A comprehensive classification of mandibular fractures: a preliminary agreement validation study.

This study evaluates a comprehensive classification system for mandibular fractures based on imaging analysis. The AO/ASIF scheme, defining three fracture types (A, B, C), three groups within each type (e.g. A1, A2, A3) and three subgroups within each group (e.g. A1.1, A1.2, A1.3) with increasing severity from A1.1 (lowest) to C3.3 (highest) was used. The mandible is divided into two vertical units (I and V), two lateral horizontal units (II and IV) and one central unit (III) comprising the symphyseal and parasymphyseal region. Type A fractures are non-displaced, type B are displaced and type C are multifragmentary/defect injuries. Groups and subgroups are further defined in the classification system. Two classification sessions using semi-automatic software with 7 and 9 surgeons were performed to evaluate 100 fracture cases in the first session and 50 in the second. Inter-observer reliability and individual rater's accuracy were evaluated by kappa coefficient and latent class analysis, respectively. The analysis of inter-observer agreement for the detailed coding showed kappa coefficients around 0.50 with higher agreement among raters in the vertical units. This system allows standardization of documentation of mandibular fractures, although improvement in the definition of categories and their application is required.

Clinical and pathological features of the murine AT-84 orthotopic model of oral cancer.

OBJECTIVE: The murine AT-84 orthotopic model of oral cancer was assessed to find how similar it is to human oral cancer. This was done because testing of new treatments for oral cancer requires the use of a realistic animal model. MATERIALS AND METHODS: Tumors were induced at orthotopic (oral) or heterotopic (flank) sites and their features were compared. The therapeutic effects of surgery, 5-fluorouracil and cisplatin were measured on the orthotopic tumors. RESULTS: Tumors had the histological appearance of a sarcomatoid carcinoma, invading locally and causing weight loss and death. The oral tumors metastasized to the lungs frequently. Tumors could be treated with some success by surgery or chemotherapy, but generally recurred. CONCLUSIONS: The similarities to human oral cancer suggest that the model will be very useful in the evaluation of experimental therapies for oral cancer.

Effect of herpes simplex virus type-1 on growth of oral cancer in an immunocompetent, orthotopic mouse model.

Herpes simplex virus type-1 has been proposed as an agent for the treatment of oral cancer. Experiments were designed to test its effectiveness in an animal model that had a high level of similarity to the human disease. The mouse oral cancer cell line, AT-84, was implanted at an orthotopic site--the base of the tongue--into syngeneic, immunocompetent C3H mice. As expected, tumors invaded the musculature of the tongue, eroded the mandible, and metastasized to the lungs. To obtain a suitable strain of HSV-1 for therapy we screened 17 fresh clinical isolates and selected one that grew to a high titer in vitro. The mouse tumors were then treated by injection of HSV-1 at a titer of 10(9) plaque-forming units/milliliter. To prolong the anti-tumor effect some mice were also given cyclophosphamide, hydrocortisone, or a second injection of virus. To find the importance of bystander killing of tumor cells, some mice were given virus with ganciclovir. A reduction in tumor volume for a limited period was seen after treatment by HSV-1, and was increased by a second injection of virus or by the administration of cyclophosphamide. Ganciclovir negated the anti-tumor effect. Virus was detectable in the tumors for up to 7 days, and loss of virus coincided with the time at which growth of tumors resumed. The mortality of the mice varied up to around 50%. It appears that (1) a non-attenuated strain of HSV-1 can inhibit the growth of an aggressive malignant oral tumor, but only to a limited extent and (2) inhibition depends on the ability of the virus to replicate in the tumor. It is suggested that mutations in the virus will be necessary to prevent mortality, but must be designed carefully so as not to reduce the virulence of the virus.

Minimally invasive approaches to mandibular fractures.

Excellence in mandibular fracture repair requires anatomic restoration of the displaced bone segments, maintenance of the reduction until bone union has been confirmed, and minimization of surgical stigmata. Repairs should ideally be cost-effective, reproducible, adaptable, and expeditiously executed. Fractures of two subregions of the mandible, the condylar neck and the symphysis, can benefit from minimally invasive surgical techniques. The use of these techniques in the mandible is reviewed.

The transglabellar/subcranial approach to the anterior skull base: a review of 72 cases.

