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1.
Diabetes Res Clin Pract ; 173: 108685, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33548336

ABSTRACT

AIMS: Pre-gestational diabetes mellitus (PGDM) is associated with adverse outcomes. We aimed to examine pregnancies affected by PGDM; report on these pregnancy outcomes and compare outcomes for patients with type 1 versus type 2 diabetes mellitus; compare our findings to published Irish and United Kingdom (UK) data and identify potential areas for improvement. METHODS: Between 2016 and 2018 information on 679 pregnancies from 415 women with type 1 Diabetes Mellitus and 244 women with type 2 diabetes was analysed. Data was collected on maternal characteristics; pregnancy preparation; glycaemic control; pregnancy related complications; foetal and maternal outcomes; unscheduled hospitalisations; congenital anomalies and perinatal deaths. RESULTS: Only 15.9% of women were adequately prepared for pregnancy. Significant deficits were identified in availability and attendance at pre-pregnancy clinic, use of folic acid, attaining appropriate glycaemic targets and appropriate retinal screening. The majority of pregnancies (n = 567, 83.5%) resulted in a live birth but the large number of infants born large for gestational age (LGA) (n = 280, 49.4%), born prematurely <37 weeks and requiring neonatal intensive care unit (NICU) admission continue to be significant issues. CONCLUSIONS: This retrospective cohort study identifies multiple targets for improvements in the provision of care to women with pre-gestational DM which are likely to translate into better pregnancy outcomes.


Subject(s)
Pregnancy Outcome , Pregnancy in Diabetics/diagnosis , Pregnancy in Diabetics/epidemiology , Adult , Cohort Studies , Female , Humans , Ireland , Pregnancy , Retrospective Studies
2.
Diabet Med ; 37(12): 2044-2049, 2020 12.
Article in English | MEDLINE | ID: mdl-30710451

ABSTRACT

AIMS: The purpose of this study was to identify the number of pregnancies affected by pre-gestational diabetes in the Republic of Ireland; to report on pregnancy outcomes and to identify areas for improvement in care delivery and clinical outcomes. METHODS: Healthcare professionals caring for women with pre-gestational diabetes during pregnancy were invited to participate in this retrospective study. Data pertaining to 185 pregnancies in women attending 15 antenatal centres nationally were collected and analysed. Included pregnancies had an estimated date of delivery between 1 January and 31 December 2015. RESULTS: The cohort consisted of 122 (65.9%) women with Type 1 diabetes and 56 (30.3%) women with Type 2 diabetes. The remaining 7 (3.8%) pregnancies were to women with maturity-onset diabetes of the young (MODY) (n = 6) and post-transplant diabetes (n = 1). Overall women were poorly prepared for pregnancy and lapses in specific areas of service delivery including pre-pregnancy care and retinal screening were identified. The majority of pregnancies 156 (84.3%) resulted in a live birth. A total of 103 (65.5%) women had a caesarean delivery and 58 (36.9%) infants were large for gestational age. CONCLUSIONS: This audit identifies clear areas for improvement in delivery of care for women with diabetes in the Republic of Ireland before and during pregnancy.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/therapy , Preconception Care/statistics & numerical data , Pregnancy Outcome/epidemiology , Pregnancy in Diabetics/therapy , Abortion, Spontaneous/epidemiology , Adult , Aspirin/therapeutic use , Cesarean Section , Clinical Audit , Delivery of Health Care , Delivery, Obstetric , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetic Retinopathy/diagnosis , Female , Fetal Macrosomia/epidemiology , Folic Acid/therapeutic use , Glycated Hemoglobin/metabolism , Humans , Hypoglycemic Agents/therapeutic use , Infant, Newborn , Infusion Pumps, Implantable , Insulin/therapeutic use , Insulin Infusion Systems , Intensive Care Units, Neonatal/statistics & numerical data , Ireland/epidemiology , Live Birth/epidemiology , Mass Screening , Metformin/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Pregnancy , Premature Birth/epidemiology , Retrospective Studies , Stillbirth/epidemiology , Vitamin B Complex/therapeutic use
3.
J Dent ; 92: 103230, 2020 01.
Article in English | MEDLINE | ID: mdl-31734257

