Endoscopic-assisted total maxillectomy with precise surgical margins

In traditional open maxillectomy, identifying the posterior margin is difficult because of its deep location and bleeding from the pterygoid venous plexus. Here, we present our endoscope-assisted total en bloc maxillectomy technique and discuss its merits and demerits compared to previously reported methods. We developed an endoscope-assisted total en bloc maxillectomy procedure. We reviewed a series of total maxillectomies performed with and without endoscopic assistance to verify the advantages of endoscopic assistance over conventional total maxillectomy. We analyzed (1) the precision using the distance of the remaining pterygoid process, (2) the operation time, and (3) blood loss. The length of the remnant pterygoid process was significantly shorter in the endoscopic assistance group. The operation time and blood loss were not significantly different between the two groups. Endoscopic assistance makes total maxillectomy more precise without requiring additional time and is a reasonable option for total maxillectomies.

Reconstruction of maxillary palatal defects after partial maxillectomy using a pedicled buccal fat pad and a nasolabial flap

The novelty of this procedure is the reconstruction of a maxillary palatal defect with two pedicled flaps: a pedicled buccal fat pad and a nasolabial flap. This use of combination flaps makes the surgery simple, short, and useful for a wide defect.The novelty of this procedure is the reconstruction of a maxillary palatal defect with two pedicled flaps: a pedicled buccal fat pad and a nasolabial flap. This use of combination flaps makes the surgery simple, short, and useful for a wide defect.

Oral squamous cell carcinoma involving the maxillae: Factors affecting local recurrence and the value of salvage treatment for overall survival

OBJECTIVE

To determine factors associated with local recurrence (LR) of oral squamous cell carcinoma involving the maxillae (MSCC) and overall survival (OS) after salvage treatment.

SUBJECTS AND METHODS

Retrospective study of MSCC operated between 2000 and 2015. Kaplan-Meier survival and Cox regression were used for analysis of MSCC-associated clinical and histopathological factors.

RESULTS

Ninety-five patients were included. LR occurred in 24% of patients. Vascular invasion significantly increased the risk of LR (hazard ratio 4.595, P = .003). Local salvage surgery, in the area of the original tumor, significantly prolonged OS, compared to palliative treatment (P = .001) and extensive salvage surgery (P = .013). Extensive salvage surgery, requiring resection of adjacent facial structures, did not prolong OS compared to palliative treatment (P = .186).

CONCLUSIONS

MSCC with vascular invasion has higher risk of LR. Salvage surgery may prolong OS in small recurrences but might have dubious value for larger recurrences infiltrating adjacent facial structures.

Particular gene upregulation and p53 heterogeneous expression in TP53-mutated maxillary carcinoma

It has been demonstrated that tumor protein p53 (TP53) mutation in maxillary squamous cell carcinoma, is more treatment-resistant compared with the carcinoma without TP53 mutation. However, the association between TP53 mutation and treatment resistance remains unclear. As a first step in understanding the biological differences between tumors with and without TP53 mutation, a comprehensive gene expression analysis of maxillary squamous cell carcinoma with or without TP53 mutation was performed. A total of 42 genes were identified to be differentially expressed by >4-fold. Quantification of their mRNA using quantitative polymerase chain reaction indicated 18 genes with high expression and three genes with low expression in TP53 mutated tumors vs. TP53 wild-type tumors. The 18 genes included eight cell adhesion (DSC3, GRHL1, EPPK1, PROM2, ANXA8, DSP, JUP, and KRT6B) and four cell growth inhibition (SFN, CLCA2, SAMD9 and TP63) genes. Among these genes, DSC3, SFN, and CSTA, whose expression was markedly increased, also demonstrated high protein expression in immunohistochemical staining of TP53 mutated tumors. The TP53 mutated tumors demonstrated high nuclear staining of the TP53 protein only in tumor cells at the tumor margins adjacent to the stroma, whereas the tumor interior was negative for TP53. However, all tumor cells of TP53 wild-type tumors exhibited positive nuclear staining for the TP53 protein. The combined findings suggest that TP53 mutated tumors possess a phenotype opposite to that associated with cancer progression and malignant transformation, and exhibit tumor cell heterogeneity between the tumor interior and margins.