OBJECTIVES: To describe the transglabellar/subcranial approach to the anterior skull base and to compare it with more traditional approaches to craniofacial resection. DESIGN: A retrospective analysis of 72 cases at 2 academic medical centers. The main parameters analyzed were the disease entities treated, the average operating room time, the average amount of blood loss, the number of transfusions, the length of intensive care unit and hospital stays, and complication rates. These were compared with published data for traditional craniofacial approaches. SETTING: All patients were operated on by the authors in collaboration with neurosurgical teams at the State University of New York Upstate Medical University, Syracuse, and the University of Michigan Hospital, Ann Arbor. PATIENTS: The transglabellar/subcranial approach was performed 72 times in 69 patients in this series. Forty-two procedures in 40 patients were performed for malignant disease and 30 procedures in 29 patients were performed for benign entities. Patients' ages ranged from 2 to 78 years. Follow-up ranged from 6 months to 4 years, with a minimum follow-up of 1 year for survivors. RESULTS: There were no operative mortalities. Operating time, average amount of blood loss, length of hospital and intensive care unit stays, and complication rates compared favorably with published results of traditional craniofacial resections. CONCLUSIONS: The transglabellar/subcranial approach to the anterior skull base may be a reasonable technique for the surgical management of lesions in the region of the anterior skull base. It provides excellent exposure of the nasal cavity, the orbits, and the ethmoid and sphenoid sinuses, while allowing wide access to the anterior fossa with a minimum amount of frontal lobe retraction.

Gene expression profiles in squamous cell carcinomas of the oral cavity: use of laser capture microdissection for the construction and analysis of stage-specific cDNA libraries.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer among men in the developed world affecting the oral cavity, salivary glands, larynx and pharynx. Utilizing tissue from patients with HNSCC, we sought to systematically identify and catalog genes expressed in HNSCC progression. Here, we demonstrate the successful use of laser capture microdissection for procuring pure populations of cells from patient tissue sets comprised of oral squamous cell carcinomas (OSCCs) and matching normal tissue. From the estimated 5000 cells procured for each sample, we were able to extract total RNA (14.7-18.6 ng) of sufficient quality to transcribe GAPDH by reverse transcriptase-polymerase chain reaction (RT-PCR). The RNA was used for the synthesis of blunt-ended, double-strand complementary DNAs (cDNAs) by oligo (dT)-mediated reverse transcription, followed by addition of linkers. Primers specific for these linkers with uracil deglycosylase-compatible ends were used to amplify these cDNAs by PCR and the product was subcloned into the pAMP10 cloning vector. Ninety-six clones from each of six libraries were randomly sequenced and results indicated that 76-96% of the inserts represent either anonymous expressed sequence tags (ESTs) (25-48%), known genes (9-29%) or novel sequences (27-51%), respectively, with very little redundancy. These results demonstrate that high quality, representative cDNA libraries can be generated from microdissected OSCC tissue. Furthermore, these finding suggest the existence of at least 132 novel genes expressed in our cDNA libraries, which may have a role in the pathogenesis of HNSCC, and may represent novel markers for early detection as well as targets for pharmacological intervention in this disease.

Transduction of normal and malignant oral epithelium by particle bombardment.

Although genetic approaches to the treatment and prevention of oral cancer are being developed, there are no suitable methods of transduction of the oral mucosa or early cancers. We therefore tested the technique of particle bombardment for its ability to transduce oral cancer cells in vitro and normal epithelium of the hamster cheek pouch in vivo. A gene gun was used to transfer a plasmid that encoded a marker/suicide fusion gene, beta-galactosidase-thymidine kinase (GAL-TEK), under control of a CMV promoter. For comparison we used the method of lipofection and an adenovirus vector. Particle bombardment transduced up to 13% of cells in culture, resulting in a 24.3% reduction in growth in the presence of ganciclovir. The efficiency of transduction was similar to that of lipofection but was much less than that of the adenovirus vector, which transduced 54% of cells and completely inhibited their growth in the presence of ganciclovir. Transduction of the hamster cheek pouch by particle bombardment produced expression of beta-galactosidase as judged by macroscopic staining, for up to 5 days. However, histological examination showed that the transduced cells were rare and superficial, and that administration of systemic ganciclovir did not lead to any changes in the tissue. Improvements in efficiency are necessary before the gene gun can be used in the management of oral cancer.

Internal fixation of maxillofacial fractures: indications and current implant technologies and materials.

Rigid fixation techniques are frequently utilized for the repair of maxillofacial skeletal injuries. This paper reviews the commonly available implants and materials along with their typical indications. The focus is primarily on the most recent trends and developments. Latticework plates and meshes provide greater fixation strength with smaller amounts of metal; modern reconstruction plates allow for fixation of the screws directly to the plates; self-drilling screws make application faster and easier. Resorbable implants made of various polyester polymers are now available, though their indications remain limited thus far. Future developments are discussed as well, including the advent of endoscopic plate placement and image-guided skeletal repositioning.

