Surgical margins in head and neck cancer: A contemporary review

Adequate resection margins are critical to the treatment decisions and prognosis of patients with head and neck squamous cell carcinoma (HNSCC). However, there are numerous controversies regarding reporting and interpretation of the status of resection margins. Fundamental issues relating to the basic definition of margin adequacy, uniform reporting standards for margins, optimal method of specimen dissection, and the role of intraoperative frozen section evaluation, all require further clarification and standardization. Future horizons for margin surveillance offer the possible use of novel methods such as “molecular margins” and contact microscopic endoscopy, However, the limitations of these approaches need to be understood. The goal of this review was to evaluate these issues to define a more rational, standardized approach for achieving resection margin adequacy for patients with HNSCC undergoing curative resection. © 2012 Wiley Periodicals, Inc. Head Neck, 2013     

A simple eyesight screening programme for dental undergraduates: Results after 7 years

This paper reports the results of a simple eyesight screening programme for dental undergraduates which has been used for 7 years. Examinations were performed by orthoptists at a general hospital associated with the dental school. Defects in visual acuity, squints, limitations of convergence, defective stereopsis and colour vision were found. Many students were unaware of their visual defects, and the findings support the continued use of visual screening to identify and encourage those with defects to seek professional treatment at an early opportunity.
Many of the defects were correctable or could be improved with help. Those with defective colour-vision were encouraged to seek assistance with shade selection during their clinical careers. The value of visual screening and the significance of the findings are discussed.     

Lingual mandibular bone defect. Case report and review of the literature

An unusual case of lingual mandibular bone defect (Stafne's bone cavity) is presented in which the lesion extended to above the inferior dental canal and caused expansion of the buccal cortical plate. The literature is reviewed with regard to the incidence, plausible aetiologic factors and methods of investigation of such lesions.     

Equipment and methods for simple sensory testing

Four simple tests which can be used for routine sensory testing following trigeminal nerve injuries are suggested. The methods for constructing the equipment needed for these tests are described.     

A method of estimating tooth life expectancy

One of the most important outcome measures for dental services is the increase in tooth life expectancy which is brought about by the interventions provided. Thus, a convenient and accurate index of tooth survival is critical both to clinical decision making and to more general assessments of public dental health policies.
This paper describes a simple method of approximating tooth life expectancy (TLE). The method is based on the assumption that tooth survival follows a simple declining exponential function. Assuming a constant mortality rate, TLE is the integral of the survival function, expressed as S (t) = e-^μt, where t is time, and μ the constant mortality rate.
Using 3-year tooth-specific mortality rates for 491 subjects aged 50 years or more, tooth-specific life expectancies for the population as a whole were found to range from 27 years for upper canines to 71 years for lower incisors. Individuals with a mean periodontal attachment loss greater than 4 mm and people on low incomes had significantly lower tooth life expectancies than their periodontally fit and more wealthy counterparts.
This technique can be used to obtain disease-specific or intervention-specific tooth life expectancies. Thus, gains in TLE for individuals with different oral, social and behavioural characteristics can be calculated. The declining exponential approximation of tooth life expectancy has the potential to become a powerful tool in the evaluation of dental services and treatments.     

Survival of patients who needed salvage surgery for recurrence after radiotherapy for oral carcinoma

Objective: To find out how long patients with oral carcinoma survived after the primary tumour had been treated by radiotherapy and who required salvage surgery for recurrence; to see if there were any significant differences in age, sex, site, size, and histology of the tumours in relation to survival; and to see if the time of the recurrence had any effect on the survival. Design: Retrospective analysis of case notes. Setting: Teaching Hospital, Scotland. Subjects: 370 consecutive patients, 187 (51%) of whom were initially treated by radiotherapy; 58 of the 187 (31%) developed a recurrence that was considered suitable for salvage surgery. Results and conclusions: 43/58 patients had died and 15 patients were still alive at the time of the study, the median (range) survival of the groups was 21 (6–89) months compared with 72 (19–212) months, respectively (P = 0.0001). Other significant differences included age at presentation for men (P = 0.004), and the increased likelihood of survival if the initial site of the tumour was the tongue (P = 0.02). There was also a highly significant correlation between time to recurrence and survival amongst those who died (P = 0.002). A short recurrence time may suggest a less radical surgical salvage option if reduced survival is likely. Why there should be such an association is unknown.     

The effect of delayed placement of capsulated cements on crown seating

The effect of delayed seating of a crown onto a die was determined when using capsulated zinc phosphate and glass ionomer cements. The space between the crown and the die was varied up to 60 μm, and the commencement of seating was from 30 to 210 seconds after mixing ended.
The zinc phosphate cement gave gradually increasing seating discrepancies with time, but providing 45 μm of space was present, the crown could be well seated up to 3 minutes after mixing. It is argued that this cement is particularly suitable for cementing burnishable inlays. The glass ionomer cement permitted reduced seating discrepancies compared with zinc phosphate cement when 45 μm of space was present, but gave poor results when the seating was delayed more than three minutes. The capsulated cements were clean and quick to use, and It is recommended that if there is a delay in seating, a new mix of cement shoud be prepared rather than attempting to complete cementation with an obviously setting cement.