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Conventional 2D miniplate versus 3D four-holed and eight-holed miniplates in the management of mandibular angle fractures
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology xxx (xxxx) xxx–xxx
Contents lists available at ScienceDirect
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology journal homepage: www.elsevier.com/locate/jomsmp
Original Research
Conventional 2D miniplate versus 3D four-holed and eight-holed miniplates in the management of mandibular angle fractures Sandeep Yadav, Sujata Mohanty*, Pankaj Sharma, Sanchaita Kohli, Chandravir Singh, Jitender Dabas Department of Oral and Maxillofacial Surgery, Maulana Azad Institute of Dental Sciences, MAMC Complex, Bahadur Shah Zafar Marg, New Delhi, 110002, India
A R T I C LE I N FO
A B S T R A C T
Keywords: Angle fracture Miniplates 3D plates Three dimensional plates Mandible fracture
Objective: To compare the efficacy of conventional 2D miniplate with 3D 4-hole and 8-hole miniplates in the management of mandibular angle fractures. Methods: A prospective study was conducted on 24 patients with isolated mandibular angle fractures that were divided into three following groups (n = 8 each) based on the osteosynthesis technique used: Group A- conventional 2D four-holed miniplate Group B- 3D- 4-holed miniplate Group C- 3D- 8-holed miniplate Post-operative pain, inter-incisal opening, range of motion, bite force and incidence of complications were assessed at various time intervals up to a period of six months. Results: A steady improvement in all parameters was seen in the three groups over six months. A significantly greater amount of 1 week post-operative trismus was observed in the 8-holed miniplate group (p < 0.05). Six months after the surgery, however, the difference in pain, inter-incisal opening, range of motion and bite force among the three groups was found to be statistically insignificant (p > 0.05). The incidence of complications was greatest in Group B (25 %). Conclusion: The conventional 2D miniplate system still holds its place as the method of choice for management of mandibular angle fractures.
1. Introduction Road traffic accidents, violence and sports injuries have had an alarming rise in the past two decades. Maxillofacial trauma is a prominent component of these accidents, with the mandible being one of the most commonly involved bone due to its forward facial projection. The mandibular angle in particular is the most commonly fractured region, accounting for approximately 30 % of all mandibular fractures [1,2]. The contemporary management of mandibular angle fractures is Open Reduction and Internal Fixation (ORIF) using one of the several available osteosynthesis techniques. A single 2.0 mm miniplate fixation at the superior border has long been the most popular of these techniques, being based on Champy’s recommendation of hardware fixation solely over the zone of tensile forces in the mandibular angle region, that being the superior border [3]. Analysis of the biomechanics of the mandible, however, shows that when the masticatory force is close to the fracture line, a reversal of the
lines of tension and compression occurs with a tendency of the fracture line to open at the inferior border [4]. Consequently, many surgeons began advocating fixation using 2 miniplates (1 at the superior and another at the inferior border) [5,6] or using a load bearing plate at the lower border. Other surgeons reported a greater incidence of biological complications (28 %) in an attempt to achieve this superior stability at the mandibular angle using 2 miniplate osteosynthesis, discouraging this technique [7]. This sequence of events led to the conundrum that is the fixation of mandibular angle fractures, with no foreseeable consensus on a single osteosynthesis technique, as each technique is fraught with its own set of pros and cons. To this end, a novel plate design was introduced in 1992, namely, the three-dimensional (3D) or matrix plate [8] to integrate the advantages of both techniques whilst alleviating their shortcomings. It includes a straight or curved ladder plate that is fixed along the lateral surface of the mandibular angle. Such plates have been found to have more resistance than the conventional miniplates against the out-of-plane movements at the fracture
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Corresponding author. E-mail addresses: [email protected] (S. Yadav), [email protected] (S. Mohanty), [email protected] (P. Sharma), [email protected] (S. Kohli), [email protected] (C. Singh), [email protected] (J. Dabas). https://doi.org/10.1016/j.ajoms.2019.12.003 Received 12 September 2019; Received in revised form 1 December 2019; Accepted 10 December 2019 2212-5558/ © 2019 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd All rights reserved.
Please cite this article as: Sandeep Yadav, et al., Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology, https://doi.org/10.1016/j.ajoms.2019.12.003
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line [9]. The ultimate goal for any fixation technique is to ensure a stable, harmonious occlusion and optimum post-operative masticatory function. In spite of numerous studies comparing the conventional 2D and 3D systems of osteosynthesis, the literature discussing post-surgical bite force achieved with these techniques is still sparse for mandibular angle fractures. Other parameters aiding in favourable functional rehabilitation viz. inter-incisal opening and range of mandibular movements have also been sparingly studied. The aim of the current study was, therefore, to evaluate and compare the functional outcome achieved among three study groups i.e. conventional 2D and 4- and 8holed 3D miniplates, in terms of post-operative pain, maximum interincisal opening, excursive movements and bite force.
cases to access the fractured site, where the incision was placed extending from the buccal alveolar mucosa adjacent to the mandibular second molar up to the anterior border of ramus. A mucoperiosteal flap was raised to expose the fracture line till the inferior border of the mandible. After anatomical reduction of the fractured segments, a 2D miniplate was fixed along the external oblique ridge at the superior border of the ramus in Group A cases (Fig. 1) while the 4- and 8- holed 3D miniplates (in Group B and C respectively) were fixed on the lateral surface of mandible in such a way that the horizontal cross bars were perpendicular to the fracture line and vertical cross bars were parallel to it [10] (Figs. 2 and 3). While fixing the 3D plates, an extra-oral stab incision was additionally placed to facilitate drilling and fixation of screws using a trans-buccal trocar and cannula. In all cases, a 2 mm non-locking plating system was used with screws of length 8 mm. All surgeries were performed by a single surgeon, i.e., the senior author (b).
2. Material and methods 2.1. Study Design
2.3. Post-operative Period A prospective comparative study was designed wherein all cases of favorable and unfavorable (vertical and horizontal) isolated mandibular angle fractures reporting to the author’s department (between October 2013 to October 2015) were planned for open reduction and internal fixation (ORIF). The diagnosis of mandibular angle fracture was established with the help of a thorough clinical examination and radiographical examination using an orthopantomogram (OPG) and a postero-anterior (PA) view of the mandible. Included were all patients ≥15 years of age, with a healthy dentition, reporting within one week of trauma. Cases with other concomitant mandibular fractures, bony or soft tissue defects, severe comminution and/or infection, edentulism, pathological fractures, pan-facial trauma and systemic illnesses precluding optimum wound healing were excluded from the study. Selected cases were randomly divided (using the block randomization technique) into three groups i.e. A, B and C, based on the osteosynthesis technique to be used: Group A: Conventional 2D 4-holed miniplate fixation on the superior border of the mandibular ramus (Fig. 1) Group B: 3D 4-holed miniplate fixation over the lateral surface of the mandibular ramus (Fig. 2) Group C: 3D 8-holed miniplate fixation on the lateral surface of the mandibular ramus (Fig. 3) Ethical approval was obtained from the institutional review board and a written informed consent was provided by all patients recruited in the study.