Cranial bone grafting in maxillofacial trauma and reconstruction.

Although manipulation of cranial bone has a long history, the use of cranial bone for reconstruction of craniomaxillofacial defects has only become popular in the last 15 years. Many refinements in harvesting and placement techniques have occurred over that time period. Cranial bone is valued for craniofacial skeletal reconstruction because of the proximity of the donor site to the recipient site, reasonable resistance to resorbtion, suitable geometry, and ability to be rigidly fixated. Although intracranial injury is a possibility, careful harvesting techniques minimize donor site morbidity. A detailed knowledge of the anatomy of the tissues around the skull is critical to safe harvesting of cranial bone grafts. Selection of appropriate graft types, proper handling techniques, and use of rigid fixation when indicated result in reliable reconstruction and augmentation of the craniofacial skeleton.

Fibromatosis colli. The utility of fine-needle aspiration in diagnosis.

BACKGROUND: Fibromatosis colli (FC), also known as sternocleidomastoid tumor of infancy, is a benign spindle cell lesion of the sternocleidomastoid muscle. It usually is seen in the first few weeks of life and is the most common cause of a neck mass in the perinatal period. Although FC may lead to congenital muscular torticollis requiring surgical intervention, if the diagnosis of FC is certain, the usual initial treatment option is conservative management. OBJECTIVE: To show the utility of fine-needle aspiration in the diagnosis of FC. PATIENTS: Five cases in which fine-needle aspiration was used in the evaluation of patients with FC were identified retrospectively by a search of the cytopathology files of the State University of New York Health Science Center at Syracuse and the Virginia Commonwealth University, Medical College of Virginia, Richmond. RESULTS: Fine-needle aspiration yielded an initial diagnosis of FC in 4 of the 5 cases. Smears made from the aspirated material were of low cellularity, but showed a characteristic population of spindle-cell fibroblasts. In addition to these fibroblasts, a variable amount of degenerating skeletal muscle was present in the background. CONCLUSION: With the collaborative efforts of otolaryngologists and pathologists, fine-needle aspiration can be used to confirm a clinical diagnosis of FC while avoiding the expense and risk of open biopsy.

Maxillofacial fixation with absorbable miniplates: computed tomographic follow-up.

Rigid internal fixation has become a mainstay of treatment for maxillofacial trauma. Refinement in materials and manufacturing have led to unobtrusive titanium miniplates and microplates. However, concerns remain regarding the presence of plates and screws after fracture healing has occurred. Absorbable rigid fixation systems ideally would provide sufficient strength and fixation to allow osseous healing and then be absorbed without sequelae. Plates and screws made from polylactic acid-polyglycolic acid copolymer approach this ideal. Four maxillofacial trauma patients underwent open reduction and internal fixation using absorbable plates and screws. Direct coronal computed tomographic (CT) scans were obtained before and after repair of the fractures. CT scan 6 months after repair shows adequate reduction of fractures and osseous healing. Clinical follow-up shows no significant sequelae.

Transnasal endoscopic surgery of the pituitary gland: technical note.

OBJECTIVE: An approach to transnasal transsphenoidal debulking of pituitary tumors using endoscopic guidance is presented. METHODS: Technical details of this approach using an endoscope inserted through one nostril and operating instruments inserted through a submucosal tunnel created via the other nostril are discussed. RESULTS: Ten patients who had operations are tabulated. Illustrative cases are presented. CONCLUSION: Endoscopic debulking of pituitary tumors can provide good results with minimal operative morbidity.

Acute internal jugular vein thrombosis associated with pseudoabscess of the retropharyngeal space.

We present four patients in whom evidence of edema or a pseudomass in the retropharyngeal space was found on CT scans obtained after thrombosis of the internal jugular vein. The clinical condition of one patient led to surgery, which documented the sterility of the retropharyngeal space despite the CT appearance of an inflammatory process. The CT findings, which are confusing initially, are found to be typical in retrospect.

Safe and dependable harvesting of large outer-table calvarial bone grafts.

