A rare acantholytic variant of squamous cell carcinoma of the maxilla: A case report and literature review.

RATIONALE: Acantholytic squamous cell carcinoma (ASCC) is an uncommon histopathologic variant of squamous cell carcinoma (SCC), which is the most common malignancy of the oral cavity. Though ASCC showed poor prognosis, the exact diagnosis is challenging. PATIENTS CONCERNS: A 59-year-old female patient with 1-month long symptoms of pain and burning sensation in the right maxilla. DIAGNOSES: Incisional biopsy in the maxilla established the pathologic diagnosis of SCC. INTERVENTION: The patient underwent mass resection with near total maxillectomy. OUTCOMES: The final diagnosis through the microscopic examination was ASCC. Palliative chemotherapy was done to relive the symptoms after the recurrence, however, the patient died of the disease at 8 months after her initial presentation. LESSONS: Special attention should be paid to this variant of SCC because most patients with ASCC have a very poor prognosis.

Radiation-Induced Sarcoma on 18F-FDG PET/CT After Treatment of Gorham-Stout Disease of the Maxilla.

Gorham-Stout disease is a rare disorder characterized by proliferation of lymphatic and vascular channels within bone resulting in osteolysis. A 53-year-old man with Gorham-Stout disease involving the left maxilla underwent previous treatment including radiation therapy and intralesional chemotherapeutic injections. He later presented with anemia, facial pain, weight loss, and nasal cavity hemorrhage. CT imaging demonstrated a mass centered within the right maxillary sinus with locoregional involvement. PET/CT showed prominent FDG activity involving the mass centered in the right maxillary sinus with low-grade avidity involving the contralateral maxilla in regions of treated Gorham-Stout disease. Biopsy of the mass confirmed radiation-induced sarcoma.

Low-intensity pulsed ultrasound reduces periodontal atrophy in occlusal hypofunctional teeth.

OBJECTIVE: To clarify whether low-intensity pulsed ultrasound (LIPUS) exposure has recovery effects on the hypofunctional periodontal ligament (PDL) and interradicular alveolar bone (IRAB). MATERIALS AND METHODS: Twelve-week-old male Sprague-Dawley rats were divided into three groups (n = 5 each): a normal occlusion (C) group, an occlusal hypofunction (H) group, and an occlusal hypofunction group subjected to LIPUS (HL) treatment. Hypofunctional occlusion of the maxillary first molar (M1) of the H and HL groups was induced by the bite-raising technique. Only the HL group was irradiated with LIPUS for 5 days. The IRAB and PDL of M1 were examined by microcomputed tomography (micro-CT) analysis. To quantify mRNA expression of cytokines involved in PDL proliferation and development, real-time reverse transcription quantitative PCR (qRT-PCR) was performed for twist family bHLH transcription factor 1 (Twist1), periostin, and connective tissue growth factor (CTGF) in the PDL samples. RESULTS: Micro-CT analysis showed that the PDL volume was decreased in the H group compared with that of the C and HL groups. Both bone volume per tissue volume (BV/TV) of IRAB was decreased in the H group compared with that in the C group. LIPUS exposure restored BV/TV in the IRAB of the HL group. qRT-PCR analysis showed that Twist1, periostin, and CTGF mRNA levels were decreased in the H group and increased in the HL group. CONCLUSION: LIPUS exposure reduced the atrophic changes of alveolar bone by inducing the upregulation of periostin and CTGF expression to promote PDL healing after induction of occlusal hypofunction.

Hyperbaric oxygen therapy for maxillary bone radiation-induced injury: A 15-year single-center experience.

