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Football injuries are responsible for many of the maxillofacial injuries sustained during sporting activities. In the Australian Capital Territory (ACT), the four major types of Australian football are played in large numbers and up to a high standard. Our objective was to analyse maxillofacial fractures that were sustained during rugby league, rugby union, Australian rules, and soccer matches. We retrospectively studied 134 patients with maxillofacial fractures during the five-year period 2010-14. All patients were assessed and treated at Canberra Hospital, the major trauma centre in the ACT. Data collected from patients' records included type of football, age, sex, mechanism of injury, site of injury, and treatment. The number of people registered to play was obtained from each football governing body to find out the incidence of fractures. League had the highest incidence of facial fractures, followed by union, Australian rules, and soccer. High speed and high collision football (league and union) had a higher rate of mandibular fractures than high speed and low contact football (Australian rules and soccer) (n=43, 45% compared with n=7, 21%). Australian rules and soccer had a higher incidence of midface fractures than league and union (n=26, 79%, compared with n=52, 55%). Clash of heads was the leading cause of fractures. Collisions against other players' shoulders and forearms were more likely to cause mandible fractures. Ninety-four patients (70%) required surgical intervention. Football-related maxillofacial fractures occur regularly, and different types of football have predictable patterns of injury. Padding of the heads and elbows of players may reduce the number and seriousness of facial fractures., (Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.)

An efficient band of tension is critical for the adequate fixation of mandibular fractures, so fixation devices that compress are helpful. We aimed to evaluate the possibility of creating compression using screws inserted divergently into miniplates placed in the tension zone of mandibular fractures and record the effects on the strength of fixation. For this in vitro experimental study we prepared 20 sheep hemimandibles. After angle fractures had been created, the specimens were divided into standard and study groups (n=10 in each). In the standard group the tension zones were fixed in the standard manner with 4-hole miniplates and 4 parallel screws. Those in the study group were fixed as for the standard group but with 4×45° divergent screws. The differences in the gap in the fracture line before and after fixation were measured as indicators of compression. The strength of fixation was also assessed with a universal testing machine in vitro. The amount of compression was significant only in the study group (p<0.001), and there was no difference in the strength of fixation between the two groups (p=0.7). We conclude that divergent drilling and insertion of screws creates more horizontal force when miniplates are used, and results in reduction in the size of the probable gap in the fracture line. Insertion of divergent screws in miniplates may create compression between fractured segments without jeopardising the strength of fixation., (Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

