Guo Cb

Factors influencing survival rate in adenoid cystic carcinoma of the salivary glands

OBJECTIVE To study factors influencing survival rate of adenoid cystic carcinoma (ACC) of the salivary glands. METHODS One hundred and twelve cases were followed up for move than ten years and were studied to investigate factors influencing the survival rate of patients. Statistical analysis was performed using a computer program (Survcalc, John Wiley Co.). The data were statistically treated for survival curves according to the kaplan-meier method. The log rank tests were employed to assess the statistical significance of various groups. RESULTS The age of the patients younger than 50 years old, early clinical stage, glandular/tubular histological type and tumor without nerve involvement had the best prognosis. Age of the patients older than 50 years old, ACC in the submandibular gland, advanced clinical stage (stage III and IV), solid histological type and tumor with nerve involvement had a poor prognosis. CONCLUSIONS Age of the patients, tumour site, clinical stage, histological type and with or without nerve involvement are the important factors influencing the prognosis.

Hand grip strength: an indicator of nutritional state and the mix of postoperative complications in patients with oral and maxillofacial cancers.

The aim of the study was to assess the reliability of hand grip strength as an indicator of nutritional state, and to see if it was of any value in the prediction of postoperative complications. One-hundred and twenty-seven patients who presented with oral and maxillofacial cancer were studied for measurement of hand grip strength, mid-arm muscle circumference, and creatinine-height index. Hand grip strength correlated well with mid-arm muscle circumference and creatinine-height index. Patients whose hand grip strength was < 85% of the control value developed significantly more postoperative complications than those in whom it was 85% or more (15/31 (48%) compared with 12/65 (18%), P = 0.004). In conclusion, hand grip strength is not only a useful, non-invasive indicator of skeletal muscle mass, but may also be of use in predicting postoperative complications.

Prevention of radiation-induced xerostomia by submandibular gland transfer.

This study was carried out for the purpose of evaluating the efficacy of submandibular gland transfer to prevent radiation‐induced xerostomia.

Applicability of the general nutritional status score to patients with oral and maxillofacial malignancies

The general nutritional status (GNS) score was used to assess the nutritional status of 127 consecutive patients with oral and maxillofacial malignancies. Forty-six of our patients (36.2%) were undernourished (group 2), while 81 (63.8%) were in good nutritional condition (group 1). Comparison of nutritional laboratory tests between these two groups showed that the differences in serum albumin, transferrin, and creatinine-height index (CHI) had statistical significance, yielding an excellent correlation between the GNS score and the nutritional laboratory test. Undernourished patients had a significantly higher postoperative complication incidence (48.3%) than well-nourished patients (19.4%) (chi 2 = 6.637; P < 0.01), indicating that the GNS score can be used as a prognostic index.

Three-Dimensional Accuracy of Virtual Planning and Surgical Navigation for Mandibular Reconstruction With Free Fibula Flap.

PURPOSE Although free fibula flaps are widely used for mandibular reconstruction, their 3-dimensional position is difficult to control during conventional surgery. We aimed to improve this process by using computer-aided design (CAD) and surgical navigation. PATIENTS AND METHODS We retrospectively reviewed 29 benign tumor patients who underwent primary unilateral mandibular reconstruction with free fibula flap. They were divided into 3 groups: group A, comprising 10 patients, underwent reconstruction based on the surgeons experience; group B, comprising 7 patients, underwent reconstruction based on CAD; and group C, comprising 12 patients, underwent reconstruction based on CAD and surgical navigation. Condyle and gonion positions and mandibular angles were measured. Operative times were recorded. RESULTS Among the 17 patients who underwent condylar resection, the average condyle shift was greater in group A than in groups B and C (P < .05). The average gonion shift was greater in groups A and B than in group C (P < .05). The difference between the reconstructed and contralateral mandibular angles was greater in group A than in groups B and C (P < .05). The mean operative time did not differ among the 3 groups. CONCLUSIONS CAD can guide mandibular angle remodeling and condyle placement. CAD and surgical navigation increase reconstruction accuracy without prolonging operative time.

Outcomes of Orbital Floor Reconstruction After Extensive Maxillectomy Using the Computer-Assisted Fabricated Individual Titanium Mesh Technique.

PURPOSE Orbital floor defects after extensive maxillectomy can cause severe esthetic and functional deformities. Orbital floor reconstruction using the computer-assisted fabricated individual titanium mesh technique is a promising method. This study evaluated the application and clinical outcomes of this technique. PATIENTS AND METHODS This retrospective study included 10 patients with orbital floor defects after maxillectomy performed from 2012 through 2014. A 3-dimensional individual stereo model based on mirror images of the unaffected orbit was obtained to fabricate an anatomically adapted titanium mesh using computer-assisted design and manufacturing. The titanium mesh was inserted into the defect using computer navigation. The postoperative globe projection and orbital volume were measured and the incidence of postoperative complications was evaluated. RESULTS The average postoperative globe projection was 15.91 ± 1.80 mm on the affected side and 16.24 ± 2.24 mm on the unaffected side (P = .505), and the average postoperative orbital volume was 26.01 ± 1.28 and 25.57 ± 1.89 mL, respectively (P = .312). The mean mesh depth was 25.11 ± 2.13 mm. The mean follow-up period was 23.4 ± 7.7 months (12 to 34 months). Of the 10 patients, 9 did not develop diplopia or a decrease in visual acuity and ocular motility. Titanium mesh exposure was not observed in any patient. All patients were satisfied with their postoperative facial symmetry. CONCLUSION Orbital floor reconstruction after extensive maxillectomy with an individual titanium mesh fabricated using computer-assisted techniques can preserve globe projection and orbital volume, resulting in successful clinical outcomes.