Parameters including post-operative pain, inter-incisal opening, mandibular range of motion (protrusion and laterotrusion) and bite force were measured at various time intervals post-operatively. Postoperative OPG was done for all patients to assess the adequacy of plate fixation. All patients were followed up for a minimum of 6 months. Pain was assessed using the Numerical Rating Scale (0–10) on post-operative day 1, day 7 and day 30. Inter-incisal opening and range of motion were measured in millimeters using calipers 1 week, 1 month and 6 months after release of MMF. Bite force (in kg) was recorded on the same visits using the Digital Bite Force Recorder (AXPERT-ISO 9001 company, Ahmadabad, India). The bite force values for each patient for the fractured and non-fractured sites were normalized using the following formula to obtain a single value per patient as a ratio: (Non-fractured value– Fractured value) / Fractured value Intra-operative and post-operative complications were duly noted. Statistical analysis of the obtained data was done with one-way ANOVA (variance analysis) using SPSS 2.0 software.
2.2. Surgical procedure
3. Results
The surgical site was aseptically prepared, isolated with drapes and infiltrated with local anesthesia. A transoral approach was used in all
A total of 24 subjects (22 males, 2 females), aged 19–48 years (mean 27.9 ± 6.9 years) with isolated mandibular angle fractures underwent
Antibiotics and analgesics were prescribed for 5 post-operative days and maxillo-mandibular fixation (MMF) using light elastics was maintained for 7 post-operative days. The patients were advised a soft diet for one month following release of MMF. 2.4. Assessment
Fig. 1. Group A: Post-operative orthopantomogram showing 2D 4-holed miniplate fixation. 2
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Fig. 2. Group B: Post-operative orthopantomogram showing 3D 4-holed miniplate fixation.
ORIF on an out-patient basis under local anesthesia. Mean duration from injury to surgery was 1.7 ± 1.1 days. 17 of these fractured sites were on the left side, while the rest (n = 7) were on the right side (Table 1). There was no significant difference among the three study groups in terms of pre-operative variables like sex ratio, mean age and duration between injury and surgery. Mean pain scores on the first post-operative day were 4.25, 4.25 and 4.14 for Group A, B and C, respectively (p = 0.985). These values were seen to decrease gradually over time with mean values of 1.63, 1.88 and 1.71 respectively, seen at 1 week follow up (p = 0.881), further dropping to a mean of 0.25, 0.88 and 0.86 respectively one month after the surgery (p = 0.294). The difference in the mean pain score among the three groups was found to be statistically insignificant at all time intervals (p > 0.05) (Table 2). One week following release of MMF, the mean inter-incisal opening value was found to be greater in Group B (mean = 23.88 mm) than that seen in Group A (mean = 18.88 mm) and Group C (mean = 12.71 mm) patients. The difference between the mean inter-incisal opening values in Group B and Group C was found to be statistically significant (p = 0.004). On all subsequent follow-up visits, however, no significant difference was seen in the inter-incisal opening among the three groups (p > 0.05). Overall, inter-incisal opening showed a gradual increase over time and by 6 months, all patients had attained a mouth opening of ≥ 35 mm. The mean protrusive movement seen 1 week after the release of MMF was 2, 2.5 and 1.43 mm in Groups A, B and C respectively, which gradually increased to 3.38, 4.75, 3.57 mm respectively at the 1-month post-operative visit. These values further increased to 5.5, 5.88 and 4.7
Table 1 Patient Distribution. PATIENT No.
AGE (years)
SEX
SITE
GROUP
ΔT (days)
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
23 28 22 29 22 35 25 34 22 26 24 33 26 48 32 23 21 27 25 29 19 43 27 26
M M M M F M M M M M M F M M M M M M M M M M M M
L L R L L L L R L L R L L L R R R L L L L R L L
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
2 2 1 0 3 1 1 1 2 2 1 1 2 4 2 0 2 1 3 2 0 4 1 2
Abbreviations: M = Male; F = Female; L = Left; R = Right. ΔT = Time difference between injury and surgery.
Fig. 3. Group C: Post-operative orthopantomogram showing 3D 8-holed miniplate fixation. 3
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Table 2 Mean Pain Scores.
Table 5 Mean Bite Force (Ratio) (Non-Fractured – Fractured Side) / Fractured Side.
GROUP
1 DAY
1 WEEK
1 MONTH
GROUP
1 WEEK
1 MONTH
6 MONTHS
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
4.25 4.25 4.14 4.21 0.985
1.63 1.88 1.71 1.75 0.881
0.25 0.88 0.86 0.62 0.294
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
0.23 ± 0.22 −0.51 ± 1.20 0.09 ± 0.38 −0.06 ± 0.09 0.131
0.28 ± 0.11 0.15 ± 0.20 0.19 ± 0.26 0.21 ± 0.19 0.441
0.12 ± 0.24 0.03 ± 0.05 0.02 ± 0.07 0.06 ± 0.15 0.422
intra-orally 18 months post-surgery. For its management, the plate and screws were removed under local anesthesia. No surgical site infection or malocclusion was encountered in any patient in the study.
