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Introduction: Fractures of the mandible angle raise the risk of infectious complications. We searched for factors predictive of these complications., Material and Methods: We reviewed retrospective all cases of mandibular angle fracture treated during a 26-month period. We compared two groups: fractures with wisdom teeth and fractures without wisdom tooth. For each group we noted clinical and radiological characteristics of the fractures and infectious complications., Results: The series included 72 mandibular angle fractures, 30 with a wisdom tooth against 42 without. Most of the patients were treated within 2 days, generally using mini-plate screw fixation. In the wisdom tooth group, 16.6% of patients developed infectious complications versus 9.5% in the without wisdom tooth group. All patients of the wisdom tooth group presented a potentially infectious focus on the preoperative x-rays. For without wisdom tooth group, irregular follow-up was found to be the only risk factor., Discussion: The angular localization increases the risk of infectious complications especially if the wisdom tooth is in the fracture. We propose a decision tree to determine when to preserve or not the wisdom tooth.

Purpose: The purpose of this study was to clarify the influence of patients age and the degree of dislocation on the healing of mandibular condyle fractures., Material and Methods: Sixty-two Japanese white rabbits (30 adolescent and 30 adult ones) were used. They underwent unilateral condylar neck osteotomy. The proximal fragments were positioned differently. In group I animals, the fragments were reduced into the original position, in group II animals the small fragment was dislocated 55-90 degrees to the ramus. In group III animals the proximal fragment was dislocated 135 degrees to the ramus. Gross and microscopic assessment was performed 4, 6, 8, 12 and 24 weeks postoperatively., Results: In adolescent animals, complete healing of the fracture was observed, irrespective of the degree of dislocation. In the adult animals, there was complete healing of the fractures in groups I and II. In group III animals, there was a decrease of ramus height accompanied by some fibro-cartilaginous changes., Conclusion: Even in rabbits condylar deformation has been found following heavily dislocated artificial condylar fractures in adult animals. This result will help to decide for or against surgical treatment of condylar fractures in humans.

Background: There are very few reports directly comparing mandibular fractures between young and adult patients in Middle Eastern countries., Aim: To review and compare the frequency and aetiology of mandibular fractures in young and adult Jordanian patients., Study Design: A retrospective review was made of patients' records and radiographs seen at two university-based maxillofacial units during a 10-year period between 1993 and 2002. Age, gender, aetiology, and site were analysed and compared between young and adult patients., Results: In total, 703 patients (502 (71%) male and 201 (29%) female) were found with 892 mandibular fractures altogether. There were 497 (71%) adults with 676 fractures, and 206 (29%) young patients with 216 fractures. The mean age of the adults was 30 years with a male-to-female ratio of 2.5:1. The mean age of the young patients was 13 years with a male-to-female ratio of 1.5:1. The most common fracture site in adult patients was the mandibular body, whereas the condyle predominated in young patients. The most common causative factor in adults was road traffic accidents, and falls in the young., Conclusion: There was a similar gender distribution in both groups of Jordanian young and adult patients. However, there were differences regarding aetiology and site of fracture. The differences found in this study between adult and young patients are similar to those from other countries.

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.

Although temporo-mandibular joint (TMJ) ankylosis is one of the most common pathologies afflicting the facial skeleton, it is also the most overlooked and under-managed problem in children. The TMJ forms the very cornerstone of cranio-facial integrity and hence its ankylosis in growing children adversely affects the growth and development of the jaws and occlusion. Impairment of speech, difficulty in mastication, poor oral hygiene, rampant caries and acute compromise of the airway pose a severe psychologic burden on the tender minds of children. The aim of this article is to present an overview of efficient management strategies, based on a case report, so as to increase its awareness among all dental surgeons involved in the treatment of children.

The case of a 36-year-old male and former patient is presented who died for initially unknown reasons, with intermaxillary wire fixation for the treatment of an infected mandibular fracture still in place. The combined investigation of forensic experts and maxillofacial surgeons excluded aspiration and asphyxia as cause of death. Evidence was found for lethal methadone concentrations after intravenous drug abuse and a broncho pneumonia. Despite the clear evidence of a fatal intoxication in this case, caution must be exercised when dealing with individuals carrying intermaxillary fixation.