Maxillary-fronto-temporal approach for removal of recurrent malignant infratemporal fossa tumors: Anatomical and clinical study.

PURPOSE For recurrent malignant tumors occurring in the infratemporal fossa, it is difficult to select a proper surgical approach. We explore the efficiency of a new approach for removal of recurrent malignant tumors involving the infratemporal fossa based on the measurement on three-dimension CT, observation of six cadaveric specimens, and our surgical experience. MATERIALS AND METHODS The distances between the surgical landmarks in the infratemporal fossa were measured using CT data to determine the safe distance. And anatomy observation was examined on 6 formalin-fixed cadaveric specimens. Data from seven patients with recurrent malignant infratemporal fossa tumors were retrospectively analyzed. RESULTS The mean distance of the medial pterygoid plate from the zygoma was 52.12 mm. The maxillary artery can be found between the deep surface of the condyle and the sphenomandibular ligament, with mean distance of 8.25 ± 3.22 mm to the inferior border of the capsule of the temporomandibular joint. All tumors got gross resection using the maxillary-fronto-temporal approach with minor complication. CONCLUSIONS The advantages of the new approach include adequate protection of facial nerve with extended operation field; the exposed temporal muscle could be used to fill the dead space. This technique is especially useful to remove recurrent malignant infratemporal tumors safely.

Surgical navigation-assisted mandibular reconstruction with fibula flaps.

The mandible has an important role in appearance and function. The aim of this study was to describe and evaluate surgical navigation-assisted mandibular reconstruction with the fibula flap. Patients recruited into the study had a custom dental splint fabricated to maintain the mandible in a fixed position. Later, the computed tomography (CT) scan, preoperative design, and operation on the mandible were done in the same position. At 1 week after surgery, a CT scan was done to evaluate the repeatability between the preoperative design and the postoperative result. Twenty patients were enrolled in this study. Good repeatability between the postoperative CT and the preoperative design was found. The repeatability between the preoperative plan and postoperative outcome was 79.1 ± 8.6% at within 1mm, 87.1 ± 6.7% at within 2mm, and 91.9 ± 5.4% at within 3mm. From this study, it can be concluded that surgical navigation techniques can precisely transfer the preoperative design to the operation in mandible reconstruction with a fibula flap. This will assist the surgeon in achieving good cosmetic and functional outcomes.

Computed tomography imaging of Medpor: Graph-cut algorithm and its accuracy.

Abstract Porous polyethylene has become a popular alloplastic material for maxillofacial reconstruction. Despite its benefits, this material is radiolucent on conventional radiography. Computed tomography of traditional graphic segmentation based on gray levels was reported by a few authors, but the accuracy has not been described. The aim of this study was to image this material using segmentation based on Graph-cut algorithm. Another object was to compare accuracy of 2 algorithms. Between 2005 and 2010, 15 patients (12 females) participated in the study. Computed tomography was used for image acquisition. Graphic segmentation based on gray level involved use of the software OsiriX. Stroke-based specification for user interaction and Graph-cut segmentation involved a self-developed module. The accuracy of both segmentation algorithms was tested by comparing the volume of reconstructed Medpor with the actual volume measured by the draining method during surgery. Twenty-seven comparisons of the computed and actual volumes were gained. Linear regression was done between reconstructed and real volume. For the volume of Graph-cut algorithm, the regression equation was = −0.19425 + 1.02692S; the difference between the population intercept and zero was not significant (t = −0.83, P = 0.4172). For the volume of gray-level algorithm, the regression equation was = −1.15282 + 1.14101S; the difference between the population intercept and zero was significant (t = −3.04, P = 0.0055).These results demonstrated porous polyethylene can be well defined by computed tomography segmentation with Graph-cut and gray-level algorithms. Graph-cut algorithm has a better accuracy compared with that of gray-level algorithm.

Imaging features of medicine-related osteonecrosis of the jaws: comparison between panoramic radiography and computed tomography

OBJECTIVE The current staging system of medicine-related osteonecrosis of the jaws (MRONJ) assigns patients to different stages based on clinical manifestations. The extent of bone disease cannot be fully determined without radiologic evaluation. Missing radiologic information may lead to incorrect classification of MRONJ, resulting in poor outcomes of treatment. The objective of this study was to compare computed tomography (CT) and panoramic radiography (PR) features of MRONJ in different stages to achieve accurate staging on the basis of combined findings from clinical staging and imaging. STUDY DESIGN A retrospective study was carried out to analyze the differences in the radiographic features of various clinical stages in MRONJ, as shown by PR and CT. RESULTS Both PR and CT could detect the typical syndrome of osseous sclerosis in grade 0 and grade 1. For the patients of grade 2, more features were observed on CT, such as periosteal reaction, cortical perforation, and periosteal bone deposition. CT was also conducive to analyzing the degree of the maxillary lesion and soft tissue involvement as compared with PR. CONCLUSIONS This study showed that CT detects changes that may not be revealed by plain radiography in patients with MRONJ.