Farhan Shah

An investigation into the effect of denture adhesives on incisal bite force of complete denture wearers using pressure transducers - a clinical study

PURPOSE Study was conducted to determine and assess the effect of different type of denture adhesives on the incisal bite force of complete denture wearers until the dislodgement of upper denture, using pressure transducer. MATERIALS AND METHODS 30 patients out of 100 were included in the study. Based on the Kapurs method of scoring denture retention and stability, these patients were divided into 3 groups- Group A - Clinically good dentures; Group B - Clinically fair dentures; and Group C - Clinically poor dentures. A custom made occlusal force meter was constructed based on the load cell type of pressure transducers. Different adhesives (powder, paste and adhesive strips) were used in the study. Complete denture wearers were asked to bite on the load cell and the readings of incisal bite force were recorded. The readings of incisal bite force were subjected to statistical analysis using Repeated measures ANOVA followed by post-hoc bonferroni test. RESULTS The result suggests that denture adhesives improved the incisal bite force of complete denture wearers significantly The incisal bite force (in kg) in Group A without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 2.48 (± 0.16), 3.43 (± 0.11), 6.01 (± 0.11), 3.22 (± 0.09) respectively. The incisal bite force (in kg) in Group B without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 1.87 (± 0.18), 3.35 (± 0.14), 5.34 (± 0.18), 3.21 (± 0.12) respectively. The incisal bite force (in kg) in Group C without using adhesives, with powder adhesive, with paste adhesive and with adhesive strips was found to be 1.00 (± 0.17), 3.07 (± 0.14), 4.37 (± 0.26), 2.99 (± 0.14) respectively. CONCLUSION Within the limitations of the study, it was concluded that the use of denture adhesive was found to be significantly effective in improving the incisal bite force of complete dentures until the dislodgement of upper denture. Fittydent paste adhesive was found to be more effective than the powder and strips adhesives. The improvement in incisal bite force was found to be higher in Group C in comparison to that of Group A and Group B.

Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity

PURPOSE To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.

Unique expression of cytoskeletal proteins in human soft palate muscles

The human oropharyngeal muscles have a unique anatomy with diverse and intricate functions. To investigate if this specialization is also reflected in the cytoarchitecture of muscle fibers, intermediate filament proteins and the dystrophin‐associated protein complex have been analyzed in two human palate muscles, musculus uvula (UV) and musculus palatopharyngeus (PP), with immunohistochenmical and morphological techniques. Human limb muscles were used as reference. The findings show that the soft palate muscle fibers have a cytoskeletal architecture that differs from the limb muscles. While all limb muscles showed immunoreaction for a panel of antibodies directed against different domains of cytoskeletal proteins desmin and dystrophin, a subpopulation of palate muscle fibers lacked or had a faint immunoreaction for desmin (UV 11.7% and PP 9.8%) and the C‐terminal of the dystrophin molecule (UV 4.2% and PP 6.4%). The vast majority of these fibers expressed slow contractile protein myosin heavy chain I. Furthermore, an unusual staining pattern was also observed in these fibers for β‐dystroglycan, caveolin‐3 and neuronal nitric oxide synthase nNOS, which are all membrane‐linking proteins associated with the dystrophin C‐terminus. While the immunoreaction for nNOS was generally weak or absent, β‐dystroglycan and caveolin‐3 showed a stronger immunostaining. The absence or a low expression of cytoskeletal proteins otherwise considered ubiquitous and important for integration and contraction of muscle cells indicate a unique cytoarchitecture designed to meet the intricate demands of the upper airway muscles. It can be concluded that a subgroup of muscle fibers in the human soft palate appears to have special biomechanical properties, and their unique cytoarchitecture must be taken into account while assessing function and pathology in oropharyngeal muscles.

Maxillofacial prosthesis in a palliative care for terminally ill patient with squamous cell carcinoma

It is the god given right of every human being to appear human. – Ernest L. DaBreo. A 55-year-old man with combined surgical and radiation therapy for buccal mucosa required the prosthetic rehabilitation for full thickness facial cheek defect. Apart from the aesthetics concerns, he had several oral debilities like difficulty in speaking, eating and swallowing. Though the carcinoma is known for high rates of morbidity and mortality, it is an obligation of a prosthodontist to help the patient to have a dignified and normal social life for their remaining lifespan. Palliative dental cares main focus is to re-establish the quality of the remaining life, in addition to the alleviation of physical and psychological suffering of the far-advanced disease patients. This case report summarises the importance of maxillofacial prosthesis in a postoperative malignancy and palliative care.

Axon and Schwann Cell Degeneration in Nerves of Upper Airway Relates to Pharyngeal Dysfunction in Snorers and Patients With Sleep Apnea

BACKGROUND: The pathophysiologic mechanism of nocturnal obstruction and swallowing dysfunction commonly occurring in patients with sleep apnea is unclear. The goal of this study was to investigate whether nerve injuries in the upper airways of snorers and patients with sleep apnea are associated with pharyngeal dysfunction and severity of sleep apnea. METHODS: Twenty‐two patients undergoing palatal surgery due to snoring and sleep apnea were investigated for a swallowing dysfunction by using videoradiography. Twelve healthy nonsnoring subjects were included as control subjects. Tissue samples from the soft palate at the base of the uvula were obtained in all patients and control subjects. Nerves and muscle were analyzed with immunohistochemical and morphologic methods, and the findings were correlated with swallowing function and degree of sleep apnea. RESULTS: In the soft palate of patients, nerve fascicles exhibited a significantly lower density of axons (5.4 vs 17.9 × 10–3 axons/&mgr;m2; P = .02), a smaller percentage area occupied by Schwann cells (17.5% vs 45.2%; P = .001) and a larger number of circular shaped Schwann cells lacking central axons (43.0% vs 12.7%; P < 0.001) compared with control subjects. The low density of axons was significantly related to degree of swallowing dysfunction (r = 0.5; P = .03) and apnea‐hypopnea index > 5 (P = .03). Regenerating axons were frequently observed in patients compared with control subjects (11.3 ± 4.2% vs 4.8 ± 2.4%; P = .02). CONCLUSIONS: Axon degeneration in preterminal nerves of the soft palate is associated with pharyngeal dysfunction in snorers and patients with sleep apnea. The most likely cause for the nerve injuries is traumatic snoring vibrations and tissue stretch, leading to swallowing dysfunction and increased risk for upper airway obstruction during sleep.

Prosthetic rehabilitation of a patient with adenoid cystic carcinoma with continuous orbital-maxillary defect

Extensive head and neck surgical procedures severely affect vital functions, physical appearance and lead to huge psychological trauma in the patients. Well-constructed maxillofacial prosthesis will help them lead a normal social life for the remaining precious time. This case report explains the prosthetic rehabilitation of continuous orbital-maxillary surgical defect in a patient with adenoid cystic carcinoma with restricted mouth opening. Maxillofacial prosthesis needs individual modification to a treatment plan according to the defect and existing clinical conditions. In this case, magnetically retained three-piece prosthesis was designed because of high recurrence rate of the adenoid cystic carcinoma, lack of adequate bone for implants and limited mouth opening in the patient. The prosthesis restored the phonetics, aesthetics and deglutition of the patient by re-establishing the separation of oral–nasal–orbital cavities.

The effect of thermocycling on the bonding of different restorative materials to access opening through porcelain fused to metal restorations

PURPOSE Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens. MATERIALS AND METHODS The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimens in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at 5℃ and the other at 55℃, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01). RESULTS The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C. CONCLUSION It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage.