Combination of Rigid and Nonrigid Fixation Versus Nonrigid Fixation for Bilateral Mandibular Fractures: A Multicenter Randomized Controlled Trial.

PURPOSE: We aimed to compare complication rates and functional outcomes in patients with bilateral mandibular fractures treated with different degrees of internal fixation rigidity. PATIENTS AND METHODS: This international, multicenter randomized controlled trial included adults with bilateral mandibular fractures located at either the angle and body, angle and symphysis, or body and symphysis. Patients were treated with either a combination of rigid fixation for the anterior fracture and nonrigid fixation for the posterior fracture (mixed fixation) or nonrigid fixation for both fractures. The primary outcome was complications within 6 weeks after surgery. Secondary outcomes were complications within 3 months, Helkimo dysfunction index, and mandibular mobility at 6 weeks and 3 months after surgery. RESULTS: Of the 315 patients enrolled, 158 were randomized to the mixed fixation group and 157 to the nonrigid fixation group. The overall complication rate at 6 weeks in the intention-to-treat population was 9.6% (95% confidence interval [CI], 5.3% to 15.6%) in the mixed fixation group and 7.8% (95% CI, 4.0% to 13.5%) in the nonrigid fixation group. With an unadjusted odds ratio of 1.25 (95% CI, 0.51 to 3.17), there were no statistically significant differences in complication rates between the 2 groups (P = .591). A multivariable model for complication risk at 6 weeks found no significant differences between treatment groups, but patients with moderate or severe displacement had a higher complication rate than those with no or minimal displacement (adjusted odds ratio, 4.58; 95% CI, 1.16 to 18.06; P = .030). There were no significant between-group differences in complication rates at 3 months. Moreover, no significant differences in Helkimo dysfunction index and mandibular mobility index at 6 weeks and 3 months were found between groups according to treatment allocated and treatment received. CONCLUSIONS: A combination of rigid and nonrigid fixation in patients with bilateral mandibular fracture has similar complication rates and functional outcomes to nonrigid fixation for both fractures.

Regeneration of Cystic Bone Cavities and Bone Defects With Bioactive Glass S53P4 in the Upper and Lower Jaws.

Cysts and tumors are common lesions in the jaws. To be able to retain a good volume of the alveolar ridge during healing as well as strengthening the angle and body of the mandible and provide an instant improved support for adjacent teeth, reliable long-term bone regeneration is needed. The purpose of this prospective study was to promote bone regeneration by filling bony defects in the upper or lower jaw with granules of the bioactive glass S53P4 (BAG), which have osteostimulative and antimicrobial properties.The authors treated 20 patients (21 defects) surgically; benign tumors, cysts, or infection related to impacted teeth in the maxilla or mandible. The tumor or cyst was removed or enucleated and thorough cleaning of the infected area was performed. The bone cavity was filled with granules of the BAG S53P4 despite signs of chronic infection in the area at the time of surgery. The patients were followed up for an average of 34 months clinically and with cone beam computerized tomography for 28 months. In 20 defects the final outcome was successful. Despite infection at the time of surgery in 65% of the patients, no material associated infection was seen during the follow-up. The BAG S53P4 granules were radiologically remodeled into bone after 2 years follow-up. The use of granules of the BAG S53P4 in the treatment of large bone defects provides infection-free reliable bone regeneration despite chronic infection at the time of surgery, which improves the prognosis of adjacent teeth.

Toll-like receptors -4 and -5 in oral and cutaneous squamous cell carcinomas.

