Comparative evaluation of the effect of the complete denture on airflow between hypertensive and non-hypertensive patients - in vivo study

Background and rationale

Edentulism is a disabling condition of oral cavity and can affect functioning of the stomatognathic system as a whole because it eventually leads to anatomic changes like retrognathia, macroglossia, micrognathia, and hyperplasia of soft tissue and muscle hypotonicity, all of which cause a reduction in the size of the airway lumen.¹ Complete dentures restore the oral function for patients with edentulism and should extend up to the retromolar tissues in the mandible and to the soft palate in the maxilla to ensure adequate retention and stability.² A complete understanding of the patient needs should be a priority for a prosthodontist in order to encourage patients to recognize the type of prosthesis they need.³ Spirometry is a technique for determining how well the respiratory system is working and its mechanical qualities by measuring lung volumes and their capacities. Birhan, Mekuriaw et al in their article⁴ “found out that hypertensive individuals’ pulmonary function measures were also significantly lower than the non-hypertensive group. Hypertensive patients had lower pulmonary function metrics, according to certain researchers. An understanding of various sciences like chemistry, biology, physics, histology, pathology, physiology, bacteriology, surgery, hygiene, and medical psychology is necessary for today’s modern dental prosthesis.⁵ The knowledge of all these disciplines is important for new modern dental appliances. By applying general medicine, the underlying biological science of dental prosthetics is gradually evolving.⁶ So, an interdisciplinary approach between general medicine and dentistry is required for the modern prosthetist to prevent any harm to the patient.⁴ We designed the current study to evaluate the effects of complete dentures on the respiratory system in light of the aforementioned facts.

Objectives

In this study we aim to evaluate the airflow in hypertensive and non-hypertensive patients, to evaluate the effect of complete dentures on the airflow in hypertensive and non-hypertensive patients, and comparing and evaluating the airflow in denture and non-denture wearers in both normal and hypertensive groups.

A further objective of the study is to compare the effect of the airflow in complete denture wearers by wearing the dentures. A control group will be considered by taking a spirometric reading of the same patients without the dentures. Four readings will be made from one patient and compared, later a comparison will be done between hypertensive and non-hypertensive complete denture wearers.

Study design

This study will be an observational study, the ethical approval has been acquired from “Datta Meghe Institute of Higher Education and Research, Sawangi, (Meghe) Wardha”. [IEC ref no.- DMIMS (DU)/IEC/2022/780]. It will be a hospital based case control study carried out in the department of Prosthodontics at Sharad Pawar dental college and hospital consisting of 20 subjects in each of the two groups. These groups will be labelled Group A and Group B. After the initial screening with Mallampati test (Class I) and determining the patient in group A or group B (Hypertensive and non-hypertensive), the airflow will be measured using spirometer at various stages of each subject. The following stages of the test will be conducted. First testing will be performed in patients without any dentures placed intraorally. As a result, the values acquired will be referred to as the control values. A second test will be performed with the patient’s dentures (maxillary and mandibular) in the oral cavity. In the third test, only the maxillary denture will be inserted intraorally. In the final testing, just the mandibular denture will be inserted intraorally (Figure 1). Along with the above-mentioned criteria Group A will include patients with a known case of hypertension, patients who are on antihypertensive medications and whose blood pressure is more than 130 mm Hg systolic and more than 90 mm Hg diastolic blood pressure from last three months. Group B will include patients without hypertension (AHA- American Heart Association Grade 1, 2). Both the groups (A and B) will be measured with PEFR and FVC of spirometry parameters. Group A and B will be divided in initial patient recruitment.

Figure 1. Study design.

Inclusion criteria

The inclusion criteria will be complete denture wearers that give consent to be a part of the study, who have worn a denture for at least 3 years and who have Class I relationship type of intraoral soft tissue according to Mallampati scale taken at the time of medical history. Will be recruited for this study.

Exclusion criteria

The exclusion criteria will be complete denture wearers unwilling to participate in this study, patients wearing a complete denture that had fabrication imperfections with any history of any systemic diseases other than hypertension, patients with any other pathology in the past affecting the respiratory system, such as asthma or chronic obstructive pulmonary disease (COPD) or with a history of smoking will all be excluded from the study.

