Does a Severely Resorbed Subantral Ridge Decrease Long-Term Implant Survival Rate with Sinus Floor Augmentation?

PURPOSE: To identify the impact of residual bone height on 5-year implant survival and prosthetic complication rates in patients who underwent maxillary sinus grafting. MATERIALS AND METHODS: A total of 87 consecutive patients were treated with 104 lateral approach maxillary sinus floor augmentation procedures with 100% deproteinized bovine bone and received 169 implants. The analysis considered patient age, sex, time of implant placement, and residual bone height. Patients with < 3 mm residual bone height were assigned to the study group; otherwise, they were placed in the control group. RESULTS: The mean follow-up was 68.2 months (0 to 103 months). The mean residual bone height was 1.8 mm in the study group and 4.1 mm in the control group. The 5-year implant survival and prosthetic complication rates were, respectively, 97.4% and 8.0% in the study group and 100% and 12.5% in the control group. Residual bone height, sex, age, and time of implant placement were not significant factors for the 5-year implant survival or prosthetic complication rate. The lateral bone wall was significantly thinner in the study group. The grafted bone height reduction was significantly different at 6 months and 2 years postoperation in both groups, but there was no difference in the change in grafted bone height reduction over time between the two groups. CONCLUSION: A residual bone height < 3 mm did not impact the survival rates of implants placed in grafted maxillary sinuses or the prosthetic complication rate after 5 years of functional loading.

Histologic and Clinical Evaluation of Ridge Augmentation of Extraction Sockets with Severe Bone Defects: A Clinical Prospective Study.

PURPOSE: To primarily evaluate the dimensional changes of bone and soft tissue following ridge augmentation in compromised molar regions. The secondary objective was to evaluate the histologic composition of augmented sites. MATERIALS AND METHODS: The study included 27 patients who underwent augmentation of extraction sites with grafts covered by a collagen membrane. CBCT was taken immediately after augmentation (T2) and after 8 months of healing, before implant placement (T3). The width and height of the extraction sites were recorded at extraction (T1) and reentry surgery (T4). A histomorphometric analysis was performed. Data were evaluated in terms of bone crest level, implant survival rates, and change in mucogingival junction. RESULTS: According to clinical measurement, horizontal and vertical bone gain was 10.15 ± 1.00 mm and 8.80 ± 1.86 mm, respectively. Radiographic measurement showed that the horizontal width changes were 1.46 ± 0.52 mm, 0.98 ± 1.29 mm, and 1.29 ± 0.82 mm, respectively, at 1, 3, and 5 mm apical to the crestal level. Vertical bone change was 2.34 ± 0.90 mm in the center of the socket. Histomorphometric analysis showed that percentages of mineralized bone, nonmineralized tissue, and bone substitute were 32.31% ± 13.25%, 25.36% ± 12.24%, and 42.34% ± 9.54%, respectively. The mucogingival junction shift was 0.6 ± 1.1 mm. Implant survival rates and crestal bone resorption were 100% and 0.78 ± 0.58 mm, respectively, after 1 year of loading. CONCLUSION: Ridge augmentation can be performed successfully to manage extraction sockets. Membrane coverage combined with primary wound closure could be conducive to new bone regeneration and peri-implant tissue health.

Suppression of G6PD induces the expression and bisecting GlcNAc-branched N-glycosylation of E-Cadherin to block epithelial-mesenchymal transition and lymphatic metastasis.