Use of the bioactive resorbable plate system for zygoma and zygomatic arch replacement and fixation with modified Crockett's method for maxillectomy: A technical note

As a surgical approach targeting the pterygopalatine fossa following maxillary cancer due to tumor invasion, Crockett's method is conventional and useful. However, if the tumor is confined to the area between the maxilla and pterygopalatine fossa, it is not necessary to include the zygomatico-orbital in the access osteotomy, and the orbital floor may be preserved. Depending on the range of tumor invasion, the current study reports a more minimally invasive, modified Crockett's surgery that may be considered, which includes resection with modified osteotomy lines and repositioning with fixation of the zygoma and zygomatic arch following maxillary cancer ablation. In addition, the majority of patients with advanced maxillary cancer may require postoperative radiotherapy or chemoradiotherapy following maxillectomy according to several guidelines. Therefore, using a low-profile bioactive resorbable plate system as a method of repositioning and fixing the resected and preserved zygoma and zygomatic arch may be more effective in this modified Crockett's method for maxillectomy.

Cancers of upper gingivobuccal sulcus, hard palate and maxilla: A tertiary care centre study in North India

Introduction:

Oral cancer is the sixth most common malignancy in the world, and the third most common in southeast Asia. Cancers of the upper gingivo-buccal complex are uncommon and reported infrequently. In this article, we have assessed the clinicopathological features of such cancers and their optimal management.

Materials and Methods:

We studied 64 patients with cancer of the upper gingivobuccal sulcus (GBS), hard palate, and maxilla seen between February 2009 and 2013 over a span of 4 years.

Results:

Of the 64 patients studied, 45 were male. The mean age at presentation was 50.59 years (24-80 years). Of the 64, 48 patients (75%) had a history of substance abuse in the form of tobacco chewing, smoking or alcohol. On presentation, 48 of the 64 patients (75%) had T4 disease, eight had T3, six had T2 lesion, one had T1 lesion, and 1 patient had a neck recurrence with distant metastatic disease (Tx). Out of the 64 patients, 31 had clinically palpable neck disease and two patients had distant metastatic disease. Of the 64 patients, 58 had squamous cell carcinoma, two had adenoid cystic carcinoma of the hard palate and one patient each had melanoma, sarcoma, neuroendocrine tumor, and mucoepidermoid carcinoma. Following imaging, 18 patients (28.13%) underwent upfront surgery and six following neoadjuvant chemotherapy. 14 of the 24 patients operated had simultaneous neck dissection. 2 patients with distant metastasis and 1 with cavernous sinus thrombosis received palliative chemotherapy. Out of the 64 patients, the other 24 who were inoperable were referred to radiotherapy.

Conclusion:

Upper GBS, hard palate and maxilla cancers are uncommon and are diagnosed at an advanced stage due to delay in presentation and ignorance of our population. Surgery offers the best form of treatment. NACT may be tried to downstage the disease in selected patients with borderline operable disease. However, generous margins should be taken post chemotherapy with concomitant neck dissection. Adjuvant radiotherapy is recommended in selected patients after surgery.

Dosimetric and delivery characterizations of full-arc and half-arc volumetric-modulated arc therapy for maxillary cancer

We compared the efficiency and accuracy of full-arc and half-arc volumetric-modulated arc therapy (VMAT) delivery for maxillary cancer. Plans for gantry rotation angles of 360° and 180° (full-arc and half-arc VMAT) were created for six maxillary cancer cases with the Monaco treatment planning system, and delivered using an Elekta Synergy linear accelerator. Full-arc and half-arc VMAT were compared with regard to homogeneity index (HI), conformity index (CI), mean dose to normal brain, total monitor units (MU), delivery times, root mean square (r.m.s.) gantry accelerations (°/s(2)), and r.m.s. gantry angle errors (°). The half-arc VMAT plans achieved comparable HI and CI to the full-arc plans. Mean doses to the normal brain and brainstem with the half-arc VMAT plans were on average 16% and 17% lower than those with the full-arc VMAT plans. For other organs at risk (OARs), no significant DVH differences were observed between plans. Half-arc VMAT resulted in 11% less total MU and 20% shorter delivery time than the full-arc VMAT, while r.m.s. gantry acceleration and r.m.s. gantry angle error during half-arc VMAT delivery were 30% and 23% less than those during full-arc VMAT delivery, respectively. Furthermore, the half-arc VMAT plans were comparable with the full-arc plans regarding dose homogeneity and conformity in maxillary cancer, and provided a statistical decrease in mean dose to OAR, total MU, delivery time and gantry angle error. Half-arc VMAT plans may be a suitable treatment option in radiotherapy for maxillary cancer.