Despite the introduction of highly active antiretroviral therapy (HAART), diffuse large B-cell lymphoma (DLBCL) remains a common malignancy in human immunodeficiency virus (HIV)-infected patients, especially the plasmablastic variant. About 50% of lymphomas in HIV patients are extranodal and half of them occur in the head and neck area. The main oral symptoms are pain, swelling, numbness and tooth mobility. We report the case of a 52-year-old patient with a known HIV infection and fracture of the angular region of the mandible. The fracture did not unite following open reduction and osteosynthesis. A biopsy performed at the time of revision revealed the diagnosis of a primary lymphoma in the mandible. After chemotherapy had induced complete remission of the lymphoma and autogenous iliac crest bone grafting had been performed the fracture united. Primary lymphoma in the mandible is a disease that presents with a nonspecific radiological appearance which may mimic osteomyelitis or periodontal pathology. A rapid and accurate diagnosis is critical for the appropriate treatment. In our experience HIV-positive patients with mandibular fracture should be treated according to the guidelines established for HIV-negative patients. However, risky compromises such as intraoral approach or hazardous fracture fixation should be avoided.

Objectives: The aim of this study was to evaluate the relationship between the fracture site and etiology in mandibular fractures., Patients and Methods: The study included 37 patients (61 fracture sites) (29 males, 8 females; mean age 26 years; range 1.5 to 77 years) who underwent surgical treatment for mandibular fractures between May 2001 and November 2003. Data on epidemiological characteristics of patients, etiology and fracture sites were retrospectively reviewed., Results: Of the patient group, 51.3% had a single, 48.6% had two or more fractures. Seventy-five percent of the assault victims had more than one fracture site. Motor vehicle accidents accounted for 36% of all the fracture sites. The most common locations of the fractures according to the etiology were as follows: fractures caused by motor vehicle accidents at the parasymphyseal area, by falls at the condyle, and by assaults at the parasymphyseal and angular areas. All the fractures resulting from bicycle accidents occurred at the condyle area., Conclusion: It is advisable to be more attentive for condyle fractures when confronted with any etiology of mandibular fractures. Etiology may be suggestive of the fracture site(s).

Current interest in minimally invasive surgery has extended to the repair of craniomaxillofacial fractures, including subcondylar fractures of the mandible. Recent experience indicates that rigid fixation by the endoscopic approach is technically feasible, particularly for subcondylar fractures with lateral displacement of the proximal fragment. The technique is more difficult (although not impossible) for medially displaced fractures. High condylar fractures and comminuted fractures may not be amenable to this approach unless there is enough bone present to allow placement of screws in the proximal fragment. Because evidence suggests that the outcome of open reduction of subcondylar fractures may be better than the outcome when closed management is performed, techniques that minimize the morbidity of open reduction should allow better long-term results. It is hoped that the endoscopic approach for the repair of subcondylar fractures of the mandible will provide these benefits. The technique is summarized with step-by-step explanations.

Purpose: The purpose of this article is to introduce the use of a resorbable material (L-lactide, Co DL-lactide) to help contain the bone graft used during the reconstruction of the edentulous atrophic mandibular fracture., Technique: After the mandibular fracture was reduced and fixated with a large reconstruction plate, the resorbable mesh was contoured with scissors and a hot water bath. The mesh was secured into position with 1.5-mm tacks to the inferior border or buccal cortical plate of the mandible. The material was then filled with particulate bone graft harvested from the medial aspect of the anterior iliac crest., Results: Two patients had augmentation of the superior aspect of the mandible and one patient had augmentation of the inferior aspect of the mandible. All patients were augmented at least 10 to 12 millimeters. The mean follow-up was 25 months. All went on to heal to complete bony union., Conclusion: This material can be used as a containment system when bone grafting the edentulous atrophic mandible fracture.

A mixed breed dog was presented for lateral luxation of the mandibular left canine tooth following oral trauma. This case report describes the management of this injury including reduction, stabilization using a wire reinforced acrylic splint, and standard endodontic therapy of the mandibular left canine tooth.

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

Distraction osteogenesis is a well-established method of endogenous tissue engineering. It is a biological process of bone neo-formation between segments subjected to tension. The concept of this study was to investigate the distraction osteogenesis with a device capable of creating a permanent and constant force during the whole process as if a very large number of small elongations were applied constantly. The mechanical testing of the device used to produce the constant force and the in vivo analysis of the bone growth after it was implanted in rabbits are presented on this work. The device consists of a NiTi coil spring, superelastic at body temperature, in order to have a stress plateau during the austenitic retransformation during the unloading. The in vivo analysis was made on six female rabbits of 12 months old. A segmental mandibulectomy at the horizontal arm of the mandible and a corticotomy at 5mm distant from the gap were made. Next, following a latency period of five days, the SMA springs were implanted to induce the bone neo-formation. The displacement at the unloading plateau shows that it is necessary to have longer springs or to use several (available commercially) in series in order to fulfil the requirements of a human distraction. The temperature variations induced changes in the spring force. However, when the temperature returns to 37 degrees C the distraction force recovers near the initial level and does so completely when the distraction process continues. For the in vivo study, all six rabbits successfully completed the distraction. The radiographies showed the gap as distraction advanced. A continuity in the newly formed bone with similar transversal and horizontal dimensions than the original bone can be observed on the histologies. In conclusion, the application of a constant force on distraction osteogenesis, using SMA springs, may be a successful alternative to the conventional gradual distraction.