BACKGROUND: Oral squamous cell carcinoma (OSCC) has a worse prognosis than cutaneous squamous cell carcinoma (CSCC). Toll-like receptor- 4 (TLR-4) and TLR-5 are transmembrane proteins that recognize endogenous and microbial agents. Their activation has been connected to cancer invasion. OBJECTIVE: The aim was to study the expression of TLR-4 and TLR-5 in OSCC and CSCC samples, and the effects of TLR-5 ligand flagellin on the proliferation, migration, and invasion of different mucocutaneous cell lines in vitro. METHODS: Samples of early-stage tumors (T1-T2N0M0) from 63 patients with OSCC and CSCC were obtained, in addition to eight normal mucosa and skin tissues from healthy subjects. Oral-cavity-derived highly aggressive HSC-3, less invasive SAS, and HPV-transformed benign IHGK as well as C-ha-ras-transformed (HaCat) skin carcinoma II-4 and non-invasive A5 cell lines were used. Flagellin-induced mucocutaneous cell lines were compared by using BrdU-proliferation, scratch migration, and myoma organotypic invasion assays. RESULTS: TLR-4 expression was similar in OSCC and CSCC tumors. TLR-5 was more abundant in OSCC than in CSCC samples. Flagellin induced the proliferation of SAS, II-4 and A5, migration of IHGK, II-4 and A5, and the invasion of II-4 cells. It had no effect on HSC-3 cells. CONCLUSIONS: Flagellin, a TLR-5 agonist, induced the migration and invasion of less aggressive mucocutaneous cell lines, but it had no effect on the most invasive oral carcinoma cells. The more aggressive clinical behavior of OSCC compared to CSCC may partially be related to the differences in the expression of TLR-5 in these malignancies.

A novel classification and online platform for planning and documentation of medical applications of additive manufacturing.

Additive manufacturing technologies are widely used in industrial settings and now increasingly also in several areas of medicine. Various techniques and numerous types of materials are used for these applications. There is a clear need to unify and harmonize the patterns of their use worldwide. We present a 5-class system to aid planning of these applications and related scientific work as well as communication between various actors involved in this field. An online, matrix-based platform and a database were developed for planning and documentation of various solutions. This platform will help the medical community to structurally develop both research innovations and clinical applications of additive manufacturing. The online platform can be accessed through http://www.medicalam.info.

Automated 3-D Computer-Aided Measurement of the Bony Orbit: Evaluation of Correlations among Volume, Depth, and Surface Area.

(1)The study aimed to measure the depth, volume, and surface area of the intact human orbit by applying an automated method of CT segmentation and to evaluate correlations among depth, volume, and surface area. Additionally, the relative increases in volume and surface area in proportion to the diagonal of the orbit were assessed. (2) CT data from 174 patients were analyzed. A ball-shaped mesh consisting of tetrahedral elements was inserted inside orbits until it encountered the bony boundaries. Orbital volume, area depth, and their correlations were measured. For the validation, an ICC was used. (3) The differences between genders were significant (p < 10-7) but there were no differences between sides. When comparing orbit from larger to smaller, a paired sample t-test indicated a significant difference in groups (p < 10-10). A simple linear model (Volume~1 + Gender + Depth + Gender:Depth) revealed that only depth had a significant effect on volume (p < 10-19). The ICCs were 1.0. (4) Orbital volume, depth, and surface area measurements based on an automated CT segmentation algorithm demonstrated high repeatability and reliability. Male orbits were always larger on average by 14%. There were no differences between the sides. The volume and surface area ratio did not differ between genders and was approximately 0.75.

Epithelial and stromal syndecan-1 and -2 are distinctly expressed in oral- and cutaneous squamous cell carcinomas.

BACKGROUND: Oral squamous cell carcinoma (OSCC) and cutaneous squamous cell carcinoma (CSCC) are epithelial neoplasms of which OSCC has worse survival and higher risk of metastasis than CSCC. The aim of this study was to explore the differences of immunoexpressions between syndecan-1 and -2 in OSCC and head and neck CSCC. METHODS: A total of 35 patients diagnosed with OSCC and 25 with CSCC, presented T1 and T2 tumors and treated at Helsinki University Central Hospital between years 2001 and 2009, were selected into this study. The levels and locations of syndecan-1 and -2 immunostainings were analyzed using formalin-fixed and paraffin-embedded tissue samples of OSCC and CSCC cases together with clinical data. RESULTS: Cell membrane epithelial syndecan-1 expression decreased significantly compared to normal tissue in both cancer types. Cell membrane syndecan-1 expression in the invasive front had negative correlation with invasion depth of both tumors (OSCC, r = -0.339, P = 0.025; CSCC, r = -0.469, P = 0.004). In cancers over 4-mm invasion depth, the number of stromal syndecan-1-positive collagen fibers and inflammatory cells were higher in OSCC than in CSCC. Syndecan-2 expression in non-malignant stroma was higher in CSCC than in OSCC tumors. In addition, unlike syndecan-1, syndecan-2 was more often and more intensively expressed in the tumor inflammatory cells in CSCC than in OSCC. CONCLUSION: Our results suggest that variable stromal expression of syndecan-1 and -2 in OSCC compared to CSCC may at least partially explain the differences in their clinical behavior.

