New accessory palatine canals and foramina in cone-beam computed tomography.

BACKGROUND: Palatal surgeries are associated with many complications. Accessory foramina may be a cause of concern. The present study was conducted to assess the presence and to evaluate the anatomical characteristics of accessory palatine foramina (APF) and related bony canals in cone beam computed tomography (CBCT) scans. MATERIALS AND METHODS: The incidence, location, and types of foramina on the palate were evaluated in 170 CBCT scans. Readings from coronal, sagittal, and axial planes were recorded using a computer programme and evaluated. RESULTS: Other than nasopalatine, greater and lesser palatine foramina, 278 foramina were seen in the palate in different locations. New APF were found posteriorly in 14.71% of the studied scans with wide anatomical variations. Unusual foraminal canals were seen crossing the antral floor laterally. The anterior APF were seen in 73.53% of scans while bilateral APF were found in 43.53% of cases. CONCLUSIONS: Accessory palatine foramina and related canals are frequently seen in CBCT with many anatomical variations. New unusual connecting canals are found passing through the antral floor from palatine foramina to the lateral antral wall. These anatomical structures should be considered in preoperative planning for local analgesia and surgical interventions in the palate.

In-vitro assessment of bone viability with different implant drill speeds.

The success of implant osseointegration is clearly impacted by the heat produced throughout the implant osteotomy site preparation. Bone necrosis of the implant bed should be prevented to maintain a stable osseointegration process. The objective of this experiment was to validate the impact of implant drill speed on the bone from the point of view of heat generation; a second objective was to evaluate viability of the osteotomised implant sites in rabbits histologically. Twenty healthy adult rabbits, were randomly categorised into 4 groups; 3 bony osteotomies in the 3 mm, 3.5 mm and 4 mm diameters of the femur were made in each rabbit. Variable speeds were used for the 3 diameters as follow: Group I: speed 1000 rpm, Group II: speed 1500 rpm, Group III: speed 2000 rpm. A combination of speed 2000 rpm for the small diameter drills and the last large diameter with speed 1000 rpm was used in Group IV. The temperature changes were recorded. After the operation, the rabbits were euthanised and the bony samples were taken for histological evaluation. In group III and Group IV, histological analysis demonstrated more bone viability compared to other groups. Furthermore, heat analysis revealed significant differences between group III, Group IV and the other groups with less heat produced with greater speeds compared with lower speeds. Drilling with higher speed in dense bone with irrigation produces less heat and maintains more bone viability compared with lower speed. In addition, increased drill diameter with the same speed or with increased speed generates less heat compared with smaller diameters.

Intra-articular injection of a mixture of hyaluronic acid and corticosteroid versus arthrocentesis in TMJ internal derangement.

BACKGROUND: Internal derangements are the commonest disorders of temporomandibular joint (TMJ). Different treatment modalities have been proposed to treat this disorder. Arthrocentesis and intra-articular injection are gaining popularity in the treatment of internal derangement of TMJ. PURPOSE: The aim of this study was to compare between the effect of arthrocentesis and intra-articular injection using a mixture of hyaluronic acid and corticosteroid in the management of TMJ internal derangement. MATERIALS AND METHODS: Sixteen patients with TMJ internal derangement were selected and divided into 2 equal groups. In group I, arthrocentesis was performed with Ringer solution. In group II, intra-articular injection was performed with a mixture of 0.5ml hyaluronic acid and 0.5ml corticosteroid. Assessment of pain, maximum mouth opening, lateral movement and clicking was done before the treatment, one week, one month and three months after the treatment. All parameters were subjected to statistical analysis. RESULTS: All studied parameters showed improvements. There was no statistically significant difference between the two groups regarding intensity of pain, maximum mouth opening, lateral movement and joint sound. CONCLUSIONS: TMJ arthrocentesis and intra-articular injection of a mixture of hyaluronic acid and corticosteroid have been found to be effective for treatment of TMJ internal derangement with reduction. Nevertheless, the simplicity of intra articular injection makes it the treatment of choice.