Table 3 Mean Protrusive Movement (in millimetres). GROUP
1 WEEK
1 MONTH
6 MONTHS
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
2 2.5 1.43 1.96 ± 1.3 > 0.05
3.38 4.75 3.57 3.92 ± 1.9 > 0.05
5.50 5.88 4.70 5.33 ± 2.3 > 0.05
4. Discussion The basic concept of 3D plate fixation is that a geometrically closed quadrangular plate secured with bone screws creates stability in three dimensions. The stability is gained over a defined surface area and is achieved by the configuration of the plate, not by its thickness or length. The large free areas between the plate arms and lesser dissection required to fix such a plate permit a generous vascular supply to the underlying bone. Overall, the advantages of 3D miniplates include: 1) Ease of operation due to compact design, 2) more resistance to the torqueing forces which helps in reducing bulk of the plates and 3) requirement of fewer screws and plates compared to conventional miniplates, hence lesser foreign material, lower risk of infection and reduced expense [9]. Studies have reported favourable outcomes with 3D plate fixation for management of mandibular angle fractures, with the added advantage of a low complication rate [11]. However, certain other studies have proven Champy’s miniplates to be superior and easier to fix than 3D grid plates, which were difficult to adapt and unfavourable for use in oblique fractures [12]. The authors of the current study, thus, felt that a comparative analysis was warranted evaluating the functional outcome achieved following ORIF using the conventional and the 3D systems in terms of post-operative pain, inter-incisal opening, range of motion, bite force and incidence of complications.
mm respectively six months after the surgery. Overall, mean maximum protrusion values recorded were highest for Group B at all stages of measurement, but the difference in mean values among the three groups was not statistically significant (p > 0.05) (Table 3). Laterotrusive movements were expressed for each patient in millimetres (as non-fractured value – fractured value) and the mean values were seen to steadily and gradually increase over time for all groups (Table 1). On comparing the difference between lateral movement towards the affected side and the contra-lateral side, it was found that greater movement was seen towards the affected side (net negative value) in Group A and B patients, a difference that persisted in Group A cases but waned off in Group B cases. In Group C, however, both sides showed similar amounts of movement throughout the six post-operative months. Overall, there was no statistically significant difference in the mean laterotrusive values among the three groups at any stage of follow-up (p > 0.05) (Table 4). Bite force values were calculated as a normalized ratio at each visit. The mean maximum bite force value 1-week post MMF release was greater in Group B (-0.51) than Group A (0.23) and Group C (0.09) (Table 5), but this difference was statistically insignificant (p = 0.131). At all subsequent visits, the bite force values were found to be similar for all groups (p > 0.05), with a mean value of 0.21 at one month and 0.06 at six months (n = 24). The incidence of complications encountered was maximum for Group B (25 %; n = 2), compared to 12.5 % for Group C (n = 1). No intra- or post-operative complications were encountered in Group A. In one patient of Group B, a screw was found to have been erroneously placed outside the screw hole of the miniplate in the post-operative radiograph (Fig. 4). This patient was re-operated, and the screw position was corrected. In yet another patient of Group B, the entire miniplate was found to have been fixed in the proximal fractured segment (Fig. 5). This was confirmed by using 2 radiographs in perpendicular planes using an OPG and a PA view of mandible. The incorrectly placed hardware was subsequently removed and re-fixed in the correct position under local anesthesia. In Group C, an exposed screw was seen
4.1. Pain There was a steady decline in the mean pain scores with time for patients of all three groups, with an overall reduction of 84.6 % over a period of 30 days (mean pain score at 1 month = 0.65, n = 24). Among the three study groups, the pain scores were comparable at all stages of follow-up, the difference in mean scores being statistically insignificant (p > 0.05), suggesting that by 1 month, all patients are largely painfree, irrespective of the fixation technique. The results of the current study were discordant with those documented by Hofer, who favoured 3D 4-holed plates over the conventional 2D system using pain as one of the parameters for assessment, concluding that isolated mandibular angle fractures can be more effectively treated using a grid plate than other techniques [13]. Yet another study, however, supported the Champy’s miniplate system owing to its ease of handling and less patient discomfort [12]. In spite of the varying results comparing postoperative pain between the two systems, it was found that the average pain score values obtained for the 3D plating system in the present study at different visits were similar to those reported by other authors who evaluated post-operative pain following ORIF of mandibular angle fractures with 3D miniplates. For instance in a study on fixation using 3D 8-holed threadlock plates, the average 1 week post-operative pain score recorded was 1.90 (n = 10) [14] while in the present study this value was 1.71 (n = 8, Group C). At 2 weeks, this score in Melek’s study had reduced to a mean of 0.70, similar to the observed mean pain score of 0.65 at 4 weeks in the present study. The trend of post-operative pain reduction for the 2D miniplate group was also in agreement with other studies of its kind, reporting significant pain reduction by 2 weeks and
Table 4 Mean Laterotrusive Movement (in millimetres) (Non-Fractured – Fractured Side). GROUP
1 WEEK
1 MONTH
6 MONTHS
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
−1.50 ± 1.77 −2.37 ± 2.77 0.42 ± 2.29 −1.21 ± 2.50 0.083
−1.62 ± 2.32 −1.75 ± 2.18 0.28 ± 1.49 −1.08 ± 2.17 0.132
−1.75 ± 0.88 −0.87 ± 2.41 −0.14 ± 1.77 −0.95 ± 1.84 0.249
4
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Fig. 4. Complication 1: Improper screw placement in Group B patient.
4.3. Range of motion
lack of pain by 8 weeks [15].
In the current cohort of patients, no significant difference among the three groups was found for mean maximum protrusive and lateral movements at any post-operative visit (p > 0.05). While a comparative assessment of the three study groups failed to yield a superior fixation technique in terms of yielding a better range of motion, a notable observation was that remarkable improvement was seen with time in maximum excursion values for all patients, with a 78.7 % increase in mean maximum protrusion over six months (mean value at 1 week =3 mm, six months =5.36 mm, n = 24). A similar rise was also seen for lateral excursions, suggesting that regardless of the plating system, internal fixation of the fracture site led to a considerable and steady improvement in the range of mandibular movements, and adequate functional rehabilitation. Although the post-surgical range of motion achieved is an important criterion to assess functional rehabilitation following ORIF, the authors could not find any study which compared this parameter among different ORIF systems.
4.2. Inter-incisal opening Analysis of the inter-incisal opening at 1-week post-MMF release showed a statistically significant difference (p = 0.004) between the mean maximum values obtained for Group B and Group C, with considerable trismus observed with the 3D 8-holed plate patients. This might be attributed to stripping of muscles over a broader surface area of mandible and muscle fatigue following excessive retraction for fixation of the larger spanning 3D 8-hole plates, and subsequently greater post-surgical edema and muscle spasm. On all subsequent visits, however, the inter-incisal opening was found to steadily increase, with no significant difference among the three groups (p > 0.05), suggesting favourable post-surgical healing. Six months after the surgery, all patients had attained a inter-incisal opening of > 35 mm. Dissimilar results were reported in a study which showed that one month post-operatively, 4 out of the 10 patients treated with the conventional 2D plating system had an inadequate inter-incisal opening (< 30 mm), compared to none in the 3D plating system group [10]. However, it must be emphasized that post-operative trismus, or lack thereof, is a function of not only the configuration of the hardware used, but also several other factors including intra-operative tissue handling, patient compliance with jaw physiotherapy, duration of the surgery, among others.