A review of a new technique for the harvesting of split (outer-table) calvarial bone grafts is presented. The use of calvarial bone grafts for facial reconstructive surgery has become more commonplace in recent years. Low donor site morbidity and availability of adequate amounts of membranous bone in close proximity to the facial surgical site make its use particularly desirable. Unfortunately, the occasional complications associated with the harvesting of these grafts can be severe, including dural tears and/or hemorrhage from a dural sinus, as well as late hematomas and meningitis. The technique herein described involves the use of a long malleable blade in a reciprocating saw. The malleability of the blade allows it to conform to the shape of the skull while elevating split grafts almost as wide as the blade is long. Twenty separate grafts were harvested in 18 patients. The largest measured 7 x 10 cm. The grafts were further contoured after harvesting and used in 37 sites. No grafts splintered, and no donor site complications were encountered. While care must of course be exercised with any technique, this one is believed to be a safe and dependable method for the harvesting of split calvarial grafts for facial reconstruction.

Bioresorbable screws for facial bone reconstruction: a pilot study in rabbits.

Rigid fixation using plates and screws is an accepted mode of repair for facial fractures and osteotomies. To avoid potential complications associated with metal implants, bioresorbable implants are being developed. A study was performed to assess the strength over time of three bioresorbable polymeric screws for facial bone reconstruction. Screws of each polymer type and a titanium control were implanted in the periorbital bones of eight rabbits. Rabbits were euthanized at various time intervals. Pull-out testing and histological analysis were performed. Results showed varying degrees of resorption and screw pull-out strength dependent on time and polymer type, and no change in the control. This study demonstrates that bioresorbable screws can be used in bone, although the optimal choices for human implantation are yet to be determined.

Assessing whether the plane of section on CT affects accuracy in demonstrating facial fractures in 3-D reconstruction when using a dried skull.

CT slice thickness and threshold value are well-known determinants of accuracy in three-dimensional (3-D) CT image reconstruction. The purpose of this study was to assess whether the plane selected for primary CT data acquisition, axial vs coronal, might also contribute to the accuracy and ease of identification of abnormalities in 3-D image reconstruction independent of the 3-D processing system used. Two sets of 10 observers evaluated fractures created in a dried skull and corresponding 3-D image data. A General Electric 9800 scanner was used to acquire the two-dimensional CT data. The 3D98 Quick software and ISG Camra Allegra workstation were used for two sets of 3-D reconstructions. The expected result was that fractures oriented perpendicularly to the initial plane of CT section would be better reconstructed on 3-D than when the initial plane of CT imaging paralleled the fracture. Our results indicate that Le Fort fractures (types I and III) are better displayed with coronal CT data and that zygomatic tripod fractures may be better displayed in 3-D with axial CT image data.

The effect of computed tomographic scan orientation on information loss in the three-dimensional reconstruction of tripod zygomatic fractures.

Fractures modeled in the dried skull indicate that the initial plane of computed tomography (CT) section contributes to the accuracy of three-dimensional (3D) images generated from two-dimensional (2D) CT data. The authors retrospectively analyzed seven clinical cases of tripod zygomatic fractures that were imaged with both axial and coronal CT scan orientations. Ten observers evaluated paired 3D CT images, one generated from 2D CT data in the axial plane and the other generated from coronal 2D CT data, for each of the seven cases of tripod fractures. A G-E 9800 CT scanner with the 3D98 Quick processing system were used for the 3D reconstructions. The axial scan orientation resulted in 3D reconstructions that had significantly less information loss in the display of the tripod fractures than did those based on coronal CT data (P less than .025).

The effects of adenotonsillectomy on growth in young children.

A history of poor weight gain can often be elicited in young children with chronic upper airway obstruction resulting from adenotonsillar hypertrophy. A series of 41 consecutive children under 3 years of age, who underwent inpatient adenotonsillectomy, were reviewed for changes in weight and height. Thirty-seven patients had adequate long-term follow-up. Of these, many had dramatic improvements in growth after adenotonsillectomy. Indications for surgery in this group were recurrent infection in three patients (7%), unilateral tonsillar mass in one patient (3%), and upper airway obstruction in 37 patients (90%). A clear history of sleep apnea was elicited in 59%. At the time of surgery, 19 of 41 patients (46%) were of the fifth percentile or lower for age-corrected weight. The inpatient hospital stay averaged 3.2 days. The postoperative complication rate was 27%, with postoperative stridor as the most common complication. After surgery, 28 children (75%) showed a change to a higher percentile for weight. Twenty-four (65%) had percentile changes of 15% or more. This change is significant according to results of the Wilcoxon signed-rank test (p less than 0.001). We conclude that a relationship exists between improved growth rate and adenotonsillectomy in our study group. The rapid improvement in growth appears to be most obvious in children with upper airway obstruction resulting from adenotonsillar hypertrophy. Upper airway obstruction (including andenotonsillar hypertrophy) should be suspected as a possible cause in the workup of children with suboptimum growth.