,7 19 63,4 30 50
3 1 3,3 1 3,3 2 3,3
Total 30 100 30 100 60 100
1 fracture line was major in the absorbable group, 2 fracture lines was
major in the other with the ratio of 60% and 63.4% respectively. 3 fracture
lines had the same rate in both groups.
3.1.8. Attached injuries: Table 3.11. Attached injuries
Group
Attached injuries
Absorbable Titanium Total
Amount
Ratio
(%)
Amount
Ratio
(%)
Amount
Ratio
(%)
Mandibular fracture
alone
25 83,3 19 63,3 44 73,3
Mandibular +
zygomatic arch
fracture
2 6,7 2 6,7 4 6,7
Mandibular +
maxillary fracture
0 0 2 6,7 2 3,3
Limb, joint injuries

19 63,3 22 73,3 41 68,3
Gummy tear 17 56,7 18 60 35 58,3
Limited opening
mouth
15 50 16 53,3 31 51,7
Soft tissue injury 13 43,3 17 56,7 30 50
Comment: There was the sharp pain signs in 100% of the 2 groups,
swelling and bruising signs appeared > 80% of cases and malocclusion>
70%.
3.2. TREATMENT RESULTS
3.2.1. Evaluation of treatment result by time:
a / Treatment result after discharge
Table 3.18. Evaluation results at discharge
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Group
Result
Absorbable Titanium
p
Amount
Ratio
(%)
Amount
Ratio
(%)
Good
24 80 23 76,7
>0,05
Medium
6 20 7 23,3
Bad

Percentage of patients with good result was higher than the one of
discharge result, with the rate of 88.5% and 84% in absorbable and
Titanium group respectively. The results decreased gradually, only 11.5%
and 16% in absorbable and Titanium group respectively. The Chi squared
test showed no difference statistically with p> 0.05 (X
2
= 0.22 < X
2
0,95
=
3,84).
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c / Results after 3-6 months: Table 3.23. Assessment after 3-6 months
Group
Result
Absorbable Titanium
p
Amount
Ratio
(%)
Amount
Ratio
(%)
Good 22 95,7 18 90
>0,05
Medium 1 4,3 2 10
Bad 0 0 0 0
Total 23 100% 20 100%
Good results occupied high rate: 95.7% (absorbable group) and 90%
(Titanium group) because all patients were removed the jaw fixation and

3
(12%)
0
1
(5%)
Bad 0 0 0 0
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Total 26 25 23 20
B. Assessment of function
To evaluate the functional results, we applied the following standards:
amplitude of opening mouth, chewing, and patient’s feelings at the surgical
position. Result of the function is only evaluated since the beginning of the sixth
month.
Table 3.25. Assessment of function
Time
Result
6 weeks 3 - 6 months
Absorbable Titanium Absorbable Titanium
Good 23
(88,5%)
22
(88%)
23
(100%)
19
(95%)
Medium 3
(11,5%)
3
(12%)

6
(24%)
1
(4,3%)
2
(10%)
16
Bad 0 0 0 0
Total 26 25 23 20
Good result increase after 6 weeks and 3-6 months with 80.8% (absorbable
group), 76% (Titanium group) and 95.7% (absorbable group), 90%
(Titanium group) respectively. The medium results increased after 3-6
months to 4.3% (absorbable group) and 10% (Titanium group), due to injuries and
lack of soft tissues.
3.2.3 Accidents, complications: Table 3.27. Complication
Group
Complications
Absorbable Titanium
Amount Ratio (%) Amount Ratio (%)
Accident
- Screw fracture 1 3,3 0 0
- Plate fracture 1 3,3 0 0
Complication
- Inflammatory 0 0 1 3,3
- Allergy 0 0 1 3,3
Total 2 6,6 2 6,6
There were 2 patients of absorbable groups with screw and plate fracture
during surgery, 2 Titanium patients had inflammatory and allergy after
surgery and having medical treatment, no reoperation. No cases reacted
with absorbable material.