BACKGROUND: As the rate-limit enzyme of the pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G6PD) plays important roles in tumour progression, but the exact mechanism through which G6PD controls cancer metastasis remains unclear. METHODS: G6PD expression in resected oral squamous cell carcinoma (OSCC) samples was analysed by immunohistochemistry. The effects and mechanism of G6PD suppression on OSCC cell lines were measured by transwell assay, wound healing assay, western and lectin blot, mass spectrometer analysis, ChIP-PCR, and luciferase reporter assay. BALB/c-nude mice were used to establish orthotopic xenograft model. RESULTS: G6PD expression in the tumours of 105 OSCC patients was associated with lymphatic metastasis and prognosis. In vitro cellular study suggested that G6PD suppression impaired cell migration, invasion, and epithelial-mesenchymal transition. Furtherly, G6PD knockdown activated the JNK pathway, which then blocked the AKT/GSK-3ß/Snail axis to induce E-Cadherin expression and transcriptionally regulated MGAT3 expression to promote bisecting GlcNAc-branched N-glycosylation of E-Cadherin. An orthotopic xenograft model further confirmed that dehydroepiandrosterone reduced lymphatic metastatic rate of OSCC, which was partially reversed by JNK inhibition. CONCLUSIONS: Suppression of G6PD promoted the expression and bisecting GlcNAc-branched N-glycosylation of E-Cadherin via activating the JNK pathway, which thus acted on OSCC metastasis.

Accuracy of 18 F-FDG PET/CT in Detection of Neck Metastases of Oral Squamous Cell Carcinoma in Patients Without Large Palpable Lymph Nodes.

OBJECTIVE: To measure the efficacy of positron emission tomography/computed tomography (PET/CT) in the diagnosis of neck metastases of oral squamous cell carcinoma (OSCC) in patients without enlarged lymph nodes and to determine the threshold of maximum standardized uptake values (SUVmax) in diagnosis. STUDY DESIGN: In total, 78 OSCC patients without large palpable lymph nodes were included. PET/CT findings were compared with histopathologic neck status. RESULTS: Neck dissection was performed in 78 patients with 98 neck sides, and 31 neck sides harbored metastases. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT were 83.9%, 73.1%, 76.5%, 59.1%, and 90.7%, respectively. The area under the curve in receiver operating characteristic analysis was 0.76, which indicated that SUVmax of lymph nodes was useful in diagnosis of pathologic neck status. The threshold SUVmax was 2.21, which was the best diagnosis threshold of neck metastasis. CONCLUSIONS: PET/CT is valuable in diagnosis of neck status. The probability of neck metastasis increased with increasing SUVmax values, but the threshold SUVmax should not be the sole criterion for determining the presence of neck metastases. Fluorodeoxyglucose PET/CT is recommended for evaluation of neck status in OSCC patients without large palpable lymph nodes.

Relationship between the maximum standardized uptake value of fluoro-2-deoxyglucose-positron emission tomography/computed tomography and clinicopathological characteristics in tongue squamous cell carcinoma.

AIM: Tongue carcinoma is one of the most common oral and maxillofacial malignant tumors worldwide, maximum standardized uptake value (SUVmax) in 18 F-fluoro-2-deoxyglucose-positron emission tomography/computed tomography (PET/CT) has been widely used in cancer research; however, there are few systematical reports on the relationship between SUVmax and clinicopathological characteristics in tongue squamous cell carcinoma (TSCC). This study aimed to investigate the relationship between them and whether SUV parameters can predict lymph node metastasis. MATERIALS AND METHODS: PET/CT manifestations and clinicopathological features of 52 patients with TSCC confirmed by pathology were retrospectively analyzed. Single-factor and multiple regression analyses were conducted on possible factors influencing TSCC SUVmax, including sex, age, smoking history, tumor location and size, histological differentiation, and tumor node metastasis (TNM) stages, T stages, and N stages. Diagnostic performance of SUVmax for lymph node metastasis was measured by the area under the receiver operating characteristic curve, and sensitivity and specificity were determined by Youden's J statistic. RESULTS: SUVmax was correlated with sex, tumor location and size, and TNM stages, T stages, and N stages (P < 0.05) but was not correlated with histological differentiation, smoking history, and age (P > 0.05). Sex, tumor location, tumor size, and N stage were influencing factors independent of TSCC SUVmax (P < 0.05). TSCC SUVmax had predictive value for lymph node metastasis. When the cutoff value was 6.57, the diagnostic efficiency was the highest, with the sensitivity being 79.2% and the specificity being 85.7%. CONCLUSIONS: SUVmax was higher among male patients with TSCC with posterior tumor location, larger tumor size, and lymph node metastasis, and TSCC SUVmax was important in predicting lymph node metastasis.