4.4. Bite force Bite force analysis for the 3D 4-holed miniplate group in the current study showed a net negative mean value 1-week post-MMF release (-0.51), suggesting a larger early bite force on the operated site compared to the contralateral side. In contrast, mean values for the other Group A and Group C, however, showed a positive value (0.23 and
Fig. 5. Complication 2: Improper miniplate fixation in Group B patient. 5
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0.09, respectively), suggesting greater forces achieved on the operated site. The overall mean bite force achieved at this stage for all 24 patients, however, was greater for the fractured side (-0.06). Nevertheless, the difference in mean bite force values among the three groups was not statistically significant (p > 0.05) at any post-operative visit. Normalization of bite force values was done in this study to offer a single, adjusted value, bearing in mind the differences in the force values between the fractured and non-fractured sides. While studying the individual measurements for either side, however, a steady and significant improvement in bite force values seen over the six post-operative months. This gradual increase in bite force values was in agreement with other similar studies, which also established that following ORIF with the 2D system, a slight reduction in load bearing at the fractured side occurs up until 1 month compared to the non-fractured side but with no statistically significant difference [16]. The complications encountered in the current study were greatest in number for the 3D 4-holed miniplate group (25 %, n = 2), both cases requiring re-surgery and added surgical morbidity, compared to lower complication rates for Group C (12.5 %, n = 1) and Group A (0 %). However, while these numbers imply that 3D plates are an inferior fixation system, the authors find it imperative to highlight that such complications should be attributed more to poor visibility or misjudgment of the surgeon than the implant system itself.
[2]
[3]
[4]
[5]
[6]
[7]
[8] [9]
[10]
[11]
5. Conclusion The present study concluded that the conventional 2D miniplate system still holds its place as the method of choice for management of isolated mandibular angle fractures owing to its ease of handling, ease of fixation, lower hardware requirement and lower incidence of complications. The 3D 4-holed and 8-holed systems are tedious to use, require greater access, necessitate more muscle stripping and amount of hardware and additional instrumentation, with no significant added advantage. Further prospective studies with a larger sample size are recommended to reinforce this deduction.
[12]
[13]
[14]
[15]
Acknowledgements [16]
None. References [1] Olson RA, Fonseca RJ, Zeitler DL, Osbon DB. Fractures of the mandible: a review of
6
580 cases. J Oral Maxillofac Surg 1982;40(January (1)):23–8. https://doi.org/10. 1016/S0278-2391(82)80011-6. Fridrich KL, Pena-Velasco G, Olson RA. Changing trends with mandibular fractures: a review of 1,067 cases. J Oral Maxillofac Surg 1992;50(June (6)):586–9. https:// doi.org/10.1016/0278-2391(92)90438-6. Champy M, Lodde JP. Mandibular synthesis. Placement of the synthesis as a function of mandibular stress. Rev Stomatol Chir Maxillofac 1976;77(December (8)):971–6. PMID:1071237. Kroon H, Mathisson M, Cordey JR, Rahn BA. The use of miniplates in mandibular fractures. J Craniomaxillofac Surg 1991;19(July (5)):199–204. https://doi.org/10. 1016/S1010-5182(05)80547-5. Choi BH, Yoo JH, Kim KN, Kang HS. Stability testing of a two miniplate fixation technique for mandibular angle fractures. An in vitro study. J Craniomaxillofac Surg 1995;23(April (2)):122–5. https://doi.org/10.1016/S1010-5182(05)80460-3. Haug RH, Fattahi TT, Goltz M. A biomechanical evaluation of mandibular angle fracture plating techniques. J Oral Maxillofac Surg 2001;59(October (10)):1199–210. https://doi.org/10.1053/joms.2001.26726. Ellis III E. A prospective study of 3 treatment methods for isolated fractures of the mandibular angle. J Oral Maxillofac Surg 2010;68(November (11)):2743–54. https://doi.org/10.1016/S0901-5027(99)80152-0. Farmand M, Dupoirieux L. The value of 3- dimensional plates in maxillofacial surgery. Rev Stomatol Chir Maxillofac 1992;93(6):353–7. PMID:1475603. Zix J, Lieger O, Iizuka T. Use of straight and curved 3-Dimensional titanium miniplates for fracture fixation at the mandibular angle. J Oral Maxillofac Surg 2007;65(September (9)):1758–63. https://doi.org/10.1016/j.joms.2007.03.013. Vineeth K, Lalitha RM, Prasad K, Ranganath K, Shwetha V, Singh J. “A comparative evaluation between single noncompression titanium miniplate and three-dimensional titanium miniplate in treatment of mandibular angle fracture” - A randomized prospective study. J Craniomaxillofac Surg 2013;41(March (2)):103–9. https://doi.org/10.1016/j.jcms.2012.05.015. Alkan A, Celebi N, Ozden B, Bas B, Inai S. Biomechanical comparison of different plating techniques in repair of mandibular angle fractures. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104(December (6)):752–6. https://doi.org/10. 1016/j.tripleo.2007.03.014. Jain MK, Manjunath KS, Bhagwan BK, Shah DK. Comparison of 3-Dimensional and standard miniplate fixation in the management of mandibular fractures. J Oral Maxillofac Surg 2010;68(July (7)):1568–72. https://doi.org/10.1016/j.joms.2009. 07.083. Höfer SH, Ha L, Ballon A, Sader R, Landes C. Treatment of mandibular angle fractures - Linea obliqua plate versus grid plate. J Craniomaxillofac Surg 2012;40(December (8)):807–11. https://doi.org/10.1016/j.jcms.2012.02.021. Melek LN, El Mahallawy AS, Sharara AA. Evaluation of the 3-dimensional threadlock plate in the management of mandibular angle fractures: a clinical and radiographic study. Tanta Dent J 2015;12(June (2)):140–8. https://doi.org/10.1016/j. tdj.2015.05.001. Elsayed SA, Mohamed FI, Khalifa GA. Clinical outcomes of three different types of hardware for the treatment of mandibular angle fractures: a comparative retrospective study. Int J Oral Maxillofac Surg 2015;44(October (10)):1260–7. https:// doi.org/10.1016/j.ijom.2015.07.005. Gerlach KL, Schwarz A. Bite forces in patients after treatment of mandibular angle fractures with miniplate osteosynthesis according to Champy. Int J Oral Maxillofac Surg 2002;31(August (4)):345–8. https://doi.org/10.1054/ijom.2002.0290.