BACKGROUND: Although hyperbaric oxygen therapy (HBOT) is used to treat chronic radiation tissue injury, clinical evidence supporting its use in maxillary bone osteoradionecrosis (ORN) is lacking. Therefore, the purpose of this study was to report our results of collected patient outcomes from a single center's large experience using HBOT to treat maxillary bone ORN. METHODS: From 1999 to 2015, 21 patients received treatment for maxillary bone ORN at our center. The medical records were retrospectively reviewed for the following variables: age, sex, comorbidities, tumor stage and site, previous surgery, previous radiotherapy or chemoradiation therapy, HBOT data, response to treatment and further management. RESULTS: A positive clinical outcome from HBOT occurred in 85.7% of patients with ORN and was proven radiologically in 14 of 15 patients (93.3%). In 5 patients, reconstructive surgery was required thereafter. CONCLUSION: Controversy exists regarding the management of ORN of the maxillofacial skeleton. Our large, single-center experience probably supports the efficacy of HBOT for maxillary bone ORN. © 2016 Wiley Periodicals, Inc. Head Neck 39: 275-278, 2017.

The Effect of a Radiation Positioning Stent (RPS) in the Reduction of Radiation Dosage to the Opposing Jaw and Maintenance of Mouth opening after Radiation Therapy.

The effect of a radiation positioning stent (RPS) in radiation dosage reduction to the opposing jaw and maintenance of mouth opening was audited. 55 Head and Neck cancer patients who received radiotherapy were reviewed. Radiation dosages at similar points in the primary/opposing jaws were measured along with the mouth opening. Results showed a significant reduction in the radiation dosage to the opposing jaw in patients given the RPS. Mouth opening was generally maintained in patients given the RPS (77.7% improvement in mouth opening) compared to patients without RPS. Patients undergoing radiotherapy who had an RPS showed a significant reduction in radiation dosage to the opposing jaw and maintained their mouth opening in the short-term.

Clinical Use of Deferoxamine in Distraction Osteogenesis of Irradiated Bone.

The deleterious effects of radiotherapy, including hypovascularity and hypocellularity, have made distraction of irradiated bones challenging. Animal studies, however, have demonstrated adjunctive measures such as the administration of deferoxamine to significantly improve bone regeneration across irradiated distraction gaps. In this report, the authors demonstrate, for the first time, enhanced bone formation following deferoxamine application in a patient following distraction of a previously irradiated maxilla. Computed tomography imaging of the pterygomaxillary buttress on the side of administration revealed significantly increased bone area and density relative to the contralateral buttress. This is the first presentation of clinical deferoxamine use to promote bone formation following irradiated bone distraction and highlights the promise for this adjunctive measure to make outcomes after distraction of irradiated bone more reliable.

Dosimetric distribution to tooth-bearing areas in intensity-modulated radiation therapy for head and neck cancer: a pilot study.

OBJECTIVES: Dosimetric distribution of intensity-modulated radiotherapy (IMRT) to tooth-bearing areas for common head and neck (H&N) cancer sites were analyzed to facilitate minimization of osteoradionecrosis (ORN) risk through preradiation dental treatment planning. STUDY DESIGN: Fifty-four patients received IMRT with prescribed doses ranging from 6000 centigrays (cGy) (adjuvant) to 6930 cGy (primary) to treat base of tongue (BOT), tonsil, larynx, nasopharynx, and hypopharynx cancers. The average maximal radiation dose delivered was recorded in tooth-bearing areas (anteriors, premolars, and first, second, and third molars) of the maxilla and mandible. RESULTS: All tooth-bearing areas in laryngeal cancer cases received less than 2500 cGy. Maxillary and mandibular molar regions for BOT, tonsil, and hypopharynx cancers received 5000 cGy or higher. In nasopharynx cancers, maxillary teeth received higher doses than mandibular teeth. CONCLUSIONS: Among 5 H&N subsites, mandibular molar regions for BOT, tonsil, and hypopharynx cancers received higher IMRT doses on average, posing the greatest ORN risk.

Survival of dental implants in patients with oral cancer treated by surgery and radiotherapy: a retrospective study.

