Retromolar Trigone Research Articles

Oral Squamous Cell Cancer Scenario in a Tertiary Hospital in Western Region of Nepal

Introduction: Oral squamous cell cancer involves oral subsites namely lip, buccal mucosa, gingivobuccal sulcus, mandible, retromolar trigone, tongue, floor of the mouth, maxilla and hard palate. It has multifactorial etiologies. Alcohol, tobacco chewing, smoking, betel quid chewing, trauma and HPV viruses are implicated as the predisposing factors of oral squamous cell carcinoma. If detected early, oral cavity cancer is easily preventable and curable. Aims: To evaluate oral squamous cell cancer demographics, as well as risk factors, site, grades, and stages. Methods: This prospective cross-sectional descriptive type of study was done in patients attending dental outdoor patient department of Nepalgunj medical college from July 2018 to August 2020. 46 patients selected by enumerative sampling method in the study after they were histopathologically confirmed with oral squamous cell carcinoma by biopsy. All included patients were having primary oral cancer, single, unilateral and untreated. After data collection current oral squamous cell cancer demographics, as well as risk factors, site, grades, and stages were established. Results: Out of 46 patients ranging from 32 to 79 years 28(60.8%) were males and 18(39.1%) were females with mean age range of 55.41 ± 10.84 years. 26(56.5%) of total displayed oral squamous cell carcinoma at buccal mucosa. 25(54.3%) of total consumed gutkha and paan with betel nut plus tobacco. 30(65.2%) of total were exposed to carcinogen for a period of 21-40 years. 32(69.5%) of total had well differentiated oral squamous cancer. 32(69.5%) of total were at stage III at the time of presentation. Conclusion: Oral cancer occurred more in males, at buccal mucosa and in people above 51 years, and in those who consumed gutka and paan, betel nut plus tobacco. It was also more in people with longer history of exposure to carcinogens.

Prosthetic Rehabilitation of a Hemimandibulectomy Case by Non-Surgical Approach- A Case Report

Hemimandibulectomy can have several consequences such as disoriented masticatory cycle, eccentric occlusion, distorted speech and facial disfigurement depending on the severity of the defect. It is challenging for the prosthodontist to rehabilitate the patients in whom osseous reconstruction has not been carried out. This clinical report describes the Prosthetic management of a patient who had undergone hemimandibulectomy due to moderately differentiated squamous cell carcinoma involving left buccal mucosa, gingivobuccal sulcus and retromolar trigone. A non- surgical approach was carried out to rehabilitate this patient, which included the fabrication of a maxillary guide flange prosthesis for correction of the frontal plane rotation and a twin occlusion prosthesis for ease of mastication. The appearance of the patient was improved drastically by the fabrication of an extraoral prosthesis.

Mucoepidermoid carcinoma: Evaluating the prognostic impact of primary tumor site

Mucoepidermoid carcinoma (MEC) is one of the most common salivary gland malignancies. Our aim was to evaluate the prognostic impact of primary tumor site in patients with MEC. Material and MethodsThis cohort identified 308 patients with MEC who underwent primary surgery between 1985 and 2015. Survival outcomes were determined using the Kaplan–Meier method. Hazard ratios for primary site were determined using the Cox proportional-hazards model. ResultsOne hundred eighty (58%) patients were diagnosed with minor and 128 (42%) with major salivary gland cancer. Primary site in the minor salivary gland group included 137 (44%) oral cavity, 38 (12%) pharynx, 3 (0.9%) nasal cavity, and 2 (0.6%) trachea and larynx. The major salivary gland group included 118 (38%) parotid, 8 (3%) submandibular, and 2 (0.6%) sublingual. With a median follow-up of 73 months, 5-year overall survival and disease-specific survival were 84% and 91%, respectively. Patients with tumors located in the hard palate and retromolar trigone had the best survival, while patients with tumors located in the paranasal sinuses and submandibular gland had the poorest survival. After controlling for tumor grade and stage, MEC primary site was not predictive of survival or recurrence. On multivariate analysis, worse DSS was associated with stage III–IV tumors (HR: 7,11; 95% CI: 1.19–26.43; p = 0.0034) and high-grade tumors (HR: 19.12; 95% CI: 2.26–162.77; p = 0.0068). ConclusionsWhile high grade and advanced overall stage were found to be independent predictors of worse survival, primary tumor site was not predictive of poor outcome.

