The association between dental arch morphology and the aetiology of obstructive sleep apnoea (OSA) is not clear. To compare dental arch morphology in 108 Asian adults with and without ''OSA, overnight'' hospital polysomnography was performed, and sleep reports were obtained for all subjects. Standardized digital photographs were also taken of the subjects' upper and lower study models. Using 25 homologous landmarks, mean OSA and control dental arch configurations were computed, and subjected to finite-element morphometry (FEM), t-tests and principal components analysis (PCA). Mean upper and lower OSA dental arch morphologies were statistically different from respective Control upper and lower arch morphologies (P < 0.05). FEM of the upper arch indicated that the mean OSA configuration was 7-11% narrower in the transverse plane in the incisor and canine regions when compared with the control configuration, and inter-landmark analysis (ILA) confirmed this finding. FEM for the lower arch indicated that the mean OSA configuration was 10-11% narrower in the antero-posterior plane in the pre-molar and molar regions, and confirmed by ILA. Using PCA, significant differences were also found between the two groups in the lower arch using the first two eigenvalues, which accounted for 90% of the total shape change (P < 0.001). Supporting their role as aetiological factors, size and shape differences in dental arch morphology are found in patients with OSA.
Nylon denture base material could be a useful alternative to poly (methyl methacrylate) (PMMA) in special circumstances such as patient allergy to the monomer. The aim of this study was to evaluate the flexural properties of a nylon denture base material (Lucitone FRS), a conventional compression-moulded heat-polymerized (Meliodent), a compression-moulded microwave-polymerized (Acron MC) and an injection-moulded microwave-polymerized (Lucitone 199) PMMA polymers. The effect of aldehyde-free, oxygen releasing disinfectant solution (Perform) on these properties was also investigated. The flexural modulus and the flexural strength were assessed with a three-point bending test. Specimens were stored in water at a temperature of 37 degrees C for 30 days. For each material, half of the prepared specimens were randomly selected and immersed in the disinfectant 24 h prior to testing. Results were compared statistically at a confidence level of 95%. The result showed that in both the control and disinfected groups, the flexural modulus of nylon was significantly lower than the three PMMA polymers. The flexural strength of nylon was significantly lower than those of Meliodent and Acron MC but was comparable with Lucitone 199. A 24-h immersion in the disinfecting solution increased the rigidity of nylon denture base material.
The aims of the study were to determine the periodontal status of the teeth in contact with removable partial dentures (RPDs) and to compare them with other teeth in the opposing arch not related to any prosthesis. The periodontal status was also assessed in relation to the age of the dentures. Four hundred and twenty-seven patients treated with RPDs from 1981 to 1986 were recalled for examination. Prior to prosthetic treatment they were given periodontal treatment and fillings when required. Initially all were given oral hygiene instructions and motivation. They were reviewed regularly only on a short-term basis. Eighteen patients were suitable for the present study comprising of eight males and 10 females whose mean age was 41 years. The RPDs were in use from 1.5 to 8 years (mean 4.6 years). The following parameters were assessed: Plaque index (P1I), Gingival index (GI), loss of attachment (LA) and tooth mobility. The wearing of RPDs resulted in higher P1I, GI and LA compared to the controls and these differences were statistically significant. There was an increased frequency of higher P1I, GI and LA with the increase in denture age. Minor changes in tooth mobility were observed. It was concluded that the wearing of RPDs was detrimental to periodontal health in patients whose oral hygiene was less than adequate.
The aim of this study was to determine the periodontal status in relation to the quality of the adjacent proximal tooth surface. The gingival index (GI) and probable pocket depth (PD) were measured in 144 contra-lateral pairs of sound vs. restored and 95 contra-lateral pairs of sound vs. carious surfaces in 124 patients. The restorations studied were silver amalgams and tooth-coloured filling materials, the margins of which were supragingival or level with the gingival margins. The results showed that the GI and PD were greater for both restored and carious tooth surfaces than for the contra-lateral sound surfaces. When all the teeth were grouped together, the differences in the mean values of GI and PD were statistically significant at the P less than or equal to 0.05 level. A comparison between restored and carious (non-paired) tooth surfaces revealed higher mean values of GI and PD for the latter, which were highly significant at the P less than 0.001 level. Thus the present study shows that proximal tooth surface quality influences the health status of the adjacent periodontium.