[Head and neck reconstructions]. / Pään ja kaulan alueen rekonstruktiot.

Tissue reconstructions of the head and neck are required both in the repair of tissue defects following the surgical excision of malignant tumors and in the treatment of various other facial deformities. While it is usually possible to repair a damaged tissue or organ region, functional restoration is very difficult. The aim is radical excision of the tumor, and successful reconstruction will provide quality of life for the patient even after an extensive surgical procedure. The goal of the new reconstructive procedures is as natural outcome as possible, but the risk for postoperative complications must be taken into account.

[Therapeutic results in oral cancer--what has been learned?]. / Suusyövän hoitotulokset--mitä on opittu?

Oral cancer is the most common head and neck cancer in Finland. The number of new cases has been on a steady rise over the last decades. Smoking and heavy drinking are the most important risk factors. The role of papilloma virus infection is under active research, albeit with a smaller role than in oropharyngeal cancer, for instance. Surgical excision of the tumor is usually the first-line treatment. Pathoanatomical investigation of the primary tumor and cervical lymph nodes is essential in evaluating the need of adjuvant therapy. The prognosis of oral cancer has improved as a result of early detection and development of treatment modalities.

Bioabsorbable plates and screws for fixation of mandibulotomies in ablative oral cancer surgery.

PURPOSE: The use of bioabsorbable self-reinforced poly(L/DL)lactide 70/30 (SR-PLDLA) miniplates and screws could offer many benefits compared with conventional metallic devices for fixation of access osteotomies in oral cancer surgery. The material neither interferes with imaging nor with postoperative radiotherapy. The plates and screws do not need to be removed. The number of operations can be diminished and rehabilitation with dental implants shortened. The purpose of the present study was to report our experience with bioabsorbable osteosynthesis in the fixation of access osteotomies of the mandible. PATIENTS AND METHODS: A total of 15 patients (11 men and 4 women, mean age 63.1 years) were enrolled in the present study. All patients had oral squamous cell carcinoma. Three patients developed tumor recurrence, 2 of whom had previously undergone radiotherapy. Nine patients had radiotherapy scheduled postoperatively. The osteotomies were a straight-line cut and were situated medially or paramedially. For fixation, SR-PLDLA miniplates and screws (Biosorb 2.0 and 2.4 systems) were used without any maxillomandibular fixation. RESULTS: The follow-up ranged from 0.3 to 7.1 years (median 3.5). No problems were encountered during the operation. One patient required reoperation owing to failure in fixation. Twelve osteotomy lines (80%) were clinically stable; radiologically, 6 were totally and 3 partly consolidated. During follow-up, 6 nonunions were radiographically noted, 3 of which were clinically stable. CONCLUSIONS: Because of the high incidence of radiologic nonunion, bioabsorbable devices should not yet be used for fixation of access osteotomies in cancer surgery.

[Reconstruction of the oral cavity and the maxillomandibular region]. / Suuontelon ja leukojen alueen rekonstruktiot.

Traumas, tumors, congenital malformations and infections of the face and the jaws may give rise to extensive tissue defects, causing esthetic disfigurement requiring challenging reconstruction. Facial and jaw defects can be repaired with various local tissue grafts. Free bone grafts can be used alone or combined with pedunculated grafts. Free tissue grafts can be taken that contain merely the skin and the subcutaneous fat, or they can be combined with bone, muscle, or a combination of these.