The aim of treatment was to restore the mandible as best as possible about
anatomy, chewing function and aesthetics for the patient later.
4.3.1. Assessment by time:
a. Treatment result at discharge
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- Evaluate overall results at discharge
Good result was 80% in the absorbable and 76.7% in Titanium group. The
medium result was 20% in absorbable group and 23.3% in Titanium group,
because the incision was slightly swollen, mild irritation in the position
which the place was put on, fractures in the patients have neck of condyle
fracture, break angle of jaw coordinate with horizontal branches or the
mental area, but patients came late or attaching brain injury. The difference
was not statistically meaning with p> 0.05. No bad results because at this
stage had not yet assessed bone healing process in both clinical and
radiological.
b. Treatment results after 6 weeks:
After 6 weeks after discharge, the amount of patients coming back was 26
and 25 in absorbable and Titanium group respectively. In my research,
almost patients have been removed the jaw fixation since fortnight, the
proportion of patients achieving good results was 86.3% (44/51 patients),
in these, the results of absorbable group was 88.5% and Titanium was
84%, equivalent with p> 0.05. The medium result was 13.7%, the majority
of these patients had coordinate injuries. No bad results after 6 weeks of
treatment.
c. Treatment results after 3-6 months:
After 3-6 months the evaluation of anatomy, function and aesthetics in
patients was more accurate because the swollen of soft tissues was better.
The amount of re-examination patients was 43 (23 in absorbable group and
20 in Titanium group), good results was 93% (40/43 patients), and was
equivalent between 2 groups. Some patients open mouth at the medium

After 6 weeks of treatment, good results achieved on average 78.4%
(40/51 patients), in which good results in absorbable group was 80.6% and
Titanium was 76%, the difference was not statistically significant with p>
20
0.05. The medium result was 21.6% (11/51 patients), the majority of those
patients combined with other fractures and surgery cases through skin by
old scars, patients often worry about the surgical scar.
After 3-6 good result increased to 93% (40/43 patients), medium result
reduced to of 7%. No bad results because no bad scar made patients
complain or surgery to repair scarring.
4.4. COMPLICATIONS:
According to author Robert and Ramond, the most common complications
of mandibular fracture was bone infection and osteitis. In 60 patients, the
rate of accident and complication is 6.7% (4/60 patients).
Absorbable group: No postoperative infection and no allergy, no rejection.
Titanium group: There were 2 patients having infectious complications and
allergy reaction, having medical treatment: antibiotics, anti-
inflammatory combination of on-site care, no need more surgery.
In Vietnam, due to many factors such as hygiene, ability to manage
patients and less sense so that the teeth in the fracture line was usually
removed. In the 60 patients, we always paid attention to the broken teeth
located on either sides of the fracture if they were loose with the level 3 or
4 would be extracted then sewing. In some cases, teeth located next to the
broken partly and were still stable and we used keep them and advice
patient to treat after removal of jaw fixation.
To conclude, all the complications of treatment depend on the patient's
objective factors and subjective factors of doctor.
CONCLUSION
After doing research using absorbable material (from January 2008 to
August 2012) with 60 patients diagnosed mandibular fractures including

absorbable material require more limited, more simple fracture line, little
amount of fracture line, major for horizontal branches fracture (1-2 fracture
lines), or fracture of angle of the jaw was little displaced and crumbling.
- Do not apply absorbable material with the fragmented, much displaced
and lots of defective bone fractures in ramus of mandible, neck of condyle
or brain injuries.
- Can be used for the mandibular fracture, go with the maxillary and
zygomatic arch injuries. In E Hospital, we had 4 cases for the positive
results.
In summary, the use of absorbable material in surgery combination
mandible can bring positive results. However, due to strict technical
requirements, specify and limited indication and higher price so that when
deciding do the surgery, need to explain clearly for the patients and their
family know the benefits of using methods. The most beneficial is not just avoiding
the second surgery. The method using absorbable material can be applied in
the treatment of mandibular fractures.
PROPOSALS
Through this research, we have some recommendations as follows:
- The mandibular fracture treatment with absorbable material brings many
benefits and the results did not differ from the use Titanium when be
diagnosed accurately. Therefore, it is necessary to introduce and replicate
this treatment for the maxillofacial surgery department to cater for the
patients by the best way.
- Absorbable materials we used in the study are imported and high price, in
future should study to produce this product with the low cost to serve lots
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of patients. Also need more researches in long term with larger sample
sizes.
- Maxillofacial trauma increasing, mainly due to traffic accidents. The
government should improve the quality of traffic safety, such as educating