Cytoplasmic translocation of MTA1 coregulator promotes de-repression of SGK1 transcription in hypoxic cancer cells.

Chromatin remodeling factor metastatic tumor protein 1 (MTA1), one of the most upregulated oncogene in human cancer, has an important role in gene expression, cell survival and promoting hypoxic response. Successful cancer progression is dependent on the ability of cells to utilize its survival pathways for adapting to hypoxic microenvironment. Although MTA1 is a stress-responsive gene, but whether hypoxia modulates its function and its role in engaging other core stress-responsive survival pathway(s) remains unknown. Here we have discovered that MTA1 is a novel corepressor of serum and glucocorticoid-inducible kinase 1 (SGK1). Surprisingly, this regulatory corepressive function of MTA1 is lost under hypoxia, allowing upregulation of SGK1 expression and engaging the MTA1-SGK1 axis for the benefit of the cell survival. The underlying mechanism of the noticed stimulation of SGK1 expression by hypoxia includes de-repression of SGK1 transcription because of hypoxia-triggered nucleus-to-cytoplasmic translocation of MTA1. In addition, the newly recognized cytoplasmic translocation of MTA1 was dependent on the chaperoning function of heat shock protein 90 (HSP90) and co-accompanied by the formation of MTA1, HSP90 and HIF1α complex under hypoxic condition but not under normoxic condition. Hypoxia-triggered redistribution of MTA1, SGK1 upregulation and cell survival functions were compromised by a pharmacological SGK1 inhibitor. In summary, for the first time, we report MTA1 regulation of SGK1 expression, hypoxia-dependent MTA1 translocation to the cytoplasm and de-repression of SGK1 transcription. These findings illustrate how cancer cells utilize a chromatin remodeling factor to engage a core survival pathway to support its cancerous phenotypes, and reveal new facets of MTA1-SGK1 axis by a physiologic signal in cancer progression.

Review of distribution of nodal disease in differentiated thyroid cancers in an oncosurgical center in Sri Lanka.

BACKGROUND: There are not many publications on the prognostic implications of nodal disease in patients with papillary thyroid cancers (PTC). This study explored the distribution of nodes with respect to the levels, optimal management of the neck for patients with PTC, and its survival advantages. METHODS: Followup of 79 patients with thyroid cancer (59 with PTC) at the National Cancer Institute, Maharagama, Sri Lanka, was analyzed. RESULTS: The most common histologic type of all thyroid cancers presenting to the Institute was differentiated PTC which affected 59 patients (74.7%). Of them, 29 (50.0%) had positive lymph node metastases in the neck these nodes were found on clinical examination and confirmed by ultrasound in all. Therefore necessitating a comprehensive neck dissection. Among the patients with nodal disease, 5 had nodes in Level 1 at the time of presentation. All patients in this group had multiple levels of positive nodes. Metachronous nodal disease was found in 9 (31.4%) patients, with a disease-free period ranging from 2 months to 37 years. Among the patients with nodal disease, 13 had a single nodal group involvement and the majority of these were Level 4 nodes (46.2%). Central node (Level 6) involvement was found in nine (15.3%) patients. Multiple nodal group involvement indicating multifocal disease was present in 16 (27.6%) patients. Extracapsular nodal spread at presentation and extracapsular thyroid disease at presentation was 10 (16.9%) and 17 (28.8%), respectively. Nodal neck recurrences during followup were present in 2 patients. CONCLUSIONS: Level 1 nodal metastases was present if 5 (8.5%) patients in our group. It is recommended that Level 1 nodes be explored during neck resection for PTC. Because 27.6% of the patients had multifocal disease, it may be important to recommend inclusion of a Level 1 clearance in the presence of multiple nodal involvement. There is a subgroup of patients who had highly aggressive nodes, indicated by extracapsular penetration, which even after radical clearance and external beam radiotherapy have a tendency to recur locally. This indicates an important prognostic feature of the nodal disease in PTC. Because 27.6% of the patients studies had multifocal nodal disease, we consider a comprehensive nodal clearance is necessary for patients with clinically positive nodes.