Desmoplastic and non-desmoplastic ameloblastoma: a comparative clinicopathological analysis

OBJECTIVES: The aim of this study was to review a large series of ameloblastomas, accessioned during a period of 35 years in a single Oral Pathology Diagnostic Center, for the incidence of desmoplastic ameloblastoma (DA) and in order to analyze the clinical features of this unusual variant.
MATERIALS AND METHODS: All cases diagnosed as ameloblastoma were reviewed and 14 were rediagnosed as DA. These cases were analyzed in terms of gender, patient age, location, clinical diagnosis, radiographic features and recurrence following treatment. Data from DA and non-desmoplastic ameloblastoma (NDA) were compared.
RESULTS: The incidence of DA in this series was 8.8%. The mean age of NDA and DA were 39.1 and 38.8 years respectively, and a higher female prevalence was observed in the latter. The mandible was the most affected bone in both groups of tumors, but with a different regional distribution. Most NDA arose in the angle and ramus of the mandible, but the premolar/molar region was the preferential location for DA. The most common radiographic feature in DA was the osteolytic type, either monolocular or multilocular. Most of these cases were clinically diagnosed as ameloblastoma. According to follow-up data available, 21.4% of DA and 10.1% of NDA recurred.
CONCLUSIONS: The results of this study do not support the hypothesis that DA should be a separate clinicopathological entity. It seems most likely that DA is another his-tologic variant of ameloblastoma.     

Histologic study of an autologous fat graft in the larynx of dogs with unilateral vocal fold paralysis

OBJECTIVE: To determine the histologic finds of autologous fat graft (AFG) in 24 paralyzed canine left vocal folds 12 weeks after introduction. STUDY DESIGN: Animal model. Experimental prospective study. METHODS: Twenty-four mongrel dogs of both genders weighing 15 to 20 kg were divided into three study groups (SGs) of eight dogs each, whose larynges were grafted by vocal fold lipoinjection (VFL-SGA), vocal fold lipoinjection plus insulin (VFLI-SGB), and by fat graft medialization laryngoplasty (FGML-SGC), respectively, and observed for 12 weeks, followed by immediate sacrifice. All 24 dogs were submitted to left vagal and recurrent laryngeal nerve resection. All animals were confirmed to have a left vocal fold paralysis four weeks later, when 2 mL of autologous fat graft were placed inside the left paraglottic space. The larynges were removed at pre-established times and, after they were studied for remaining fat graft volume by magnetic resonance imaging, they were studied histologically to evaluate the influence of the different techniques on the histologic behavior of the graft. RESULTS: Each of the three study groups had its specific finds for fat graft detection and fat absorption, and its characteristics identified and compared statistically. The groups were not statistically different. CONCLUSION: The histologic findings for the AFG applied to a vocal fold were similar in groups VFL-SGA, VFLI-SGB and FGML-SGC 12 weeks after grafting, with no statistically significant differences between groups, and revealed an almost total loss of the grafted fat.     

Effect of treatment of dentofacial deformity on masseter muscle thickness

OBJECTIVE: The objective of the present study was to determine the modifications in masseter muscle thickness before and after interdisciplinary orthodontic, oromyofunctional and surgical treatment of class III dentofacial skeletal deformities (DFSD). DESIGN: Fifteen patients with class III DFSD participated in the study, denoted P1 group before the interdisciplinary treatment and P2 group (same patients) 6-8 months after surgery. Fifteen individuals with no DFSD were used as the control group. Bilateral ultrasonography (US) of the masseter muscle under resting and biting conditions was performed in the three groups. RESULTS: There was a significant difference (P<0.01) for all muscles tested between the control, P1 and P2 groups, with greater thickness for controls, intermediate thickness for P2, and the lowest thickness for P1 in all situations evaluated. CONCLUSION: We conclude that there was an increase in masseter muscle thickness after surgical correction of DFSD accompanied by interdisciplinary treatment, although the values were still lower than those observed in the control group.     

Do social networks affect the use of residential aged care among older Australians?

Background

Older people's social networks with family and friends can affect residential aged care use. It remains unclear if there are differences in the effects of specific (with children, other relatives, friends and confidants) and total social networks upon use of low-level residential care and nursing homes.

Methods

Data were drawn from the Australian Longitudinal Study of Ageing. Six waves of data from 1477 people aged ≥ 70 collected over nine years of follow-up were used. Multinomial logistic regressions of the effects of specific and total social networks on residential care use were carried out. Propensity scores were used in the analyses to adjust for differences in participant's health, demographic and lifestyle characteristics with respect to social networks.

Results

Higher scores for confidant networks were protective against nursing home use (odds ratio [OR] upper versus lower tertile of confidant networks = 0.50; 95%CI 0.33–0.75). Similarly, a significant effect of upper versus lower total network tertile on nursing home use was observed (OR = 0.62; 95%CI 0.43–0.90). Evidence of an effect of children networks on nursing home use was equivocal. Nursing home use was not predicted by other relatives or friends social networks. Use of lower-level residential care was unrelated to social networks of any type. Social networks of any type did not have a significant effect upon low-level residential care use.

Discussion

Better confidant and total social networks predict nursing home use in a large cohort of older Australians. Policy needs to reflect the importance of these particular relationships in considering where older people want to live in the later years of life.     

