Application of fractal analysis in hyperparathyroidism.

OBJECTIVES: Primary hyperparathyroidism (HPT) is a condition caused by an overproduction of parathormone, in excess of the amount required by the body. Its most common cause is a parathyroid gland adenoma and parathyroidectomy is currently the only curative treatment for primary HPT. We present a case history of a 65-year-old patient who was diagnosed with primary HPT after the recognition of dental problems. METHODS: Dental complaints of the patient alerted the dentists, and the patient was referred for further medical evaluation. In addition to his current medical status, his medical records including the biochemical parameters of bone metabolism recorded between 2001 and 2006 were reviewed. The panoramic films of the patient obtained between 1997 and 2008 were also assessed with the fractal analysis method. RESULTS: After consideration of the radiographical, biochemical and clinical evaluations of the patient, the final diagnosis was made as hyperparathyroid adenoma and surgical removal was scheduled. Soon after surgery, alkaline phosphatase, calcium and intact parathormone levels returned to normal. The fractal analysis value of the mandibular alveolar bone also increased. CONCLUSIONS: Dentoalveolar changes observed in HPT include alveolar bone demineralization. The fractal dimension (FD) analysis of the bone tissue has been introduced as an alternative method to investigate the quality of the alveolar bone. FD values of the patient showed osteoporotic bone characteristics between 1997 and 2006 until the date of parathyroidectomy. Mandibular bone FD analyses revealed a prominent development, which was also observed in dual energy X-ray absorptiometry values.

Bond strengths of all-ceramics: acid vs laser etching.

Various applications of dental lasers on dental materials have been proposed for surface modifications. This study evaluated whether laser etching could be an alternative to hydrofluoric acid (HF) etching. One hundred and ten lithia-based all-ceramic specimens (Empress 2) (R: 4 mm, h: 4 mm) were prepared and divided into five groups (n = 22/group). The untreated specimens served as the control, while one of the experimental groups was treated with 9.5% HF for 30 seconds. Three remaining test groups were treated with different laser (Er:YAG laser wavelength:2940 nm, OpusDent) power settings: 300 mJ, 600 mJ and 900 mJ. Ten specimens in each group were luted to the other 10 specimens by a dual-curing cement (Variolink II), and shear-bond strength (SBS) tests were performed (Autograph, crosshead speed: 0.5 mm/minute). The results were statistically analyzed (Kruskal Wallis and Mann Whitney-U, alpha = .05). Mean SBS (MPa) were 31.9 +/- 4.0, 41.4 +/- 4.3, 42.8 +/- 6.2, 29.2 +/- 4.5 and 27.4 +/- 3.8 for the control and HF, 300, 600 and 900 mJ groups, respectively. SEM evaluations revealed different surface morphologies depending on the laser parameters. The differences between HF acid and 300 mJ, when compared with the control, 600 and 900 mJ groups, were significant (p < .05). The 300 mJ laser group exhibited the highest shear-bond strength values, indicating that laser etching could also be used for surface treatments.

The efficacy of intra-articular sodium hyaluronate in patients with reducing displaced disc of the temporomandibular joint.

In this clinical trial, we examined the efficacy of intra-articular hyaluronic acid (HA) treatment in 38 patients with reducing displaced disc of the temporomandibular joint (TMJ). Subjects received two unilateral upper space injections of HA or physiological saline solution with 1 week apart. Efficacy was based on the following measurements: pain and sound intensity of the joint measured by visual analogue scale (VAS), modified Helkimo's clinical dysfunction index and the intensity of joint vibration during opening and closing the mouth measured by accelerometers. These measurements were performed before the first injection and 1 and 6 months after the last injection. In the treatment group (n=19), all measurements improved significantly at month 1 and at month 6 compared with the baseline (P < 0.01). The same measurements, in the placebo group (n=19), did not show any change, except for the pain intensity which improved at month 1 and month 6 (P < 0.05). The change in baseline measurements of all of the efficacy criteria at month 1 and at month 6 in the treatment group was significantly better compared with the change obtained with placebo at the same time intervals. This study demonstrates that intra-articular sodium hyaluronate (Orthovisc) injection into the TMJ is an effective treatment for a reducing displaced disc.