To investigate the clinical significance of magnetic resonance (MR) evidence of joint effusion of the temporomandibular joint after mandibular condylar fractures, magnetic resonance imaging (MRI) was performed on 18 joints in 15 patients with either unilateral or bilateral mandibular condylar fractures using a 1.5 Tesla MRI scanner (Signa, General Electric, Milwaukee, WI). MR evidence of joint effusion was evaluated and compared with the types and the positions of the fractures. MR evidence of joint effusion was observed in 11 of 18 TMJs, which was 61% of the condylar fractures. It appeared more frequently after fractures with dislocation than those without dislocation (p < 0.05). In addition, MR evidence of effusion appeared more frequently in TMJs after high condylar fractures (head to upper neck) than low condylar fractures (lower neck to subcondylar) (p < 0.05). These findings indicate that MR evidence of joint effusion may serve as a marker for the detection of severe intra-articular damage to the TMJ after mandibular condyle fractures.

The authors report a rare case of mandibular fracture caused by a flying object, discuss the mechanism of the fracture, and review the literature. The patient was a 40-year-old male soldier in the Self Defense Force (SDF). During a mock battle of the SDF Agency, a shell splinter penetrated his mentum and caused a fracture of the mandibular symphysis that resembled horizontal osteotomy for genioplasty. A horizontal fracture of the mandibular symphysis is very rare, and on clinical inspection, the authors found the general course of the clinical fracture line coincided with the weakest portion of the mandible. A powerful blast can cause an object to become airborne and injure persons in the vicinity, as did the metallic fragments that caused the mandibular fracture in patient reported here. Thus, when examining victims of such traumas, the possibility that a foreign object might have penetrated the body should be kept in mind. A thorough inspection of injuries resulting from explosions is mandatory.

A new method was developed in this study for testing excised sheep mandibles as a cantilever. The method was used to determine the strength and stiffness of sheep hemi-mandibles including a 35 mm defect bridged by regenerated bone. Recombinant human bone morphogenetic protein-7 (rhBMP-7) in a bovine collagen type-I carrier was used for the bone regeneration. Initial tests on ten intact sheep mandibles confirmed that the strength, stiffness and area beneath the load-deformation curves of the right and left hemi-mandibles were not significantly different, confirming the validity of using the contra-lateral hemi-mandible as a control side. Complete bone regeneration occurred in six hemi-mandibles treated with rhBMP, but the quality and mechanical properties of the bone were very variable. The new bone in three samples contained fibrous tissue and was weaker and less stiff than the contra-lateral side (strength, 10-20 per cent; stiffness, 6-15 per cent). The other half had better-quality bone and was significantly stiffer and stronger (p < 0.05), with strength 45-63 per cent and stiffness 35-46 per cent of the contra-lateral side. Hemi-mandibles treated with collagen alone had no regenerated bone bridge suggesting that 35 mm is a critical-size bone defect.

Approximately half of the skeleton of an adult male (minus the cranium) was found in a forested part of Greater Vancouver, Canada, in August 2000 by the Royal Canadian Mounted Police (RCMP). Authorities ruled the death as suicide. The only compelling signs of perimortem trauma were symmetrically fractured coronoid processes of the mandible, which can be attributed to a gunshot in the mouth. However, the remains had also been scavenged by canids, raising a problem in differential diagnosis. Could canid scavenging produce bilateral fracturing of the mandible indistinguishable from gunshot wounds to the mouth? We found that canid scavengers could not mimic the type of damage to the mandible caused by intra-oral gunshot wounding using a sheep model (n = 20). Bilateral fracturing of the coronoid processes was found to be characteristic of intra-oral gunshot wounding, while canid scavengers typically ignore this region of the mandible.

