Post-orthodontic occlusal function

The significance of orthodontic treatment in the aetiology of temporomandibular dysfunction continues to be a matter of controversy. However, the evidence of any association has been generally negative. This investigation involved the examination of a study group of 87 post-orthodontic patients, the average time out of all retention being 52 months. They were compared with an untreated control group. Signs and symptoms of temporomandibular disfunction were assessed for both groups. In only one instance, soft joint click, was there found to be a significant association between the treatment category and the occurrence of the symptom, there being a higher rate of soft clicks in the post-treatment group. While this may be ascribed to orthodontic treatment, there was also a different restorative pattern in the two groups. No other significant associations were found.     

The design and construction of dental elevators

Three new elevators for use in dentoalveolar surgery have been designed and tested. Their mechanical efficiency was examined experimentally, and clinical trials have been completed. Used in appropriate circumstances, these elevators approach the ‘ideal’ for safe effective exodontia.     

A clinical study of horizontal jaw relationships in edentulous patients

Six methods of registering horizontal jaw relationships were investigated on 13 edentulous patients in order to find the consistency of each method and any differences in location between them.

Graphical recordings were made using intra-oral acrylic resin appliances. The upper appliance incorporated a central bearing point and the lower a recess for accommodating interchangeable steel plates. Each tracing was made on a separate plate which had been painted with blue layout fluid. The recordings were measured on a modified microscope to give mediolateral and anteroposterior readings.

The results showed that the active gothic arch tracing method was the most consistent of the methods studied. Passive retruded closure and active closure from rest position showed low consistency in comparison. Passive retruded closure was recorded an average of 0·21 mm posteriorly to the active gothic arch tracing. Active closure from rest position was recorded an average of 0·63 mm anteriorly to the active gothic arch tracing.     

Neuro-ophthalmological manifestations of systemic lupus erythematosus in Asian patients

Purpose : To report eight patients with diagnosed systemic lupus erythematosus (SLE) who presented with a variety of neuro‐ophthalmological complications and outcomes. Methods : A review of the follow up, subsequent management and outcomes of the neuro‐ophthalmological complications of eight patients with SLE. Results : The patients presented with a myriad of symptoms of varying severities. The most common manifestations were that of optic neuropathy and eye movement abnormalities. The outcome was variable ranging from complete recovery to optic atrophy with navigational visual acuity. Treatment was often empirical, although early treatment with corticosteroids has been tried with varying success. Conclusions : The pathophysiology in the neuro‐ ophthalmological manifestations of SLE is thought be due to vaso‐occlusive disease of the small vessels of the nerve and brain, secondary to an autoimmune process. Ophthalmologists may need to consider the diagnosis of SLE in young women who present with a recent onset of neuro‐ophthalmological symptoms and signs.     

Development of Noncarious Cervical Notch Lesions in Vitro

Abstract: Purpose : The initiation and progression of noncarious cervical notch lesions (NCCL) continues to perplex clinicians worldwide and poses a considerable restorative challenge. The purpose of this brief communication is to report what is believed to be the first in vitro production of notch-shaped lesions in the cervical third of premolar teeth.
Materials and Methods : The lesions, were produced by axial loading of selected permanent premolar teeth in a 10% aqueous solution of sulfuric acid over a period of 5 days, followed by immersion in water for 7 days.
Results : Results revealed macroscopic and microscopic features similar to those observed in noncarious cervical lesions in vivo. The lesions were incidental findings while the authors were studying stress corrosion of enamel at low pH. Although much remains to be investigated regarding the etiology and pathogenesis of NCCL, axial loading and a corrosive environment may be implicated in these processes. The artificial lesions arose in clinically sound teeth, suggesting that there is no simple clinical examination to identify teeth at risk from NCCL.     

Oral Cancer: A Prosthodontic Diagnosis

The prosthodontic literature is replete with articles addressing the reconstruction, psychological adaption, prosthesis success, quality of life, need for careful follow-up, and many other issues related to the patient who has undergone surgery, radiation, and/or chemotherapy for oral malignant neoplasms. However, in the prosthodontic professional literature, there is a paucity of information related to the early diagnosis and referral of lesions that may represent premalignant or malignant neoplasia. This article will describe the rationale, epidemiology, and appearance of oral premalignant and malignant mucosal lesions as well as the state-of-the-art diagnostic tools currently available to prosthodontists to ensure that their patients are diagnosed at the earliest possible time.     

Ethnic variations in sagittal condylar guidance angles

Observations of a Chinese population seem to indicate that certain ethnic differences exist which may invalidate the use of dental articulators constructed as the result of measurements made on a Caucasian population. A group of Caucasian students had been examined for a previous study. Upper and lower study models of the jaws of a group of Singaporean Chinese students were articulated in the tooth position on a Dentatus ARL articulator. Measurements were made of the angle between the occlusal plane and the Frankfort plane, the S. C. G. As and the Balkwill angle.

The results indicate that considerable anatomical differences do exist between these two distinctive ethnic groups. These findings have important implications for all restorative and prosthetic dentistry which requires the use of a dental articulator.     

Lorazepam as a premedicant for day-case surgery: an assessment

The sedative effect of 2 mg of lorazepam was assessed in eleven patients undergoing minor "day case" surgery and the results compared with a control group of eleven patients receiving a placebo. Sedation was assessed by a scoring method and quantified in terms of change in plasma cortisol levels. The results indicate that 2 mg of oral lorazepam produces good sedation (superior to nitrazepam in terms of plasma cortisol reduction) and has a postoperative anti-emetic effect but its prolonged duration of action makes it unsuitable for patients returning home within 8 hours of premedication.