Anaplastic Thyroid Cancer Patterns of Nodal Disease and Proposed Radiotherapy Target Volumes

Radiotherapy (RT) plays an important role in locoregional control for anaplastic thyroid cancer (ATC). Due to its rarity, RT guidelines for ATC are lacking. In this single institution retrospective analysis, we describe ATC patterns of nodal disease at presentation, recurrence, and progression and propose corresponding RT target volumes.We used a prospectively maintained database to identify all ATC patients with definitive or adjuvant IMRT and chemotherapy from 2006 to 2020. Patients receiving palliative RT were excluded. We identified in-field, marginal (within the 40-50 Gy isodose line), and out-of-field sites of locoregional recurrence and progression (LRR). Sites of disease at presentation and LRR were mapped to inform RT target volume recommendations.Forty-seven patients met inclusion. Median follow-up was 6.6 months (IQR: 1.9-19.6). Forty-four (93.6%) patients underwent resection. Table 1 summarizes RT nodal coverage and sites of disease. All patients received elective nodal RT to levels II-IV and VI. RT volumes also included: IA (23.4%), IB (44.7%), V (87.2%), VII (27.7%), and mediastinal 1-6 (53.2%). Cumulative incidence of LRR at 3- and 12-months was 26.1% (95% CI: 15.9-42.8) and 35.7% (23.9-53.4). Isolated LRR risk at 3- and 12-months was 6.5% (2.2-19.8) and 8.9% (3.4-22.9). Fourteen (29.8%) in-field LRRs occurred at a median interval of 44 days (range: 15-208) from completion of RT. Sites of in-field LRR included the postoperative thyroid bed, ipsilateral III-IV, VI, 1, and 3A. Four (8.5%) patients experienced marginal LRRs at a median of 35 days (range: 32-139), 3 of whom progressed in the mediastinum at 2, 3P, 4, and 6. Two (4.3%) patients experienced out-of-field LRRs at VII and the contralateral retromolar trigone, respectively. Throughout the pre-treatment and follow-up period, no patients had disease at IA and 1 (2.1%) patient each had disease at IB and VII. Five (10.6%) patients had bilateral neck disease. No baseline or treatment characteristics, including RT dose (stratified by < or ≥66 Gy), were significant predictors of LRR on univariate analysis. Twelve (25.5%) patients were alive at last follow-up, of whom 8 (17.0%) had no evidence of LRR or distant progression.Isolated LRR risk in ATC patients treated with comprehensive RT and chemotherapy is low. Complete inclusion of mediastinal levels 1-6 is warranted to avoid marginal failures. Distant recurrence remains common and additional efforts are needed to appropriately select patients for comprehensive treatment. No dose-response relationship was observed between 51 and 70 Gy.

Morphology of the temporalis muscle focusing on the tendinous attachment onto the coronoid process.

The temporalis muscle is usually described as a single layer originating at the temporal line, converging to a tendon, and inserting onto a narrow site of the coronoid process. However, recent studies have shown that the temporalis muscle can be divided into two or three separate segments and the distal attachment continues inferiorly beyond the coronoid process. Therefore, the aims of this study were to analyze the morphology of the temporalis muscle focusing on the tendinous attachment onto the coronoid process and to provide educational values. The temporalis muscle was carefully dissected in 26 cadavers and classified based on the muscle fascicle direction. Each divided part was sketched and measured based on bony landmarks to elucidate its tendinous insertion site onto the coronoid process, and the results obtained were reviewed through the literature. The temporalis muscle ends at two distinct terminal tendons with wider insertion sites than usually presented in textbooks and atlases and separates into two parts that combine to act as a single structural unit. The superficial part is a large fan-shaped muscle commonly recognized as the temporalis muscle. This converges infero-medially to form the superficial tendon and the lateral boundary of the retromolar triangle. Meanwhile, the deep part is a narrow vertically oriented rectangular muscle that converges postero-laterally to form the deep tendon and the medial boundary of the retromolar triangle. These results indicate that understanding the temporalis muscle’s insertion site onto the coronoid process will be useful clinically with educational values during surgical procedures.