Purpose: In this study, we investigated the relationship between oxidative stress and apoptosis in synovial tissues in temporomandibular joint diseases (TMDs), including internal derangement (ID) and osteoarthritis (OA), comparing immunohistochemical, arthroscopic, and histologic findings., Materials and Methods: Synovial specimens obtained from patients with ID (31 patients), osteoarthritis (11 patients), and condylar fractures of the mandible (5 patients) during arthroscopy were examined immunohistochemically using antibodies against CD68, inducible nitric oxide synthase (iNOS), Fas, and single-stranded DNA (ssDNA)., Results: CD68 and iNOS immunoreactivity were detected mainly in synovial lining cells and subintimal macrophages, and tended to increase with synovial hyperplasia. Fas and ssDNA immunoreactivity was detected mainly in synovial lining cells, and Fas-positive regions exhibited a number of ssDNA-positive cells. Fas expression was significantly greater in fractures than in OA, and ssDNA expression was significantly greater in OA than in ID. Fas expression was significantly greater in iNOS-positive versus iNOS-negative TMJs, and ssDNA expression tended to increase with iNOS expression., Conclusion: These immunohistochemical findings suggest that oxidative stress and apoptosis in synovial tissues are involved in the onset and progression of TMDs.

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.

Purpose: Many studies focusing on the pattern of presentation of mandibular fractures are inconclusive. This is largely due to a multifactorial involvement of associated factors and the role of anatomic factors., Patients and Methods: We reviewed a 10-year retrospective analysis of the pattern of presentation of mandibular fractures at an urban level I trauma center in Washington, DC, and the significance of the variables in association with the fractures. These include mechanism of action, age group, illicit drug use, seasonal variation, and the incidence of multiple fracture sites. We also looked at the evolving pattern of mandibular fractures in comparison to an earlier study conducted in the 1960s at the same hospital. Data collection was done through the use of medical records and all documented radiographs. Variables that were analyzed in association with the fractures include age, gender, mechanism of action, seasonal variation, and anatomic location. Data analysis was done using subjective analysis, frequency distribution, and multiple regression tests, where appropriate., Results: Data analysis shows that 86% of all fracture patients are male, and 37% of all patients were in the 25- to 34-year-old age group. Use of an illicit substance at the time of trauma was seen in 55% of all cases. Interpersonal violence accounted for 79% of all patients, with prevalence in the summer (31%) and winter (28%) months. The most common location of fracture is in the angle region (36%), followed by the body (21%) and parasympyhseal region (17%), with 52% presenting with more than one fracture site., Conclusion: The evolving pattern of fractures in urban trauma centers is showing an increasing trend of association with illicit substances and interpersonal violence as a major causative factor., (Copyright 2003 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 61:713-718, 2003)

The aim of this study was to attempt to establish a correlation between condylar localized fracture, onset of anatomicopathological lesions of the articular structures, and determination of ankylosis so as to define appropriate diagnostic and therapeutic procedures. Clinical, arthroscopic, and histological studies were carried out in two patients with a severe temporomandibular joint disorder after a condylar localized fracture. Treatment included removal of the displaced fragments, condylar surface remodeling, suture of retrodiskal perforations, and diskal repositioning. The histological study of the condylar specimens revealed signs of osteoarthrosis of the articular surface and chondroid metaplasia of the bilaminar zone with early onset of ankylosis. Results of this study confirmed the presence of causal relations between condylar localized fracture and ankylosis with alterations in retrodiskal tissue. These relations are found in 1) tissue damage caused by bony fragments remaining in the articular cavity (underestimated and poorly treated fractures), 2) the lesion that occurs in association with mechanical trauma; and, particularly, c) the disk and retrodiskal impairments caused by catabolic and degenerative osteoarthrotic changes secondary to condylar marrow damage. Thus, timeliness and accuracy of the diagnosis of condylar localized fracture are most important, as are correct diagnosis and treatment before the onset of degenerative anatomicopathological lesions.

This study evaluated the effect of pulsed ultrasound on tissue repair and bone growth during mandibular osteodistraction. Twenty-one rabbits were divided into three groups of 7. The distraction started 72 h after surgically severing both sides of the mandible and proceeded at a rate of 1.5 mm/12 h for 5 days. Group I received pulsed ultrasound (nominally 200 micros pulse of 1.5 MHz at a 1.1 kHz pulse repetition frequency, 30 mW/cm2) for 20 min on both sides of the mandible every other day (alternating sides). Group 2 received the same pulsed ultrasound treatment on one side of the mandible every day for 20 min. Group 3 did not receive any ultrasound treatment. Bone formation at the distraction site was assessed by photodensitometry on head radiographs, a vibratory coherence test across the distraction site, a postmortem three-point bending mechanical stiffness test, and a postmortem histological examination. Statistical analyses performed using analysis of variance revealed that pulsed ultrasound enhanced bone formation at the distraction site with a high level of significance when assessed by the increase in new bone photodensity (p = 0.001), vibratory coherence (p = 0.001), mechanical stiffness (p = 0.003), and qualitative histological studies, especially when the pulsed ultrasound treatment was directly applied daily.