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Original Research
Conventional 2D miniplate versus 3D four-holed and eight-holed miniplates in the management of mandibular angle fractures Sandeep Yadav, Sujata Mohanty*, Pankaj Sharma, Sanchaita Kohli, Chandravir Singh, Jitender Dabas Department of Oral and Maxillofacial Surgery, Maulana Azad Institute of Dental Sciences, MAMC Complex, Bahadur Shah Zafar Marg, New Delhi, 110002, India
A R T I C LE I N FO
A B S T R A C T
Keywords: Angle fracture Miniplates 3D plates Three dimensional plates Mandible fracture
Objective: To compare the efficacy of conventional 2D miniplate with 3D 4-hole and 8-hole miniplates in the management of mandibular angle fractures. Methods: A prospective study was conducted on 24 patients with isolated mandibular angle fractures that were divided into three following groups (n = 8 each) based on the osteosynthesis technique used: Group A- conventional 2D four-holed miniplate Group B- 3D- 4-holed miniplate Group C- 3D- 8-holed miniplate Post-operative pain, inter-incisal opening, range of motion, bite force and incidence of complications were assessed at various time intervals up to a period of six months. Results: A steady improvement in all parameters was seen in the three groups over six months. A significantly greater amount of 1 week post-operative trismus was observed in the 8-holed miniplate group (p < 0.05). Six months after the surgery, however, the difference in pain, inter-incisal opening, range of motion and bite force among the three groups was found to be statistically insignificant (p > 0.05). The incidence of complications was greatest in Group B (25 %). Conclusion: The conventional 2D miniplate system still holds its place as the method of choice for management of mandibular angle fractures.
1. Introduction Road traffic accidents, violence and sports injuries have had an alarming rise in the past two decades. Maxillofacial trauma is a prominent component of these accidents, with the mandible being one of the most commonly involved bone due to its forward facial projection. The mandibular angle in particular is the most commonly fractured region, accounting for approximately 30 % of all mandibular fractures [1,2]. The contemporary management of mandibular angle fractures is Open Reduction and Internal Fixation (ORIF) using one of the several available osteosynthesis techniques. A single 2.0 mm miniplate fixation at the superior border has long been the most popular of these techniques, being based on Champy’s recommendation of hardware fixation solely over the zone of tensile forces in the mandibular angle region, that being the superior border [3]. Analysis of the biomechanics of the mandible, however, shows that when the masticatory force is close to the fracture line, a reversal of the
lines of tension and compression occurs with a tendency of the fracture line to open at the inferior border [4]. Consequently, many surgeons began advocating fixation using 2 miniplates (1 at the superior and another at the inferior border) [5,6] or using a load bearing plate at the lower border. Other surgeons reported a greater incidence of biological complications (28 %) in an attempt to achieve this superior stability at the mandibular angle using 2 miniplate osteosynthesis, discouraging this technique [7]. This sequence of events led to the conundrum that is the fixation of mandibular angle fractures, with no foreseeable consensus on a single osteosynthesis technique, as each technique is fraught with its own set of pros and cons. To this end, a novel plate design was introduced in 1992, namely, the three-dimensional (3D) or matrix plate [8] to integrate the advantages of both techniques whilst alleviating their shortcomings. It includes a straight or curved ladder plate that is fixed along the lateral surface of the mandibular angle. Such plates have been found to have more resistance than the conventional miniplates against the out-of-plane movements at the fracture
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Corresponding author. E-mail addresses: [email protected] (S. Yadav), [email protected] (S. Mohanty), [email protected] (P. Sharma), [email protected] (S. Kohli), [email protected] (C. Singh), [email protected] (J. Dabas). https://doi.org/10.1016/j.ajoms.2019.12.003 Received 12 September 2019; Received in revised form 1 December 2019; Accepted 10 December 2019 2212-5558/ © 2019 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd All rights reserved.
Please cite this article as: Sandeep Yadav, et al., Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology, https://doi.org/10.1016/j.ajoms.2019.12.003
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line [9]. The ultimate goal for any fixation technique is to ensure a stable, harmonious occlusion and optimum post-operative masticatory function. In spite of numerous studies comparing the conventional 2D and 3D systems of osteosynthesis, the literature discussing post-surgical bite force achieved with these techniques is still sparse for mandibular angle fractures. Other parameters aiding in favourable functional rehabilitation viz. inter-incisal opening and range of mandibular movements have also been sparingly studied. The aim of the current study was, therefore, to evaluate and compare the functional outcome achieved among three study groups i.e. conventional 2D and 4- and 8holed 3D miniplates, in terms of post-operative pain, maximum interincisal opening, excursive movements and bite force.
cases to access the fractured site, where the incision was placed extending from the buccal alveolar mucosa adjacent to the mandibular second molar up to the anterior border of ramus. A mucoperiosteal flap was raised to expose the fracture line till the inferior border of the mandible. After anatomical reduction of the fractured segments, a 2D miniplate was fixed along the external oblique ridge at the superior border of the ramus in Group A cases (Fig. 1) while the 4- and 8- holed 3D miniplates (in Group B and C respectively) were fixed on the lateral surface of mandible in such a way that the horizontal cross bars were perpendicular to the fracture line and vertical cross bars were parallel to it [10] (Figs. 2 and 3). While fixing the 3D plates, an extra-oral stab incision was additionally placed to facilitate drilling and fixation of screws using a trans-buccal trocar and cannula. In all cases, a 2 mm non-locking plating system was used with screws of length 8 mm. All surgeries were performed by a single surgeon, i.e., the senior author (b).
2. Material and methods 2.1. Study Design
2.3. Post-operative Period A prospective comparative study was designed wherein all cases of favorable and unfavorable (vertical and horizontal) isolated mandibular angle fractures reporting to the author’s department (between October 2013 to October 2015) were planned for open reduction and internal fixation (ORIF). The diagnosis of mandibular angle fracture was established with the help of a thorough clinical examination and radiographical examination using an orthopantomogram (OPG) and a postero-anterior (PA) view of the mandible. Included were all patients ≥15 years of age, with a healthy dentition, reporting within one week of trauma. Cases with other concomitant mandibular fractures, bony or soft tissue defects, severe comminution and/or infection, edentulism, pathological fractures, pan-facial trauma and systemic illnesses precluding optimum wound healing were excluded from the study. Selected cases were randomly divided (using the block randomization technique) into three groups i.e. A, B and C, based on the osteosynthesis technique to be used: Group A: Conventional 2D 4-holed miniplate fixation on the superior border of the mandibular ramus (Fig. 1) Group B: 3D 4-holed miniplate fixation over the lateral surface of the mandibular ramus (Fig. 2) Group C: 3D 8-holed miniplate fixation on the lateral surface of the mandibular ramus (Fig. 3) Ethical approval was obtained from the institutional review board and a written informed consent was provided by all patients recruited in the study.