Minisatellite rearrangements are increased in liver tumours induced by transplacental aflatoxin B1 treatment of hepatitis B virus transgenic mice, but not in spontaneously arising tumours

Transgenic mice carrying an integrated subgenomic human hepatitis B virus (HBV) DNA fragment coding for the viral envelope polypeptides, represent a model for the study of the mechanisms involved in hepatocarcinogenesis. The mice develop a progressive liver injury characterized by inflammation, regenerative hyperplasia and dysplasia terminating in hepatocellular carcinoma (HCC) at around 18-21 months of age. No alterations in specific oncogenes and tumour suppressor genes in the HCC arising in this transgenic model have been observed. However, onset of liver tumours is significantly earlier in mice treated with aflatoxin B1 (AFB1). In order to examine more generally for genetic rearrangements during the natural history of the disease, DNA multilocus fingerprinting was performed using probes recognizing mouse minisatellites. Liver tumour samples from HBV transgenic mice either untreated or treated with AFB1 transplacentally were included in the study. In a total of 28 tumour samples from HBV transgenic mice receiving no carcinogen treatment, using three minisatellite probes, no alterations were detected. The frequency of rearrangements using any one of the three probes is calculated to be below 0.2%. This result demonstrates that genetic instability in minisatellite sequences is not a common event associated with HBV gene expression and liver injury in this model. In 11 liver tumours from mice exposed to AFB1 transplacentally six had minisatellite alterations (band gains and losses) revealed by at least one of the three probes used. The frequency of rearrangements was between 1.1% and 2% depending on the minisatellite probe. These data show that genetic alterations can be induced by transplacental exposure to AFB1 and suggest that genetic instability could be important in hepatocarcinogenesis with combined exposures to AFB1 and HBV.      

Reconstruction of two mandible defects with one fibular flap

The present report describes an original surgical procedure for the mandibular reconstruction of 2 different defects using a single fibular flap. In addition to the habitual osteotomies, we resected a bone fragment from the middle portion of the flap, with care taken to maintain the integrity of the pedicle throughout its extension to guarantee an adequate blood supply also for the distal portion of the bone flap used for the treatment of the smaller mandibular defect. This simple maneuver permitted the reconstruction of 2 mandibular regions with well-vascularized bone tissue using a single microsurgical flap.     

Time necessary for neovascularization of a tracheal segment by the sternohyoid muscle.

INTRODUCTION: The reimplantation of a complete tracheal segment (CTS) as an autograft or homograft often results in total or partial necrosis of the CTS. However, previous experiments suggested that when the CTS is first vascularized by the sternohyoid muscle (SM) 21 days before the reimplantation, the CTS can be reimplanted without ischemia or stenosis. However, it is not clear if the CTS requires 21 days to attain full revascularization. GOAL: This study aims to ascertain the minimum time necessary for revascularization of the 6 rings CTS by the SM allowing reimplantation free of ischemia. METHODS: Fifteen mongrel dogs, divided into 3 groups were submitted to 2 sequential surgical procedures. In the first procedure, a SM flap was used to envelop 6 rings CTS in all dogs. After periods of 21 days (group 1, n = 5), 14 days (group 2, n = 5) and 7 days (group 3, n = 5), the compound flaps (CTS and SM) were neovascularized. Each CTS was transected and mobilized from the trachea and then replaced again in its original site, as an autoflap. RESULTS: After a period of at least 60 days, none of dogs presented any respiratory alteration. Macroscopic and microscopic analyses demonstrated adequate viability and no stenosis. CONCLUSION: Our findings suggest that it is possible to neovascularize the CTS using a SM flap within a period as short as 1 week.     

Effect of class II and class III dentofacial deformities under orthodontic treatment on maximal isometric bite force

Objective

To determine whether dentofacial deformities influence maximal isometric bite force in affected individuals compared to a control group.

Design

A total of 125 volunteer adult patients attended at a hospital participated in the study. Of these, 44 had a confirmed diagnosis of class II deformity (GII: 13 men and 31 women; mean age: 27 years) and 81 had class III deformity (GIII: 35 men and 46 women; mean age 25 years), all of them with indication of orthognathic surgery and under orthodontic treatment. Fifty adult volunteers (CG: 17 men and 33 women; mean age: 22 years) with no alterations of dental occlusion or clinical signs of temporomandibular joint dysfunction participated as controls. Maximal isometric bite force was measured with an electronic gnathodynamometer alternately positioned on each side of the dental arch in the region of the molar teeth and the subjects were instructed to bite it as strongly as possible, with the value being recorded in Newtons. Individuals with good understanding of oral language and with no cognitive or neuromuscular deficits were selected. Data were analysed statistically by the mixed effects model.

Results

There was no statistically significant difference (P > .05) in maximal isometric bite force between subjects with class II and class III dentofacial deformities, although the values for both groups were lower than those of control individuals.

Conclusion

Dentofacial deformity affected maximal isometric bite force regardless of its pattern.     

Ovarian carcinoma relapsing as a cerebellopontine angle tumour

Involvement of the central nervous system in epithelial ovarian carcinoma is rare. A 46-year-old woman with ovarian carcinoma relapsing with brain metastasis is described. She received radiotherapy for the metastasis and survived for 18 months.