BACKGROUND: The aim of this retrospective study was to evaluate the survival of dental implants placed after ablative surgery, in patients affected by oral cancer treated with or without radiotherapy. METHODS: We collected data for 34 subjects (22 females, 12 males; mean age: 51 ± 19) with malignant oral tumors who had been treated with ablative surgery and received dental implant rehabilitation between 2007 and 2012. Postoperative radiation therapy (less than 50 Gy) was delivered before implant placement in 12 patients. A total of 144 titanium implants were placed, at a minimum interval of 12 months, in irradiated and non-irradiated residual bone. RESULTS: Implant loss was dependent on the position and location of the implants (P = 0.05-0.1). Moreover, implant survival was dependent on whether the patient had received radiotherapy. This result was highly statistically significant (P < 0.01). Whether the implant was loaded is another highly significant (P < 0.01) factor determining survival. We observed significantly better outcomes when the implant was not loaded until at least 6 months after placement. CONCLUSIONS: Although the retrospective design of this study could be affected by selection and information biases, we conclude that a delayed loading protocol will give the best chance of implant osseointegration, stability and, ultimately, effective dental rehabilitation.

Assessment of implant stability of patients with and without radiotherapy using resonance frequency analysis.

The purpose of this study was to clinically monitor the stability of dental implants in patients with and without a history of radiotherapy, using resonance frequency analysis over 1 year. The stability of patients with 80 implants was monitored with resonance frequency analysis (Osstell Mentor) over 1 year. Data were assessed with Mann-Whitney U test and correlation analysis. Irradiated maxillary implants showed statistically lower values than the mandibular implants at a significant level (P < .05).

The effect of dosage on the efficiency of LLLT in new bone formation at the expanded suture in rats.

The aim of this study was to investigate the effect that dosage has on the efficiency of low-level laser therapy (LLLT) in bone formation in a rat study model. Twenty-eight rats were divided into four groups as only expansion (OE), expansion + low dose (0.15 J) (LD), expansion + medium dose (0.65 J) (MD), and expansion + high dose (198 J) (HD) laser therapy groups. The midpalatal suture was expanded during 5 days. Afterwards, irradiations were started and performed with an 820 nm, continuous wave, Ga-Al-As diode laser (Doris, CTL-1106MX, Warsaw, Poland). At the end of experiment, the premaxillae of the animals were dissected. The sections were transferred into PC environment and analyzed by using Image Analysis program. Number of osteoblasts, osteoclasts, fibroblasts, vessels, transforming growth factor beta (TGF-ß) expression, and new bone formation were evaluated with this program. Amount of expansion did not show any difference among the groups. All parameters except the number of osteoclasts were increased in all lased groups while that parameter was significantly decreased. Vessels, TGF-ß expression, and new bone formation were mostly increased in LD group followed by HD group. Among the lased groups, a significant difference was observed only for the amount of new bone formation, which was between the LD and the MD groups. On the other hand, the difference in this parameter was insignificant between OE and MD groups. Low-level laser therapy with both 5 and 6,300 J/cm(2) doses was found to be significantly effective, while the 20 J/cm(2) dose did not show a significant effect in increasing new bone formation. This finding reveals that the efficiency of the therapy is affected by the dosage.

Predicting cancer risks from dental computed tomography.

Dental computed tomography (CT) has become a common tool when carrying out dental implants, yet there is little information available on its associated cancer risk. The objective of this study was to estimate the lifetime-attributable risk (LAR) of cancer incidence that is associated with the radiation dose from dental CT scans and to evaluate the effect of scan position, sex, and age on the cancer risk. This retrospective cohort study involved 505 participants who underwent CT scans. The mean effective doses for male and female patients in the maxilla group were 408 and 389 µSv (P = 0.055), respectively, whereas the mean effective doses for male and female patients in the mandible groups were 475 and 450 µSv (P < 0.001), respectively. The LAR for cancer incidence after mandible CT scanning varied from 1 in 16,196 for a 30-y-old woman to 1 in 114,680 for a 70-y-old man. The organ-specific cancer risks for thyroid cancer, other cancers, leukemia, and lung cancer account for 99% of the LAR. Among patients of all ages, the estimated LAR of a mandible scan was higher than that of a maxilla scan. Furthermore, the LAR for female thyroid cancer had a peak before age 45 y. The risk for a woman aged 30 y is roughly 8 times higher than that of a woman aged 50 y. After undergoing a dental CT scan, the possible cancer risks related to sex and age across various different anatomical regions are not similar. The greatest risk due to a dental CT scan is for a mandible scan when the woman is younger than 45 y. Given the limits of the sample size, machine parameters, and the retrospective nature of this study, the results need to be interpreted within the context of this patient population. Future studies will be of value to corroborate these findings.