[Medical applications of rapid prototyping--three-dimensional bodies for planning and implementation of treatment and for tissue replacement]. / Teollisen pikavalmistuksen lääketieteelliset sovellukset.

The possibilities of medical applications of rapid prototyping are continuously expanding and developing. In current applications, five main groups are distinguished: (1) preoperative planning, surgical training and teaching, (2) inert implants, (3) surgical instruments and special equipment associated with the operations, (4) postoperative guides, long-term supports and aids and (5) artificial tissue. The first four of these are already in general use, whereas the last one is still under investigation.

The Comprehensive AO CMF Classification System for Mandibular Fractures: A Multicenter Validation Study.

The AO CMF has recently launched the first comprehensive classification system for craniomaxillofacial (CMF) fractures. The AO CMF classification system uses a hierarchical framework with three levels of growing complexity (levels 1, 2, and 3). Level 1 of the system identifies the presence of fractures in four anatomic areas (mandible, midface, skull base, and cranial vault). Level 2 variables describe the location of the fractures within those defined areas. Level 3 variables describe details of fracture morphology such as fragmentation, displacement, and dislocation. This multiplanar radiographic image-based AO CMF trauma classification system is constantly evolving and beginning to enter worldwide application. A validation of the system is mandatory prior to a reliable communication and data processing in clinical and research environments. This interobserver reliability and accuracy study is aiming to validate the three current modules of the AO CMF classification system for mandible trauma in adults. To assess the performance of the system at the different precision levels, it focuses on the fracture location within the mandibular regions and condylar process subregions as core components giving only secondary attention to morphologic variables. A total of 15 subjects individually assigned the location and features of mandibular fractures in 200 CT scans using the AO CMF classification system. The results of these ratings were then statistically evaluated for interobserver reliability by Fleiss' kappa and accuracy by percentage agreement with an experienced reference assessor. The scores were used to determine if the variables of levels 2 and 3 were appropriate tools for valid classification. Interobserver reliability and accuracy were compared by hierarchy of variables (level 2 vs. level 3), by anatomical region and subregion, and by assessor experience level using Kruskal-Wallis and Wilcoxon's rank-sum tests. The AO CMF classification system was determined to be reliable and accurate for classifying mandibular fractures for most levels 2 and 3 variables. Level 2 variables had significantly higher interobserver reliability than level 3 variables (median kappa: 0.69 vs. 0.59, p < 0.001) as well as higher accuracy (median agreement: 94 vs. 91%, p < 0.001). Accuracy was adequate for most variables, but lower reliability was observed for condylar head fractures, fragmentation of condylar neck fractures, displacement types and direction of the condylar process overall, as well as the condylar neck and base fractures. Assessors with more clinical experience demonstrated higher reliability (median kappa high experience 0.66 vs. medium 0.59 vs. low 0.48, p < 0.001). Assessors with experience using the classification software also had higher reliability than their less experienced counterparts (median kappa: 0.76 vs. 0.57, p < 0.001). At present, the AO CMF classification system for mandibular fractures is suited for both clinical and research settings for level 2 variables. Accuracy and reliability decrease for level 3 variables specifically concerning fractures and displacement of condylar process fractures. This will require further investigation into why these fractures were characterized unreliably, which would guide modifications of the system and future instructions for its usage.

Sentinel lymph node biopsy as an alternative to wait and see policy in patients with small T1 oral cavity squamous cell carcinoma.

