Biomedical subjects

A S McMillan

Publications and source records attributed to A S McMillan.

At least 19 recordsLinked to original sources

PubMed2006

Oral health-related quality of life and severe hypodontia.

The aims of the study were to assess oral health-related quality of life (ohqol) impact among patients with severe hypodontia and to determine the association between ohqol and the number of missing teeth. Twenty-five patients with severe hypodontia (four or more missing permanent teeth) self-completed the child perception questionnaire (CPQ) to assess oral symptoms (OS), functional limitation (FL), emotional well-being (EWB) and social well-being (SWB). Correlation between CPQ scores (overall and at domain level) and the number of missing teeth was assessed. All participants reported ohqol impact, 100% reported experiencing OS, 88% FL, 55% EWB and 100% SWB impacts. The correlation between the number of missing permanent teeth and the CPQ scores was moderate: overall CPQ score (r = 0.54), OS (r = 0.41), FL (0.52), EWB (0.52), SWB (0.49), P < 0.05. Having accounted for retained primary teeth (where a retained primary tooth was considered to have compensated for a missing permanent tooth), the correlation between the number of missing teeth and CPQ scores was strong: overall CPQ score (r = 0.94), OS (r = 0.78), FL (0.88), EWB (0.92), SWB (0.70), P < 0.001. Subjects with severe hypodontia report considerable ohqol impact. The number of missing permanent teeth was moderately correlated with ohqol. However, when retained primary teeth were taken into account, the number of missing teeth was highly correlated with ohqol. This study has implications in understanding the impact of hypodontia on quality of life and highlights the importance of retaining primary teeth in children and adolescents with severe hypodontia.

Adolescent↗

PubMed2005

Influence of sensory deprivation and perturbation of trigeminal afferent fibers on corticomotor control of human tongue musculature.

Several recent studies with transcranial magnetic stimulation (TMS) have demonstrated changes in motor evoked potentials (MEPs) in human limb muscles following modulation of sensory afferent inputs, but little is known about the regulation of the human tongue motor control. To test the effect of local anesthesia (LA) of the lingual nerve and topical application of capsaicin stimulation on tongue MEPs. Fourteen volunteers participated (21-30 years) in two randomized sessions; before, during a nerve block of the lingual nerve or topical capsaicin application (30 microl 5%) on the tongue, and after anesthesia or pain had subsided. EMG electrodes were placed on the tongue and the first dorsal interosseous (FDI) muscle (control). EMG signals were amplified, filtered (20 Hz-1 kHz), and sampled at 4 kHz (Nicolet, USA). TMS were delivered with a figure-of-eight coil (Magstim 200, UK). Scalp sites at which EMG responses were evoked in the relaxed tongue or FDI at the lowest stimulus strength were determined, i.e., motor threshold (T). MEPs were assessed using stimulus-response curves in steps of 10% T. Eight stimuli were presented at each stimulus level. The proximal hypoglossal nerve was activated by TMS delivered over the parieto-occipital skull distal to the right ear. Eight stimuli were delivered at 50% of maximum stimulator output. ANOVAs were used to analyze latency and peak-to-peak amplitudes. Capsaicin evoked mild pain (2.8+/-0.5), and a strong burning sensation (6.2+/-0.4) on 0-10 visual analogue scales. MEP amplitudes in tongue and FDI were not influenced by capsaicin (P>0.44) but by stimulus strength (P<0.001). MEP latencies in tongue (8.9+/-0.2 ms) and FDI (22.4+/-0.4 ms) were not affected by capsaicin (P>0.19). Hypoglossal nerve stimulation evoked a short-latency (3.6+/-0.9 ms) response (mean amplitude 65+/-9 microV); but was unaffected by capsaicin (P>0.54). LA did not have any effect on FDI MEPs but was associated with a significant facilitation of tongue MEPs at T+50% and T+60% about 50 min after the nerve block in the recovery phase. Also in this condition, the direct motor responses evoked by hypoglossal nerve stimulation remained constant. No direct effect of a strong burning sensation could be shown on peripheral or central corticomotor pathways to the relaxed tongue musculature, however, LA of the lingual nerve (cranial nerve V) seems able to induce a delayed change in corticomotor control of tongue musculature (cranial nerve XII) possibly related to unmasking effects at the cortical level but not completely excluding excitability changes at the brain stem level.