Effects of laser vs ultrasound on bone healing after distraction osteogenesis: A histomorphometric analysis.

OBJECTIVE: To assess the effects of low-level laser irradiation vs ultrasound irradiation on bone healing after distraction osteogenesis. MATERIALS AND METHODS: Distraction osteogenesis was performed with rapid maxillary expansion devices (Hyrax-Morelli, Sorocaba, São Paulo Brazil) in 24 rabbits (Oryctolagus cuniculus). After a 2-day latency period, the distraction devices were activated for 10 days at a rate of 1 mm/d. Four groups of six animals were treated as follows: (1) control, (2) laser irradiation on the right side, (3) ultrasound irradiation on the right side, and (4) laser irradiation on the right side and ultrasound on the left side. Histomorphometric analysis was used to assess the bone healing area. Analysis of variance was used to perform the statistical analyses. RESULTS: The influence of low-intensity laser associated with ultrasound irradiation on bone healing was statistically significant. The analyses showed the greatest amount of bone healing in the jaws of animals in group 4, which received treatment with both ultrasound and laser. CONCLUSION: This study concluded that bone healing is accelerated with the application of laser irradiation. The greatest effects were observed with combined ultrasound and laser treatment.

Benefits of an intraoral stent in decreasing the irradiation dose to oral healthy tissue: dosimetric and clinical features.

OBJECTIVE: To determine whether an intraoral stent may decrease radiation dose to health tissues during intensity-modulated radiotherapy (IMRT) and to evaluate the effect on mucositis. STUDY DESIGN: A total of 33 patients with tongue or floor of the mouth cancer were retrospectively evaluated and divided into 2 groups: group 1 (with stent, n = 19) and group 2 (without stent, n = 14). Data were collected on dosimetric and mucositis outcomes. RESULTS: The mean dose to the maxilla was significantly lower in group 1 (20.9 Gy) than in group 2 (35.8 Gy) (P = .05). The mean dose to the ipsilateral parotid was 35.0 Gy in group 1 vs 41.8 Gy in group 2 (P = .05). No difference was seen in the severity of mucositis between groups (P = .82). However, grade III mucositis was present in group 1 at 4 weeks after IMRT, 1 week after its occurrence in group 2. CONCLUSIONS: A stent was effective in decreasing doses to healthy structures and delaying the emergence of mucositis.

Effects of a low level laser on periodontal tissue in hypofunctional teeth.

Malocclusions, such as an open bite and high canines, are often encountered in orthodontic practice. Teeth without occlusal stimuli are known as hypofunctional teeth, and numerous atrophic changes have been reported in the periodontal tissue, including reductions in blood vessels in the periodontal ligament (PDL), heavy root resorption, and reduced bone mineral density (BMD) in the alveolar bone. Low Level Laser (LLL) has been shown to have a positive effect on bone formation and the vasculature. Although the recovery of hypofunctional teeth remains unclear, LLL is expected to have a positive influence on periodontal tissue in occlusal hypofunction. The aim of the present study was to elucidate the relationship between LLL and periodontal tissue in occlusal hypofunction. Twenty-four male rats aged 5 weeks were randomly divided into control and hypofunctional groups. An anterior metal cap and bite plate were attached to the maxillary and mandibular incisors in the hypofunctional group to simulate occlusal hypofunction in the molars. LLL irradiation was applied to the maxillary first molar through the gingival sulcus in half of the rats. Rats were divided into four groups; control, control+LLL, hypofunctional, and hypofunctional+LLL. Exposure to LLL irradiation was performed for 3 minutes every other day for 2 weeks. Animals were examined by Micro-CT at 5 and 7 weeks and were subsequently sacrificed. Heads were resected and examined histologically and immunohistologically. The hypofunctional group had obvious stricture of the PDL. However, no significant differences were observed in the PDL and alveolar bone between the hypofunctional+LLL and the control groups. In addition, the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF)-positive cells were higher in the hypofunctional + LLL group than in the hypofunctional group. These results indicated that LLL enhanced the production of bFGF and VEGF in the periodontal tissue of hypofunctional teeth.

