Straight Miniplate Research Articles

Comparative evaluation of stress distribution and transverse displacement of novel designs of miniplates for sagittal split ramus osteotomy in 10 mm advancements: a finite element analysis

The aim of this study was to evaluate the stress distribution and displacement values of six different miniplate systems in large mandibular advancement after sagittal split ramus osteotomy (SSRO) with finite element analysis (FEA). A three-dimensional model of a mandible was created and a 10 mm advancement SSRO was simulated. The model was fixed using a four-hole miniplate, a six-hole miniplate, a newly designed six-hole miniplate and their curved versions. Maximum principal stress values for bone, von Mises stress values for osteosynthesis materials, and the amount of displacement between segments were measured. The highest von Mises value was observed in the curved version of the newly designed six-hole miniplate; the lowest value was detected in the four-hole curved miniplate. The lowest value of maximum principal stress in the bone was found in the curved version of the novel design six-hole miniplate. The least displacements between segments were also recorded in the new design of straight miniplate; therefore, for large mandibular advancement surgery, this novel six-hole miniplate may be a promising option with positive biomechanical characteristics.

The Use of Titanium 3D Mini-Plates in the Surgical Treatment of Fractures of the Mandibular Condyle: A Systematic Review and Meta-Analysis of Clinical Trials.

Introduction: Fixing fractures of the base and neck of mandibular condyles is demanding due to the difficulties in surgical access and the various shapes of bone fragments. Classic fixation techniques assume the use of straight mini-plates, utilized for other craniofacial bone fractures. Three dimensional mini-plates may provide a reasonable alternative due to their ease of use and steadily improved mechanical properties. The multitude of different shapes of 3D mini-plates proves the need for their evaluation. Aim: This paper aims to summarize the clinical trials regarding the use of various types of 3D condylar mini-plates in terms of need for reoperation and the incidence of loosening and damage to the osteosynthetic material. Materials and Methods: A systematic review was conducted in accordance with PICOS criteria and PRISMA protocol. The risk of bias was assessed using ROBINS-I and RoB 2 Cochrane protocols. The obtained data series was analyzed for correlations (Pearson’s r) respecting statistical significance (Student’s t-test p > 0.05) and visualized using OriginLab. Results: 13 clinical trials with low overall risk of bias regarding 6 shapes of 3D mini-plates were included in the synthesis. The number of reoperations correlates with the number of fixations (r = 0.53; p = 0.015) and the total number of screw holes in the mini-plate (r = −0.45; p = 0.006). There is a strong correlation between the number of loosened osteosynthetic screws and the total number of fractures treated with 3D mini-plates (r = 0.79; p = 0.001 for each study and r = 0.99; p = 0.015 for each mini-plate shape). A correlation between the percentage of lost screws and the number of distal screw holes is weak regarding individual studies (r = −0.27; p = 0.000) and strong regarding individual mini-plate shape (r = −0.82; p = 0.001). Three cases of 3D mini-plate fractures are noted, which account for 0.7% of all analyzed fixation cases. Discussion: The reasons for reoperations indicated by the authors of the analyzed articles were: mispositioning of the bone fragments, lack of bone fragment union, secondary dislocation, and hematoma. The known screw loosening factors were poor bone quality, bilateral condylar fractures, difficulties in the correct positioning of the osteosynthetic material due to the limitations of the surgical approach, fracture line pattern, including the presence of intermediate fragments, and mechanical overload. Fractures of the straight mini-plates fixing the mandibular condyles amounts for up to 16% of cases in the reference articles. Conclusions: There is no convincing data that the number of reoperations depends on the type of 3D mini-plate used. The frequency of osteosynthetic screw loosening does not seem to depend on the 3D mini-plate’s shape. Clinical fractures of 3D mini-plates are extremely rare.

Finite element analysis of different titanium miniplates: Evaluation of three-dimensional designs applied on condylar neck fractures

IntroductionThe fixation of condylar neck fractures is raising difficulties and for this reason, many plate designs have been developed. The current study compares the performance of four miniplates used in the condylar neck. Material and MethodsA virtual condylar neck fracture in a mandible obtained from a CT scan was fixed with four miniplates (two straight miniplates, lambda, strut, and trapezoidal). Using finite element analysis, we examined the fragments' displacements and stress distribution in the titanium material and bone. The models were analyzed under two loading conditions: a reduced bite force of 135 N and a force of 500 N. ResultsNo risk of material failure was observed. For a load of 135 N, all four plates offer an adequate fixation. For 500 N of applied loading, the lambda and strut plates showed the best rigidity and lowest bone strains. The two parallel plates showed the lowest rigidity and the trapezoidal plate the highest bone strains around all screws. DiscussionThese findings imply that three-dimensional miniplates (lambda, strut) perform better when higher loads are applied. On the other hand, the trapezoidal plate has an increased risk of screw loosening and the two straight plates higher mobility of the fragments.