A systematic review of therapeutic outcomes following treatment of squamous cell carcinoma of the retromolar trigone.

Squamous cell carcinoma (SCC) of the retromolar trigone (RMT) is a rare but potentially fatal disease that carries a poor prognosis due to its unique anatomic position. RMT SCCs tend to spread to vital nearby structures, including the tonsillar pillar, masticatory muscles, and underlying mandibular bone, even in their early stages, and aggressive treatment is often warranted. This systematic review appraises and qualitatively analyzes all available literature regarding the survival outcomes and prognosis of RMT SCC. Four databases were searched to identify all eligible articles published since January 1980. Of the 1,248 studies, a total of 15 studies representing 4,838 cases met the inclusion criteria. The evaluated patients had a high rate of advanced tumor stage (T3 or T4: 61.4%), lymph node metastasis (38.8%), and mandibular bone invasion (24%) at the time of diagnosis. Aggressive surgical treatments such as lip-splitting (92%), segmental mandibulectomy (61.1%), radical neck dissection (44.1%), and reconstruction using free flaps (49.5%) was undertaken for 92% of the pooled patient population. The mean rates for local, regional, and systemic recurrence were 23.40%, 8.40%, and 8.50%, respectively. The mean 5-year overall survival rate was 38.90%. Osteonecrosis was noted in 11.6% of the 328 patients who received radiotherapy. In conclusion, RMT SCC is generally associated with high recurrence, low survival, and high postoperative complication rates. Early diagnosis and aggressive treatment are thus warranted. However, significant methodological problems hamper current knowledge. Future studies of this topic that use randomized or cohort designs are thus needed.

Image guided biopsy/FNAC in head and neck cancers in covid 19 pandemic

Suspected growth in the region of base of tongue, pharynx, and larynx need direct/indirect laryngoscopy for establishing Diagnosis and for Staging of the disease. The Covid 19 Pandemic has severely affected these modes of examination because they are Aerosol Generating Procedures and carry very high risk of transmission of the Virus. The Department of Head And Neck Oncosurgery at KCHRC is one of the busiest department at our Institute with an average annual footfall of around 20,000 new patients. The main objective of our study is to know the role of Image Guided Biopsy/FNAC for primary diagnosis in Head and Neck Cancers. Retrospective analysis of prospectively collected data of 35 patients was done from April to September 2020. Histopathological records along with patient’s clinical records were reviewed. Of the 35 patients, 23 patients underwent CT Guided biopsies, 11 patients had CT Guided FNA and one patient had USG guided biopsy. In 23 patients (CT Guided Biopsy), the biopsy was taken from tongue in 16 patients, Larynx in two patient, Pyriform sinus(PFS), posterior pharyngeal wall, RMT (retromolar trigone), lower GBS and Tonsil sites had one patient each. Of the 11 CT Guided FNAC patients, the site of FNA was from PFS in 7 patients, Tongue in 2 patients RMT and soft palate had one patient each. One patient had undergone USG Guided biopsy for PFS lesion. Out of 35 patients, tissue specimen taken was adequate in 33 patients and inadequate in two patients. The results were supported both histologically and clinically. The histological confirmation was found in 88.6% cases (31/35), squamous cell carcinoma was found in 74.3% cases (26/35), no malignancy in 8.5% cases(3/35), no specific lesion in 5.7% cases(2/35), no definitive diagnosis in 2.8% cases(1/35) and in inadequate in 8.5% cases(3/35). Repeat biopsy in one patient revealed no malignancy. There were no post procedure complications noted. Image guided biopsy/FNAC is a safe, reliable minimally invasive technique and can be used for primary diagnosis of Head and Neck cancers without the risk of Aerosol generation in the current Covid -19 Pandemic.