Effect of frequent application of low-level laser therapy on corticotomized tooth movement in dogs: a pilot study.

PURPOSE: The purposes of the present study were to evaluate the effects of frequent applications of low-level laser therapy (LLLT) on corticotomy-assisted tooth movement in a beagle dog model and to compare the effects in the mandible and maxilla. MATERIALS AND METHODS: In 4 male beagles, the maxillary and mandibular second premolars were extracted. The third premolars were corticotomized and then protracted from the canines with a continuous force of 200 g. Daily LLLT (using an aluminum gallium indium phosphide [AlGaInP] diode) was applied at the buccal mucosa of the corticotomized premolars on 1 side only. The tooth movement was measured for 8 weeks. Fluorochromes were injected intravenously at the start of the experiment (T0) and after 2 (T2), 4 (T4), and 8 (T8) weeks to evaluate new bone formation on the tension sides. Histomorphometric and immunohistologic evaluations were performed. RESULTS: In the mandible, the movement of the corticotomized premolars in the LLLT plus corticotomy group was less than that in the corticotomy-only group, although the difference was not statistically significant. In the maxilla, no significant differences between the 2 groups were found. Osteoclastic and proliferating cell activities and the amount of new bone formation were greater in the mandibular LLLT plus corticotomy group than in the corticotomy-only group. CONCLUSIONS: The frequent application of LLLT showed no significant effect on the corticotomized tooth movement.

Effect of the laser and light-emitting diode (LED) phototherapy on midpalatal suture bone formation after rapid maxilla expansion: a Raman spectroscopy analysis.

The aim of this study was to analyze the effect of laser or light-emitting diode (LED) phototherapy on the bone formation at the midpalatal suture after rapid maxilla expansion. Twenty young adult male rats were divided into four groups with 8 days of experimental time: group 1, no treatment; group 2, expansion; group 3, expansion and laser irradiation; and group 4, expansion and LED irradiation. In groups 3 and 4, light irradiation was in the first, third, and fifth experimental days. In all groups, the expansion was accomplished with a helicoid 0.020" stainless steel orthodontic spring. A diode laser (λ780 nm, 70 mW, spot of 0.04 cm(2), t = 257 s, spatial average energy fluence (SAEF) of 18 J/cm(2)) or a LED (λ850 nm, 150 mW ± 10 mW, spot of 0.5 cm(2), t = 120 s, SAEF of 18 J/cm(2)) were used. The samples were analyzed by Raman spectroscopy carried out at midpalatal suture and at the cortical area close to the suture. Two Raman shifts were analyzed: ∼ 960 (phosphate hydroxyapatite) and ∼ 1,450 cm(-1) (lipids and protein). Data was submitted to statistical analysis. Significant statistical difference (p ≤ 0.05) was found in the hydroxyapatite (CHA) peaks among the expansion group and the expansion and laser or LED groups. The LED group presented higher mean peak values of CHA. No statistical differences were found between the treated groups as for collagen deposition, although LED also presented higher mean peak values. The results of this study using Raman spectral analysis indicate that laser and LED light irradiation improves deposition of CHA in the midpalatal suture after orthopedic expansion.

Dental implant survival in irradiated oral cancer patients: a systematic review of the literature.