Purpose: In this study, we measured the relationship between the presence of mandibular third molars (M3s) and angle fractures. In addition, the study examined the relationship between M3 impaction level and angle fracture susceptibility., Patients and Methods: We used a multicenter retrospective cohort study design and a sample composed of patients treated for mandibular fractures. The predictor variables were 1) the presence of an M3 and 2) the position of an M3 classified according to the Pell and Gregory system. The outcome variable was the presence or absence of an angle fracture., Results: The study sample was composed of 1,210 patients. Patients with M3s present had a 2.1 times greater chance of an angle fracture than did patients without M3s (P <.001). There was a statistically significant variation in the risk for an angle fracture depending on M3 position (P <.001)., Conclusions: In patients who sustain a mandible fracture, the presence of M3s significantly increases the likelihood of an angle fracture. In addition, the risk for an angle fracture depends on M3 position., (Copyright 2002 American Association of Oral and Maxillofacial Surgeons)

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.

Purpose: This study compared the number of unfavorable fractures after sagittal split osteotomies (SSOs) of the mandible when third molars were present or absent., Patients and Methods: The treatment records of 262 patients (500 SSOs) were retrospectively evaluated. Group 1 consisted of 250 SSOs and concomitant removal of impacted mandibular third molars and group 2 consisted of 250 SSOs with absence of third molars. A modified SSO technique with inferior border cuts was used on all patients, and the third molars, when present, were removed after separation of the proximal and distal segments. Rigid fixation was applied using bicortical bone screws. Bone plates with monocortical screws were additionally used to secure the free bony segments of the proximal segment in cases with unfavorable fracture., Results: There were 11 (2.2%) unfavorable fractures in 500 SSO procedures. The incidence of unfavorable splits was 3.2% in group 1 and 1.2 % in group 2. In group 1, all fractures occurred in teenagers, with 7 of 8 fractures extending through the extraction socket in the distal segment. Six of the 8 fractures were associated with completely impacted third molars, and 2 involved partially impacted teeth. All 3 fractures in group 2 occurred in the proximal segment. No significant difference was seen in the amount of relapse in patients with unfavorable or favorable splits., Conclusions: The occurrence of unfavorable splits is uncommon when using a modification of the SSO that includes an inferior border osteotomy. Although more unfavorable fractures occurred in teenage patients with third molars, this had no impact on the stability of the final result., (Copyright 2001 American Association of Oral and Maxillofacial Surgeons)

Thirty-two human mandibles were marked with three typical fracture lines: a low condylar fracture, a fracture of the mandibular angle, and one through the mental foramen on each side. The mandibles were sectioned at the fixation sites of the miniplate screws. The thickness of the cortical layer was measured with a scaled magnifying glass at the points of anthropological interest and at the marked screw holes. The inferior cortical layer turned out to be thickest in the anterior area. In contrast, it was very thin at the mandibular angle, which might explain the higher complication rate in treating fractures in this region. The thickness of the lingual cortex increased up to the symphysis, whereas the buccal cortical layer showed a decline in size from the mandibular angle up to the chin. The cortical bone at the alveolar ridge was porous. The cortical supply for miniplate osteosynthesis at the condylus ranged from 1.1 mm up to 1.74 mm, which seems to be limited, but due to the small diameter of the condylus most common screws obtain additional anchorage in the inner cortex. The thickness of the cortical layer at the mandibular angle increased from 1.47 mm at the ramus up to 1.97 mm at the beginning of the corpus, reaching 2.14-2.38 mm for the lower plate at the mental foramen. The results for the upper plate were slightly lower.