ABSTRACT

OBJECTIVES: To describe the correlation between changes in the surface area and depth of the face in individuals wearing an obturator compared with it not being in place, and self-reported Quality of Life in relation to appearance. METHODS: Difference images were created from stereophotogrammetry images recorded from research participants with and without their obturators in place. On the difference images of the face, surface areas and mean depths were calculated. Oral health impact profile questionnaires (OHIP-49) were completed. RESULTS: Data from 19 research participants were recorded. The mean size of the outlined area of the face when the obturators were present compared to when they were not was 1411 mm2 (SD ± 848). Similarly the mean depth differences ranged up to 6.14 mm. Although a proportion of the individuals reported effects in relation to their quality of life, there were no statistically significant relations between the surface areas and mean depths with the participants' responses to the quality of life questions. CONCLUSIONS: There are clear changes in facial tissues, both in relation to surface area and depths when obturators are worn compared to when they are not. There is no simple relationship between the extent of facial change with and without an obturator and quality of life around appearance. The determinants of changed quality of life in this group of patients require greater exploration.


Subject(s)
Face , Head and Neck Neoplasms/surgery , Palatal Obturators , Quality of Life , Humans , Photogrammetry , Surveys and Questionnaires
4.
J Dent ; 41(2): 143-7, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23123497

ABSTRACT

OBJECTIVES: To investigate how nutritional advice and denture adhesives may be associated with eating healthier foods. METHODS: 35 edentulous subjects (13 males and 22 females, mean age 73.9 years (55-84 years)), wearing complete dentures more than one year old, completed validated questionnaires analysing saturated fat, protein, Vitamin C, the number of servings of fruit/vegetables. In addition subjects completed the NDNS and OHIP Edent questionnaires. At baseline, nutritional information and the use of denture adhesive was provided. Subjects returned after 30 consecutive days and the questionnaires were repeated. A Wilcoxon signed rank test was used to test the effect of the denture adhesive on diet and on quality of life measures. RESULTS: The subjects increased mean intake from 2.2 portions of fruit/vegetables a day to 3.6. Fat and saturated fats were reduced from 23.2g to 11.3g and Vitamin C intake increased by 34.4mg. All were statistically significant (p<0.0001). There was a statistically significant improvement over the 30-day treatment period in subjects' ability as measured by using OHIP Edent scores to bite (p=0.017) and chew a range of foods (p=0.007). CONCLUSION: Within the confines of the study, use of simple dietary advice and denture adhesives improved diet. CLINICAL SIGNIFICANCE: The results of this pilot study suggest that denture fixatives may improve dietary behaviour of complete denture wearers.


Subject(s)
Adhesives/therapeutic use , Counseling , Denture Retention , Denture, Complete , Diet , Aged , Aged, 80 and over , Ascorbic Acid/administration & dosage , Bite Force , Dietary Fats/administration & dosage , Dietary Proteins/administration & dosage , Fatty Acids/administration & dosage , Female , Follow-Up Studies , Fruit , Humans , Male , Mastication/physiology , Middle Aged , Nutrition Policy , Nutritional Physiological Phenomena , Quality of Life , Vegetables
5.
Mol Oral Microbiol ; 25(3): 190-9, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20536746