CONCLUSION: Although sentinel lymph node (SLN) biopsy is not yet validated for clinical use to replace elective neck dissection in patients with oral squamous cell carcinoma, it can be recommended for patients who do not fulfil the criteria for elective neck treatment according to current treatment protocols. OBJECTIVE: To examine the benefits of SLN biopsy in oral cancer patients who have a small risk for occult metastasis and therefore are not considered candidates for elective neck treatment. PATIENTS AND METHODS: Thirteen consecutive patients with a small T1 oral cavity squamous cell carcinoma, clinically staged NO, and who did not meet the indications for elective neck treatment, underwent SLN biopsy. The SLNs were cut at 1-2 mm intervals and stained with haematoxylin and eosin and cytokeratin AE1/AE3. RESULTS: Histopathological examination of SLNs revealed micrometastases in two patients. A selective neck dissection was performed on these patients and no further metastases were encountered. All patients had a minimum follow-up of 12 months and no cervical or other recurrences were encountered.

Rapid prototyped patient specific guiding implants in critical mandibular reconstruction.

Large tumours of the mandible need immediate reconstruction to provide continuity of the mandible, satisfactory function of the jaw, as well as an acceptable aesthetic outcome. In this prospective study we described the immediate reconstruction of the mandible using computer aided design and 15 rapid prototyped patient specific implants (PSI) in 14 patients suffering from benign or malignant tumours demanding continuity resection of the mandible. The scaffold PSI was filled with ß-tricalcium phosphate granules and autologous bone. Microvascular reconstruction was additionally needed in 12/15 cases. The clinical follow up was on average 33 months and the radiological follow up was on average 21 months. In nine cases the healing was uneventful. One patient lost the microvascular flap during the first postoperative week and one patient needed a revision due to perforation of the mucosa at the site of the PSI. Four patients had a major complication due to perforation of the mucosa leading to infection, which resulted in the total or partial removal of the PSI. The PSI seems to be a promising solution for treatment of patients demanding large reconstruction after mandible resection. The benefits are decreased rate of donor site complications and more accurate and prompt surgical procedure.

Modelling of orbital deformation using finite-element analysis.

The purpose of this study was to develop a three-dimensional finite-element model (FEM) of the human orbit, containing the globe, to predict orbital deformation in subjects following a blunt injury. This study investigated the hypothesis that such deformation could be modelled using finite-element techniques. One patient who had CT-scan examination to the maxillofacial skeleton including the orbits, as part of her treatment, was selected for this study. A FEM of one of the orbits containing the globe was constructed, based on CT-scan images. Simulations were performed with a computer using the finite-element software NISA (EMRC, Troy, USA). The orbit was subjected to a blunt injury of a 0.5 kg missile with 30 ms(-1) velocity. The FEM was then used to predict principal and shear stresses or strains at each node position. Two types of orbital deformation were predicted during different impact simulations: (i) horizontal distortion and (ii) rotational distortion. Stress values ranged from 213.4 to 363.3 MPa for the maximum principal stress, from -327.8 to -653.1 MPa for the minimum principal stress, and from 212.3 to 444.3 MPa for the maximum shear stress. This is the first finite-element study, which demonstrates different and concurrent patterns of orbital deformation in a subject following a blunt injury. Finite element modelling is a powerful and invaluable tool to study the multifaceted phenomenon of orbital deformation.

Multidisciplinary Approach to Management of Temporal Bone Giant Cell Tumor.

Background Giant cell tumors (GCTs) are rare osseous tumors that rarely appear in the skull. Methods We review the clinical course of a 28-year-old previously healthy woman with a complicated GCT. Results The reviewed patient presented with a middle cranial fossa tumor acutely complicated by reactive mastoiditis. Left tympanomastoidectomy was performed for drainage of the mastoiditis and for biopsies of the tumor. Due to the challenging tumor location, the patient was treated with denosumab, a fully humanized monoclonal antibody against receptor activator of nuclear factor kappa-B ligand, for 7 months, which resulted in significant preoperative tumor shrinkage. Extensive temporal craniotomy and resection of the tumor followed utilizing a temporomandibular joint total endoprosthesis for reconstruction. A recurrence of the tumor was detected on computed tomography at 19 months after surgery and treated with transtemporal tumor resection, parotidectomy, and mandible re-reconstruction. Conclusion A multidisciplinary approach resulted in a good functional result and, finally, an eradication of the challengingly located middle cranial fossa tumor.

