Efficacy and safety of diode laser during circumvestibular incision for Le Fort I osteotomy in orthognathic surgery: a triple-blind randomized clinical trial.

The aim of this triple-blind randomized clinical trial was to evaluate the efficacy and safety of diode laser during circumvestibular incisions for Le Fort I osteotomy in orthognathic surgeries in comparison with conventional techniques using electrocautery and scalpel. Patients were randomly allocated to one of three groups based on the technique employed to perform incisions: diode laser, electrocautery, and scalpel. The parameters used to evaluate the efficacy and safety of diode laser were incision velocity, duration of surgery, bleeding rate, alterations in postoperative functions, pain, edema, wound clinical healing, and infection. Thirty patients were enrolled in the study (10 per group). Regarding bleeding, the incisions performed with diode laser promoted a lower bleeding rate compared with scalpel and electrocautery (p = 0.00). The diode surgical laser was effective during the incision procedure, but required a longer time to perform the incisions compared with the other techniques evaluated (p < 0.05). No statistically significant difference was detected between groups regarding total surgical time or other safety parameters (p > 0.05). Thus, diode laser proved to be effective and safer during circumvestibular incisions for Le Fort I osteotomy than conventional devices.

High-power diode laser in the circumvestibular incision for Le Fort I osteotomy in orthognathic surgery: a prospective case series study.

The incisions during orthognathic surgery are classically performed with conventional scalpel or electrocautery. Considering that the high-power diode laser surgery may provide advantages when compared to conventional incision techniques, the current study aimed to present a prospective case series of patients submitted to circumvestibular incision for Le Fort I osteotomy. Ten patients with dentofacial deformities who underwent to rapid assisted maxillary expansion or bimaxillary orthognathic surgery were enrolled in the study. All incisions were performed by a single surgeon using an 808-nm diode laser, with an optical fiber of 600 µm, at a power of 2.5 W, in a continuous-wave mode. The performance of the incision was evaluated by incision velocity, bleeding, edema, secondary infection, clinical healing, and pain. The velocity of the incision ranged from 0.10 to 0.20 mm/s (mean 0.13 ± 0.03 mm/s). Considering bleeding during the soft tissue incision, all surgeries were classified as absent bleeding. All patients presented a clinical healing of the surgical wound in a period that range from 3 to 5 weeks and experienced swelling during the follow-up period. On average, approximately 50% of the swelling had resolved after the third postoperative week, and 28.8% of swelling remained after 2 months after the surgery. The pain decreased after 2 and 3 days, and 90.0% of the patients reported no pain after 7 postoperative days. High-power diode laser is effective and safety during circumvestibular incisions for Le Fort I osteotomy in orthognathic surgery decreasing bleeding, surgery time, pain, and edema after orthognathic surgery.

Odontogenic myxoma: A 63-year retrospective multicenter study of 85 cases in a Brazil population and a review of 999 cases from literature.

BACKGROUND: Odontogenic myxoma (OM) is an uncommon neoplasm of the jaws. Considering the importance of defining the relative incidence and demographic profile of these lesions in South America, the aim of this study was to analyze the clinical and imagiological features of OM from three South American oral pathology services and to discuss these findings in light of the literature. METHODS: Data regarding age, gender, anatomic site, and imagiological features from 85 cases of OM were collected. Additionally, we did a review of OM studies published in three electronic databases. RESULTS: Among 63 450 oral biopsies, 1178 (1.85%) were odontogenic tumors (World Health Organization - 2017), of which 85 (7.21%) met the criteria of OM. The mean age was 30.7 years (range: 10-61 years; SD: 12.22). Forty-five (52.9%) cases occurred in females and 40 (47.1%) in males (ratio: 1:1.12). Maxilla was affected in 44 cases (53%) and mandible in 39 (47%). Of the 41 informed cases (48.2%), all of them were radiolucent lesions. The literature review indicated a majority of mean ages in third decade and a predilection for females, mandible, and multilocular radiolucent lesions. CONCLUSIONS: The features of OM samples have strong similarity to that reported in studies from other continents. It is possible to infer that geographic variation does not help to explain some differences observed in the clinical features of OM.