ABSTRACT

The microbiota of the denture plaque biofilm colonizing the fitting surface of dentures in edentulous subjects with healthy palates (n = 20) and in edentulous subjects with denture stomatitis (n = 20) was studied. The numbers of bacteria colonizing the dentures of healthy subjects was significantly less than the numbers colonizing the dentures of stomatitis subjects. The proportions and frequency of isolation of mutans streptococci, lactobacilli, bifidobacteria and yeasts were significantly (P < 0.05) greater in the subjects with denture stomatitis. The proportions of these organisms in the denture plaque biofilm of the subjects with denture stomatitis were similar to those found in carious lesions, indicating that the site is a low pH environment. The predominant bifidobacterial species in the mouths of dentate subjects is Bifidobacterium dentium but in the edentulous subjects wearing dentures B. dentium was isolated from only one of the 20 subjects with denture stomatitis and from none of the 20 subjects with healthy palates. Instead, Bifidobacterium breve, Bifidobacterium scardovii and Bifidobacterium longum subsp. longum were isolated. Only a single non-oral bifidobacterial species was isolated from each individual and repetitive extragenic palindromic- and BOX-polymerase chain reaction typing methods indicated that the same genotypes were shared between subjects. Using deferred antagonism spot plate assays, interspecies inhibition was demonstrated between oral isolates of B. dentium, B. breve, B. scardovii and B. longum subsp. longum. Here we have shown that bifidobacteria and caries-associated microbiota are present in denture plaque at levels similar to those of carious lesions and B. dentium cannot be maintained in an edentulous mouth.


Subject(s)
Bifidobacterium/physiology , Dental Caries/microbiology , Dental Plaque/microbiology , Denture, Complete, Upper/microbiology , Stomatitis, Denture/microbiology , Aged , Antibiosis , Bifidobacterium/isolation & purification , Biofilms , Case-Control Studies , Chi-Square Distribution , Colony Count, Microbial , DNA, Bacterial/analysis , Female , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Statistics, Nonparametric
6.
Caries Res ; 43(4): 308-13, 2009.
Article in English | MEDLINE | ID: mdl-19494490

ABSTRACT

The aim of this study was to enumerate and identify bifidobacteria from occlusal carious lesions in permanent and deciduous teeth. Samples of infected dentine were obtained from 24 active occlusal lesions in deciduous teeth and from 15 occlusal lesions in permanent teeth. Plaque samples from sound occlusal surfaces of 12 caries-free adults and 12 children were also obtained. The bifidobacterial strains were isolated in mupirocin-containing selective media, Gram-stained and subcultured for identification. Total bacterial counts were determined using fastidious anaerobic agar, and isolates were identified using genus-specific PCR primers and were confirmed by 16S rRNA sequencing. Bifidobacteria were isolated from 13 of the 15 occlusal lesions in the adults and formed 5.09 +/- 2.11% of the total cultivable flora. In the children, bifidobacteria were isolated from 16 of the 24 occlusal lesions and formed 7.4 +/- 2.6% of the total flora. No bifidobacteria were isolated from the occlusal surfaces of caries-free adults or children. A total of 424 bifidobacteria were identified and these were Bifidobacteriumdentium, Parascardovia denticolens, Scardoviainopicata, Bifidobacterium longum, Scardovia genomosp. C1 and Bifidobacterium breve. B. dentium was present in 14 out of the 16 bifidobacteria-positive samples from the lesions on the deciduous teeth and in 7 out of the 13 positive lesions in adults (p = 0.04). The present data suggest that bifidobacteria may play a role in the progression of occlusal caries lesions in both children and adults.


Subject(s)
Bifidobacterium/isolation & purification , Dental Caries/microbiology , Dental Enamel/microbiology , Dental Plaque/microbiology , RNA, Ribosomal, 16S/analysis , Adult , Bifidobacterium/classification , Bifidobacterium/genetics , Case-Control Studies , Child , Colony Count, Microbial , Dental Caries/pathology , Dental Enamel/pathology , Dentition, Permanent , Humans , RNA, Bacterial/analysis , Reference Values , Tooth, Deciduous/microbiology
7.
J Dent ; 37(5): 357-9, 2009 May.
Article in English | MEDLINE | ID: mdl-19201516