Correlation analysis between the SUVmax of FDG-PET/CT and clinicopathological characteristics in oral squamous cell carcinoma.

OBJECTIVES:: To investigate the relationship between maximum standardized uptake value (SUVmax) of 18F-FDG PET/CT and clinicopathological features of oral squamous cell carcinoma (OSCC), in order to formulate a better clinical guideline. METHODS:: In 104 patients with OSCC confirmed by pathology, there were 67 males and 37 females (age, 33-76 years; mean age, 56 years).18FDG, 18-fludeoxyglucose (18F-FDG) PET/CT manifestations and the clinicopathological features of the 104 patients were retrospectively analysed. Single-factor analysis and multiple regression analysis were conducted on possible factors influencing primary tumour SUVmax, including gender, age, smoking history, tumour location, tumour size, histological differentiation, TNM stage, T stage, N stage. Diagnostic performance of SUVmax for invading peri-tissue of OSCC was measured by the area under receiver operating characteristic curve, and sensitivity and specificity were determined at the Youdons index. RESULTS:: The single-analysis results showed that SUVmax was correlated with the histological differentiation, tumour size, TNM stage, T stage, N stage(p < 0.05), yet it was not correlated with gender, age, smoking history, tumour location (p > 0.05). Multivariate liner regression analysis showed that tumour size, TNM stage were influencing factors independent of primary tumour SUVmax (p < 0.05). Primary tumour SUVmax had predictive value for invading peri-tissue of OSCC. When the cutoff value was 7.98, the diagnostic efficiency was the highest, with the sensitivity being 90.0％ and the specificity being 76.2%. CONCLUSIONS:: OSCC 18F-FDG PET/CT SUVmax is higher among patients with larger tumour size, poorer stage, and that primary tumour SUVmax is of important significance in predicting invading peri-tissue.

New classification of maxillary sinus contours and its relation to sinus floor elevation surgery.

BACKGROUND: It is complicated to select an appropriate sinus floor elevation and the procedure for sinus floor elevation lacks of consensus. Sinus contour plays an important role in choosing a surgery approach. But there are still no published articles revealing the influence of sinus contours to sinus floor elevation surgery. PURPOSE: We propose a new classification depending on sinus contours from cone-beam computed tomography (CBCT), analyze clinical characters of different types, and investigate the relationship between sinus contours and sinus floor elevation. MATERIALS AND METHODS: We divide sinus into five categories: narrow tapered, tapering, ovoid, square, and irregular. For the first four types, subtypes are classified into three categories: without recess, with buccal-sinus-recess (BSR), and with palate-nasal-recess (PNR). For irregular type, subtypes are classified into three categories: tooth protruding into sinus floor, irregular floor, and septa/exostosis on sinus floor. Then the distribution features of sinuses of 698 patients are described. Sinus widths are measured at second premolar, first and second molar on both sides, and are compared among different types and subtypes. RESULTS: Narrow tapered sinus occupies 88% at second premolar sites, while tapered sinus occupies almost 50% at first and second molar sites. At second premolar and first molar sites, 62% are without recess types. While 92% are without recess types at second molar. Sinuses with BSR present in only three of 3765 sites. There is an increasing trend of sinus width from narrow tapered to irregular type. Sinus width of the group with recesses is significantly higher than the one without recess. At the end, we provide corresponding treatment recommendations for each sinus types and subtypes. CONCLUSION: This is the first classification system that gives treatment recommendations for sinus floor elevation surgery based on sinus contours. The classification system is consistent, easy to visualize, and practicable.