Adult↗

PubMed2005

Development and evaluation of a questionnaire to evaluate clinical dental teachers (ECDT).

OBJECTIVES: To develop and test the psychometric properties (validity and reliability) of a questionnaire to evaluate clinical dental teachers. METHODS: An item (question) pool was generated with the use of a literature review, feedback from faculty staff, and from focus group discussions with dental students. Following factor analysis the validity and reliability of a revised questionnaire was assessed. This involved 148 dental students and 453 assessments of 29 clinical dental teachers. RESULTS: Effective clinical dental teaching (ECDT) scores were associated with 'global ratings' of the effectiveness of clinical dental teaching (P<0.01), indicating strong criterion validity. In comparison analysis there was strong agreement between students regarding ratings of individual clinical dental teachers, indicating good construct validity. Reliability was assessed by examining internal consistency of sub-scales and overall ECDT scale, and found to be good (Cronbach alpha's > 0.80). CONCLUSION: A valid and reliable measure to evaluate clinical dental teachers has been developed for use in a clinical academia setting, and has potential use as a quality assurance measure.

Clinical Competence↗

PubMed2005

Oral health of southern Chinese children and adolescents with severe hypodontia.

OBJECTIVE: The aim of this study was to assess the oral health condition of southern Chinese children and adolescents with severe hypodontia. METHODS: This was a cross-sectional clinical study in the dental teaching hospital in Hong Kong. Twenty-five children and adolescents with severe hypodontia, and a comparison group of 25 age- and gender-matched controls took part. Verified clinical examination techniques were used to assess the pattern of missing teeth, tooth spacing, dental caries, periodontal condition, enamel defects, and tooth wear. Statistical comparisons were made between groups using independent Student t-tests and chi-square tests. RESULTS: The mean number of congenitally missing permanent teeth in the severe hypodontia group was 9.1 (SD = 5.0), with the maxillary lateral incisor being the most common missing tooth (14.5%). There were significant space discrepancies in both jaws between groups (P < 0.001). Caries prevalence was low with no difference between groups. There was no difference in periodontal condition between groups, with about half of the participants having no gingival inflammation. The severe hypodontia group had more enamel defects (P = 0.043), enamel hypoplasia (P = 0.044) and tooth wear (P = 0.005) than the comparison group. Three of the severe hypodontia group had ectodermal dysplasia. CONCLUSIONS: The oral health condition of southern Chinese children and adolescents with severe hypodontia was good in terms of caries experience and periodontal health. However, the increased prevalence of developmental defects of enamel and tooth wear complicates already complex interim and definitive prosthodontic management, and may increase psychosocial impact.

Adolescent↗

PubMed2005

Oral health-related quality of life of stroke survivors on discharge from hospital after rehabilitation.

The study aimed to investigate oral health-related quality of life (OHR-QoL) of stroke survivors on hospital discharge after rehabilitation. It was a cross-sectional study involving 43 elderly survivors of mild to moderate stroke about to be discharged from hospital after rehabilitation and a comparison group of 43 community-dwelling elderly people. The Medical Outcomes Short Form 36 (SF-36) measure, the General Oral Health Assessment Index (GOHAI) and an oral health transition scale were administered prior to a dental examination. Median SF-36 subscale scores were significantly different between groups (P < 0.05). In physical function, role-physical, role-emotional and mental health domains, stroke survivors had significantly lower scores indicating poorer health. The median GOHAI score for the stroke group was 52 and 54 for the comparison group with no significant difference between groups although more stroke survivors had difficulty speaking compared with the comparison group. About 75% of stroke survivors considered their appearance to be worse, half of them felt that speech was worse and about a third had difficulty chewing hard food compared with the pre-stroke condition (P < 0.05). Most participants were partially dentate with no significant difference in DMFT scores or prosthetic status between groups (P > 0.05). Health-related quality of life in general was significantly poorer after stroke although patients were considered physically well enough to be discharged from hospital. There was some impairment of OHR-QoL. The nature of the stroke, the hospital environment including diet, coping strategies and elderly Chinese peoples' perception of health should be taken into account when interpreting measures of health status in stroke survivors.

Activities of Daily Living↗

PubMed2004

Oral health-related quality of life in southern Chinese following radiotherapy for nasopharyngeal carcinoma.