ABSTRACT

OBJECTIVES: The aim of this study was to investigate the possible association between the short form, 14-item Oral Health Impact Profile (OHIP-14) and 12-item General Health Questionnaire (GHQ-12) for patients requiring restorative dental work on Implant Assessment Clinic at Guy's Dental Institute. METHODS: A total of 216 patients aged 18-83 years old were recruited when attended the Implant Assessment Clinic. Restorative treatment needs were classified as hypodontia, trauma related missing teeth, edentulousness (complete denture wearers) and partially dentate (removable partial denture wearers). The OHIP-14, which assesses the adverse impact of oral conditions on quality of life and GHQ-12, a measure of global distress, were subsequently completed by the patients. RESULTS: Statistical analyses showed that there is a strong correlation between OHIP-14 and GHQ-12 within all the categories of treatment needs (p<0.0001). CONCLUSION: The impact of oral health on the life quality of these patients seeking dental implant treatment was strongly associated with the General Health Questionnaire status.


Subject(s)
Dental Implants , Health Status , Quality of Life , Sickness Impact Profile , Tooth Loss/psychology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Oral Health , Psychometrics , Sex Factors , Surveys and Questionnaires , Young Adult
8.
Oral Microbiol Immunol ; 24(1): 32-7, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19121067

ABSTRACT

BACKGROUND/AIMS: The isolation of members of the family Bifidobacteriaceae (bifids) from oral samples has been sporadic and a recent cloning study has suggested that they are not detectable in root caries lesions. METHODS: To better understand the presence of bifids in root caries we obtained clinical samples (15 of each) from sound exposed root surfaces, leathery remineralizing root lesions, and soft active root lesions. We investigated each for the presence of bifids using a mupirocin-containing selective medium and identified the isolates using 16S recombinant RNA sequencing. RESULTS: The proportion of bifids, as a percentage of the total anaerobic count, was significantly related to the clinical status of the sites sampled, being 7.88 +/- 1.93 in the infected dentine from soft lesions, 1.61 +/- 0.91 in leathery lesions, and 0.05 +/- 0.39 in plaque from sound exposed root surfaces. Bifids were isolated from all soft lesions, 13 of 15 leathery lesions, and five of the plaque samples. Bifidobacterium dentium was isolated from four of the plaque samples, from 13 samples from leathery lesions, and from 12 of the 15 samples of infected dentine from the soft active lesions. Parascardovia denticolens and Scardovia genomospecies C1 were each isolated from samples associated with all three clinical conditions whereas Scardovia inopicata and Bifidobacterium subtile were both isolated from the infected dentine of the leathery and soft lesions. Bifidobacterium breve was isolated from the infected dentine of soft root caries lesions. CONCLUSION: Bifids may be routinely isolated from root caries lesions using appropriate cultural methods.


Subject(s)
Bifidobacterium/pathogenicity , Root Caries/microbiology , Root Caries/pathology , Adult , Aged , Aged, 80 and over , Bifidobacterium/isolation & purification , Colony Count, Microbial , DNA, Bacterial/analysis , Dental Plaque/microbiology , Dentin/microbiology , Female , Humans , Male , Middle Aged
9.
Br Dent J ; 198(9): 571-8, discussion 559, 2005 May 14.
Article in English | MEDLINE | ID: mdl-15895058

ABSTRACT

AIMS: To investigate experiences and expectations of parents/siblings of adults with Down Syndrome (DS) regarding oral healthcare, and explore factors impacting on access and experience of dental care for this group. DESIGN: A two phase qualitative and quantitative study using in-depth interviews with a convenience sample of six parents/siblings, and a postal questionnaire of 200 parents/siblings of adults with DS who are members of the Down Syndrome Association. RESULTS: The main themes elicited from the qualitative interviews related to concern, experiences, parents'/siblings' attitudes, preferences and information. The response rate from the postal questionnaire was 63.5%. Adults with DS attended the dentist regularly but received little restorative treatment. Experience of oral healthcare was influenced by the attitudes and skills of dental health professionals; stigma; and relatives' expectations of dentists, their oral health beliefs, information and support received, knowledge and priorities. Parents/siblings wanted dentists to be proactive in providing more information on oral health issues in collaboration with other health and social care professionals. CONCLUSIONS: Whilst most adults with DS visited the dentist regularly, relatively little treatment had been provided. Parents highlighted a need for appropriate and timely oral health information early in their child's life, and access to dentists who were sympathetic, good communicators and well-informed about DS.


