Fractal analysis of the effects on mandibular bone of botulinum toxin therapy of the masseter muscle in patients with bruxism.

OBJECTIVE: We examined changes in the mandibular angle, ramus, and condylar neck of patients with bruxism after botulinum toxin-A (BTX-A) injection into the masseter muscle as calculated with fractal analysis (FA) on panoramic radiographs (PRs). METHODS: We examined the PRs of 3 groups of 22 patients each (n = 66) obtained upon presentation and 6 months later. One group included healthy controls without bruxism, one group included patients with untreated bruxism, and one group included patients with bruxism who had undergone BTX-A injection into the masseter muscle. We performed FA of the bilateral angle, ramus, and condylar neck of the PRs to calculate fractal dimension (FD). RESULTS: The FD values of the angle on the second PRs of the untreated bruxism group were significantly higher than those of the other groups (P = .026), specifically when compared to the BTX-A injection group (P = .017). The FD values in the angle and ramus of the bruxism group were significantly higher on the second PRs (P ≤..005)) Conversely, the FD values in the angle of the BTX-A injection group were significantly lower on the second PR (P = .039). CONCLUSIONS: Masseter muscle hyperactivity due to bruxism increases bone density in masseter muscle attachment regions. BTX-A injection restricts muscle activity, thereby chnging bone structure and decreasing FD.

Assessment of blood mercury levels in practicing Turkish clinicians, dental students, and dental nurses.

OBJECTIVES: Potential sources of exposure of the dental health team and their patients to mercury vapor in the dental clinic include accidental spillage of elemental mercury, use of mechanical amalgamators, and dry cutting of old amalgam restorations using high-speed instrumentation. The purpose of this study was to evaluate the extent of mercury exposure in Turkish dental staff by cold-vapor atomic absorption spectrometry. METHOD AND MATERIALS: A total of 211 clinicians, dental students, and dental nurses answered a questionnaire concerning sex, age, occupation, number of amalgam restorations performed per week, number of amalgam restorations removed per week, methods of trituration, number of amalgam restorations present in their own mouths, frequency of fish consumption, smoking, vitamin intake, and bruxism. For each subject, a 5-mL sample of whole blood was drawn and frozen until the time of analysis. Blood mercury levels were measured by means of cold-vapor atomic absorption spectrometry. Blood mercury levels were also analyzed in a control group of 58 non-dental-staff blood donors. RESULTS: Normal blood mercury values are considered to be in the range of 0 to 5 ng Hg/mL. Of the dental staff evaluated, 51.7% had a blood concentration of mercury less than 5 ng Hg/mL, and 33.6% had a blood concentration above 5 ng Hg/mL. The difference between the test and control groups was statistically significant (P < .01). CONCLUSION: Mercury is being absorbed as a result of dental practice but that although there is, in general, a low level of mercury contamination in the dental operatory because of amalgam work, sufficient care is being taken to prevent higher levels of contamination with an increased use of mercury.

Assessment of bone density differences between conventional and bone-condensing techniques using dual energy x-ray absorptiometry and radiography.

OBJECTIVES: We used dual energy x-ray absorptiometry (DEXA) and periapical radiography to assess bone density differences after conventional and bone-condensing dental implant techniques. STUDY DESIGN: Single-tooth dental implants were placed by both conventional and bone-condensing techniques in 14 patients with bilateral missing teeth. Dual energy x-ray absorptiometry was used to calculate bone mineral density (BMD) and bone mineral content (BMC) before and 6 and 12 months after implant placement. Furthermore, photodensitometry of periapical radiographs was also assessed. RESULTS: The success rate was 92.9% for the conventional technique and 71.5% for the bone-condensing technique. The BMD was observed to be significantly higher 6 and 12 months after implant placement. The BMC and photodensitometry were significantly increased 6 months after implant placement but showed no further after 12 months. CONCLUSIONS: There were no significant differences in BMD, BMC, and photodensitometry between the two implant placement techniques. However, success rate of the conventional technique was greater than the bone-condensing technique, which may be the result of trabecular fracture associated with the bone-condensing.

Rhinolithiasis: an uncommon entity of the nasal cavity.

Rhinoliths are uncommon foreign bodies of the nose formed by in situ calcification of intranasal endogenous or exogenous foreign material. They are often an asymptomatic condition diagnosed accidentally during a routine examination. Although nasal foreign bodies are more frequently seen in children, and appear to be more common in women, they have been reported in patients of all ages. This article describes a case of rhinolith involving a 38-year-old male. The etiology, thin-sectioned microscopic findings, differential diagnoses, and treatment are also discussed.