Impact on patients with oral squamous cell carcinoma in different anatomical subsites: a single-center study in Taiwan

The incidence of oral cavity squamous cell carcinoma (OSCC) is particularly high in South Asia. According to the National Comprehensive Cancer Network, OSCC can arise in several subsites. We investigated survival rates and the clinical and pathological characteristics of OSCC in different anatomical subsites in the Taiwanese population. We retrospectively analyzed data for 3010 patients with OSCC treated at the Changhua Christian Hospital. Subsequently, we compared clinical and pathological features of OSCC in different subsites. Pathological T4 stage OSCCs occurred in the alveolar ridge and retromolar trigone in 56.4% and 43.7% of cases, respectively. More than 25% of patients with tongue OSCC and 23.4% of those with retromolar OSCC had lymph node metastasis. The prognosis was worst for hard palate OSCC (hazard ratio 1.848; p < 0.001) and alveolar ridge OSCC (hazard ratio 1.220; p = 0.017). Retromolar OSCC recurred most often and tongue OSCC second most often. The risk for cancer-related mortality was highest for hard palate OSCC, followed by alveolar ridge and retromolar OSCC. We found distinct differences in survival among the different subsites of OSCC. Our findings may also help prompt future investigations of OSCC in different subsites in Taiwanese patients.

FDG-PET predicts bone invasion and prognosis in patients with oral squamous cell carcinoma

18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is widely used for tumor staging. This study sought to determine the relationship of preoperative primary tumor SUVmax (tSUVmax) with the clinicopathological features of patients with OSCC and to compare the prognostic ability of tSUVmax with that of other recurrence factors. Data of 340 patients with OSCC who were diagnosed, treated, and followed up at the Changhua Christian Hospital were retrospectively analyzed. Only patients with OSCC arising from gingiva, palate, floor of the mouth, and retromolar trigone and those who had received preoperative FDG-PET within 2 weeks before surgery were included. tSUVmax value > 9.2 was the strong predictor of bone invasion (area under the receiver operating characteristic curve, 0.844). tSUVmax value > 7.2 showed a strong association with advanced pathological T stage and recurrence factors and was associated with poor survival; tSUVmax > 7.2 showed stronger predictive power for poor disease-free survival (DFS) than pT stage and the other recurrence factors related to primary tumor. FDG-PET can be a useful supplement to contrast-enhanced computed tomography or contrast-enhanced magnetic resonance imaging for diagnosing bone invasion by OSCC. The tSUVmax value was an independent predictor of DFS in this study.

Single-Stage Peninsula-Shaped Lateral Tongue Flap Reconstruction for Buccal Defects in Two Patients: Revisiting a Simple and Safe Reconstructive Option

Intraoral defects are increasingly reconstructed using free flaps. However, certain situations may render free flap reconstruction difficult. This study presents two cases with underlying comorbidities that underwent reconstruction of buccal defects involving the retromolar trigone (RMT), using a single-stage peninsula-shaped lateral tongue flap (pLTF). A 58-year-old woman and a 75-year-old man were diagnosed with left buccal squamous cell carcinoma and right buccal adenoid cystic carcinoma, respectively. The buccal defects extending to the RMT area were detected and covered with an ipsilateral posteriorly based pLTF after wide excision of the lesion. All flaps survived without any postoperative complications. Moreover, no tumor recurrences or functional problems were observed during the final follow-up. A single-stage pLTF is believed to represent a good alternative to free flaps in buccal and RMT defects.

PATTERNS OF ORAL MUCOSITIS IN ADVANCED OSCC PATIENTS MANAGED WITH PROPHYLACTIC PHOTOBIOMODULATION THERAPY – INSIGHTS FOR FUTURE PROTOCOL DEVELOPMENT

<h3>Background</h3> Photobiomodulation therapy (PBMT) is recommended for the prevention of radiation-induced oral mucositis (OM) in head and neck patients. It is unclear to what extent the delivered PBMT therapy effectively provides an adequate uniform dose to the at-risk tissues. <h3>Objective</h3> To characterize oral sites affected by radiation-induced OM and its clinicopathologic outcomes in oral squamous cell carcinoma (OSCC) patients subjected to prophylactic PBMT. <h3>Methods</h3> The site distribution of OM, OM grading (NCI, Version 4.0), OM-related pain (visual analog scale), analgesic protocol (WHO), and use of enteral nutrition were evaluated weekly during treatment for OSCC patients with prophylactic PBMT. Data analysis was performed using descriptive statistics. <h3>Results</h3> One hundred forty-five OSCC patients were included. The most frequently affected sites by OM included lateral tongue (44.1%) and buccal mucosa (37.2%). Keratinized oral mucosae sites, including the tongue dorsum (6.21%) and retromolar trigone (8.3%), were also affected. Peak OM scores were observed at weeks 5, 6 and 7, with severe OM (NCI grades 3 and 4) rates of 11%, 20%, and 25%, respectively. The cumulative occurrence of severe OM was 23%, which developed as early as week 3 and as late as week 7. The highest mean value of OM-related pain (2.7) was observed in the sixth week, and 13.8% of the patients required feeding support. <h3>Conclusions</h3> Compared to previously published studies that did not provide PBMT, OM, pain and analgesia and tube feeding use reduction was seen. Keratinized surfaces should also be included in the prophylactic PBMT for OM aiming to reduce severe OM.