The purpose of this study was to verify the role of the lateral pterygoid muscle in the reconstruction of the condyle shape during the sagittal fracture healing process by histological methods. Twenty-four adult sheep underwent an osteotomy to create a sagittal fracture of the left condyle; the sheep were then divided randomly into two groups. The lateral pterygoid muscles of the sheep in the experimental group were maintained on the internal poles of the condyles, and their functions remained stable. The lateral pterygoid muscles of the sheep in the control group were cut, and their functions were blocked. The shape, erosion, and calcification of the condyles were observed and measured after 4, 12, and 24 weeks of healing (n=4 from each group). The condyles were then submitted to haematoxylin and eosin, Ponceau S, and Sirius red studies. The results of the histology studies showed increased bone formation in the experimental group in which the functions of the lateral pterygoid muscle remained the same. The results of this study suggest that the lateral pterygoid muscle affects the reconstruction of the condylar shape during the healing process of a sagittal fracture of the mandibular condyle, and may even be involved in the formation of ankylosis., (Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Low intensity pulsed ultrasound (LIPUS) stimulation is a clinically established treatment method used to accelerate long bone fracture healing; however, this method is currently not applied to mandibular fractures. In this study, we investigated the effects of LIPUS on human mandibular fracture haematoma-derived cells (MHCs) in order to explore the possibility of applying LIPUS treatment to mandibular fractures. MHCs were isolated from five patients. The cells were divided into two groups: (1) LIPUS (+) group: MHCs cultured in osteogenic medium with LIPUS treatment; and (2) LIPUS (-) group: MHCs cultured in osteogenic medium without LIPUS treatment. The osteogenic differentiation potential and proliferation of the MHCs were compared between the two groups. The waveform used was equal to the wave conditions of a clinical fracture healing system. The gene expression levels of ALP, OC, Runx2, OSX, OPN, and PTH-R1 and mineralization were increased in the LIPUS (+) group compared to the LIPUS (-) group. There were no significant differences in cell proliferation between the two groups. These findings demonstrate the significant effects of LIPUS on the osteogenic differentiation of MHCs. This study provides significant evidence for the potential usefulness of the clinical application of LIPUS to accelerate mandibular fracture healing., (Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Fractures of the coronoid process are uncommon and can easily be missed. The purpose of this study was to classify the fracture patterns and explore the treatment options. This retrospective study included 39 patients with fractures of the mandibular coronoid process. Treatment protocols were developed based on the time of fracture, degree of mouth opening, location of the coronoid fracture, types of fracture, and other concomitant fractures. All patients were followed up for 12-60 months. Sixteen patients underwent conservative management and four of these patients developed progressive trismus, which improved significantly after removal of the coronoid process. Twenty-three patients underwent open reduction and internal fixation (ORIF) via the modified retromandibular approach. Follow-up data showed significant improvement in maximum mouth opening and symptoms (diet and pain) compared to their preoperative status. In summary, conservative management is first recommended for fractures of the coronoid process with minimal displacement or restriction of mouth opening. For patients with significant fracture displacement and limited mouth opening, or with concomitant fractures of the zygoma, zygomatic arch, or mandibular ramus, ORIF via the modified retromandibular approach through the anterior border of the parotid gland is an alternative treatment method., (Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

We evaluated the osteosynthesis of condylar fractures using resorbable mini plates and ultrasound-aided insertion of pins clinically and histologically. Stability was greater than that with resorbable screws because of the fusion of pin and plate. Long term evaluation showed complete resorption of the polymeric osteosynthesis material., (Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Unilateral fracture of the condylar neck in immature subjects might lead to mandible asymmetry and condyle remodelling. A rat model was used to investigate mandibular deviation and condylar remodelling associated with condyle fracture. 72 4-week-old male rats were randomly divided into three groups: an experimental group (unilateral transverse condylar fracture induced surgically), a sham operation group (surgical exposure but no fracture), and a non-operative control group (no operation). The rats were killed at intervals up to 9weeks after surgery, and outcomes were assessed using various measures of mandible deviation, histological and X-ray observation, and immunohistochemical measures of expression levels of connective tissue growth factor (CTGF) and type II collagen (Col II). The fracture led to the degeneration of mandibular size, associated with atrophy of fractured condylar process. Progressive remodelling of cartilage and increasing expression levels of CTGF and Col II were found. The authors conclude that condylar fracture can lead to asymmetries in mandible and condyle remodelling and expression of CTGF and Col II in condylar cartilage on both the ipsilateral and the contralateral sides., (Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Blast trauma is the primary cause of maxillofacial injury sustained by British service personnel on deployment, and the mandible is the maxillofacial structure most likely to be injured in combat, but there are few reports about the effect of blast trauma on it. The Joint Theatre Trauma Registry identified all mandibular fractures sustained by British servicemen secondary to blast injury between 1 January 2004 and 30 September 2009. These were matched to corresponding hospital notes from the Royal Centre for Defence Medicine (RCDM) for those evacuated servicemen and autopsy records for those who died of wounds. Seventy-four mandibular fractures were identified in 60 servicemen. Twenty-two soldiers were evacuated to the RCDM and the remaining 38 died from wounds. Fractures of the symphysis (39/106, 37%) and body (31/106, 29%) were more common than those of the angle (26/106, 25%) and condyle (10/106, 9%). This pattern of injury differs from that of civilian blunt trauma where the condyle is the site that is injured most often. Those fractures thought to result from the blast wave itself usually caused simple localised fractures, whereas those fractures thought to result from fragments of the blast caused comminution that affected several areas of the mandible. The pattern of fractures in personnel injured while they were inside a vehicle resembled that traditionally seen in blunt trauma, which supports the requirement for mandatory wearing of seat-belts in the rear of vehicles whenever tactically viable. All mandibular fractures in servicemen injured while in the turret of a vehicle had evidence of foreign bodies or radio-opaque fragments as a result of their exposed position. Many of these injuries could therefore be potentially prevented by the adoption of facial protection., (Copyright © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Although the route of invasion of oral squamous cell carcinoma into the intact mandible is well-documented we know of no reports about whether malignant cells invade through non-pathological fractures. A 68-year-old patient presented with a traumatic fracture of the mandible at the site of an existing carcinoma. He had asegmental resection but histological examination showed no evidence of invasion into the bone.

