Novel insights into maladaptive behaviours in Prader-Willi syndrome: serendipitous findings from an open trial of vagus nerve stimulation.

BACKGROUND: We report striking and unanticipated improvements in maladaptive behaviours in Prader-Willi syndrome (PWS) during a trial of vagus nerve stimulation (VNS) initially designed to investigate effects on the overeating behaviour. PWS is a genetically determined neurodevelopmental disorder associated with mild-moderate intellectual disability (ID) and social and behavioural difficulties, alongside a characteristic and severe hyperphagia. METHODS: Three individuals with PWS underwent surgery to implant the VNS device. VNS was switched on 3 months post-implantation, with an initial 0.25 mA output current incrementally increased to a maximum of 1.5 mA as tolerated by each individual. Participants were followed up monthly. RESULTS: Vagal nerve stimulation in these individuals with PWS, within the stimulation parameters used here, was safe and acceptable. However, changes in eating behaviour were equivocal. Intriguingly, unanticipated, although consistent, beneficial effects were reported by two participants and their carers in maladaptive behaviour, temperament and social functioning. These improvements and associated effects on food-seeking behaviour, but not weight, indicate that VNS may have potential as a novel treatment for such behaviours. CONCLUSIONS: We propose that these changes are mediated through afferent and efferent vagal projections and their effects on specific neural networks and functioning of the autonomic nervous system and provide new insights into the mechanisms that underpin what are serious and common problems affecting people with IDs more generally.

24-hour shear bond strength of metal orthodontic brackets bonded to porcelain using various adhesion promoters.

Clinically, orthodontists are often faced with the difficulties of bonding to porcelain crowns, veneers, or bridges. Traditional methods of dealing with this are often time-consuming and generally esthetically unacceptable to patients. Current interest involves the use of organosilane primers with or without NTG-GMA and BPDM resins to aid in chemically bonding porcelain with traditional orthodontic adhesives. This study compared the bond strength of three types of adhesion promoters: Ormco Porcelain Primer (OR) (Ormco Corp., Glendora, Calif.), All-Bond2 (AB2) (Bisco Dental Products, Inc., Itasca, Ill.), and Scotchprime Ceramic Primer (SP) (3M, St. Paul, Minn.) with two orthodontic adhesives: Phase II (Reliance, Inc., Itasca, Ill.) and Rely-a-bond (Reliance, Inc., Itasca, Ill.). Eighty ceramometal samples were fabricated and hydrated for 1 week in distilled water before bonding. Next, the samples were etched with 2.5 % HF acid for 90 seconds, rinsed and upper central incisor metal orthodontic brackets were bonded with the various primers and adhesives. After 24 hours they were sheared off with an MTS machine at at rate of 0.5 mm/min, and the bond strength was measured. The mean shear bond strengths (MPa) with Phase II were as follows; Control 0.44 (sigma = 0.22), AB2 8.40 (sigma = 3.61), OR 13.31 (sigma = 5.79), SP 13.53 (sigma = 3.34). With Rely-a-bond, the shear bond strengths were Control 0.41 (sigma = 0.67), AB2 4.34 (sigma = 1.88), OR 9.73 (sigma = 4.58), and SP 12.40 (sigma = 3.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Factors to consider for predictable post and core build-ups of endodontically treated teeth. Part I: Basic theoretical concepts.

Post and core build-ups represent an important pre-prosthetic procedure prior to the restoration of an endodontically treated tooth. The dental practitioner is presented with the dilemma of selecting from an ever increasing variety of materials, techniques and designs related to this procedure, many of which are harmful and mired in controversy. Part I of this paper reviews some basic theoretical concepts for the dentist to consider when producing a predictable post and core build-up. An understanding of these basic concepts will assist the dentist in gathering data and establishing a risk/benefit equation, and will also provide an additional aid during the decision-making process for the restoration of an endodontically treated tooth.

Factors to consider for predictable post and core build-ups of endodontically treated teeth. Part II: Clinical application of basic concepts.

Post and core build-ups represent an important pre-prosthetic procedure prior to the restoration of an endodontically treated tooth. The dental practitioner is presented with the dilemma of selecting from an ever increasing variety of materials, techniques and designs related to this procedure, many of which are harmful and mired in controversy. Part II of this paper will review some basic theoretical concepts related to post and core build-ups with the objective of applying these concepts to address a number of pertinent clinical questions related to the above selection process. This review should provide the dentist with a reference to produce a more predictable post and core build-up.

The use of an anterior cantilever design for an implant retained overdenture: a case report.

Dental implants, while providing dentistry with some additional unique options previously unavailable, have also demanded innovation and imagination from the restorative dentist, as illustrated in this unusual prosthetic application. An extremely atrophic anterior mandibular ridge was restored to function, aided by the placement of 3-13 mm titanium fixtures in massive genoid prominences. Second-stage surgery confirmed osseo-integration and 3-7 mm abutment cylinders united by a stable tripod superstructure, and provided for a bar assembly extending approximately 10 mm anteriorly to a position representative of the missing anterior ridge. A mandibular implant-retained denture was then fabricated opposing a maxillary metal base denture. The combination resulted in a stable, functional prosthesis and a satisfied patient.