SYNCHRONOUS MALIGNANT GRANULAR CELL TUMORS OF THE RIGHT RETROMOLAR TRIGONE AND LEFT PAROTID GLAND: A CASE REPORT

<h3>Introduction</h3> Granular cell tumors (GCTs) are uncommon, benign mesenchymal neoplasms of Schwann cell origin. In the head and neck, the tongue is the most common site. Malignant tumors comprise about 2% of all granular cell tumors. Herein, we report a case of a malignant granular cell tumor (MGCT) in the right retromolar trigone and a synchronous tumor in the left parotid gland. The literature suggests that this may be the second case of a malignant granular cell tumor described in the oral cavity. <h3>Case Report</h3> A 51-year-old male patient presented to the otorhinolaryngology clinic for a progressively enlarging right retromolar trigone lesion, extending to the buccal mucosa and floor of mouth and posteriorly to the tonsil. Extraorally a left parotid swelling, right-sided lymphadenopathy, and cranial nerve fallout of V1, V2, III, and VI were noted. Computed tomography showed a homogeneously enhancing soft tissue mass in the right oral cavity extending intracranially, as well as a mass in the left parotid. Histopathologic examination revealed synchronous MGCTs. The tumors were deemed inoperable and the patient was offered palliative radiotherapy. <h3>Discussion</h3> MGCTs are rare high-grade malignant mesenchymal tumors representing only 1% to 2% of all GCTs. MGCTs commonly affect the thigh, extremities, and trunk, and involvement of the oral cavity is rare. The prognosis is poor, with a 39% mortality rate in 3 years. <h3>Conclusions</h3> Although malignant granular cell tumors are rare, clinicians and histopathologists must be familiar with this entity. However, distinction between benign and malignant tumors can be difficult owing to striking histologic similarities.

Intraductal carcinoma of the retromolar trigone found with elevated serum CEA and CA19-9 levels: a case report

Intraductal carcinoma (IDC) is a rare salivary gland tumor, classified according to the 4th WHO Classification of Head and Neck Tumors in 2017. The tumor affects the parotid gland much more frequently than the minor salivary glands. It’s often asymptomatic. We report a case of IDC of the left retromolar trigon occurring in an 81-year-old woman. She was diagnosed with high serum CEA and CA19-9 at a medical examination. Examinations of her gastrointestinal tract, lungs, and mammary glands were conducted, resulting in no abnormal findings. FDG-PET showed abnormal uptake only in the left retromolar trigon, and a painless mass was observed. A biopsy of this tumor indicated it was likely a low-grade salivary gland tumor. The tumor was completely removed, along with sufficient margins. Histological examination revealed that the lesion was composed of alveolar nests showing an expanded duct-like structure surrounded by an intact myoepithelial layer, with no evidence of infiltration. The final diagnosis was IDC. The postoperative course was uneventful and the patient’s serum CEA and CA19-9 levels decreased to within normal range. We believe that serum CEA and CA19-9 levels could be used for the diagnosis and evaluation of therapeutic effect for this tumor.

Quality of life analysis of HPV-positive oropharyngeal cancer patients in a randomized trial of reduced-dose (rdCRT) versus standard (sdCRT) chemoradiotherapy: Five-year follow-up.

6062 Background: Human papillomavirus-positive oropharyngeal cancer (HPV OPC) portends a more favorable prognosis compared to HPV-negative cases. To prevent overtreatment, long-term morbidity and deterioration in functionality and quality of life (QoL), multiple studies have focused on de-intensification techniques for HPV OPC treatment. To this end, we prospectively assessed differences in patient reported QoL in locally advanced HPV OPC patients receiving rdCRTversus sdCRT)in a randomized trial using a sequential therapy plan. Methods: Patients were enrolled between December 2012 and February 2016; received 3 cycles of induction docetaxel, cisplatin, and 5-FU; and were randomized to sdCRT (70 Gy) or rdCRT (56 Gy) with weekly carboplatin. Patients were followed for Progression Free Survival (PFS), Overall Survival (OS), and changes in QoL as assessed by the MD Anderson Dysphagia Inventory (MDADI), MD Anderson Symptom Inventory (MDASI Head and Neck), Xerostomia Questionnaire (XQ), and the European Organization for Research and Treatment of Cancer Questionnaire (EORTC QLQ-C30) with the head and neck module (EORTC HN). A mixed model ANOVA was used to estimate changes from baseline QoL to that at each follow-up timepoint and to compare the difference in QoL changes between the treatment arms. Results: We randomized 20 HPV+ locally advanced (LA) patients (median age: 56.5 yrs) to rdCRT (12 subjects) or sdCRT (8 subjects). 70% had high risk features. At a median follow-up of 81.5 mos, PFS and OS were 87.5% and 83.3% for sdCRT and rdCRT, respectively with a median OS of 76 mos in both arms. One patient in the sdCRT arm developed an HPV negative retromolar trigone squamous cell cancer in the radiation field 7 yrs after therapy. Baseline QoL was identical in the 15 patients who completed the QoL modules. Patients receiving rdCRT hadsignificantly lower declines in QoL scores at 3-6 month follow-up. At 5 yrs, differences in QoL changes all favored the rdCRT arm (Table) and two QoL scales reached statistical significance (P&lt;0.05). Conclusions: In HPV OPC patients, rdCRT resulted in comparable long-term survival and greater improvement in specific domains of QoL when compared to sdCRT. Our results support the need for a larger, long-term Phase 3 study in LA HPVOPC to assess these two treatments with respect to survival, QoL, and safety. Clinical trial information: NCT02945631. [Table: see text]

Prelaminated flaps in head and neck cancer reconstructive surgery: A systematic review.

BackgroundPrelamination is a reconstructive technique providing fasciomucosal or composite flaps with low donor‐site morbidity. We conducted a systematic review of retrospective studies to assess the application of prelaminated flaps in reconstructive surgery of head and neck cancer patients, and to evaluate the advantages and disadvantages of this technique.MethodsThis systematic review adhered to the recommendations of the PRISMA (Preferred Reporting Items of Systematic Reviews and Meta‐analysis) 2009 guidelines. A computerized MEDLINE search was performed using the PubMed service of the U.S. National Library of Medicine (www.pubmed.org) and Scopus database (www.scopus.com), running the following search string: “prelamination OR prelaminated AND flap.” Two authors screened the articles, then selected and extracted data on malignancies characteristics, reconstructive techniques, outcomes and complications.ResultsA total of 19 articles were selected and reviewed from 128 identified. Seven of 19 articles were case reports, 12 articles were case series. One‐hundred‐two patients underwent reconstructive treatment by prelamination technique using a wide variety of flaps (92 free, 10 pedicled). The sites of reconstruction were oral cavity (66 floor of the mouth, 3 retromolar trigone, 6 hard palate, 4 cheek, 4 tongue), 8 facial skin (5 of them sited on the nose), 4 oropharyngeal defects, 1 laryngotracheal region. No case of total flap loss was reported. Partial flap loss or shrinkage requiring minor surgical revisions was observed in 18 patients (17.6%). Primary closure of the donor site was achieved in 97 cases (97%) and 3 (3%) required revision surgery of the donor site.ConclusionPrelamination is an effective and versatile technique, with low donor‐site morbidity. Further studies would be needed to investigate the impact on the patient's oncologic outcome. More comparative studies with standard reconstructive techniques are essential to understand when it is worth performing this sophisticated procedure.

Osteonecrosis of mandible secondary to sickle cell crisis

<h3>Background</h3> Sickle cell disease (SCD) is an autosomal recessive hemoglobinopathy causing amino acid substitution in the B-hemoglobin chain of erythrocytes. SCD affects 1 in 500 African American children. SCD is associated with multiorgan morbidity and significant reduction in life expectancy. Vaso-occlusive crisis associated with SCD is characterized by acute pain and local tissue hypoxia and necrosis. The extremities, back, and chest are frequently affected, and jaw involvement is very rare. To the best of our knowledge, only 3 cases of jaw osteonecrosis secondary to SCD have been reported in the English-language literature. <h3>Case Summary</h3> A 38-year-old African American man with a history of SCD and avascular necrosis of the hips presented to an emergency department with severe pain in his back, legs, and chest due to a vaso-occlusive episode precipitated by physical overexertion. A few days later, the patient complained of left jaw pain and paresthesia. Computed tomography (CT) of the head with intravenous (IV) contrast, maxillofacial CT with IV contrast, and the remainder of the neurologic examinations were unremarkable. The oral medicine service was consulted, and physical examination of the patient demonstrated lingual gingival tissue swelling of the lower left molars. The mass was nonfluctuant with ulceration causing malalignment of tooth number 18. Bone biopsy revealed squamous mucosa with hemorrhagic foci, ulceration, and ectatic blood vessels with fragments of necrotic bone consistent with osteonecrosis. At the patient's 2-week follow-up visit, a small area of exposed necrotic bone was noted in the affected area. Maxillofacial CT without IV contrast showed mixed radiolucency and sclerosis with dehiscence along the lingual cortex of the posterior mandibular body and along the cortex of the retromolar trigone. Chlorhexidine gluconate 0.12% oral solution was prescribed, and debridement of the left posterior mandible and extraction of the lower left molars with local flap reconstruction were recommended by an oral and maxillofacial surgeon. The patient did not return for follow-up management. <h3>Conclusions</h3> Acute pain and chronic vasculopathy are significant complications of SCD. Jaw involvement in SCD is very rare, as illustrated in this case. It is important for oral health care professionals to understand the pathophysiology and clinical manifestations of SCD.

Comprehensive assessments of the open mouth dynamic maneuver and metal artifact reduction algorithm on computed tomography images of the oral cavity and oropharynx.

ObjectivesTo determine the optimal utility of the open mouth maneuver and Metal Artifact Reduction for the Orthopedic Implants (O-MAR) technique for CT of the oral cavity and oropharynx.MethodsBetween July 2017 and May 2019, 59 subjects who underwent both conventional and open mouth head and neck CT scans were included in this retrospective study. All images were reconstructed using the O-MAR algorithm. With conventional CT with/without the O-MAR (CTc_O/CTc) and open mouth CT with/without O-MAR (CTo_O/CTo), one reader measured the noise level in multiple anatomic regions of the oral cavity and oropharynx. Visual scores for the streak artifact and overall subjective image quality were assessed by two independent readers.ResultsFor the mobile tongue, retromolar trigone, and palatine tonsil, the mean noise was significantly lower, and the mean visual scores were significantly higher, with CTo than with CTc or CTc_O (all, P < 0.001). The mean visual scores were higher with CTo_O than with CTo for the mobile tongue and palatine tonsil (all, P < 0.001). Contrarily, for the mouth floor and tongue base, the mean noise was significantly higher with CTo_O than with CTc or CTc_O, and the mean visual scores were significantly higher with CTc than with CTo or CTo_O (all, P < 0.001).ConclusionsThe open mouth maneuver and O-MAR technique can have different influences on the CT image quality according to the anatomical subsites of the oral cavity and oropharynx.

The Hippocampus: A New Organ at Risk for Postoperative Radiation Therapy for Bucco-alveolar Cancer? A Dosimetric and Biological Analysis