Fixation of subcondylar fractures of the mandible: a randomized clinical trial comparing one trapezoidal plate with two miniplates

Subcondylar fracture of the mandible accounts for 25–35% of all mandibular fractures. In the past, most subcondylar fractures were managed non-surgically. The traditional method of fixation for subcondylar fractures uses two miniplates; however some bench studies have reported that trapezoidal plates are superior. The aim of this study was to compare the outcomes of subcondylar fractures fixed either with two non-parallel straight miniplates or with one trapezoidal plate. A randomized clinical trial was designed and implemented. Fifty-two consecutive patients with subcondylar fractures were recruited. All patients underwent surgery via a retromandibular approach. The time taken for fixation of the plate after fracture reduction and postoperative outcomes and complications were compared between the groups. The trapezoidal plates were superior in terms of ease of adaptation and time taken for fixation (P= 0.0001). Plate fracture was observed only in the two miniplates group, in four (16%) patients. Outcomes were similar in the two groups in terms of occlusion, mouth opening, protrusion, and lateral excursion. In conclusion, both systems – two miniplates and the trapezoidal plate – provide functionally stable fixation. The outcome was significantly better for the trapezoidal plate than for two miniplates regarding the time taken for insertion and ease of adaptation, but not for other parameters.

Assessment of biomechanical properties of specially-designed miniplate patterns in a mandibular subcondylar fracture model with finite element analysis and a servohydraulic testing unit.

The aim of our study was to compare the biomechanical stability of three different systems used to fix mandibular condylar fractures on synthetic polyurethane mandibles using a servohydraulic testing unit and finite element analysis (FEA). We measured the resistance to displacement loads causing 1.75 and 3.5mm displacements of the fragments, and the maximum resistance values before failure of the fixation system in 30 condylar necks of 15 polyurethane mandible models. The three subgroups investigated were arranged as a triangular plate (n=10), a quadrangular plate (n=10), and a straight miniplate (n=10). The most successful fixation pattern was achieved with two straight four-hole miniplates. However, the triangular plate can easily be applied as a second option by an endoscopic approach. The rectangular plates showed no success in mandibular condylar fractures.

Comparative Evaluation of 7 Fixation Plates in Mandibular Angle Fractures Using Finite Element Analysis

Background: The finite element method is a used computational technique in obtaining detailed displacement of the fractured mandible with a fixation system. Objectives: The aim of the study was the evaluation of the biomechanical performance of different rigid fixation methods in mandibular angle fractures. Methods: Computed Tomography (CT) scans applied to prepare a model of the mandible with a mandibular fracture angle. The fracture line was fixed with 7 different fixation plates. The CT scans were transferred and converted to the finite element model. The commercial ANSYS software was applied to analyze the Von Mises stresses and the amount of displacement on bones, plates, and screws. 150-newton vertical force was applied to central incisors in order to simulate the most critical loading. Results: The maximum Von Mises stress values were found in the Champy technique with 474 Mpa in bones and 579 Mpa in screws, whereas the lowest Von Mises stress values observed in the square plate which was 180 Mpa. The minimum displacement observed in the Reconstructive plate & mini-plate which was 0.25 millimeters. Conclusion: The application of Reconstructive Plate & Mini-Plate, Dual straight mini-plates, Square Mini-Plate led to lower stress and displacement than other techniques in the bone, Plate, and screw. Reconstructive Plate & Mini-Plate, Dual straight mini-plates, Square mini-plate offers more resistance and stability at the fracture site than other techniques used in the current study. This study was done based on the analysis of computer data. Clinical evidence showed that other procedures were used for many years with success. There are many other factors in the clinical application that have a critical role in stability.