An unusual fracture of the mandible is reported that occurred 20 months after a bilateral split sagittal osteotomy.

We describe the pattern of mandibular fractures in Chennai, and confirm that, as in most other large cities, the main cause is road traffic accidents.

The aim of this study was to create in a sheep model an intracapsular oblique vertical split fracture, and observe the histopathological changes in the temporomandibular joint (TMJ) condylar head. In 10 sheep, the right TMJ was operated through the preauricular region. The anterior and posterior attachments of the disc were cut; an oblique vertical osteotomy was made from the lateral pole of the condyle to the medial side of condylar neck. The condylar fragment was pushed anteriorly, inferiorly and medially together with the disc. The non-operated left TMJ served as control. Two sheep were killed at 1 week and four at both 4 and 12 weeks. Computed tomography scans were taken and histopathological changes of the joint observed. There was severe bone erosion and a new bony outgrowth on the lateral side of the condylar stump and temporal bone. The joint spaces were filled with fibrous tissue, cartilage tissue and bone in the 4 and 12 weeks operated groups. These results show that an oblique vertical intracapsular fracture through the lateral condylar pole, combined with an anteriorly and medially displaced condylar fragment and disc and damaged lateral capsule, are likely to result in the pathological changes of osteoarthritis, and the progressive development of ankylosis in a sheep TMJ.

The fixation of diacapitular fractures of the mandibular condyle utilising a headless cannulated bone screw (Martin HBS((R))) is described. An open approach was used with primary fixation of the fracture with a K-wire, over which the cannulated screw was inserted. The method and results are described.

Recent studies have suggested magnetic resonance imaging (MRI) as useful in the evaluation of soft-tissue changes that occur in the temporomandibular joint (TMJ) after acute condylar trauma. The aim of this study was to investigate whether MRI findings of disc displacement, capsular tear and haemarthrosis are linked to the degree of condylar injury. Nineteen patients were assigned a diagnosis of uni- or bilateral condylar fracture (n=17), or condylar contusion with a uni- or bilateral diagnosis of TMJ sprain/strain (n=2). Condylar injuries were classified as grade I (absence of condylar fracture), grade II (type I, II or III condylar fracture), and grade III (type IV, V or VI condylar fracture). Bilateral sagittal and coronal MR images were obtained immediately after injury to establish the presence or absence of disc displacement, haemarthrosis and capsular tear. The data revealed a significant relationship between the degree of condylar injury and the MRI findings of capsular tear (P=0.000) and haemarthrosis (P=0.000), and between the MRI diagnoses of capsular tear and haemarthrosis (P=0.000). There was good diagnostic agreement between the presence of grade III condylar injury and the MRI diagnoses of capsular tear (K=0.62) and haemarthrosis (K=0.60). The results suggest that degree of condylar injury is related to MRI findings of capsular tear and haemarthrosis, and that MRI to supplement diagnosis of grade III condylar injury is warranted.

The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I-rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period.

Small cell carcinoma either primary or metastatic is an uncommon malignancy in the oral and perioral tissues. We are reporting such a case.