Purpose: This study evaluated variability in the clinical parameters commonly used to characterize mandible fractures., Patients and Methods: Inter-rater reliability of 18 oral and maxillofacial surgeons was assessed using radiographs of 22 cases of mandible fractures. Raters were asked to evaluate each case based on several parameters including number, location, and displacement of the individual fractures and severity of the composite injury. To evaluate intra-rater reliability, selected cases were reviewed at a second session by a subgroup of these surgeons. Tests of concordance used to quantify measurement reliability included the interclass correlation coefficient and multiple-rater kappa statistics., Results: Inter-rater agreement on the number of constituent fractures ranged from excellent for simpler fractures to poor for complex gunshot injuries. Even within raters, the range of interclass correlation for complex injuries was only 0.33 to 0.42 between the 2 assessments. Clinicians appeared to be better at delineating coronoid, condyle, ramus, and angle fractures; symphyseal and canine region fractures had lower inter- and intrarater agreement. Tests of concordance showed moderate to excellent reliability when fracture displacements were expressed in millimeters, but only fair reliability when displacements were expressed as categories. Even when the clinicians concurred on displacement measurements, a large overlap was observed in their categorization of these displacements. Despite the differences in the assessment of individual parameters, the high intrarater reliability coefficient (0.78) indicated that the individual clinicians had a high internal consistency in their assignment of summary severity scores. Multiple regression analysis revealed the number of constituent fractures, the type of fracture, and amount of fracture displacement (millimeters) to be significant predictors of clinician ratings of injury severity., Conclusions: The clinician variability underscores the difficulties involved in trauma description and scoring. The study identifies some sources of clinician variability and emphasizes the need to standardize the characterization of mandible fractures by using explicit guidelines.

A new classification of mandibular fractures is suggested. Unlike fractures of the upper and middle zones of the face, mandibular injuries are characterized by typical location and configuration, which prompted us to undertake this study. Literal and digital symbols were used in formulation of the diagnosis. These symbols characterize the line of fracture, involved teeth, site of fracture, presence (or absence) of dislocated fragments, occlusive disorders, combined injuries, status of soft tissues at the site of injury, presence of inflammation in the fracture fissure and its severity. Examples demonstrating the convenience of the formula are presented.

Morphological reactions in tissue adjacent to mandibular angular fracture were studied in guinea pigs treated with sodium succinate and laser magnetotherapy. Due to succinate therapy the exudative component of inflammation was less expressed in comparison with the control, macrophagal reaction and neoangiogenesis were activated, the volume of damaged muscle tissue and the incidence of suppurations decreased. The number of osteoblasts increased and new bone structures acquired a lamellar pattern earlier than in the control. Sodium succinate therapy in combination with laser magnetotherapy had a more pronounced positive effect as regards activation of macrophagal reaction and neoangiogenesis and a decrease in the area of fibrosclerotic changes in the zone of damaged muscles, where newly formed myosymplasts differentiated into myotubes and even in muscle fibers. Suppuration of the wound was prevented. Bone tissue in the fracture zone formed without preliminary formation of cartilaginous tissue, which resulted in more rapid osteogenesis (lamellar bone growth in the fracture zone).

A retrospective study of patients referred to the Department of Oral and Maxillofacial Surgery at Singapore General Hospital/National Dental Centre with mandibular fractures over a 3-year period from June 1995 to May 1998 was carried out. The cause, age, sex, race and anatomical distribution of the fractures were analysed for each of the 123 patients. The main cause of trauma was road traffic accidents (RTAs) (35.8%), of which 79.5% were motorcyclists. The highest incidence of trauma was in the 20-29 year age group (46.3%). Males outnumbered females in a ratio of 7.8:1. The parasymphysis was the most common site of injury (30.9%), and combined condylar and parasymphyseal fractures (26.0%) was the most common combination seen.

Purpose: This study compared the complication rate with different types of mandibular fracture treatment (maxillomandibular fixation, 2-mm miniplates, 2.4-mm AO plates, and 2.7-mm AO plates)., Patients and Methods: A total of 245 patients who presented with 386 fractures were retrospectively analyzed. Patient characteristics, type of fracture, severity of fracture, type of treatment used, and occurrence of complications were recorded. Statistical analysis was used to compare complication rates, fracture severity, and type of treatment., Results: There were no differences in the complication rates for the different types of treatment. There was a significant correlation (P < .05) between fracture severity and the overall complication rate, postoperative infection, and postoperative malocclusion, but there was no significant correlation between these complications and the type of treatment applied., Conclusion: The occurrence of postoperative complications in the treatment of mandibular fractures is fundamentally related to the severity of the fracture rather than to the type of treatment used.

Purpose: This study was designed to determine how well fractured condylar processes were reduced and the stability of the internal fixation in a group of patients whose fractures were treated by open reduction., Patients and Methods: Sixty-one patients treated by open reduction and internal fixation for unilateral condylar process fractures were studied prospectively using Towne's and panoramic radiographs. The radiographs were made before surgery, and immediately, 6 weeks, and 6 months postoperatively. The images were traced and digitized, and the position of the fractured condylar process was statistically compared with the position of the nonfractured condylar process in both the coronal and sagittal planes. Additionally, 2 observers examined the images and assessed these same 2 factors., Results: After surgery, the difference in position between the fractured and nonfractured sides averaged less than 2 degrees (not significantly different), indicating good reduction of the fractures. However, subsequently, between 10% and 20% of condylar processes had postsurgical changes in position of more than 10 degrees., Conclusions: This study showed that it is possible to anatomically reduce the fractured condylar process, but changes in position of the condylar fragment may then result from a loss of fixation.