Simultaneous Use of 3 D Locking Square Plate and 2 Mm Straight Miniplate for Mandibular Fracture: A Case Report and Review of Literature

Champy plates are becoming more and more accepted for the fixation of simple mandibular fractures. Champy plates have the following advantages over other metbods: the plates are small, flexible, easily adaptable and the monocortical screws allow a rapid surgical application. This case report and literature review examined the use of a locking bone plate/screw system for use in mandibular surgery. The use of a locking plate/screw system was found to be simple, and it offers advantages over conventional bone plates by not requiring the plate to be compressed to the bone to provide stability.

Efficacy of different fixation techniques in repair of anterior mandibular fractures

Objective: To compare between double straight miniplates, double inverted L- shaped miniplates ,and three dimensional ( 3 D) rectangular miniplate in fixation of anterior mandibular (symphyseal / parasymphyseal area) fractures .Patients and methods: Thirty adult patients with anterior mandibular fractures were included in this study. The patients were divided randomly into three equal groups, group I was treated by superior and inferior straight miniplate while group II was treated by double L- shaped miniplates fixation technique and group III was treated by 3D rectangular miniplate. Postoperative clinical, radiographic evaluation and quantitative measurements were performed.Results: Wound healing was optimal in all cases except two cases in group I and one case in group II. Satisfactory occlusion was obtained in all cases except three cases in group I where it had mild to moderate occlusal derangement. Other parameters including maximal mouth opening, sensory nerve function, and patient's tolerance to the plate were comparable. There were the similarity between the density changes for the three groups as there was highly significant difference in G(I) compared to G(II) at six months, and G(I) compared to G(III) at three and six months also between G (II) compared to G(III) at six months. .Conclusion: Both double L-shaped miniplates and 3D rectangular miniplate provided enough stability for proper bone healing, establishment of optimal occlusion and early return to normal function more than with double straight miniplates. Additionally, there is superiority of 3 D rectangular miniplate over double inverted L- shaped miniplates in these parameters.

Study of the effect of the shape of the miniplate on the stability of mandibular symphyseal fracture using finite element analysis

Introduction: Finite element analysis is a new technology used for mechanical designing, and showing the behavior of the body when subjected to different loads as regards the resulted stresses and displacement.Aim: The aim of this research was to detect the effect of the miniplate shape on stability of the mandibular symphyseal fracture.Patients/Methods: Through this study two configurations of the miniplates were compared. The two miniplates are equal in length, width, thickness and of the same material, only they are different in shapes, one plate was straight and the other was L shaped, they are investigated using three dimensional finite element software.Results: There was no significant difference between straight and L shaped miniplate, however the L shaped miniplate was slightly superior to straight miniplate as regard plate stability.Conclusion: There is no significant difference between the different systems. The shape of miniplate may have a role in stability of mandibular fracture stability, the same plate shows different behavior when fixed at different positions double plate shows more stability than single one ,of the same shape finite element technology is helpful means for designing of different fixation systems.

Which fixation methods are better between three-dimensional anatomical plate and two miniplates for the mandibular subcondylar fracture open treatment?

PurposeTo compare the clinical outcomes of a single three-dimensional (3-D) anatomical plate versus two conventional straight miniplates for the open treatment of mandibular subcondylar fractures. MethodsThis retrospective clinical study included patients with mandibular subcondylar fractures treated by the retromandibular transparotid approach using a 3-D plate or two straight miniplates. Outcome variables included preoperative conditions of patients and fractures, extent of postoperative bone healing, and incidence of complications. Other variables included age, sex, fracture site, and follow-up duration. Variables were evaluated using descriptive statistics and compared between groups. ResultsTwenty-eight fractures were analyzed: 13 fractures using 3-D plate and 15 fractures using two straight miniplates. None of the assessed variables showed significant differences between the two groups (p < 0.05). Unfortunately, in the 3-D plate group, reoperation was necessary for nonunion owing to plate breakage in one case with a bone defect around the fracture. ConclusionThe 3-D plate and two straight miniplates were equally effective for the surgical management of mandibular subcondylar fractures. Although a 3-D plate is sufficient for a typical simple fracture, in cases with a bone defect around the fracture, selection of the plate fixation method should be carefully considered.