We studied the effects of platelet-derived growth factor-B (PDGF-B) and bone morphogenetic protein-2 (BMP-2) during the healing of mandibular closed fractures in rats by immunohistochemical methods. Unilateral closed fractures were created in the mandibles of thirty 12-week-old rats. BMP-2 was expressed during all stages of healing, but PDGF-B was expressed mainly in the early and middle stages, and not in the later stage of the healing process. We conclude that PDGF-B was associated with the proliferation and migration of primitive mesenchymal cells. BMP-2 was related to the differentiation of mesenchymal cells into osteoblasts and chondroblasts. PDGF-B and BMP-2 both have distinct regulatory effects on the healing of fractures.

Unilateral, rotated subcondylar fractures were surgically induced in young rats under general anaesthesia. A decrease in body weight was observed in the fractured animals, with recovery at the end of the experimental period. A tendency of deviation of the mandible to the fracture side was noticed on axial radiographs, but without significant difference between experimental and sham-operated animals. Histological data initially demonstrated acute inflammation along the articular capsule and adjacent muscle fibres. Within 2 weeks, exuberant callus formation occurred. Neither devitalized bone ends nor intra-articular granulation tissue were seen. After 1 month, the temporomandibular joint presented characteristics of normality, with the condylar process centralized into the temporal fossa, interposed by the articular disc. These results were preserved after 3 months. We concluded that rotational subcondylar fractures in young rats heal by callus formation, with simultaneous and prompt repositioning of the condyle.

A retrospective study was undertaken to analyse the etiology, site and treatment procedures of 30 pathological fractures of the mandible. Fifty percent of the fractures had an inflammatory cause. The remaining cases were associated with severe atrophy of edentulous mandibles (4), benign tumours (3), cysts (3), and primary or secondary malignancies (5). Regardless of the cause, the majority of the fractures occurred in the body of the mandible. Pathological fractures of the mandible most often have to be treated by eliminating the cause of the underlying condition while immobilizing the fragments either with osteosynthesis or archbars and intermaxillary fixation.

The position and functioning of discs in ten adult patients, whose bilateral condylar fractures were treated following a nonsurgical protocol, were investigated by means of magnetic resonance imaging. In seven temporomandibular joints (TMJs), where the condylar fragments were situated in the confines of the glenoid fossa, the discs were not displaced and were functioning normally. In 13 TMJs, where the condylar fragments were medially dislocated out of the fossa, the discs were displaced together with the condylar head but moved forward together with the condyle during mouth opening. This relationship between disc and condyle appears to play an important role in the reestablishment of function using nonsurgical treatment in patients with condylar fractures.

The aim of the study was to determine and compare bending and torsion moments across mandibular fractures, for different positions of the bite point and different sites of the fracture. Three identical resin mandibles, each with a single fracture, were used. The fracture sites were in the angle, body and symphyseal regions. A polyethylene bone plate was used for fixation. Simulated bite forces were applied at 13 bite points. For each bite point, the displacements of the fragments were registered and converted into bending and torsion moments across the fracture. Positive bending moments were defined as those moments that caused compression at the lower border and tension at the alveolar side of the mandible; negative bending moments did the opposite. Angle fractures had relatively high positive bending moments. Body fractures had positive as well as negative bending moments and the highest torsion moments. Symphyseal fractures had negative bending moments only and relatively high torsion moments. It was found that angle, body and symphyseal fractures each have a characteristic load pattern. These load patterns should play a decisive role in the treatment of mandibular fractures with regard to number and positioning of plates.

Objective: To find out how the site and type of condylar fracture are affected by its aetiology and the age and sex of the patient., Design: Retrospective study., Setting: Tertiary referral centre, Finland., Material: Radiographs of 101 children (aged 15 years or less) with 119 condylar fractures., Main Outcome Measures: Site of fracture and degree of displacement., Results: A total of 26 of the 119 fractures were intracapsular (22%) and 93 (78%) extracapsular. Only among patients less than 6 years of age was there a preponderance of intracapsular fractures (7/12 fractures in 10 patients, 58%). In the older children 78% (83/107) were in the condylar neck. There were few subcondylar fractures (5/119, 4%). Only 6 fractures were displaced (5%). Dislocation of the condyle from the glenoid fossa was common in all age groups., Conclusion: The site of condylar fracture is age related, but not associated with sex or aetiology.