Parameters including post-operative pain, inter-incisal opening, mandibular range of motion (protrusion and laterotrusion) and bite force were measured at various time intervals post-operatively. Postoperative OPG was done for all patients to assess the adequacy of plate fixation. All patients were followed up for a minimum of 6 months. Pain was assessed using the Numerical Rating Scale (0–10) on post-operative day 1, day 7 and day 30. Inter-incisal opening and range of motion were measured in millimeters using calipers 1 week, 1 month and 6 months after release of MMF. Bite force (in kg) was recorded on the same visits using the Digital Bite Force Recorder (AXPERT-ISO 9001 company, Ahmadabad, India). The bite force values for each patient for the fractured and non-fractured sites were normalized using the following formula to obtain a single value per patient as a ratio: (Non-fractured value– Fractured value) / Fractured value Intra-operative and post-operative complications were duly noted. Statistical analysis of the obtained data was done with one-way ANOVA (variance analysis) using SPSS 2.0 software.
2.2. Surgical procedure
3. Results
The surgical site was aseptically prepared, isolated with drapes and infiltrated with local anesthesia. A transoral approach was used in all
A total of 24 subjects (22 males, 2 females), aged 19–48 years (mean 27.9 ± 6.9 years) with isolated mandibular angle fractures underwent
Antibiotics and analgesics were prescribed for 5 post-operative days and maxillo-mandibular fixation (MMF) using light elastics was maintained for 7 post-operative days. The patients were advised a soft diet for one month following release of MMF. 2.4. Assessment
Fig. 1. Group A: Post-operative orthopantomogram showing 2D 4-holed miniplate fixation. 2
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Fig. 2. Group B: Post-operative orthopantomogram showing 3D 4-holed miniplate fixation.
ORIF on an out-patient basis under local anesthesia. Mean duration from injury to surgery was 1.7 ± 1.1 days. 17 of these fractured sites were on the left side, while the rest (n = 7) were on the right side (Table 1). There was no significant difference among the three study groups in terms of pre-operative variables like sex ratio, mean age and duration between injury and surgery. Mean pain scores on the first post-operative day were 4.25, 4.25 and 4.14 for Group A, B and C, respectively (p = 0.985). These values were seen to decrease gradually over time with mean values of 1.63, 1.88 and 1.71 respectively, seen at 1 week follow up (p = 0.881), further dropping to a mean of 0.25, 0.88 and 0.86 respectively one month after the surgery (p = 0.294). The difference in the mean pain score among the three groups was found to be statistically insignificant at all time intervals (p > 0.05) (Table 2). One week following release of MMF, the mean inter-incisal opening value was found to be greater in Group B (mean = 23.88 mm) than that seen in Group A (mean = 18.88 mm) and Group C (mean = 12.71 mm) patients. The difference between the mean inter-incisal opening values in Group B and Group C was found to be statistically significant (p = 0.004). On all subsequent follow-up visits, however, no significant difference was seen in the inter-incisal opening among the three groups (p > 0.05). Overall, inter-incisal opening showed a gradual increase over time and by 6 months, all patients had attained a mouth opening of ≥ 35 mm. The mean protrusive movement seen 1 week after the release of MMF was 2, 2.5 and 1.43 mm in Groups A, B and C respectively, which gradually increased to 3.38, 4.75, 3.57 mm respectively at the 1-month post-operative visit. These values further increased to 5.5, 5.88 and 4.7
Table 1 Patient Distribution. PATIENT No.
AGE (years)
SEX
SITE
GROUP
ΔT (days)
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
23 28 22 29 22 35 25 34 22 26 24 33 26 48 32 23 21 27 25 29 19 43 27 26
M M M M F M M M M M M F M M M M M M M M M M M M
L L R L L L L R L L R L L L R R R L L L L R L L
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
2 2 1 0 3 1 1 1 2 2 1 1 2 4 2 0 2 1 3 2 0 4 1 2
Abbreviations: M = Male; F = Female; L = Left; R = Right. ΔT = Time difference between injury and surgery.
Fig. 3. Group C: Post-operative orthopantomogram showing 3D 8-holed miniplate fixation. 3
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Table 2 Mean Pain Scores.
Table 5 Mean Bite Force (Ratio) (Non-Fractured – Fractured Side) / Fractured Side.
GROUP
1 DAY
1 WEEK
1 MONTH
GROUP
1 WEEK
1 MONTH
6 MONTHS
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
4.25 4.25 4.14 4.21 0.985
1.63 1.88 1.71 1.75 0.881
0.25 0.88 0.86 0.62 0.294
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
0.23 ± 0.22 −0.51 ± 1.20 0.09 ± 0.38 −0.06 ± 0.09 0.131
0.28 ± 0.11 0.15 ± 0.20 0.19 ± 0.26 0.21 ± 0.19 0.441
0.12 ± 0.24 0.03 ± 0.05 0.02 ± 0.07 0.06 ± 0.15 0.422
intra-orally 18 months post-surgery. For its management, the plate and screws were removed under local anesthesia. No surgical site infection or malocclusion was encountered in any patient in the study.
Table 3 Mean Protrusive Movement (in millimetres). GROUP
1 WEEK
1 MONTH
6 MONTHS
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
2 2.5 1.43 1.96 ± 1.3 > 0.05
3.38 4.75 3.57 3.92 ± 1.9 > 0.05
5.50 5.88 4.70 5.33 ± 2.3 > 0.05
4. Discussion The basic concept of 3D plate fixation is that a geometrically closed quadrangular plate secured with bone screws creates stability in three dimensions. The stability is gained over a defined surface area and is achieved by the configuration of the plate, not by its thickness or length. The large free areas between the plate arms and lesser dissection required to fix such a plate permit a generous vascular supply to the underlying bone. Overall, the advantages of 3D miniplates include: 1) Ease of operation due to compact design, 2) more resistance to the torqueing forces which helps in reducing bulk of the plates and 3) requirement of fewer screws and plates compared to conventional miniplates, hence lesser foreign material, lower risk of infection and reduced expense [9]. Studies have reported favourable outcomes with 3D plate fixation for management of mandibular angle fractures, with the added advantage of a low complication rate [11]. However, certain other studies have proven Champy’s miniplates to be superior and easier to fix than 3D grid plates, which were difficult to adapt and unfavourable for use in oblique fractures [12]. The authors of the current study, thus, felt that a comparative analysis was warranted evaluating the functional outcome achieved following ORIF using the conventional and the 3D systems in terms of post-operative pain, inter-incisal opening, range of motion, bite force and incidence of complications.