PURPOSE: Oral cancer therapy with surgery and radiation is associated with comorbidities; this affects rehabilitation with osseointegrated dental implants. The aim of this systematic review was to evaluate the effect of radiation therapy on osseointegrated dental implant survival in oral cancer patients. MATERIALS AND METHODS: A review of the literature published between 1990 and June 2012 was conducted. Pertinent studies evaluating the effect of radiation therapy on osseointegration of implants were identified through searches of PubMed, SCIRUS, and Google Scholar. Overall implant survival rates were compared with respect to timing of radiation (prior to or after implantation), site of implant placement (maxilla, mandible, vascularized free flaps, nonvascular bone grafts), radiation dose, time interval between radiation therapy and implant placement, and the effect of hyperbaric oxygen therapy. RESULTS: Thirty-eight articles were eligible for inclusion in the review. Overall implant survival rates with radiation therapy done pre- and postimplantation were 88.9% and 92.2%, respectively. In preimplantation radiation therapy, the implant survival rate was significantly higher for the mandible (93.3%) than for the maxilla (78.9%) or for grafted bone (87.5%). Similarly, the implant survival rate was higher when implants were placed in free flaps (89.3%) than in nonvascularized bone grafts (81.7%). While a radiation dose above 55 Gy significantly decreased implant survival, no significant relationship between increased implant survival and the remaining variables were found. CONCLUSION: There, was no significant difference in dental implant survival rates between preimplantation and postimplantation radiation therapy. The anatomical site of implant placement in preimplantation radiation therapy was the most pertinent variable affecting implant survival, with a better survival rate in the mandible compared to the maxilla and grafted bone.

Comparison of adult and child radiation equivalent doses from 2 dental cone-beam computed tomography units.

INTRODUCTION: With the advent of cone-beam computed tomography (CBCT) scans, there has been a transition toward these scans' replacing traditional radiographs for orthodontic diagnosis and treatment planning. Children represent a significant proportion of orthodontic patients. Similar CBCT exposure settings are predicted to result in higher equivalent doses to the head and neck organs in children than in adults. The purpose of this study was to measure the difference in equivalent organ doses from different scanners under similar settings in children compared with adults. METHODS: Two phantom heads were used, representing a 33-year-old woman and a 5-year-old boy. Optically stimulated dosimeters were placed at 8 key head and neck organs, and equivalent doses to these organs were calculated after scanning. The manufacturers' predefined exposure settings were used. RESULTS: One scanner had a pediatric preset option; the other did not. Scanning the child's phantom head with the adult settings resulted in significantly higher equivalent radiation doses to children compared with adults, ranging from a 117% average ratio of equivalent dose to 341%. Readings at the cervical spine level were decreased significantly, down to 30% of the adult equivalent dose. When the pediatric preset was used for the scans, there was a decrease in the ratio of equivalent dose to the child mandible and thyroid. CONCLUSIONS: CBCT scans with adult settings on both phantom heads resulted in higher radiation doses to the head and neck organs in the child compared with the adult. In practice, this might result in excessive radiation to children scanned with default adult settings. Collimation should be used when possible to reduce the radiation dose to the patient. While CBCT scans offer a valuable tool, use of CBCT scans should be justified on a specific case-by-case basis.

Impact of intraoral stent on the side effects of radiotherapy for oral cancer.

BACKGROUND: The intraoral stent is a mouth-opening device which may be used during head and neck cancer radiotherapy with the intention of preventing unnecessary irradiation in normal adjacent tissue. The use of this device during intensity-modulated radiation therapy (IMRT) has not been reported in the literature. METHODS: A 30-year-old woman with squamous cell carcinoma of the tongue was submitted to a CT for IMRT treatment planning with and without the use of the intraoral stent. RESULTS: Dosimetric analysis showed that the irradiation dose to the maxilla, both parotid glands, and left submandibular gland decreased with the use of this device. CONCLUSION: This article shows that intraoral stents seem to be useful in decreasing the radiation dose to healthy structures, especially in bone structures and salivary glands during radiotherapy, and emphasizes the importance of a multidisciplinary team during oncological therapy.