The treatment results and the incidence of complications were evaluated retrospectively in a group of 68 patients. They all had mandibular fractures with a tooth in the line of fracture and were treated using miniplates for fixation. The follow up ranged from 1 to 6 years (mean 2.6 years) and 90 fracture sites were involved. Results showed that the incidence of complications when the tooth was extracted was higher (3/12) than when it was left in place (8/78). With regard to both healing of the fracture and fate of the tooth in the line of fracture, it is recommended to retain teeth in the line of fracture, unless there is an absolute indication for extraction. It is advisable to monitor the vitality of teeth adjacent to the fracture line for at least one year.

This study compares the internal fixation of mandibular fractures using either rigid 2.7 mm AO/ASIF plates or mini-plates. In the rigid plate group, 88 fractures were fixed with 88 plates. In the mini-plate group, 116 fractures were fixed with 170 plates. All the cases were consecutive and were treated in two South Wales hospitals during a 3-year period from 1988 to 1991. The aetiology of injury, timing of surgery, site of fracture, antibiotic policy and demographic features were evenly distributed between the two groups but there was a higher incidence of females in the mini-plate group. Both plating systems were successful in restoring functional occlusion. Rigid plates avoided the use of postoperative elastics better than mini-plates but the difference was not significant. There was a significantly higher incidence (P = 0.013) of infection in the mini-plate (12.9%) compared with the rigid plate (2.3%) group but 7.9% of the rigid group developed facial nerve weakness. A significantly higher proportion of mini-plates needed to be removed (P = 0.00019). A better treatment outcome for angle and comminuted fractures was noted with rigid plates.

The authors report on a retrospective study of 205 consecutive patients at the Maxillofacial Unit of The Royal Melbourne Hospital to assess if adherence to Champy's principles in placement of miniplates in mandibular fractures minimises morbidity. 205 well documented cases of mandibular fractures treated with internal fixation, January 1985 to April 1990 were studied. The patients were assigned into three groups according to the type of fixation; 83 patients had miniplate fixation according to Champy's principles, 40 patients had miniplate fixation ignoring Champy's principles, 82 patients had transosseous wire (TOW) fixation. Outcome was measured by preoperative variables (age, gender, mechanism of fracture, site and number of fractures, nerve function, associated injuries and treatment delay) and postoperative variables (duration of admission, duration of intermaxillary fixation (IMF), malocclusion, infection, dehiscence, union, removal of fixation and nerve function which were assessed and compared. The results show that the preoperative variables were statistically similar in all groups. The postoperative variables indicated a statistically higher complication rate for the transosseous wire group compared with the miniplate groups, and morbidity was reduced in the group following Champy's principles. The morbidity rates in this study compare favourably with other studies even though the patients in this study had a much higher incidence of multiple fractures. Titanium miniplates appear as effective as miniplates constructed of other materials used in previous studies, especially when Champy's principles are followed.

This retrospective study assessed the temporomandibular joint (TMJ) state of children who had suffered unilateral condylar fractures at least 5 years before and had been treated by functional orthopedic methods alone. The sample group were examined radiologically by computed tomography (CT) spiral scans which were reformatted to two-dimensional (2-D) images in different anatomic planes and to 3-D reconstructions in various projections. Although the seven patients who formed the sample group showed good-to-excellent functional results, the quantitative and qualitative analysis of the scans revealed alterations of size, shape, bony remodeling, and position of the condyle on the fracture side, as well as adaptive changes of the temporal component of the joint. We recommend spiral CT for assessment of TMJ disorders and fractures of the condyle at the time of injury and for follow-up assessment.

Sagittal or vertical fractures of the mandibular condyle and chip fractures of the medial part of the condylar head are very rare entities and their identification is difficult with conventional radiographs. We report a case of a unilateral bifid mandibular condyle which resulted following a sagittal condylar fracture. This was associated with a chip fracture of the medial part of the condylar head on the contralateral side. These types of condylar fracture do not require any surgical treatment, but early mobilization is indicated.