Basic impairments of the muscular fibre in fractures of the lower jaw with different localization within terms from several hours to several weeks in persons with various clinical course were studied with help of electronic microscopy. Following treatment of the injury with a "quiet" course, in the tissues studied there was activation of reparative processes up to normalization of the submicroscopic structures. Despite the given treatment, the injury accompanied with predominance of destructive changes in the muscular tissue. In the muscles, a disturbed permeability of depolarization waves was revealed, they causing contraction and relaxation of the muscles.

Experiments on developing animals showed that mandibular fractures of any location can be complicated by pronounced growth disorders and abnormal development of mandibular bone, leading to deformations of the site of fracture. Abnormal mandibular development was particularly obvious after injuries to the condyle and condylar process, after fractures of mandibular body and angle with dissection of the neurovascular bundle, and in cases with osteomyelitis. Disorders in endochondral bone formation (which is normally most active in the condyle) caused by traumatic processes and disorders in neurotrophic regulation and blood supply to the bone, developing in neurovascular obstruction, underlie the mechanisms of posttraumatic mandibular deformations. These complications were observed in patients with fractures of different sites because of improper joining and fixation of fragments. Children should be regularly checked up after mandibular fractures. Measures aimed at prevention of growth disorders and development of mandibular bone lesions are obligatory at all stages of examination.

This study reviews the treatment of mandibular fractures in children for the period 1986-1995. The sample included 107 children under 15 years of age, which were studied by age, sex, cause and type of fracture, method of treatment and complications. The children were divided into four groups according to the development of the dentition: 0-5 years, 6-9 years, 10-12 years and 13-15 years. Boys to girls ratio was 3.46:1 and the highest incidence was observed in boys over 13 years of age. Associated injuries were more common in younger children (56%). Most of the fractures were the results of traffic accidents (28.97%), games and sports (25.23%), beating (19.63%) or falls (15.88%). Unilateral fractures were more common (69.16%) than bilateral (30.84%). Intermaxillar fixation for 3 weeks was the method of treatment used in 84.12% of the patients. Complications appeared to be rare.

Background and Objectives: The estimates of mandibular condyle fracture incidence lack consensus, as these fractures are frequently overlooked or misdiagnosed, resulting in adverse effects. The purpose of this article is to review the anatomy of the mandibular condyle and the surgical approaches currently available., Methods and Materials: Surgical treatment of mandibular condyle fractures remains controversial, due to the indications and difficulty with the associated vital structures. To aid in selecting the appropriate approach, the authors present a review of the mandibular anatomy and the approaches utilized, as reported in the literature and observed in the clinical practice of the authors., Results And/or Conclusions: In selecting the approach, the knowledge of the mandibular anatomy is vitally important. A survey found that the preauricular, submandibular, and intraoral approaches (in that order) were preferred. When treating the fractured mandibular condyle with open reduction and internal fixation, a thorough knowledge of the anatomy of vital structures, exercise of care, and careful dissection through the soft tissues will reduce the risk for morbidity.

Oral squamous cell carcinoma often invades the mandible. However, the incidence of pathological fractures of the maxillofacial bones is low and their treatment is rarely satisfactory. A patient, too weak to undergo surgery, affected by squamous cell carcinoma of the mandibular region with bone involvement and pathological fracture of the mandible, underwent chemotherapy with carboplatin associated with diphosphonate.

Objective: To evaluate the secondary effect of childhood miniature pig longitudinal fracture and transverse fracture of mandibular condyle to Temporomandibular Joint (TMJ)., Methods: Longitudinal and transverse fractures on condyle of 14 childhood miniature pigs were created respectively. After 3 and 6 months the TMJs were studied macroscopically and microscopically., Results: The transverse fracture of mandibular condyle brought about TMJ adaptive changes. There was no adhesion between disc and condyle. The longitudinal fracture led usually to bifid condyle deformity and adhesion between disc and condyle. Many fibroblasts and chondrocytes were seen in the adhesion between disc and condyle. Blood vessels and fatty degeneration appeared in the articular disc., Conclusion: Two different types of childhood condylar fractures are apparently different in the aspects of secondary lesions on TMJ. It suggests that an evident correlation between mandibular condyle longitudinal fracture and TMJ ankylosis.