PurposeA significant proportion of patients with bucco-alveolar cancer are long-term survivors, warranting attention to survivorship issues. Decline in neurocognitive function after cranial irradiation for brain tumors correlates with a hippocampal maximum dose (Dmax) of more than 16 Gy, minimum dose (Dmin) of more than 9 Gy, and dose to 40% of the hippocampal volume (D40%) exceeding 7.3 Gy in 2-Gy equivalent dose (EQD2), respectively. We analyzed the utility of sparing the hippocampus in postoperative radiation therapy (PORT) for patients with bucco-alveolar cancer, given the proximity of target volumes to the hippocampus, by virtue of inclusion of the infratemporal fossa. Methods and MaterialsWe instituted hippocampal sparing for patients with bucco-alveolar cancer receiving PORT in March 2018. Ten prior and 10 subsequent consecutive patients with pathologically staged I-IVA cancers of the buccal mucosa, alveolus, and retromolar trigone formed the control group (no hippocampal sparing) and the study group (hippocampal sparing), respectively. The brain and temporal lobes were prescribed dose constraints in both groups. Patients received doses of 60 to 66 Gy at 2 Gy per fraction using the image-guided intensity modulated radiation therapy / volumetric modulated arc therapy technique. Treatment plans were evaluated for (1) hippocampal dosimetric parameters, (2) planning target volume dosimetry and plan-quality indices, and (3) biological indices of equivalent uniform dose (EUD) and normal-tissue complication probability (NTCP) for impaired neurocognitive function. ResultsHippocampal sparing significantly reduced the hippocampal DmaxEQD2, DmeanEQD2, and D40%EQD2 from 27 Gy to 10.9 Gy (P = .002), 14.3 Gy to 6.4 Gy (P = .002), and 15.5 Gy to 6.6 Gy (P = .005), respectively, with comparable plan-quality indices. The radiobiologically robust endpoints of ipsilateral hippocampal EUD (P = .005) and NTCP (P = .01) were statistically significantly improved. ConclusionsMeaningful dosimetric benefit, corroborated with radiobiological indices, was observed with hippocampal sparing. The feasibility and benefit of hippocampal sparing supports our view that the hippocampus should be incorporated as an organ at risk and attention should be given to neurocognitive function in patients with bucco-alveolar cancer who are receiving PORT.

Is Site-Specific Assessment of Neck Nodes Relevant for Neck Dissection.

To highlight the strategy of neck dissection for various subsites of oral squamous cell carcinoma. Retrospective study of 153 patients with 164 neck dissection was involved between 2010 and 2016. Predictor variables were patient demographics, biopsy reports, imaging assessment and outcome variables were type of neck dissection and reconstruction performed and histological assessment of regional metastasis to the neck in relation to various primary subsites was carried out. Out of 153 patients, 126 (82.3%) were males and 27 (17.6%) were females with male-to-female ratio being 4.6:1. The mean age among the patients was 49.9 which ranged from 20 to 80years. Lymph node metastasis was found in 22.6% of T1 and T2 tumors and 77.4% of T3 and T4 tumors. Incidence for gingivobuccal sulcus accounted for 49.6% of primary sites, tongue and floor of the mouth for 15.2%, retromolar trigone for 11.7%, lower alveolus for 8.6%, upper alveolus for 5.9%, lower lip for 3.9%, buccal mucosa for 3.3% and hard palate for 2.6%. Histologically metastasis was seen in level Ib (46%), IIa (33.1%) followed by others. Level V involvement was seen only in 5.5%. For all subsites for N0 neck, minimum level III clearance should be performed, and for positive neck in RMT region, level IV or level V clearance is warranted. Apart from subsite, other factors to be considered are tumor stage, tumor thickness (DOI) and morphological characteristics of the primary tumor. The role of lymph node metastasis, number, size, extracapsular spread, its proximity and fixity to greater vessels in the neck.

Surgical Removal of Orthodontic Mini-screw Accidentally Displaced Into the Pterygomandibular Space Via Intraoral Approach

The mini-screw is widely used in orthodontic treatment for anchorage reinforcement. In mild skeletal Class III patient, retraction of mandibular dentition using mini-screw has been accepted as a reliable and stable treatment approach. In addition, the mini-screw placed in the retromolar area could be used for the uprighting of the lower molar. However, the placement of the mini-screw on the retromolar trigone or anterior ramus region need to be careful because of the possible risk of the “slippage” or “displacement”. Once the mini-screw is displaced to the fascial space such as pterygomandibular space, sub- mandibular space or lateral pharyngeal space, it is difficult to remove. In this case report, we present a mini-screw removal case via an intraoral approach that was displaced into the pterygomandibular space while placing the orthodontic mini-screw on the anterior margin of mandibular ramus.