Overexpression of immunomodulatory mediators in oral precancerous lesions.

Human leukocyte antigen (HLA) G and E, programmed cell death 1 ligand 1 (PD-L1), IL-10 and TGF-ß are proteins involved in failure of the antitumor immune response. We investigated the expression of these immunomodulatory mediators in oral precancerous lesions (oral leukoplakia-OL; n=80) and whether these molecules were related to the risk of malignant transformation. Samples of normal mucosa (n=20) and oral squamous cells carcinoma (OSCC, n=20) were included as controls. Tissue and saliva samples were analyzed by immunohistochemistry and ELISA respectively. Fifteen OL samples showed severe dysplasia (18.7%) and 40 samples (50%) presented combined high Ki-67/p53. Irrespective of the degree of epithelial dysplasia and the proliferation/apoptosis index of OL, the expression of HLA-G, -E, PD-L1, IL-10, TGF-ß2 and -ß3 was higher to control (P<0.05) and similar to OSCC (P>0.05). The number of granzyme B+ cells in OL was similar to control (P=0.28) and lower compared to OSCC (P<0.01). Salivary concentrations of sHLA-G, IL-10 and TGF-ß did not allow for a distinction between OL and healthy individuals. Overexpression of immunosuppressive mediators in the OL reflects the immune evasion potential of this lesion, which is apparently independent of at cytological and proliferation/apoptosis status.

Prevalence profile of odontogenic cysts and tumors on Brazilian sample after the reclassification of odontogenic keratocyst.

PURPOSE: The aim of this study was to evaluate the impact of the reclassification of odontogenic keratocyst (OKC) as a tumor on the prevalence profile of odontogenic cysts (OCs) and odontogenic tumors (OTs). STUDY DESIGN: Two referral Oral and Maxillofacial Pathology services in Brazil were evaluated. All cases diagnosed as OCs or OTs were selected and classified according to the 1992 WHO-classification (cases before 2005 WHO classification of tumors excluding OKC) and the 2005 WHO classification of tumors, going forward including cases of odontogenic keratocyst tumor (KCOT). The frequency and prevalence of OCs and OTs were compared before and after the reclassification. RESULTS: Among 27,854 oral biopsies, 4920 (17.66%) were OCs and 992 (3.56%) were OTs. The prevalence of OTs before 2005 WHO classification of tumors was 2.04%, while the prevalence after 2005 WHO classification was 11.51% (p < 0.0001). Before 2006, the most frequent tumor diagnosed was odontoma with 194 cases (39.67%), and after 2005 WHO classification of tumors the KCOT was the most frequent with 207 cases (41.07%). CONCLUSIONS: The increase in the prevalence of OTs after 2005 WHO is related to the improvement of pathology services and to the inclusion of KCOT in the OTs group.

Oral Spindle Cell Lipoma in a Rare Location: A Differential Diagnosis.

BACKGROUND: Spindle cell lipoma (SCL) is an uncommon and histologically distinct variant of lipoma. It usually occurs as a solitary, subcutaneous, and well-circumscribed lesion in the posterior neck, shoulders, and back of older men. SCL of the oral cavity is rare. We present the clinical-pathologic features of the third case of SCL located on the hard palate and discuss the histological differential diagnosis with other fusiform neoplasms. CASE REPORT: A 56-year-old man was evaluated for an asymptomatic swelling on the right side of the hard palate. The intraoral examination showed a 25×20 mm sessile and circumscribed tumor, underlying an apparently healthy mucosa of normal color. The lesion revealed a floating consistency during palpation. Excisional biopsy was carried out based on a clinical diagnosis of lipoma or a benign minor salivary gland tumor. The histopathology demonstrated a well-circumscribed but unencapsulated proliferation of bland spindle cells admixed with mature adipocytes in a collagenous/myxoid stroma. The spindle cells were uniform, exhibiting elongated nuclei and narrow cytoplasmic processes without atypia. They were positive to CD34 and negative to factor VIII, alpha-smooth muscle actin, S100, cytokeratin, and actin. Mitotic activity was low, as confirmed by Ki-67 immunostaining. No lipoblastic activity was found. The diagnosis of SCL was therefore established. CONCLUSIONS: Oral spindle cell lipoma is a rare benign lipomatous tumor. The histologic picture shows a range of variations and the observation of morphological features is important to distinguish this lesion from other fusiform tumors. Immunohistochemistry should be helpful in this differentiation.