Although the complications of head and neck radiotherapy in the treatment of nasopharyngeal carcinoma (NPC) have been described, there is limited information on the effect of oral complications on oral health related quality of life. The aim of this study was to describe the psychosocial and functional impact of oral conditions in southern Chinese following radiotherapy for NPC. A cross-sectional study design was used with a sample of 109 subjects including NPC survivors, newly diagnosed NPC cases and a control group. Oral health related quality of life was assessed through the SF-36 and the Oral Health Impact Profile measures and a dry mouth measure. Data on socio-demographic variables and treatment seeking were also collected. The psychosocial and functional impact of oral conditions as revealed by the health status measures was significantly greater in NPC survivors than newly diagnosed NPC cases and controls. The oral specific and condition specific measures appeared to discriminate more effectively between groups than the generic measure. NPC survivors sought significantly more dental treatment than the other groups. The oral complications of radiotherapy for NPC, notably sequelae of salivary gland damage, have a significant negative effect on oral health related quality of life and result in an increased burden of dental care in the long-term.

Adult↗

PubMed2004

Impact of Sjögren's syndrome on oral health-related quality of life in southern Chinese.

The effect of oral symptoms of Sjögren's syndrome (SS) on health-related quality of life is presently uncertain. This study aimed to investigate oral health-related quality of life (OHRQOL) among southern Chinese people with SS. Twenty-six primary SS cases, 25 secondary cases and 29 matched controls took part in this cross-sectional study. Each participant completed a SF-36 questionnaire, the Oral Health Impact Profile and a dry mouth measure, assisted by a trained interviewer. Data on socio-demographic variables were also collected. The dry mouth measure revealed that people with primary and secondary SS had significant problems associated with subjective symptoms of dry mouth generally, and dry mouth when eating and speaking (P < 0.01). Sticky saliva and coughing were also problems in some primary SS cases. OHIP summary and sub-scale scores did not reveal differences in negative impacts between groups. Mean SF-36 sub-scale scores were significantly different between groups (P < 0.05). In physical function, role-physical and general health domains, primary and secondary SS sufferers had lower scores indicating poorer health. Oral symptoms of SS, notably xerostomia, had a negative effect on OHRQOL. Health-related quality of life in general was also impaired in SS sufferers. The OHIP did not appear to discriminate oral problems of concern to SS sufferers.

Adult↗

PubMed2003

A longitudinal study of quality of life outcomes in older adults requesting implant prostheses and complete removable dentures.

A longitudinal clinical trial involving 103 subjects was undertaken to assess the impact of oral implant therapy on the psychosocial well-being of subjects with complete denture wearing problems. There were four experimental groups: (1) an implant group, where subjects were edentulous/edentate in one jaw and requested and received implants to retain an oral prosthesis (IG); (2) subjects edentulous/edentate in one jaw requesting implants but who received conventional dentures (CDG1); (3) edentulous subjects requesting replacement of their dentures by conventional means (CDG2); (4) dentate subjects requiring routine treatment, who were included for comparison. Data were collected in each group pre- and post-treatment using validated oral specific [the Oral Health Impact Profile (OHIP)], and generic (the SF36) health status measures. Subjects in IG, CDG1 and CDG2 also completed a denture satisfaction scale. IG and CDG1 subjects reported that tooth loss and denture wearing problems had a much greater impact on their quality of life than subjects seeking conventional dentures. Dentate subjects had a much better oral health status compared with denture-wearing subjects. Following treatment, subjects who received implant-retained prostheses (IG) reported a significant improvement in satisfaction and health-related quality of life, as did subjects who requested and received conventional dentures (CDG2). Subjects who requested implants, but received conventional dentures (CDG1), reported little improvement in denture satisfaction and only modest improvement in their quality of life. None of the denture-wearing subjects reported health-related quality of life that was as good as that of dentate subjects. The findings have significant implications in the assessment of outcomes in future clinical trials.

Adult↗

PubMed2003

Oral health condition in southern Chinese after radiotherapy for nasopharyngeal carcinoma: extent and nature of the problem.