In recent years lengthening of the human mandible by distraction osteogenesis has become an accepted treatment for correction of severe mandibular disto-basal discrepancies. Using extra-oral and intra-oral distraction devices the technique of osseous anchorage is usually preferred. To avoid the disadvantages of this method it is the aim of many research groups to develop a tooth-borne distraction. In the present animal study, six minipigs were treated with a new solely dentally fixed orthodontic device for mandibular distraction osteogenesis. Following bilateral osteotomy in the dentigerous area of the mandibular body and a latent period of 2-7 days, a mandibular lengthening of 9 mm was reached within a period of 9 days. This situation was retained using the distraction device for 6 weeks. After the removal of the apparatus, there followed a period of another 6 weeks of consolidation. The callus and bone formation and potential dental, periodontal and nerval reactions were radiologically examined and histological examination was performed at the end of the experiment. At 12 weeks after the mandibular lengthening, the osteogenesis in the distraction areas was complete. No destructive processes were recognizable, either at the roots or at the periodontium of the teeth near the osteotomy gap. The mandibular nerve at the osteotomy site remained intact. The results justified transferring this procedure to humans. The clinical application of the device is presented.

A life-size nylon model of a traumatized mandible was produced from CT scan data by the process of laser sintering. The model was used for pre-operative planning and for production of surgical aids in order to facilitate the restoration of a large bony defect. Vascularized iliac crest bone was harvested, titanium implants placed and the bone then grafted to the mandible.

Objective: The purpose of this investigation was to study the radiologic outcomes of pediatric condylar fractures., Study Design: Radiographs of 37 patients with 45 condylar fractures that had been diagnosed at the Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital were retrospectively reviewed. The frequency and characteristics of incomplete remodeling at an average of 4.1 years after the injury were studied. The influence of age and fracture type on remodeling were considered., Results: Incomplete remodeling was observed after 56% of the fractures. The most frequent signs of incomplete remodeling were alteration in the configuration of the surface of the condylar head and deformation of the condylar neck. Incomplete remodeling was frequently (83%) related to fracture dislocation. For this fracture type the radiologic prognosis seems poor in all age groups. A difference in ramus height between the 2 sides was observed in 52% of the fractures, particularly frequently (80%) after fracture dislocation., Conclusions: Radiologic aberrations are frequent after pediatric condylar fractures. Dislocated fractures, in particular, need special attention and long-lasting clinical follow-up.

Healing of the displaced condylar process fracture was analysed by means of an experimental model using adults rats. Displaced fractures of the right condylar process were achieved under general anaesthesia. Histological data initially demonstrated neutrophilic exudation along the articular capsule and adjacent muscle fibres. One week later, devitalized bone areas at the fracture site, as well as proliferation of cartilaginous and osseous tissue were observed. Subsequently, exuberant callus formation and a decrease in the inflammatory process occurred. After 3 months, the condylar process presented characteristics of normality and was centralized into the temporal fossa, with interposition of the articular disc. These results indicate that experimentally induced, displaced condylar process fractures heal by callus formation with simultaneous repositioning of the condyle.

Gunshot wounds to the maxillofacial region are unpredictable and run the gamut from minor injuries to severe mutilating and life threatening injuries. This patient although unfortunate to have been the victim of mistaken identify resulting in the gunshot wound, was fortunate that the bullet hit his bicuspid, which probably served to deflect its path away from vital structures, thus saving his life. This accounts for the buried bicuspid crown found in the midline of the body of the tongue. Rigid internal fixation of maxillofacial fractures minimizes risks to the airway that may occur if patients are in post-operative maxillo-mandibular fixation during the post-anesthetic recovery phase. In addition, the use of rigid internal fixation speeds up the recovery and the patient's ability to return to function after surgery. Above, we presented an interesting case of a mandibular anterior body fracture resulting from a gunshot wound in the face and resulting in the burying of a bicuspid crown in the substance of the tongue, treated under general nasoendotracheal anesthesia and the use of rigid internal fixation (EDCP).

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 mandible is often fractured during maxillofacial trauma because of its prominence within the facial skeleton and the fact that it is a favorite target in interpersonal violence. Treatment of mandibular fractures has made significant advances over the years due to the study of biomechanical principles, advancements in biomaterials and instrumentation and scientifically based research of treatment outcomes. This article will review the principles and philosophy of AO/ASIF techniques as applied to treatment of mandible fractures. Representative cases of different mandible fractures and their treatment will reinforce the clinical application of rigid fixation techniques.