Trismus in head and neck cancer patients in Sweden: incidence and risk factors.

BACKGROUND: The aim was to retrospectively investigate trismus (reduced mandible mobility) development in specified head and neck (H&N) cancer diagnosis according to different radiotherapy dosage regimens. MATERIAL/METHODS: Sixty-nine out of 246 patients with different H&N cancer diagnoses and available maximum interincisal opening (MIO) measurements before and after treatment were analyzed according to age, gender, radiation dose, tumor site and stage, and Karnofsky Performance Status Scale index. MIO was measured over time (range: 3-48 months), with a cutoff criterion for trismus of 35 mm. RESULTS: Overall, 42% of the patients had post-treatment MIO <35 mm, and trismus incidence was highest in patients treated for parotid gland tumors followed by those treated for nasopharyngeal cancers. The mean MIO values at baseline were significantly different (p=0.0078) between patients who developed trismus (i.e. MIO <35 mm; mean: 43 mm) and those who did not (mean: 51 mm). The trismus patients also had significantly larger tumors (p=0.0437), poorer physical function before start of treatment (p=0.0344), and had more often received a higher total tumor radiation dose (p=0.0418). CONCLUSIONS: This study reports a high incidence of trismus in H&N cancer patients after treatment. Furthermore, it was found that poor physical function before the start of treatment and high external beam radiation therapy (EBRT) dosages (>50 Gy) were related to significantly more trismus. Future prospective studies are needed to provide a better understanding of different risk factors associated with trismus development, the impact on health-related quality of life, and the effects of early treatment.

Biofilm formation on the Provox ActiValve: Composition and ingrowth analyzed by Illumina paired-end RNA sequencing, fluorescence in situ hybridization, and confocal laser scanning microscopy.

BACKGROUND: The most frequent cause of voice prosthesis failure is microbial biofilm formation on the silicone valve, leading to destruction of the material and transprosthetic leakage. The Provox ActiValve valve is made of fluoroplastic, which should be insusceptible to destruction. The purpose of this study was to determine if fluoroplastic is insusceptible to destruction by Candida species. METHODS: Thirty-three dysfunctional Provox ActiValves (collected 2011-2013). Biofilm analysis was performed with Illumina paired-end sequencing (IPES), assessment of biofilm-material interaction with fluorescence in situ hybridization (FISH), and confocal laser scanning microscopy (CLSM). RESULTS: IPES (n = 10) showed that Candida albicans and Candida tropicalis are dominant populations on fluoroplastic and silicone. Microbial diversity is significantly lower on fluoroplastic. Lactobacillus gasseri is the prevalent bacterial strain on most voice prostheses. FISH and CLSM (n = 23): in none of the cases was ingrowth of Candida species present in the fluoroplastic. CONCLUSION: Fluoroplastic material of Provox ActiValve seems insusceptible to destruction by Candida species, which could help improve durability of voice prostheses. © 2015 Wiley Periodicals, Inc. Head Neck 38: E432-E440, 2016.