Comparative evaluation of different fixation techniques for sagittal split ramus osteotomy in 10 mm advancements. Part two: Finite element analysis

PurposeTo evaluate three rigid, stable fixation methods for sagittal split ramus osteotomy (SSRO), using finite element analysis. The hypothesis is that a customized miniplate presents better stress concentration and distribution. Materials and methodsA 3D model of a hemimandible was created, and a 10-mm-advancement SSRO was simulated and fixed as follows: 3-DCP group — one custom miniplate fixed by eight screws; 4-H2P group — two miniplates of four holes each, fixed by eight screws; and 6-H2P group — two miniplates of six holes each fixed by 12 screws. After a vertical loading of 100 N, the values for von Mises stress, modified von Mises stress, and maximum and minimum principal stresses were measured. ResultsThe area of maximum principal stress was similar for the three groups — located in the upper miniplate, in the screw near the proximal segment osteotomy. The maximum von Mises stresses were 1580.4 MPa, 1005 MPa, and 977.56 MPa for the 3DCP, 4-H2P, and 6-H2P groups, respectively, showing an allowable displacement of 2.57 mm, 1.62 mm, and 1.52 mm for the 3DCP, 4-H2P, and 6-H2P groups, respectively. ConclusionThe customized miniplate did not present better stress distribution than two commonly used types of fixation. Fixation with two straight miniplates, either with four or six holes, offers adequate resistance for 10 mm linear advancements.

Comparative evaluation of different fixation techniques of the sagittal split ramus osteotomy in 10 mm advancements: Mechanical testing and screw insertion torque

PurposeTo compare the mechanical characteristics of five techniques for the functionally stable fixation of simulated sagittal split ramus osteotomy with 10 mm of advancement and to evaluate the screw insertion torque. Materials and methodsFifty polyurethane hemimandibles with sagittal split ramus osteotomy and containing an advancement of 10 mm fixed and distributed as follows: Customized 3D Plate Group: 1 customized 3D miniplate; 4-Hole Plate Group: 2 miniplates with 4 holes; 6-Hole Plate Group: 2 miniplates with 6 holes; Hybrid Group: 1 flat miniplate with 4 holes and 1 bicortical screw; and Bicortical Screw Group: 3 bicortical screws. We conducted a mechanical test using vertical linear loading with a displacement velocity of 1 mm/min on a universal testing machine and assessed the screw insertion torque using a digital torque wrench. ResultsThe means of strength for the 1-, 3- and 5-mm displacements were determined by a one-way analysis of variance (ANOVA) followed by the post hoc Tukey test. Statistically significant differences were observed only for the 5-mm displacement (F = 3.36; p = 0.01). There was a difference between the 4-H2P and HG groups (p = 0.04). ConclusionThe customized miniplate, the fixation methods with three bicortical screws, or with two straight miniplates with either 4 or 6 holes, all offer a similar mechanical resistance suitable for fixation.

Comparison of the Stability of Mandibular Sagittal Osteotomy Fixation between Two Types of Titanium Miniplates: A Biomechanical Study in Sheep Mandibles.

This study aimed to compare the biomechanical stability of the fixation of mandibular sagittal split osteotomy of the ramus by two types of titanium miniplates in sheep mandibles. Seven preserved sheep mandibles with similar weight and size were selected, dissected with complete removal of soft-tissue structures, and sectioned in their midline. After performing sagittal split osteotomy, 5 mm of advancement was standardized and samples were divided into two groups according to the type of titanium miniplate (GI = seven hemimandibles were fixed with straight titanium miniplate, GII = seven hemimandibles were fixed with L-shaped titanium miniplates), and then subjected to compressive load. The means (standard deviation) of the compressive load and extension values were 70.68 N (22.26) and 63.36 mm (15.60) to straight miniplates, and 78.80 N (32.54) and 70.55 mm (5.42) to L-shaped miniplates. After comparison and statistical analysis, the results showed no significant difference between the two types of titanium miniplates.

Biomechanical evaluation of hybrid fixation method of sagittal split ramus osteotomy in mandibular advancement

PurposeIn this study, eight different fixation methods applied after sagittal split ramus osteotomy (SSRO) were compared experimentally. Materials and methodsSSRO was performed to 48 sheep hemimandibles in eight groups of 6 each. Group A- a four hole standard miniplate; Group B- a four hole standard miniplate and one bicortical screw; Group C-a four hole locking plate; Group D-a four hole locking plate and one bicortical screw; Group E-a six hole straight miniplate; Group F-a six hole straight miniplate and one bicortical screw; Group G- a sliding plate, which was specifically designed for SSRO; Group H- sliding plate and one bicortical screw. ResultsIn terms of measured values of displacement, the highest degrees of displacement were observed in decreasing order in Groups G, C, A, and E. The least displacement values were detected in Groups H, F, D and B with values being very close to each other. For linear force applied up to 70N, 3 mm or higher displacement values were not seen in any fixation system. ConclusionAccording to the results of study, all systems are suitable for clinic usage. However, intermaxillary fixation or functional elastics may be needed for sliding plate systems during the healing period of hard tissue.