Is salivary epidermal growth factor a biomarker for oral leukoplakia? A preliminary study.

OBJECTIVES: The aim of this study was to compare the salivary epidermal growth factor (EGF) levels between patients with oral leukoplakia (OL) and clinically healthy individuals, to evaluate the association between salivary and tissular EGF, and to correlate EGF with clinicopathologic data, including the presence of dysplasia. STUDY DESIGN: Salivary EGF levels were measured in 32 patients and 32 controls. The tissue expressions of EGF and its receptor (EGFR) were immunohistochemically evaluated. RESULTS: Salivary EGF levels were similar in patients with OL compared with controls. There was no association between the salivary levels and immunohistochemical expression of EGF. An absence of EGF detection by immunohistochemistry was associated with development of multiple lesions. Dysplastic lesions showed a tendency toward presenting higher salivary EGF levels. CONCLUSIONS: Currently, it is not possible to indicate salivary EGF as a biomarker for OL. Further studies are needed to elucidate the role of EGF in oral carcinogenesis. A follow-up study is necessary to evaluate the changes in EGF values following the surgical excision of OL.

Immunosuppressive mediators of oral squamous cell carcinoma in tumour samples and saliva.

The goal of this study was to compare the salivary concentrations of IL-10, TGF-ß1 and soluble HLA-G (sHLA-G) in patients with oral squamous cell carcinoma (OSCC) to those in healthy individuals (control group), and to correlate the expression of these mediators in saliva with that in the tumour microenvironment. Neoplastic tissue and saliva samples from patients with OSCC (n=22) were analysed by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) respectively. We detected high expression of IL-10 and HLA-G in the tumour microenvironment when compared to healthy oral mucosa samples. Determination of IL-10 salivary concentration enabled us to distinguish patients with OSCC from healthy individuals (P=0.038), which showed correlation with tissue expression of this cytokine. HLA-G salivary release was similar in both groups (P=0.17) and no correlation with tumour expression was observed. TGF-ß1 expression was low or absent in tumours, and salivary concentration was similar between groups. Our results suggest that of the three markers analysed, IL-10 is a potential salivary biomarker. Furthermore, the elevated expression of HLA-G and IL-10 in tumour sites could favour the escape of tumour cells from immune defense mechanisms.

Two-stage surgical removal of large complex odontoma.

PURPOSE: The surgical treatment of a large complex odontoma in the mandibular angle is reported. Four possible surgical approaches to remove a benign tumor in the mandibular angle are discussed. PATIENT: A two-stage surgical treatment was chosen; first, removing most part of the lesion and preserving the second molar, decreasing the risk of a pathological mandibular fracture. A maxillo-mandibular fixation for a period of 4 weeks was used. The patient was oriented to maintain a soft diet. The second surgical stage occurred 3 months after the first one due to the significant bone consolidation observed, reducing the possibility of a mandibular fracture. The remaining lesion and the second molar were then completely removed. CONCLUSIONS: This case demonstrates the value of the tridimensional computed tomography in treatment planning prior to any definitive surgery. A computed tomography should be made in every case of intraosseous lesion in order to establish the intraosseous extent of the tumor, cortical perforation, and soft tissue involvement for precise guidance for the surgical planning. It is recommended that the surgeon considers excision by an intraoral, lingual approach when indicated, and in two stages, when an extremely thin mandibular base is present.