The chronology of dentinal defects related to medical findings in hypoparathyroidism

The medical findings in three siblings suffering from hypoparathyroidism are described and the results of independent histological examination of their extracted teeth are given. There was general agreement between the chronology of the medical and dental findings. In two of the siblings the earliest dentinal defects predated clinical signs of hypocalcaemia and in all three cases dentine formed after the initiation of medical treatment became normal in structure.     

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.     

Basic techniques and materials for conservative dentistry: I cavity preparation

This series of articles presents a review of current techniques and materials for basic conservative dentistry. The importance of correct diagnosis and the formulation of a sound treatment plan is stressed. Areas where there has been a change of emphasis in treatment are presented in detail. This includes the development of the ‘conservative’ cavity for amalgam and the management of the deep carious lesion.     

Microleakage of selected composite restorative resins

Five selected composite restorative resins were used to restore Class V preparations in extracted human maxillary canine teeth. In addition, a low-viscosity bonding resin was used in conjunction with one of the restorative resins. Microleakage, at both the incisal and cervical margins of the restorations, was assessed by means of a radioisotope after the restored teeth had been subjected to 2500 cyclic temperature changes at 5° and 55°, respectively. Incisal microleakage was not significantly different but severe microleakage was recorded at the cervical margins of the restorations.     

Ossifying fibroma: Management of a case with a 20-year history

A patient with an ossifying fibroma of 20-year duration is described. The case illustrates some features of ossifying fibroma and also some of the diagnostic and surgical problems in a developing country.     

The Gingival Health of Eight-Year-Old Nigerian Children*

A total of 860 eight-year-old schoolchildren in Lagos Nigeria, were examined between April 1981 and March 1982: 409 from private schools and 451 from government schools. Half were boys and the other half were girls. The mean Gingival Index score for children in private schools is 0.4 and 0.5 in the government schools. The GI score was slightly higher for boys than for girls in each group. The prevalence of calculus (24.7 percent) and gingivitis (46.5 percent) in the private schoolchildren is significantly lower than that found in the government schoolchildren (59.6 percent and 61.6 percent respectively) (p values < 0.002). The mean OHI-S score is lower in the private schools (0.8 for boys and 0.7 for girls) than in the government school (1.1 for both boys and girls). These findings suggest better oral hygiene habits in the higher socioeconomic group of private schoolchildren. Among the boys, 47.3 percent had calculus and 52.2 percent had gingivitis while 38.7 percent of the girls had calculus and 56.6 percent had gingivitis. Overall, 43 percent of the children examined had calculus, 54.4 percent had gingivitis. The mean GI Score was 0.4 and the mean OHI Score was 1.0. The results indicate a trend toward a lower prevalence of gingivitis and better oral hygiene among Nigerian children now when compared with studies reported two decades ago.     

Can normal knee kinematics be restored with unicompartmental knee replacement?

BACKGROUND: Unicompartmental replacement can be an alternative to tibial osteotomy in younger, active patients with unicompartmental knee disease. In unicompartmental replacement, the other compartments and knee ligaments are largely untouched. Therefore, it was hypothesized that the knee kinematics after unicompartmental replacement may also be unchanged. To test this hypothesis, knee kinematics and quadriceps tension were recorded before and after replacement with a unicompartmental design and then with a tricompartmental design. METHODS: Six human cadaver knees were tested before implantation, after implantation with a bicruciate-retaining unicompartmental knee prosthesis, and after implantation with a posterior cruciate-retaining tricompartmental knee prosthesis. The unicompartmental prosthesis was initially implanted, and it was then revised to a total condylar knee replacement. The knee kinematics were measured with use of an electromagnetic tracking device while the knee was put through dynamic simulated stair-climbing under peak flexion moments of approximately 40 N-m. Quadriceps tension was also measured for all three conditions. RESULTS: No significant differences in tibial axial rotation were noted between the intact and unicompartmental conditions. However, tricompartmental replacement significantly affected tibial axial rotation (p = 0.001). Femoral rollback was not significantly affected by either unicompartmental or tricompartmental arthroplasty. Quadriceps tension was also similar among all three conditions. CONCLUSIONS: In this in vitro cadaver study, the tricompartmental replacement significantly changed knee kinematics while the unicompartmental replacement preserved normal knee kinematics.