Biomechanical evaluation of different osteosynthesis methods after mandibular sagittal split osteotomy in major advancements

The aim of this study was to assess the biomechanical stability of six different osteosynthesis methods after sagittal split osteotomy. Sixty polyurethane hemimandibles were divided into two groups, with six subgroups in each. After 10-mm advancement of the distal segment (group 1) and 10-mm advancement combined with 20° counterclockwise rotation (group 2), the bone segments were fixed using 2.0-mm plates/screws as follows: subgroup A, one conventional straight plate; subgroup B, two conventional straight plates; subgroup C, one conventional sagittal plate; subgroup D, one locking straight plate; subgroup E, two locking straight plates; subgroup F, one locking sagittal plate. The hemimandibles were tested for compressive strength by three-point biomechanical test, until there was 3mm of displacement between the segments. The fixations showed better performance in group 1 than in group 2 in all cases, with statistical significance for subgroups A, C, and D. In both groups, the use of two straight miniplates showed the most resistance, followed by the sagittal miniplates. However, in counterclockwise rotations, no statistically significant difference was found between two conventional straight plates and the sagittal locking plate. This study shows that the use of two plates is the form of fixation with the minimum displacement. If the clinician opts to use one plate, a sagittal plate is the best alternative.

Biomechanical evaluation of different plates osteosyntheses, for fixing sagittal split osteotomy in major mandibular advancements, with or without counterclockwise rotation

Objective: The aim of this study was to assess the biomechanical stability of six different osteosynthesis, in major advancements after sagittal split osteotomy, simulating the masticatory forces by a three-point biomechanical test. Methods: 60 polyurethane hemimandibles were assigned to two groups, containing six subdivisions each (n = 5). After 10 mm advancement of the distal segment (group 1) and 10 mm advancement combined with 20 degrees counterclockwise rotation (group 2), the bone segments were fixed by different osteosynthesis methods using 2.0 mm miniplates/screws: Subdivision A, one conventional straight miniplate; Subdivision B, two conventional straight miniplate; Subdivision C, one conventional sagittal miniplate; Subdivision D, one locking straight miniplate; Subdivision E, two locking straight miniplate; Subdivision F, one locking sagittal miniplate. The hemimandibles were loaded in compressive strength until 3 mm displacement occurred between segments vertically or horizontally. Findings: In all cases, the fixations showed better performance in group 1 against group 2, with statistic signification in subdivions A,C,D. The use of two straight miniplates shows more resistant, followed by sagittal miniplates in both groups. However, in counterclockwise rotations, the use of two straight miniplates of conventional system showed no statistical significance against sagittal locking plate. Conclusions: Two miniplates still remain as a form of fixation with less displacement. If surgeon opts to use only one miniplate, the sagittal miniplate must be preferred.

Resistance and Stress Finite Element Analysis of Different Types of Fixation for Mandibular Orthognathic Surgery.

The aim of this study was to evaluate the stress and dislodgement resistance by finite element analysis of different types of fixation in mandibular orthognathic surgery. A 3D solid finite element model of a hemi-mandible was obtained. A bilateral sagittal split osteotomy was simulated and the distal segment was advanced 5 mm forward. After the adjustment and superimposing of segments, 9 different types of osteosynthesis with 2.0 miniplates and screws were simulated: A, one 4-hole conventional straight miniplate; B, one 4-hole locking straight miniplate; C, one 4-hole conventional miniplate and one bicortical screw; D, one 4-hole locking miniplate and 1 bicortical screws; E, one 6-hole conventional straight miniplate; F, one 6-hole locking miniplate; G, two 4-hole conventional straight miniplates; H, two 4-hole locking straight miniplates; and I, 3 bicortical screws in an inverted-L pattern. In each model, forces simulating the masticatory muscles were applied. The values of stress in the plates and screws were checked. The dislodgement resistance was checked at the proximal segment since the distal segment was stable because of the screen at the occlusal tooth. The regions with the lowest and highest displacement were measured. The offset between the osteotomized segments was verified by millimeter intervals. Inverted-L with bicortical screws was the model that had the lowest dislodgment and the model with the lowest tension was the one with two conventional plates. The results suggest that the tension was better distributed in the locking miniplates, but the locking screws presented higher concentration of tension.