OBJECTIVE: To measure the oral health status of southern Chinese nasopharyngeal carcinoma (NPC) survivors 1-4 years after radiotherapy. SUBJECTS AND METHODS: A total of 109 subjects participated in this cross-sectional study. Thirty-eight subjects were NPC survivors, 40 subjects were patients newly diagnosed with NPC and 31 were healthy subjects. Verified clinical examination techniques were used to assess limitation of jaw opening, the presence of mucositis, candidiasis, dental caries, periodontal disease [community periodontal index (CPI)] including attachment loss (ALoss) and prosthetic status/need. Differences among three groups were tested by chi-squared and Kruskal-Wallis tests. Relationships between selected clinical variables and radiation parameters were analysed using Spearman's rank correlation coefficients. RESULTS: The NPC survivors attended for dental treatment more frequently than the other groups (P < 0.01). NPC survivors had significant xerostomia (92%, P < 0.01), trismus (29%, P < 0.01), a higher prevalence of clinical candidiasis (24%, P < 0.01), a greater DMFT (16.4 +/- 7.0, P < 0.01), more decay/filled roots (2.1 +/- 2.9, P = 0.01) compared with new NPC patients and controls. No difference was found in CPI, ALoss, prosthetic status and need between groups. Dry mouth and tooth hypersensitivity were the most common oral problems perceived by the NPC survivors. CONCLUSION: Despite having regular dental follow-ups, oral health was compromised in NPC survivors 1-4 years postradiotherapy.

Candidiasis, Oral↗

PubMed2003

The impact of oral disease among the institutionalized and non-institutionalized elderly in Hong Kong.

The study aimed to describe and compare the psychosocial and functional impact of oral disease on the quality of life of the institutionalized and non-institutionalized elderly in Hong Kong. A total of 268 institutionalized and 318 non-institutionalized elderly aged 60-80 years took part. The 49-statement Oral Health Impact Profile (OHIP) was administered in a structured interview format and sociodemographic information collected prior to a clinical, oral examination. A greater number of the institutionalized were edentulous (19%); they also had more untreated dental disease. The number of elderly reporting negative impacts was generally low. The percentage of institutionalized elderly reporting a negative impact was significantly lower in one of the OHIP subscales (handicap, P < 0.001) and similar in the other six. The main factors affecting the OHIP score were living location, socio-economic status, dental disease and treatment seeking behaviour. In conclusion, the psychosocial and functional impact of oral conditions was low and similar in the institutionalized and non-institutionalized elderly although the pattern of oral disease was different. Life events and socially and culturally derived values appeared to affect the elderly perception of the impact of oral disease.

Aged↗

PubMed2002

Oral perception and oral motor ability in edentulous patients with stroke and Parkinson's disease.

Oral perception and oral motor ability were assessed in edentulous patients with stroke, Parkinson's disease, and an age and gender matched control group. Standard stereognosis and oral motor ability tests were performed, with and without complete dentures in situ. Statistical comparisons were made using ANOVA, Levene's test and paired t-tests. Stroke patients had significantly poorer stereognostic measures than Parkinson's disease patients and controls (P < 0.02). Stereognostic measures were better in all groups when dentures were worn. There were no differences in oral motor ability between groups. Oral stereognosis was significantly impaired in stroke patients. Oral stereognostic ability was better in all groups when dentures were worn. The oral motor ability test lacked the sensitivity to detect differences in motor ability between experimental groups. Edentulous patients with stroke should be encouraged to wear dentures during the rehabilitation phase as oral stereognosis is then less impaired.

Aged↗

PubMed2001

The emotional effects of tooth loss in partially dentate people attending prosthodontic clinics in dental schools in England, Scotland and Hong Kong: a preliminary investigation.

AIM: To compare the emotional effects of tooth loss in three partially dentate populations. DESIGN: A questionnaire survey. MATERIALS AND METHODS: A questionnaire was completed by 150 partially dentate subjects undergoing routine prosthodontic care at Guy's, King's and St Thomas's Dental Institute, London; the Dental School, Dundee, Scotland; and the Faculty of Dentistry, University of Hong Kong. Data were analysed using the Chi-square test. RESULTS: Forty nine per cent of all participants reported difficulties in accepting the loss of some of their teeth. People from Dundee were less likely to have difficulties accepting tooth loss (P = 0.001). People from London took longer to come to terms with their tooth loss and were more likely to feel less confident (P < 0.001). Fifty five per cent of all participants restricted their choice of foods and 54 per cent had not enjoyed their food as much as before. Fewer people in Dundee restricted their choice of food (P < 0.001) and were more likely to enjoy their food (P = 0.009). People in Hong Kong were most likely to restrict their choice of food (P = 0.006). Thirty five percent of all subjects felt unprepared for the effects that tooth loss had upon them. People in Hong Kong were more prepared for tooth loss than those in Dundee and London (P = 0.003). In addition, they were less concerned about leaving their dentures out overnight (P = 0.024). CONCLUSIONS: The emotional effects of tooth loss were significant in all groups. People from London took longer to come to terms with their tooth loss.