A case is reported of a 49-year-old edentulous patient who suffered a posterior dislocation of the right fractured mandibular condyle causing a fracture of the tympanic plate. This was associated with a right transverse fracture of the petrous bone and an intact tympanic membrane. Some of the problems related to this condition are discussed.

Twenty-eight patients have been followed up for an average of 15.1 years after uni- or bilateral subcondylar fractures sustained during their growth period. The conservative treatment, using orovestibular plates, has been evaluated with special reference to clinical, radiographic and functional parameters. TMJ function was tested using an electronic computer-assisted recording system. Condylar remodelling occurred in only about half of the individuals. Nevertheless, because of the good esthetic and functional results there seems to be no indication for operative reduction of the displaced condyle during the growth period.

The results are reported on 214 patients treated for 270 mandibular fractures, using rigid internal fixation. Of these, 172 fractures (63.7%) in 131 patients had been re-evaluated at final follow-up in connection with plate and screw removal, on average 15.2 months, postoperatively. Although one-third of the patients had a history of alcohol abuse, and 86% were treated with a delay of more than 24 h (mean 3.2 days), good primary bone healing was observed in 93.9% of the patients. Infections, seen in 6.1% of the patients, were related exclusively to inadequate stability of the fracture. Malocclusion, observed in 18.2% of 159 dentate patients, was caused by incorrect plate bending and insufficient fracture reduction. Immediate postoperative dysfunction of the inferior alveolar nerve in 58.1% of the cases, and of the mandibular branch of the facial nerve in 12.7%, was followed by almost total recovery 1 year after operation. It is concluded that rigid internal fixation is a reliable method of treatment, especially indicated for patients with reduced healing capacity and poor co-operation.

A study of 80 consecutive cases of mandibular fractures treated utilizing miniplate osteosynthesis is reported. Analysis of the data collected from 2 inner city hospitals revealed a high incidence of males (90%), alcohol abusers (44%), smokers (77%) and unemployed (36%). Assault was the aetiological factor in 72.5% of cases, with alcohol implicated in 58%. The injuries were predominantly non-complex in nature, 94% having one or 2 mandibular fractures and only 11% having additional facial fractures. The results compared favourably with those found in previous studies with 8% having complications. The efficacy and advantages of miniplate osteosynthesis as a method of treatment of mandibular fractures is discussed.

A case of an unusual bilateral mediolateral dislocation of the mandibular joints is reported. The condyle of the laterally displaced side was additionally fractured at the neck. No other fractures were present.

Analysis of 355 cases with fractures of the mandible indicated that 74.9% of the cases were due to interpersonal violence and 13.8% were caused by road traffic accidents. The men to women ratio was 8.4:1 and 75.5% of the fracture cases had single fractures while 24.5% had multiple fractures. In cases with a single fracture, the most commonly involved mandibular site was the body (42.2%). The angle of mandible was most frequently fractured (50.5%) in cases with multiple fractures.

Nine male patients were treated for condylar fractures of the mandible by a method involving detachment of the condylar head. Pre-operatively, all patients had severe malocclusion. Radiologically, most condyles were anteromedially displaced. Open reduction was indicated but repositioning of the condyle was impossible without ramus osteotomy followed by temporary condylectomy. On follow-up roughly 32 months after surgery no permanent complications were seen. Joint function was almost completely restored. Radiographic evaluation revealed some shortening and deformation of the condyles which had been operated. Translation and rotation movements were almost normal. The method described appears useful in those rare cases of fractures in which normal repositioning of a dislocated condyle is difficult.

Fracture of the mandible is a common maxillofacial injury. A case is presented of an unusual type of mandibular fracture.

Poly (L-lactide), a polymer of lactic acid (PLLA), with an extremely high molecular weight (Mv up to 1 x 10(6] has been synthesised under strictly controlled conditions resulting in a new microporous material with excellent mechanical properties. Bone-plates and screws machined from PLLA were used for fixation of two artificial mandibular fractures in sheep effected by a specially designed bone clamp. Fracture healing was uneventful without visible callus formation. Plates and screws of PLLA gave good stability over a sufficiently long period to enable normal fracture healing. Application in humans seems to be justified.