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.