Subject(s)
Dental Care for Chronically Ill/psychology , Down Syndrome/psychology , Health Education, Dental , Parents/psychology , Professional-Family Relations , Siblings/psychology , Adult , Attitude of Health Personnel , Data Interpretation, Statistical , Dehumanization , Dental Care for Chronically Ill/statistics & numerical data , Dental Research/methods , Female , Health Services Accessibility , Humans , Interviews as Topic , Male , Surveys and Questionnaires
10.
Br Dent J ; 196(9): 571-5, 2004 May 08.
Article in English | MEDLINE | ID: mdl-15131629

ABSTRACT

Due to changes in the amount of curriculum time available for teaching complete denture construction to undergraduate students, course content requires reconsideration and possible modification. The idea that a replica complete denture technique may offer some advantages is explored. A review of the relevant literature fails to support many of the claimed benefits of this technique such as relative ease of adaptation by the elderly to new dentures. This article suggests that the replica denture technique should be considered as no more than an alternative method of making dentures. The relative demerits of the technique are discussed. A modification of the replica block technique to include important aspects of conventional complete denture courses is described. It is suggested that, because less clinical time is required, it may be a suitable way of introducing students to complete denture construction and educating them to a level which would encourage some to take further postgraduate study and would allow all graduates to treat routine cases or diagnose, treatment plan and refer to clinical dental technicians.


Subject(s)
Dental Care for Aged , Denture Design/methods , Denture, Complete , Education, Dental/methods , Prosthodontics/education , Adaptation, Psychological , Aged , Curriculum , Humans , Technology, Dental/education , United Kingdom
11.
Br J Sports Med ; 38(1): 69-73, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14751950

ABSTRACT

BACKGROUND: Temporomandibular dysfunction (TMD) has been reported to be a common problem in divers, with a prevalence of up to 68%. No evidence for this is available. OBJECTIVE: To investigate the prevalence of TMD in divers. METHOD: Sixty three subjects were asked to retrospectively complete a questionnaire on symptoms of TMD after diving in warm and cold water areas and in daily life. RESULTS: The prevalence of TMD was greater in female divers. The prevalence of TMD while diving was about 26%, comparable to that experienced in daily life. CONCLUSION: Improvements in mouthpiece design and lighter demand valves mean that TMD is now probably exacerbated by diving rather than caused by it.


Subject(s)
Diving/adverse effects , Temporomandibular Joint Dysfunction Syndrome/epidemiology , Adolescent , Adult , Child , Female , Humans , London/epidemiology , Male , Polynesia/epidemiology , Prevalence , Retrospective Studies , Risk Factors , Sex Factors , Surveys and Questionnaires , Temperature , Temporomandibular Joint Dysfunction Syndrome/etiology
12.
Eur J Dent Educ ; 5(4): 173-6, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11683895

ABSTRACT

The personality characteristics of students from two dental schools, one in the United Kingdom which admitted students using interviews, and one in Ireland which accepted students solely on examination results, were assessed using the short form of the Eysenck Personality Questionnaire. Results were compared with norms for age and sex. Personality scores of students from the Irish dental school were not significantly different from normal scores. Female and male students from the United Kingdom school scored higher than would be expected on extraversion, and male students from the same school scored lower than would be expected on neuroticism. The differences in personality between the two schools may be explained by the different methods of admission.


