Role of the artificial tooth arch during swallowing in edentates

Influence of dental factors on oropharyngeal dysphagia among recipients of long-term care

OBJECTIVE

The study evaluated the association of the sociodemographic, behavioural variables and the oral conditions with the presence of oropharyngeal dysphagia in long-term care older persons.

BACKGROUND

Due to the influence of ageing, swallowing may be altered both in people with natural teeth and in those who have dentures or tooth loss.

MATERIALS AND METHODS

This cross-sectional study evaluated 115 individuals older than 60 years, living in long-term care institutions of the State of Rio Grande do Sul in 2016. The diagnosis of dysphagia happen using a clinical speech evaluation, based on the research of signals and symptoms of alterations during deglutition, and on an oral sensory-motor evaluation. The dental clinical evaluation examined the oral cavity, teeth and dental prostheses, including a Xerostomia assessment. Poisson Regressions with robust variance was calculated were used to estimate crude and adjusted Prevalence Ratios(PR) and their IC95%.

RESULTS

The sample was mostly comprised of older women (67.0%), with more than 81 years of age (44.3%) and edentulous (54.3%). Diagnosis of oropharyngeal dysphagia was verified in 60.9% of the participants. In the final model, older persons who presented no pair (PR=1.52(CI95%=1.02-2.40)) had a highest prevalence of oropharyngeal dysphagia, when compared to older persons who presented 8 to 14 mixed pairs, as well as those older persons who had more complaints related to symptoms of Xerostomia (PR=2.86(CI95% 1.58-5.18)).

CONCLUSION

Institutionalised older persons with a poor oral health condition are associated with a higher prevalence of oropharyngeal dysphagia, as well as with the presence of Xerostomia.

Wearing complete dentures is associated with changes in the three-dimensional shape of the oropharynx in edentulous older people that affect swallowing

OBJECTIVE

To investigate the effects of wearing complete dentures on pharyngeal shape for swallowing in edentulous older people.

BACKGROUND

In the absence of complete dentures, edentulous older people often lose the occlusal support necessary to position the mandible, which leads to an anterosuperior shift of the mandible during swallowing. This may result in pharyngeal shape changes effecting swallowing function in older people. However, the details of this phenomenon are currently unclear.

MATERIALS AND METHODS

Participants were 17 older edentulous volunteers. Cone-beam computed tomography imaging was performed with the participant in the seated position and wearing (i) both maxillary and mandibular dentures, (ii) maxillary dentures only and (iii) no dentures. During imaging, participants were instructed to keep their mouth closed to the mandibular position determined in advance during swallowing for each denture-wearing condition. The volume, height and average cross-sectional area of the velopharynx and oropharynx were measured, and the positions of the epiglottis and mandible were recorded.

RESULTS

While the vertical height of the oral cavity and pharynx significantly decreased, the volume and average cross-sectional area of the oropharynx significantly increased when dentures were not worn (p < 0.01). The absence of dentures caused an anterosuperior shift of the mandible when swallowing and drew the epiglottis forward, resulting in expansion of the oropharynx where the tongue base forms the anterior wall.

CONCLUSION

The absence of dentures results in anatomical changes in oropharyngeal shape that may exacerbate the pharyngeal expansion caused by ageing and reduce the swallowing reserve.

Videoendoscopic measurement of food bolus formation for quantitative evaluation of masticatory function

PURPOSE

In the field of prosthodontics, many methods for evaluating the masticatory function involve ejection of the food bolus from the mouth. In addition, these methods could not evaluate mastication and swallowing function comprehensively. The present study aimed to quantitatively evaluate masticatory functions during a series of masticatory and swallowing movements by using videoendoscopy.

METHODS

Subjects are ten healthy dentulous adults without dysphagia. The test foods used were 2-colored (green and white) molded rice and uirou (rice cake). The test foods were consumed under the restriction on the number of mastication (10, 15, 20, and 30), and under the instruction to "chew normally" or "chew well". The masticatory function was evaluated by observing the food bolus in the oropharynx with a videoendoscope. The bolus formation index (BFI), in terms of the degree of mixing of the green and white parts, was quantitatively determined using an image measurement software.

RESULTS

The BFI of the rice and uirou increased significantly with increase in the number of mastication times (p<0.01). A significantly correlation coefficient was observed between the BFI and the number of mastication (0.84 for rice and 0.89 for uirou). The BFI obtained by "chewing well" was significantly higher than that obtained by "chewing normally" (p<0.01).

CONCLUSIONS

The results of this study confirm that the endoscopic measurement of food bolus formation by mastication in terms of the color tones of 2-colored test foods enables quantitative evaluation of the masticatory function during a series of masticatory and swallowing movements.