Mechanical evaluation of six techniques for stable fixation of the sagittal split osteotomy after counterclockwise mandibular advancement

We have evaluated the resistance to displacement of six stable methods of fixation of a sagittal split ramus osteotomy (SSRO) in the mandibular advancement with counterclockwise rotation. We tested 60 synthetic hemimandibles in six groups of 10 each: Group I – fixation with a straight four-hole 2.0mm miniplate; Group II – a straight six-hole 2.0mm miniplate; Group III – two straight 2.0mm four-hole miniplates; Group IV – an eight-hole 2.0mm (grid plate); Group V – a 2.0mm four-hole straight miniplate and 2.0×12mm bicortical screw; and Group VI – a straight four-hole 2.0mm locking miniplate. We applied a linear force in the region between the canine and the first premolar using a universal testing machine (EMIC- DL2000) with a loading cell of 10 KN. The loads at 1, 3, and 5mm displacement were recorded (N) and the data transmitted from the load cell to a computer. Results were analysed using analysis of variance (ANOVA) (p<0.001) and the Tukey post-test for comparison of the significance of the differences between the groups. For the three degrees of displacement, fixation with two straight 2.0mm plates and with the grid plate gave higher load values.

Assessment of sagittal split ramus osteotomy rigid internal fixation techniques using a finite element method

In this study, finite element analysis (FEA) was used to evaluate nine rigid internal fixation techniques for sagittal split ramus osteotomy. To achieve this, a computed tomography (CT) scan of a healthy patient was obtained and used to generate the geometry of a half-mandible. The geometries of bicortical screws, miniplates, and monocortical screws were designed and combined with the mandible in nine models simulating various techniques. Four models used bicortical screws in various arrangements and four used miniplates of various designs. One model represented a hybrid technique. A load of 500N was applied to the posterior teeth and FEA was applied. The most stable techniques were the hybrid technique and a single straight miniplate, presenting the least displacement among all models. Bicortical screws, while presenting reasonable stability, showed high strain areas near the anterior ramus ridge, superoposterior to the screws, implying a risk of bone fracture in this area. On the other hand, the T-shaped and double Y-shaped miniplates were associated with high von Mises stresses that would impair their rigidity, especially where angles appeared in their designs. We recommend the use of a single straight miniplate because it provides sufficient stable fixation with minimal risks or disadvantages.

Comparative biomechanical study on three miniplates osteosynthesis systems for stabilisation of low condylar fractures of the mandible

Open reduction and fixation of low condylar fractures of the mandible can be achieved by many osteosynthesis systems that differ in size, shape, and site of placement according to the surgical approach. We investigated the maximum load and rigidity of 4 osteosynthesis systems: the standard double 4-hole straight miniplates, the inverted y-miniplate (with and without self-drilling screws), and the TriLock Delta condyle trauma plate. The standard double 4-hole straight miniplate osteosynthesis achieved the best fixation and resistance in view of a mean (SD) maximum load of 539.8 (100.2)N, followed by the inverted y-miniplate with the self-drilling screws (246.5 (23.8)N), the inverted y-miniplate with standard screws (242.4 (27.2)N), and finally the TriLock Delta plate (167.4 (39.2)N). Analysis of the slope of the force–displacement diagram from 80N to 100N in each group showed that the TriLock Delta miniplate had the highest values for rigidity (17.3 (5.1)N/μm), followed by the inverted y-miniplate groups with self-drilling screws (14.1 (6.4)N/μm), and with standard screws (12.6 (2.5)N/μm). The double 4-hole straight miniplate osteosynthesis had the lowest rigidity (8.7 1.4)N/μm). Despite the significant difference in the maximum load between the double 4-hole miniplates and other investigated osteosynthesis patterns, all groups had sufficient load for the fixation of low condylar fractures of the mandible when postoperative bite forces and the slowly increasing voluntary clenching during healing were considered.