Subject(s)
Personality , Students, Dental , Adult , Age Factors , Educational Measurement , Extraversion, Psychological , Female , Humans , Interviews as Topic , Ireland , London , Male , Neurotic Disorders/psychology , Personality Inventory , Psychotic Disorders/psychology , School Admission Criteria , Schools, Dental , Sex Factors , United Kingdom
13.
J Prosthet Dent ; 83(4): 482-5, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10756302

ABSTRACT

This article presents a procedure for fabricating a locking acrylic resin dental stent for use in image-guided base-of-skull surgery and neurosurgery. The stent offers advantages over conventional bone screw-anchored systems to surgeons and patients. In view of the increasing use of image guidance in base-of-skull surgery and neurosurgery, prosthodontists will meet a growing demand for this type of device in the future.


Subject(s)
Acrylic Resins , Diagnostic Imaging , Oral Surgical Procedures, Preprosthetic/instrumentation , Therapy, Computer-Assisted , Electronics, Medical/instrumentation , Humans , Intraoperative Care/instrumentation , Jaw Relation Record/instrumentation , Magnetic Resonance Imaging , Maxilla , Stereotaxic Techniques/instrumentation , Tomography, X-Ray Computed
14.
Community Dent Oral Epidemiol ; 28(2): 133-40, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10730722

ABSTRACT

UNLABELLED: A review of the literature demonstrated that research had not identified a set of prognostic indicators for prospective complete denture patients, with different authors publishing contradictory results. OBJECTIVE: To investigate possible relationships between patient and clinical factors and denture wear and use of dentures for eating. METHODS: Patients attending Guy's Dental Hospital, London, for provision of complete dentures were recruited. For each patient relevant history was recorded and an examination of the edentulous mouth and existing dentures, where present, was undertaken at the beginning of treatment. At the first post-insertion appointment the edentulous mouth, previous and new dentures were examined. Three months after the review appointment patients were sent a postal questionnaire to assess patient use of dentures and patient satisfaction. Data were analysed using structural equation modelling techniques. RESULTS: 723 patients were recruited. Significant relationships were found between quality of complete dentures and patients' use of complete dentures and between quality of residual edentulous ridges and patients' use of complete dentures. These results contrast with most previous research into prognostic indicators for success in complete denture treatments. CONCLUSIONS: Quality of residual edentulous ridges and quality of new complete dentures predict patients' use of new complete dentures.


Subject(s)
Alveolar Bone Loss/rehabilitation , Denture, Complete/statistics & numerical data , Models, Statistical , Mouth, Edentulous/rehabilitation , Patient Satisfaction/statistics & numerical data , Aged , Analysis of Variance , Denture Retention , Eating , Factor Analysis, Statistical , Female , Humans , Male , Patient Acceptance of Health Care , Prognosis , Quality of Health Care , Statistics, Nonparametric , Surveys and Questionnaires
15.
Int J Oral Maxillofac Implants ; 15(1): 111-8, 2000.
Article in English | MEDLINE | ID: mdl-10697945

ABSTRACT

Measurement of misfit at the implant-prosthesis interface is a difficult procedure. One factor common to all methods that attempt to measure 3-dimensional distortion to the micron level is the difficulty in providing verifiably consistent reference points between individual measurement sets. Consequently, the majority of studies use a relative distortion model in which the coordinate reference system is integral to the framework, thus limiting the value of the data gathered. In the method described, the datum plane and the coordinate reference system were set up external to the framework and could be re-established between measurement sets in a verifiable manner.


Subject(s)
Dental Prosthesis, Implant-Supported/statistics & numerical data , Denture, Partial, Removable/statistics & numerical data , Data Interpretation, Statistical , Dental Abutments , Dental Casting Technique , Dental Prosthesis Design/statistics & numerical data , Denture Design/statistics & numerical data , Humans , Prosthesis Fitting/statistics & numerical data , Statistics, Nonparametric , Weights and Measures
16.
IEEE Trans Med Imaging ; 19(11): 1082-93, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11204846