Attitude to Health↗

PubMed2001

Oral stereognosis in stroke and Parkinson's disease: a comparison of partially dentate and edentulous individuals.

Oral stereognosis was measured in partially dentate and edentulous patients with stroke, Parkinson's disease, and an age and gender-matched control group. Stereognostic tests involving conventional free intra-oral manipulation of test objects were undertaken in the partially dentate and edentulous with and without complete dentures. Comparisons were made using the unpaired t-test and ANOVA. Edentulous stroke patients without dentures had significantly greater error scores and fewer correct identifications compared with partially dentate stroke patients. Stereognostic measures were similar in the partially dentate and edentulous with dentures, within experimental groups. In the partially dentate, there were no differences in stereognostic measures between the three groups. Stereognostic measures were poorer in edentulous stroke patients with and without dentures compared with the edentulous control group. Partially dentate stroke patients are less likely to have impaired oral stereognosis than edentulous stroke patients.

Aged↗

PubMed2001

Motor potentials evoked by transcranial magnetic stimulation during isometric and dynamic masseter muscle contraction in humans.

The facilitation of muscle motor potentials evoked by transcranial magnetic stimulation (TMS) has been demonstrated convincingly during both isometric and dynamic activity in the limbs but not in the jaw muscles. An experimental design involving TMS, surface electromyography and controlled muscle-activity was employed to investigate the motor response of the human masseter during voluntary isometric and dynamic voluntary conditions. During the isometric condition, an increase in muscle facilitation resulted in a progressive increase in motor-evoked potential (MEP) amplitude that was consistently greater on the side contralateral to that subjected to TMS (P < 0.05). No difference in MEP amplitude or laterality of response was revealed for the two dynamic conditions. The sample size may have been too small to reveal any differences. The modulation of MEPs during isometric activity was probably due to cortical and brainstem mechanisms. Putative variation in masseter MEPs during dynamic conditions cannot be discounted.

Adult↗

PubMed2001

An assessment of sensitivity to change of the Oral Health Impact Profile in a clinical trial.

UNLABELLED: Patient-based assessment of oral health outcomes is of growing interest. Measurement of change following clinical intervention is a key property of a health status measure. To date, most of the research on oral health status measurement has focused on construct and discriminant validity of health status measures. OBJECTIVES: The objective of this study was to assess sensitivity to change of an oral-specific health status measure, the Oral Health Impact Profile (OHIP). METHODS: Study subjects were in three groups, namely, edentulous/edentate subjects who requested and received complete implant stabilised oral prostheses (IG, n=26), edentulous/edentate subjects who requested implants but received conventional dentures (CDG1, n=22), and edentulous subjects who had new conventional complete dentures (CDG2, n=35). Data were collected pre- and post-operatively using the OHIP and a validated denture satisfaction questionnaire. RESULTS: All subjects reported similar low levels of denture satisfaction pre-operatively. Denture problems had a more significant impact on oral health-related quality of life (OHRQL) for implant seekers (IG and CDG1 subjects) than subjects seeking conventional dentures (CDG2). Following treatment, significant improvement in satisfaction with oral prostheses and OHRQL was reported by IG and CDG2 subjects; the level of improvement was more moderate for CDG1 subjects. OHIP change scores were correlated with denture satisfaction change scores. CONCLUSIONS: It was concluded that sensitivity to change of the OHIP was good. This property was not improved by using statement weights.

Analysis of Variance↗

PubMed2001

A patient-based assessment of implant-stabilized and conventional complete dentures.

