Effect modifiers influencing the periodontal healing of the adjacent second molar following mandibular third molar removal.

DATA SOURCES: Studies were selected, using appropriate key words, from the following databases: Cochrane Central Register of Controlled Trials; Medline (via Pubmed); Scopus/Elsevier; and Embase. A manual search was also conducted of five periodontology and oral and maxillofacial surgery journals. It was not clarified what proportion of studies included were derived from which source. STUDY SELECTION: Inclusion criteria included prospective studies and randomised controlled trials published in English, with a minimum 6-month follow-up reporting on parameters of periodontal healing distal to the mandibular second molar following removal of M3M in human subjects. These parameters included pocket probing depth (PPD) reduction and final depth (FD), clinical attachment loss (CAL) reduction and FD, alveolar bone defect (ABD) change and FD. Given prognostic indictors and interventions were investigated, the studies were screened using PICO and PECO (Population, Intervention, Exposure, Comparison, Outcome). Cohen's kappa statistic measured the level of agreement between 2 selecting authors (0.96 stage 1 screening, 1.00 stage 2 screening). Disagreements were resolved with a tie-breaker 3rd author. Ultimately, from 918 studies, 17 met the inclusion criteria and 14 were included in the meta-analysis. Studies were excluded on the basis of same patient pools, non-representative outcomes of interest, insufficient follow-up period, and unclear results. DATA EXTRACTION AND SYNTHESIS: The 17 studies meeting the inclusion criteria underwent validity assessment and data extraction, including risk of bias analysis. Meta-analysis was performed to calculate mean difference and standard error for each outcome measure. If these were unavailable, a correlation coefficient was calculated. Meta-regression was used on different subgroups to determine factors affecting periodontal healing. For all analyses, statistical significance was determined as p < 0.05. Statistical variability in outcomes beyond the expected was estimated using I2 analyses, with a value >50% indicating significant heterogeneity. RESULTS: The periodontal parameters investigated yielded the following results after meta-analysis: overall PPD reduction of 1.06 mm at 6 months and 1.67 mm at 12 months; final PPD of 3.81 mm at 6 months; CAL change of 0.69 mm at 6 months; final CAL of 4.28 mm at 6 months and 4.37 mm at 12 months; ABD reduction of 2.62 mm at 6 months; ABD of 3.2 mm at 6 months. The authors found no statistically significant effect on periodontal healing from the following confounding factors: age; M3M angulation (specifically, mesioangular impaction); optimisation of periodontal health prior to surgery; scaling and root planing of the distal second molar at the time of surgery; post-operative antibiotics or chlorhexidine prophylaxis. There were statistically significant correlations between baseline PPD and final PPD. There was improved PPD reduction at 6 months with a three-sided flap compared to others, and regenerative materials and bone grafts improved all periodontal parameters. CONCLUSIONS: Although M3M removal results in modest improvement in periodontal health distally of the second mandibular molar, periodontal defects remain onwards of 6 months. There is limited evidence suggesting a three-sided flap is more beneficial than an envelope flap in PPD reduction at 6 months. Regenerative materials and bone grafts result in significant improvements across all periodontal health parameters. The most important predictive factor in final PPD of the distal second mandibular molar is baseline PPD.

Knotted fields and explicit fibrations for lemniscate knots.

We give an explicit construction of complex maps whose nodal lines have the form of lemniscate knots. We review the properties of lemniscate knots, defined as closures of braids where all strands follow the same transverse (1, ℓ) Lissajous figure, and are therefore a subfamily of spiral knots generalizing the torus knots. We then prove that such maps exist and are in fact fibrations with appropriate choices of parameters. We describe how this may be useful in physics for creating knotted fields, in quantum mechanics, optics and generalizing to rational maps with application to the Skyrme-Faddeev model. We also prove how this construction extends to maps with weakly isolated singularities.

A simple method for electron energy constancy measurement.

A device is described for use in confirming the energy constancy of clinical electron beams. A wedge shaped absorber is placed over an ionization chamber leading to an energy dependent response. A measurement under the energy filter is divided by a measurement in air to correct for the inherent energy dependence of the chamber. A nearly linear response is demonstrated.

Geometry function of a linear brachytherapy source.

An equation is derived for the TG43 geometry function, G(r,theta), of a linear brachytherapy source in terms of its active length. This equation is validated by comparison to published values. It is then used to calculate values of the geometry function for the Model 200 (103)Pd seed, which is a segmented linear source.

Nursing grand rounds.

Therapeutic touch is an energy-based nursing intervention performed with the goals of restoring harmony and balance in the human energy field and helping the patient self-heal. This article discusses the process of therapeutic touch and describes case studies of CCU patients on whom therapeutic touch was used as part of the treatment plan. Therapeutic touch was applied to help stabilize patients, calm agitated and intubated patients, and relieve pain. The experiences related had a calming effect on the practitioner and positive family responses.

Massive pulmonary embolism: a complication of the technique of tourniquet ischemia.

Various neurologic and vascular injuries complicating the technique of tourniquet ischemia for limb surgery are well known. We found no reports of the serious complication of massive pulmonary embolism as a consequence of this technique. This is surprising when one considers the type of patients surgeons deal with in the use of the technique of tourniquet ischemia. These patients are traumatized and immobile, with high potential for development of deep venous thromboembolic disease, and are subjected to extensive extremity manipulation. Such patients are ideal candidates for the development of massive pulmonary embolism. We have encountered and successfully treated a patient with such a complication.