The aims of this study were to determine the dental and periodontal status and the associated treatment needs, other than that for prosthetic care, in patients who requested removable partial dentures. Forty-six patients who had never worn removable partial dentures before were examined for plaque index, tooth status, gingival index, loss of periodontal attachment and tooth mobility. Prior to prosthetic treatment, 15% of the teeth needed conservative treatment and 1% needed extractions. From the periodontal point of view, 65% of the teeth needed some form of related therapy, and 2% of the teeth were at risk of extraction due to advanced mobility.
This study aimed to investigate residual ridge resorption (RRR) of anterior and posterior maxillary and mandibular edentulous ridges, in patients treated with mandibular implant overdentures (IOD) and compare with conventional complete denture (CD) wearers, and to determine at each location, the association of RRR with the occlusal forces distribution and other patients' variables. The anterior and posterior RRR of IOD (six males, 17 females) and CD (12 males, 11 females) groups were determined using baseline and follow-up dental panaromic radiographs (DPT) (mean intervals 4 ± 1·8 years). The bone ratios were calculated using proportional area: anatomic to fixed reference areas and mean difference of ratios between the intervals determined RRR. The ridge locations included anterior and posterior maxillary and posterior mandibular arches. The T-Scan III digital occlusal system was used to record anterior and posterior percentage occlusal force (%OF) distributions. There were significant differences in anterior and posterior %OF between treatment groups. Two-way anova showed RRR was significant for arch locations (P = 0·005), treatment group (IOD versus CD) (P = 0·001), however, no significant interaction (P = 0·799). Multivariate regression analyses showed significant association between RRR and %OF at anterior maxilla (P = 0·000) and posterior mandible (P = 0·023) and for treatment groups at posterior maxilla (P = 0·033) and mandibular areas (P = 0·021). Resorption was observed in IOD compared to CD groups, with 8·5% chance of less resorption in former and 7·8% in the latter location. Depending on arch location, ridge resorption at various locations was associated with occlusal force distribution and/or treatment groups (implant prostheses or conventional complete dentures).
The aim of this systematic review (SR) was to determine the association between temporomandibular disorders (TMDs) and pubertal development. Due to the inadequacy of the conventional PICO (Population, Interventions, Comparisons and Outcome) format used for intervention-based SRs, the Joanna Briggs Institute's guidelines for synthesising evidence related to associations with a focus on aetiology were adopted. A search of the PubMed and LIVIVO databases covering the period from January 1980 to May 2018 yielded four publications, which fulfilled the inclusion criteria. Analysis of articles based on the Pubertal Development Scale showed that TMD prevalence increases with pubertal development. Although no sex difference in TMD prevalence and diagnosis was observed, more females reported TMD anamnestic variables, including accounts of temporomandibular pain during pubertal maturity. The higher prevalence of depression and somatisation during pubertal development may contribute to more TMD symptom reporting in females. More prospective studies incorporating standardised methods for diagnosing TMDs and detecting comorbid psychosocial and somatic problems are desired to further elucidate the relationship between TMDs and pubertal development.
Maintaining good oral hygiene is important following stroke. This study aimed to evaluate the effectiveness of two oral health promotion (OHP) programmes to reduce dental plaque levels following stroke. A multi-centre randomised clinical control trial was conducted among patients hospitalised following stroke in Malaysia. Patients were randomly allocated to two OHP groups: (i) control group who received the conventional method for plaque control-daily manual tooth brushing with a standardised commercial toothpaste, (ii) test group-who received an intense method for plaque control-daily powered tooth brushing with 1% Chlorhexidine gel. Oral health assessments were performed at baseline, at 3 months and 6 months post-intervention. Within- and between-group changes in dental plaque were assessed over time. Regression analyses were conducted on dental plaque levels at 6 months controlling for OHP group, medical, dental and socio-demographic status. The retention rate was 62.7% (54 of 86 subjects). Significant within-group changes of dental plaque levels were evident among the test group (P .05). Regression analyses identified that baseline plaque levels (adjusted ß = 0.79, P