ABSTRACT

The problem of providing surgical navigation using image overlays on the operative scene can be split into four main tasks--calibration of the optical system; registration of preoperative images to the patient; system and patient tracking, and display using a suitable visualization scheme. To achieve a convincing result in the magnified microscope view a very high alignment accuracy is required. We have simulated an entire image overlay system to establish the most significant sources of error and improved each of the stages involved. The microscope calibration process has been automated. We have introduced bone-implanted markers for registration and incorporated a locking acrylic dental stent (LADS) for patient tracking. The LADS can also provide a less-invasive registration device with mean target error of 0.7 mm in volunteer experiments. These improvements have significantly increased the alignment accuracy of our overlays. Phantom accuracy is 0.3-0.5 mm and clinical overlay errors were 0.5-1.0 mm on the bone fiducials and 0.5-4 mm on target structures. We have improved the graphical representation of the stereo overlays. The resulting system provides three-dimensional surgical navigation for microscope-assisted guided interventions (MAGI).


Subject(s)
Surgical Procedures, Operative/methods , Computer Simulation , Equipment Design , Humans , Microscopy
17.
Stud Health Technol Inform ; 62: 102-8, 1999.
Article in English | MEDLINE | ID: mdl-10538337

ABSTRACT

We present an augmented reality system that allows surgeons to view features from preoperative radiological images accurately overlaid in stereo in the optical path of a surgical microscope. The purpose of the system is to show the surgeon structures beneath the viewed surface in the correct 3-D position. The technical challenges are registration, tracking, calibration and visualisation. For patient registration, or alignment to preoperative images, we use bone-implanted markers and a dental splint is used for patient tracking. Both microscope and patient are tracked by an optical localiser. Calibration uses an accurately manufactured object with high contrast circular markers which are identified automatically. All ten camera parameters are modelled as a bivariate polynomial function of zoom and focus. The overall system has a theoretical overlay accuracy of better than 1 mm. Implementations of the system have been tested on seven patients. Recent measurements in the operating room conformed to our accuracy predictions. For visualisation the system has been implemented on a graphics workstation to enable high frame rates with a variety of rendering schemes. Several issues of 3-D depth perception remain unsolved, but early results suggest that perception of structures in the correct 3-D position beneath the viewed surface is possible.


Subject(s)
Image Processing, Computer-Assisted/methods , Microscopy , Otolaryngology/methods , Depth Perception , Humans
18.
Br Dent J ; 186(7): 316, 1999 Apr 10.
Article in English | MEDLINE | ID: mdl-10333632
19.
J Prosthet Dent ; 81(5): 520-5, 1999 May.
Article in English | MEDLINE | ID: mdl-10220655

ABSTRACT

STATEMENT OF PROBLEM: Previous studies have investigated possible associations between the accuracy of intermaxillary relations and complete denture usage with variable results. PURPOSE: This study investigated the association between the intermaxillary relations in new complete dentures and the use of these dentures for daily wear and eating. METHODS: A prospective study of patients (n = 523) attending Guy's Dental Hospital for complete dentures was undertaken. Patients were examined at the beginning of treatment and at the first post insertion visit. Rest vertical dimension and vertical dimension of occlusion were measured with a Willis gauge. Quality of registration of centric relation position was assessed and, 3 months later, a postal questionnaire was sent to investigate patients' use of dentures. Data were analyzed with Pearson's chi-squared test with exact nonparametric inference. RESULTS: Adequate interocclusal rest space was associated with daily wear of dentures (chi2 = 7.97, P =. 018). Quality of registration of centric relation was associated with daily wear (chi2 = 32.43, P <.001) and use of dentures for eating (chi2 = 20.23, P =.003). CONCLUSION: Positive associations were found between the accuracy of intermaxillary relations and complete denture usage.


Subject(s)
Dental Occlusion , Denture, Complete , Jaw Relation Record , Aged , Centric Relation , Chi-Square Distribution , Denture, Complete/statistics & numerical data , Eating , Female , Follow-Up Studies , Humans , Jaw, Edentulous/rehabilitation , Male , Patient Satisfaction , Pilot Projects , Prospective Studies , Surveys and Questionnaires , Treatment Outcome , Vertical Dimension
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