mm respectively six months after the surgery. Overall, mean maximum protrusion values recorded were highest for Group B at all stages of measurement, but the difference in mean values among the three groups was not statistically significant (p > 0.05) (Table 3). Laterotrusive movements were expressed for each patient in millimetres (as non-fractured value – fractured value) and the mean values were seen to steadily and gradually increase over time for all groups (Table 1). On comparing the difference between lateral movement towards the affected side and the contra-lateral side, it was found that greater movement was seen towards the affected side (net negative value) in Group A and B patients, a difference that persisted in Group A cases but waned off in Group B cases. In Group C, however, both sides showed similar amounts of movement throughout the six post-operative months. Overall, there was no statistically significant difference in the mean laterotrusive values among the three groups at any stage of follow-up (p > 0.05) (Table 4). Bite force values were calculated as a normalized ratio at each visit. The mean maximum bite force value 1-week post MMF release was greater in Group B (-0.51) than Group A (0.23) and Group C (0.09) (Table 5), but this difference was statistically insignificant (p = 0.131). At all subsequent visits, the bite force values were found to be similar for all groups (p > 0.05), with a mean value of 0.21 at one month and 0.06 at six months (n = 24). The incidence of complications encountered was maximum for Group B (25 %; n = 2), compared to 12.5 % for Group C (n = 1). No intra- or post-operative complications were encountered in Group A. In one patient of Group B, a screw was found to have been erroneously placed outside the screw hole of the miniplate in the post-operative radiograph (Fig. 4). This patient was re-operated, and the screw position was corrected. In yet another patient of Group B, the entire miniplate was found to have been fixed in the proximal fractured segment (Fig. 5). This was confirmed by using 2 radiographs in perpendicular planes using an OPG and a PA view of mandible. The incorrectly placed hardware was subsequently removed and re-fixed in the correct position under local anesthesia. In Group C, an exposed screw was seen
4.1. Pain There was a steady decline in the mean pain scores with time for patients of all three groups, with an overall reduction of 84.6 % over a period of 30 days (mean pain score at 1 month = 0.65, n = 24). Among the three study groups, the pain scores were comparable at all stages of follow-up, the difference in mean scores being statistically insignificant (p > 0.05), suggesting that by 1 month, all patients are largely painfree, irrespective of the fixation technique. The results of the current study were discordant with those documented by Hofer, who favoured 3D 4-holed plates over the conventional 2D system using pain as one of the parameters for assessment, concluding that isolated mandibular angle fractures can be more effectively treated using a grid plate than other techniques [13]. Yet another study, however, supported the Champy’s miniplate system owing to its ease of handling and less patient discomfort [12]. In spite of the varying results comparing postoperative pain between the two systems, it was found that the average pain score values obtained for the 3D plating system in the present study at different visits were similar to those reported by other authors who evaluated post-operative pain following ORIF of mandibular angle fractures with 3D miniplates. For instance in a study on fixation using 3D 8-holed threadlock plates, the average 1 week post-operative pain score recorded was 1.90 (n = 10) [14] while in the present study this value was 1.71 (n = 8, Group C). At 2 weeks, this score in Melek’s study had reduced to a mean of 0.70, similar to the observed mean pain score of 0.65 at 4 weeks in the present study. The trend of post-operative pain reduction for the 2D miniplate group was also in agreement with other studies of its kind, reporting significant pain reduction by 2 weeks and
Table 4 Mean Laterotrusive Movement (in millimetres) (Non-Fractured – Fractured Side). GROUP
1 WEEK
1 MONTH
6 MONTHS
GROUP A (n = 8) GROUP B (n = 8) GROUP C (n = 8) TOTAL (n = 24) P value
−1.50 ± 1.77 −2.37 ± 2.77 0.42 ± 2.29 −1.21 ± 2.50 0.083
−1.62 ± 2.32 −1.75 ± 2.18 0.28 ± 1.49 −1.08 ± 2.17 0.132
−1.75 ± 0.88 −0.87 ± 2.41 −0.14 ± 1.77 −0.95 ± 1.84 0.249
4
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Fig. 4. Complication 1: Improper screw placement in Group B patient.
4.3. Range of motion
lack of pain by 8 weeks [15].
In the current cohort of patients, no significant difference among the three groups was found for mean maximum protrusive and lateral movements at any post-operative visit (p > 0.05). While a comparative assessment of the three study groups failed to yield a superior fixation technique in terms of yielding a better range of motion, a notable observation was that remarkable improvement was seen with time in maximum excursion values for all patients, with a 78.7 % increase in mean maximum protrusion over six months (mean value at 1 week =3 mm, six months =5.36 mm, n = 24). A similar rise was also seen for lateral excursions, suggesting that regardless of the plating system, internal fixation of the fracture site led to a considerable and steady improvement in the range of mandibular movements, and adequate functional rehabilitation. Although the post-surgical range of motion achieved is an important criterion to assess functional rehabilitation following ORIF, the authors could not find any study which compared this parameter among different ORIF systems.
4.2. Inter-incisal opening Analysis of the inter-incisal opening at 1-week post-MMF release showed a statistically significant difference (p = 0.004) between the mean maximum values obtained for Group B and Group C, with considerable trismus observed with the 3D 8-holed plate patients. This might be attributed to stripping of muscles over a broader surface area of mandible and muscle fatigue following excessive retraction for fixation of the larger spanning 3D 8-hole plates, and subsequently greater post-surgical edema and muscle spasm. On all subsequent visits, however, the inter-incisal opening was found to steadily increase, with no significant difference among the three groups (p > 0.05), suggesting favourable post-surgical healing. Six months after the surgery, all patients had attained a inter-incisal opening of > 35 mm. Dissimilar results were reported in a study which showed that one month post-operatively, 4 out of the 10 patients treated with the conventional 2D plating system had an inadequate inter-incisal opening (< 30 mm), compared to none in the 3D plating system group [10]. However, it must be emphasized that post-operative trismus, or lack thereof, is a function of not only the configuration of the hardware used, but also several other factors including intra-operative tissue handling, patient compliance with jaw physiotherapy, duration of the surgery, among others.