Instruments

A spirometer - (RMS HELIOS 401, Ios – VYAIRE), is an apparatus for measuring the volume of air inspired and expired by the lungs and various readings are recorded with American thoracic guidelines (ATS). Patient has to breath in and has to exhale for 6 seconds in the mouth piece which is attached to the desktop spirometer, all the spirometric readings are then directly acquired on the desktop. (Method for using the spirometer is given in depth in user manual - https://www.vyaire.com/products?product_type%5B103%5D=103).⁷

Experimental procedure

This in vivo study will be carried out in the “Prosthodontics department of Sharad Pawar Dental College and Hospital, DMIMS (DU), Sawangi (Meghe), Wardha”. This study will comprise of 80 patients of more than 40 years of age, split into four different groups. Patients will be given full information regarding the study and the study will be carried out after filling out a written informed consent form for the subjects. Patients will be advised not to engage in any strenuous physical activity, such as jogging, walking, or even stair climbing. Patients with complete dentures will be advised to dress in loose-fitting cotton clothing to allow for unrestrained, natural movement during the physiologic respiratory mechanism.

These airway parameters will be measured in all denture patients – peak expiratory flow rate (PEFR) and forced vital capacity (FVC) with the help of experienced technicians on the spirometer.⁷ This test will be done for those patients who have worn the denture for more than 3 years, this measurement will be done only once After the initial screening with Mallampati test (Class I) and determining the patient in group A or group B (Hypertensive and non-hypertensive), the airflow will be measured using a spirometer at various stages of each subject. The following stages (parameters) of the test will be conducted. First testing will be performed in patients without any dentures placed intraorally. As a result, the values acquired will be referred to as the control values. A second test will be performed with the patient’s dentures (maxillary and mandibular) in the oral cavity. In the third test, only the maxillary denture will be inserted intraorally. In the final testing, just the mandibular denture will be inserted intraorally (Figure 1). Along with the above-mentioned criteria Group A will include patients with a known case of hypertension, patients who are on antihypertensive medications and whose blood pressure is more than 130 mmHg systolic and more than 90 mmHg diastolic blood pressure from last three months. Group B will include patients without hypertension (AHA – American Heart Association Grade 1, 2). Both the groups (A and B) will be measured with PEFR and FVC of spirometry parameters with the help of the Spirometer – RMS HELIOS 401, Ios – VYAIRE which measures the airflow.

All of the findings will be gathered and recorded on an Excel (RRID:SCR_016137) spreadsheet. SPSS software (RRID:SCR_002865) will be used to compare the values collected at the four different tests. The degree of significance will be determined using the Chi-square test, one-way analysis of variance, and Fisher t-test.

Bias

Bias will be minimized by random selection of patients based on inclusion and exclusion criteria. Simple randomized sampling will be done according to the patients visiting the out patient department in which each and every patient has an equal chance of getting selected.

Sample size

The minimum sample size required for piloting the study as no other studies were found before for power analysis. We would be considering 20 samples per group for the comparative evaluation of the results between the groups to factor any potential loss to follow up.

Sample size for superiority parallel experimental study.

Primary variable FVC (liters)

FVC (liters) in hypertensive group 3.52 ± 1.02 (Group 1)

FVC (liters) in control group 4.31 ± 0.82 (Group 2)

The difference in mean (δ) = 0.79

Pooled std.dev.(σ) = 0.92

${\mathrm{Z}}_{\mathrm{\alpha }}=1.64$

$\mathrm{\alpha }=\text{Type I error at 5\%}$

${\mathrm{Z}}_{\mathrm{\beta }}=0.84\left(\text{for equivalence two tailed}\right)$

$\mathrm{\beta }=\text{Type II error at 20\%}$

$\mathrm{\sigma }=\mathrm{std}.\mathrm{dev}.$

Standard deviation value = 6.08.

${\mathrm{Z}}_{\mathrm{\alpha }}=1.64\text{at 5\% l.o.s. for superiority}$

${\mathrm{Z}}_{\mathrm{\beta }}=0.84\text{at 80\% power}$

Sample size.

Minimum sample required = 17 per group.

Statistical analysis

Statistical analysis will be performed using the students unpaired t-test FVC and PEFR readings and for Group A and Group B comparison of the difference in spirometric values. All analysis will be done using SPSS 24.0 version software and p > 0.05 is considered the level of significance.

Limitations

Other parameters like forced expiratory volume in 1 s (FEV1) value, Peak inspiratory flow (PIFR) value and forced expiratory flow 25%–75% (FEF25–75) were not considered as there was no significant difference in the values according to the literature.

Scope

A search for better rehabilitation without increasing this problem should be considered if many alterations of airflow values are seen. Other modalities of treatment like fully implant-supported prostheses, and flangeless dentures can be studied.

Study status

Study not yet started.