The use of role-play and psychodrama in the education of the dental undergraduate

The delivery of effective information flow through self learning, critical thinking and problem solving is one of the objectives of current curriculum development within the Dental Faculty of the University of Hong Kong. These objectives reflect a desire to encourage skills related to 'comprehension learning' and 'meaning orientation' rather than 'rote' learning and 'surface' approaches. This paper explains the way in which role-play and psychodrama are used in an effort to achieve these objectives.     

Limitation of mandibular opening due to enlarged coronoid processes

The causes of limited mandibular opening are summarized. Coronoid process enlargement in five patients is discussed; two cases of bilateral coronoid hyperplasia and a unilateral coronoid-zygomatic ankylosis case underwent successful surgery. One of these bilateral patients exhibited bone regrowth a year later.     

A study of the accuracy of predicted soft tissue changes produced by a computer software package (COG 3.4) in a series of patients treated by the Le Fort I osteotomy

This study was performed to compare soft tissue movements resulting from a series of Le Fort I osteotomies with those predicted for the same cases by means of a computerised software package (COG 3.4). The source material consisted of serial lateral cephalometric radiographs for 25 consecutive patients that had received similar Le Fort I osteotomies primarily to correct an antero-posterior skeletal discrepancy.Generally it was found that many of the digitised points on the facial profile were surprisingly well predicted. In addition, the chin and profile changes resulting from mandibular auto-rotation also were reasonably well predicted. However, in a number of cases prediction was less consistent and this was particularly true in the region of the nose and lips. In such instances, initial size, thickness and the existing morphology of the soft tissues appeared to be important factors. The tendency of the software occasionally to ‘cross-over’ the plots for the upper and lower lip profile made the judgement in this area of predicted profile change difficult in some cases.     

The postural basis of malocclusion: A philosophical overview

Over the last 100 years, many theories have attempted to explain the cause of malocclusion. Most have stated that it is inherited, but, more recently, greater emphasis has been placed on the influence of the environment, especially the activity and the posture of the oral soft tissues. Unfortunately, it is not possible to measure long-term posture with any precision, and this has reduced its perceived importance. When some evidence is missing and much of the rest conflicting, there is merit in moving from the traditional "prove-it" attitude to philosophical reasoning to separate the probable from the improbable. We do not know to what extent posture and parafunction might be inherited, but there can be no doubt that facial and dental structures are, at times, strongly influenced by the soft tissues and that some malocclusions appear to have a postural basis. This article undertakes a philosophical examination of the conflicting strands of evidence that link oral posture with malocclusion, hoping to create a theory based solely on the restricted evidence that is broadly accepted by all sides in this age-old debate.     

The success and failure of denture soft-lining materials in clinical use

There is ample evidence for the clinical success of soft-lining materials, but their use is often discouraged because of reported inadequate physical properties. The desire to correlate properties determined under simulated clinical conditions in the laboratory with success and failure of denture soft-lining materials in clinical use stimulated the present study, the objectives of which were:

1. 1. A retrospective study of the clinical success of existing soft-lining materials.

2. 2. The collection and measurement of data relating to a group of edentulous patients wearing soft-lined mandibular dentures.

3. 3. A longitudinal study of the clinical success of both existing and new soft-lining materials over a three-year period.

This investigation has been in progress for 18 months, and this paper comprises a report of the retrospective study together with preliminary results associated with other objectives. Despite the ability of the subjects to remove their dentures from the mouth for inspection they were generally unaware of the condition of the soft lining and assessed its success in terms of comfort and functional effectiveness. From this perspective soft-lining materials could be considered successful, but the clinical examination gives a much less satisfactory assessment.     

Durability of Resin Cement Bond to Aluminium Oxide and Zirconia Ceramics after Air Abrasion and Laser Treatment

Purpose: The erbium laser has been introduced for cutting enamel and dentin and may have an application in the surface modification of high‐strength aluminum oxide and zirconia ceramics. The aim of this study was to evaluate the durability of the bond of conventional dual‐cured resin cements to Procera Al₂O₃ and zirconium oxide ceramics after surface treatment with air abrasion and erbium laser. Materials and Methods: One hundred twenty Al₂O₃ and 120 zirconia specimens measuring 3 × 3 × 0.7 mm³ were divided equally into three groups, and their surfaces treated as follows: either untreated (controls), air abraded with Al₂O₃ particles, or erbium‐laser‐treated at a power setting of 200 mJ. The surface of each specimen was then primed and bonded with one of two dual‐cured resin cements (either SCP‐100 Ceramic Primer and NAC‐100 or Monobond S and Variolink II) using a 1‐mm thick Tygon tube mold with a 0.75‐mm internal bore diameter. After 24 hours and 6 months of water storage at 37°C, a microshear bond strength test was performed at a crosshead speed of 1 mm/min. Surface morphology was examined using a confocal microscope, and failure modes were observed using an optical microscope. The data were analyzed using the Kaplan‐Meier nonparametric survival analysis. Results: In the case of zirconia, air abrasion and Erbium:yttrium‐aluminum‐garnet (Er:YAG) laser treatment of the ceramic surface resulted in a significant reduction in the bond strengths of both resin cements after 6 months water storage; however, when the zirconia surface was left untreated, the SCP‐100/NAC‐100 group did not significantly reduce in bond strength. In the case of alumina, no treatment, air abrasion and Er:YAG laser treatment of the surface led to no significant reduction in the bond strengths of the three SCP‐100/NAC‐100 groups after 6 months water storage, whereas all three Monobond S/Variolink II groups showed a significant reduction. Conclusion: Er:YAG laser treatment of the zirconia surface did not result in a durable resin cement/ceramic bond; however, a durable bond between a conventional dual‐cured resin cement and Procera All Ceram and Procera All Zirkon was formed using a ceramic primer containing the phosphate monomer, MDP, without any additional surface treatment.     

Development of a screening tool to assess the suitability of people with a disability for oral care under sedation or general anesthesia

The aim of this study was to develop a screening tool to assess the suitability of people with disabilities for oral care in different settings. The objectives were to investigate retrospectively the uptake of general anesthetic (GA) services and use this information to develop a composite tool.
One hundred cases referred for GA were reviewed to generate data for a Delphi Panel. Patients with disabilities were the subject of a tool, devised by the Delphi Panel, to appropriately allocate patients to the most suitable care, including the patients' medical, behavioral, and social status as well as planned dental treatment complexity. A total of 124 patients, between the ages of 4 and 75 years, in seven centers were treated under sedation or GA, according to the tool. Agreement on behavior assessment between dentists and anesthesiologists was poor.
The tool has the potential to identify which people with disabilities can be effectively allocated for treatment under sedation or GA.