STATEMENT OF PROBLEM: Outcomes of oral implant therapy have been described primarily in terms of implant survival rates and the durability of implant superstructures. Reports of patient-based outcomes of implant therapy have been sparse, and none of these studies have used oral-specific health status measures. PURPOSE: This study assessed the impact of implant-stabilized prostheses on the health status of complete denture wearers using patient-based, oral-specific health status measures. It also assessed the influence of preoperative expectations on outcome. MATERIAL AND METHODS: Three experimental groups requesting replacement of their conventional complete dentures completed an Oral Health Impact Profile (OHIP) and a validated denture satisfaction scale before treatment. One group received an implant-stabilized prosthesis (IG), and 2 groups received new conventional complete dentures (CDG1 and CDG2). After treatment, all subjects completed the health status measures again; preoperative data were compared with postoperative data. RESULTS: Before treatment, satisfaction with complete dentures was low in all 3 groups. Subjects requesting implants (IG and CDG1) had high expectations for implant-stabilized prostheses. Improvement in denture satisfaction and OHIP scores was reported by all 3 groups after treatment. Subjects who received their preferred treatment (IG and CDG2 subjects) reported a much greater improvement than CDG1 subjects. Preoperative expectation levels did not appear to influence satisfaction with the outcomes of implant therapy in IG subjects. CONCLUSION: Subjects who received implants (IG) that replaced conventional complete dentures reported significant improvement after treatment, as did subjects who requested conventional replacement dentures (CDG2). The OHIP appears useful in identifying patients likely to benefit from implant-stabilized prostheses.

Aged↗

PubMed2001

Prevalence of symptoms associated with temporomandibular disorders in Hong Kong Chinese.

AIMS: To estimate the prevalence of self-reported symptoms associated with temporomandibular disorders (TMD) and treatment-seeking in adult Chinese in Hong Kong. METHODS: A telephone survey technique was used to identify 1,526 randomly selected Cantonese-speaking individuals aged 18 years or over. Standard questions were asked about joint and jaw muscle pain, jaw opening, and joint sounds. In addition, questions on tooth grinding and clenching, sleep patterns, and treatment-seeking behavior were posed. RESULTS: Jaw pain was reported by 33% of the population. Only 5% of them had frequent pain, with two thirds of this subgroup having moderate to severe symptoms. The prevalence of frequent problems with jaw opening and joint clicking was 0.3% and 1.8%, respectively. There were no gender-related differences in the reporting of TMD symptoms or related conditions. CONCLUSION: One percent of the Hong Kong Chinese population had TMD-related jaw pain that was of moderate or severe intensity and occurred frequently; 0.6% of the population had sought treatment for jaw pain, impaired jaw opening, or joint clicking that occurred often in the previous year.

Adolescent↗

PubMed2000

Effect of experimental pain from trigeminal muscle and skin on motor cortex excitability in humans.

The pathophysiology of many orofacial pain syndromes is still unclear. We investigated the effect of tonic muscle and skin pain on the excitability of the trigeminal motor pathways using transcranial magnetic stimulation (TMS). Motor evoked potentials (MEPs) were recorded in the masseter surface electromyogram (EMG). Magnetic pulses were delivered with a large coil at intensities 1.1 and 1.5 times the motor threshold, and for each intensity, MEPs were recorded at three different clenching levels: 15, 30 and 45% of maximum voluntary contraction (MVC). Baseline, pain and post-baseline recordings were compared in two sessions. Firstly, muscle pain was induced by infusion of hypertonic saline (5.8%) into the left masseter. Secondly, skin pain was induced by topical application of capsaicin (5%) on the left cheek. Muscle and skin pain did not induce significant effects on the amplitude or latency of the MEPs (ANOVAs: P>0.50). In both sessions, the amplitude of the MEPs increased with the increase of the clenching level and stimulus intensity (P<0.0001; P<0.005) whereas the latency was not significantly changed (P>0.05; P=0.11). Muscle pain was associated with an increase in the pre-stimulus EMG activity on the non-painful side compared with baseline (P<0.01), which could be due to compensatory changes in the activation of the painful muscle. The need for voluntary contraction to evoke MEPs in the masseter muscles and compensatory mechanisms both at the brainstem and cortical level might explain the lack of detectable modulation of MEPs. Nonetheless, the present findings did not support the so-called 'vicious cycle' between pain - central hyperexcitability - muscle hyperactivity.

Adult↗