4.4. Bite force Bite force analysis for the 3D 4-holed miniplate group in the current study showed a net negative mean value 1-week post-MMF release (-0.51), suggesting a larger early bite force on the operated site compared to the contralateral side. In contrast, mean values for the other Group A and Group C, however, showed a positive value (0.23 and
Fig. 5. Complication 2: Improper miniplate fixation in Group B patient. 5
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0.09, respectively), suggesting greater forces achieved on the operated site. The overall mean bite force achieved at this stage for all 24 patients, however, was greater for the fractured side (-0.06). Nevertheless, the difference in mean bite force values among the three groups was not statistically significant (p > 0.05) at any post-operative visit. Normalization of bite force values was done in this study to offer a single, adjusted value, bearing in mind the differences in the force values between the fractured and non-fractured sides. While studying the individual measurements for either side, however, a steady and significant improvement in bite force values seen over the six post-operative months. This gradual increase in bite force values was in agreement with other similar studies, which also established that following ORIF with the 2D system, a slight reduction in load bearing at the fractured side occurs up until 1 month compared to the non-fractured side but with no statistically significant difference [16]. The complications encountered in the current study were greatest in number for the 3D 4-holed miniplate group (25 %, n = 2), both cases requiring re-surgery and added surgical morbidity, compared to lower complication rates for Group C (12.5 %, n = 1) and Group A (0 %). However, while these numbers imply that 3D plates are an inferior fixation system, the authors find it imperative to highlight that such complications should be attributed more to poor visibility or misjudgment of the surgeon than the implant system itself.
[2]
[3]
[4]
[5]
[6]
[7]
[8] [9]
[10]
[11]
5. Conclusion The present study concluded that the conventional 2D miniplate system still holds its place as the method of choice for management of isolated mandibular angle fractures owing to its ease of handling, ease of fixation, lower hardware requirement and lower incidence of complications. The 3D 4-holed and 8-holed systems are tedious to use, require greater access, necessitate more muscle stripping and amount of hardware and additional instrumentation, with no significant added advantage. Further prospective studies with a larger sample size are recommended to reinforce this deduction.
[12]
[13]
[14]
[15]
Acknowledgements [16]
None. References [1] Olson RA, Fonseca RJ, Zeitler DL, Osbon DB. Fractures of the mandible: a review of
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580 cases. J Oral Maxillofac Surg 1982;40(January (1)):23–8. https://doi.org/10. 1016/S0278-2391(82)80011-6. Fridrich KL, Pena-Velasco G, Olson RA. Changing trends with mandibular fractures: a review of 1,067 cases. J Oral Maxillofac Surg 1992;50(June (6)):586–9. https:// doi.org/10.1016/0278-2391(92)90438-6. Champy M, Lodde JP. Mandibular synthesis. Placement of the synthesis as a function of mandibular stress. Rev Stomatol Chir Maxillofac 1976;77(December (8)):971–6. PMID:1071237. Kroon H, Mathisson M, Cordey JR, Rahn BA. The use of miniplates in mandibular fractures. J Craniomaxillofac Surg 1991;19(July (5)):199–204. https://doi.org/10. 1016/S1010-5182(05)80547-5. Choi BH, Yoo JH, Kim KN, Kang HS. Stability testing of a two miniplate fixation technique for mandibular angle fractures. An in vitro study. J Craniomaxillofac Surg 1995;23(April (2)):122–5. https://doi.org/10.1016/S1010-5182(05)80460-3. Haug RH, Fattahi TT, Goltz M. A biomechanical evaluation of mandibular angle fracture plating techniques. J Oral Maxillofac Surg 2001;59(October (10)):1199–210. https://doi.org/10.1053/joms.2001.26726. Ellis III E. A prospective study of 3 treatment methods for isolated fractures of the mandibular angle. J Oral Maxillofac Surg 2010;68(November (11)):2743–54. https://doi.org/10.1016/S0901-5027(99)80152-0. Farmand M, Dupoirieux L. The value of 3- dimensional plates in maxillofacial surgery. Rev Stomatol Chir Maxillofac 1992;93(6):353–7. PMID:1475603. Zix J, Lieger O, Iizuka T. Use of straight and curved 3-Dimensional titanium miniplates for fracture fixation at the mandibular angle. J Oral Maxillofac Surg 2007;65(September (9)):1758–63. https://doi.org/10.1016/j.joms.2007.03.013. Vineeth K, Lalitha RM, Prasad K, Ranganath K, Shwetha V, Singh J. “A comparative evaluation between single noncompression titanium miniplate and three-dimensional titanium miniplate in treatment of mandibular angle fracture” - A randomized prospective study. J Craniomaxillofac Surg 2013;41(March (2)):103–9. https://doi.org/10.1016/j.jcms.2012.05.015. Alkan A, Celebi N, Ozden B, Bas B, Inai S. Biomechanical comparison of different plating techniques in repair of mandibular angle fractures. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104(December (6)):752–6. https://doi.org/10. 1016/j.tripleo.2007.03.014. Jain MK, Manjunath KS, Bhagwan BK, Shah DK. Comparison of 3-Dimensional and standard miniplate fixation in the management of mandibular fractures. J Oral Maxillofac Surg 2010;68(July (7)):1568–72. https://doi.org/10.1016/j.joms.2009. 07.083. Höfer SH, Ha L, Ballon A, Sader R, Landes C. Treatment of mandibular angle fractures - Linea obliqua plate versus grid plate. J Craniomaxillofac Surg 2012;40(December (8)):807–11. https://doi.org/10.1016/j.jcms.2012.02.021. Melek LN, El Mahallawy AS, Sharara AA. Evaluation of the 3-dimensional threadlock plate in the management of mandibular angle fractures: a clinical and radiographic study. Tanta Dent J 2015;12(June (2)):140–8. https://doi.org/10.1016/j. tdj.2015.05.001. Elsayed SA, Mohamed FI, Khalifa GA. Clinical outcomes of three different types of hardware for the treatment of mandibular angle fractures: a comparative retrospective study. Int J Oral Maxillofac Surg 2015;44(October (10)):1260–7. https:// doi.org/10.1016/j.ijom.2015.07.005. Gerlach KL, Schwarz A. Bite forces in patients after treatment of mandibular angle fractures with miniplate osteosynthesis according to Champy. Int J Oral Maxillofac Surg 2002;31(August (4)):345–8. https://doi.org/10.1054/ijom.2002.0290.