Failed dental implants - clinical, radiological and bacteriological findings in 17 patients.

AIM: The aim of this study was to evaluate the reasons for implant failure in two Oral and Maxillofacial Units in Helsinki. Seventeen patients, who lost 30 implants were included in this study. MATERIAL AND METHODS: The patients and implants were studied clinically, radiologically and microbiologically. RESULTS: Most patients did not have any symptom indicating failure; hence, the failures were noticed mainly by the clinicians when instability of the fixture or of the prosthetic reconstruction became obvious. Radiolucency around the fixture was the most frequent radiological finding. Twenty per cent of the fixtures were located in insufficient bone. Ninety seven per cent of the bacterial cultures were positive, Streptococcus milleri being the most commonly identified aerobic and Fusobacterium nucleatum the most commonly anaerobic bacteria. CONCLUSION: The most critical time for success is immediately after prosthetic loading. Hence, implants should be placed in the optimal position to facilitate prosthetic reconstruction and loading.

The use of anatomically drop-shaped bioactive glass S53P4 implants in the reconstruction of orbital floor fractures--A prospective long-term follow-up study.

An isolated fracture of the orbital floor needs reconstruction if there is a clear herniation of adipose tissue or of the rectus inferior muscle into the maxillary sinus. A prospective study was carried out treating 20 patients with an isolated blow-out fracture of the orbital floor or with a combined zygomatico-orbito-maxillary complex fracture, using a newly designed anatomically drop-shaped implants made of bioactive glass (BAG) S53P4. Computed tomography (CT) was performed immediately postoperatively to confirm the correct position of the plate. The patients were followed up for an average of 32 months clinically and radiologically with magnetic resonance imaging (MRI) for an average of 31 months. None of the patients had any signs of complications related to the implant and the clinical outcome was very good. None of the patients had persisting diplopia. The level of the pupillas was normal in 15 of 20 patients. Minor hypo-ophthalmos ranging from 0.5 to 1.0 mm was observed in three patients, and moderate hypo-ophthalmos of 2.0 mm was seen in one patient. Hyperophthalmos of 1.0 mm was seen in one patient. Minor enophthalmos on the operated side ranging from 0.5 to 1.0 mm was seen in eight patients. Mild to moderate paraesthesia of the infraorbital nerve was observed in six patients. The immediate postoperative CT and the long term follow-up MRI revealed that the drop-shaped BAG implants retained their correct position in the orbital floor and did not show any evidence of losing their original shape or material resorption. No adverse tissue reaction was associated with the material. Due to the anatomical drop shape, the implants could successfully maintain the orbital volume and compensate for the retrobulbar adipose tissue atrophy.

Imaging characteristics of ameloblastomas and diagnostic value of computed tomography and magnetic resonance imaging in a series of 26 patients.

OBJECTIVES: To evaluate the imaging characteristics of ameloblastomas and to analyze the diagnostic value of computed tomography (CT) and magnetic resonance imaging (MRI) compared with conventional dentoalveolar imaging. STUDY DESIGN: In this observational retrospective study, the panoramic radiographs (n = 25) and the CT (n = 26) and MRI (n = 5) images of histopathologically verified ameloblastomas in 26 patients were reviewed. RESULTS: Characteristic findings were multilocularity, marked expansion of the cortical plate, perforation at an earlier stage, and extensive root resorption. On contrast-enhanced CT or MRI, the majority (14 of 17) of the nonunicystic ameloblastomas contained a mixed cystic and solid pattern. Unicystic ameloblastomas (n = 6) and ameloblastomas derived from the cyst epithelium (n = 2) showed thick rim enhancement or a mural solid component in an otherwise cystic lesion. CONCLUSIONS: Contrast-enhanced CT and MRI greatly aid in distinguishing between ameloblastomas and other cystlike lesions because they allow for visualization of the mixed cystic and solid content characteristic of nonunicystic ameloblastomas. The differential diagnostic value of CT and MRI is significant with regard to unicystic ameloblastomas.