Predictors of early postoperative pneumonia after oncologic surgery with the patients receiving professional oral health care: A prospective, multicentre, cohort study.

This study was a prospective, multicentre, cohort study on 685 patients who had undergone oncologic surgery. The patients were divided into two groups according to the presence or absence of postoperative pneumonia. The two groups were compared with respect to their background, index operation, food eaten, oral condition, contents of oral care and dental treatment, laboratory data, and bacterial flora. All postoperative pneumonias occurred in six cases within four days postoperatively. The multivariable logistic regression analysis showed that preoperative serum C-reactive protein was the strongest predictor of postoperative pneumonia. In addition, decreased postoperative Candida albicans colonies was an effective predictor of postoperative pneumonia. For patients with predictors of postoperative pneumonia, perioperative strategies for its prevention should be considered in addition to professional oral health care. This study was approved by the National Hospital Organization's Central Ethics Review Board and was also approved by the directors of the participating institutions.

Subjective and qualitative assessment of neural disturbance after inferior alveolar nerve transposition for dental implant placement.

BACKGROUND: The purpose of this retrospective study was to accumulate data regarding the quality of postoperative neurosensory function after inferior alveolar nerve (IAN) transposition for dental implant placement. METHODS: The study included seven consecutive patients who underwent IAN transposition surgery for the insertion of a dental implant into the atrophic posterior mandible. Of these, six patients (seven sides) were available for long-term assessment of postoperative IAN function. Neurosensory disturbance of the IAN was assessed objectively using the modified SW perception test reported by Semmes and Weinstein. In addition, the quality of nerve paralysis was assessed according to the criteria reported by Highet. RESULTS: The median follow-up time was 49 months (range 12-105 months). No implant loss was observed during the follow-up. All patients experienced numbness immediately and the days after surgery. Complete recovery of neural function was observed on two sides; weak hypoesthesia was observed on two sides, moderate hypoesthesia on two sides, and severe hypoesthesia on one side. However, only one patient expressed concern about IAN function. CONCLUSIONS: IAN transposition is a useful method for placing implants in the atrophic posterior mandible. However, the procedure is complicated, with the possibility of some degree of neurosensory disturbance, although in most of our cases, it resolved within a clinically acceptable period.

Impact of different surgical margin conditions on local recurrence of oral squamous cell carcinoma.

The purpose of this study was to analyze the impact of different surgical margin conditions on local recurrence of oral squamous cell carcinoma (SCC) in 148 consecutive patients who underwent planned radical resection of oral SCC. The patients were classified into four categories according to the status of the surgical margin: clear (no SCC within 5mm, n=103), close (SCC within 5mm, n=21), dysplasia (dysplastic epithelium at margin, n=13), and involved (SCC at margin, n=11). Cox's proportional hazard model showed that the status of the surgical margin had a significant impact on local recurrence (p<0.003); hazard ratio was 3.79 (95%CI: 1.17-12.28) with a close and 7.89 (2.38-26.17) with an involved margin. The presence of mucosal dysplasia at the surgical margin was also a significant predictor of local recurrence (hazard ratio: 5.29, 95%CI: 1.31-21.29). Local recurrence was observed only with severe dysplasia, while no recurrence with mild and moderate dysplasia. In the patients with a clear and closed surgical margin, local recurrence was related with T4 tumor and an advanced mode of tumor invasion. The results of this study suggested that the presence of tumor cells at or close to the surgical margin increased the risk of local recurrence. The presence of dysplastic epithelium (especially severe dysplasia) at the mucosal surgical margin has a significant impact on local control. It was also suggested that not simply the width of the free margin but also clinical and histological risk factors should be included in deciding the necessity for adjuvant radiotherapy.

The 2G allele of promoter region of matrix metalloproteinase-1 as an essential pre-condition for the early onset of oral squamous cell carcinoma.

BACKGROUND: Matrix metalloproteinase (MMP) is known to be involved in the initial and progressive stages of cancer development, and in the aggressive phenotypes of cancer. This study examines the association of single nucleotide polymorphisms in promoter regions of MMP-1 and MMP-3 with susceptibility to oral squamous cell carcinoma (OSCC). METHODS: We compared 170 Japanese OSCC cases and 164 healthy controls for genotypes of MMP-1 and MMP-3. RESULTS: The frequency of the MMP-1 2G allele was higher and that of the 1G homozygote was lower in the OSCC cases (p = 0.034). A multivariate logistic regression analysis revealed that subjects who were 45 years old or older had a significantly increased (2.47-fold) risk of OSCC (95%CI 1.47-4.14, p = 0.0006), and those carrying the MMP-1 2G allele had a 2.30-fold risk (95%CI 1.15-4.58, p = 0.018), indicating independent involvement of these factors in OSCC. One of the key discoveries of this research is the apparent reduction of the MMP-1 1G/1G and 1G/2G genotype distributions among the early onset OSCC cases under the ages of 45 years. It should be noted that the tongue was the primary site in 86.2% of these early onset cases. This could suggest the specific carcinogenic mechanisms, i.e. specific carcinogenic stimulations and/or genetic factors in the tongue. CONCLUSION: Since the 2G allele is a majority of the MMP-1 genotype in the general population, it seems to act as a genetic pre-condition in OSCC development. However this report suggests a crucial impact of the MMP-1 2G allele in the early onset OSCC.