Journal of Dr. NTR University of Health Sciences

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 6  |  Issue : 1  |  Page : 45--51

Collation of chewing efficiency and dentures with diverse occlusal schemes


Vijay Kumar Peddinti1, Chiramana Sandeep2, Anne Gopinadh2, Suresh Babu Muvva2, Jyothula Ravi Rakesh Dev2, Aiswarya Suggala2,  
1 Department of Prosthodontics and Crown and Bridge Including Implantology, Consultant Prosthodontist at Denty's Dental Care, Secunderabad, Telangana, India
2 Department of Prosthodontics and Crown and Bridge Including Implantology, SIBAR Institute of Dental Sciences, Guntur, Andhra Pradesh, India

Correspondence Address:
Vijay Kumar Peddinti
H. No. 13-72, P&T Colony, Dilsukhnagar, Hyderabad - 500 060, Telangana
India

Abstract

Background: Rehabilitation of an edentulous patient nurtures satisfaction and this lies in the chewing ability provided by the prosthesis. Aim: To evaluate and compare the masticatory efficiencies of complete dentures with different occlusal schemes. Materials and Methods: Fourteen completely edentulous patients from the age group of 50-70 years were selected according to the inclusion criteria followed in this study. The dentures were made with three different occlusal schemes, i.e., anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion and stored in water till the date of denture insertion. Post-insertion instructions were given to the patients at the time of delivery of the dentures. Patients were recalled after seven days and then masticatory efficiency was performed. The test was performed using boiled peanuts and Sieve system. Statistical Analysis: One-way analysis of variance (ANOVA) test and unpaired t-test were carried out. Results: The obtained masticatory efficiency values with anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusion LO were analyzed using one-way ANOVA test and unpaired “t” test. The tests showed that lingualized scheme had highest masticatory efficiency. Conclusion: Within the scope of this study, it can be concluded that the masticatory efficiency will be generally higher in patients provided with complete dentures fabricated using the lingualized occlusal scheme.



How to cite this article:
Peddinti VK, Sandeep C, Gopinadh A, Muvva SB, Dev JR, Suggala A. Collation of chewing efficiency and dentures with diverse occlusal schemes.J NTR Univ Health Sci 2017;6:45-51


How to cite this URL:
Peddinti VK, Sandeep C, Gopinadh A, Muvva SB, Dev JR, Suggala A. Collation of chewing efficiency and dentures with diverse occlusal schemes. J NTR Univ Health Sci [serial online] 2017 [cited 2019 Jun 16 ];6:45-51
Available from: http://www.jdrntruhs.org/text.asp?2017/6/1/45/202580


Full Text



 Introduction



Edentulism is a debilitating irreversible condition. It is a cripple for the geriatric populace. It leads to a series of deleterious consequences on general and oral health. These consequences can be overcome with different treatment modalities. Complete denture is one of the treatment options for restoring appearance, speech, and function.[1] Function is nothing but mastication, and masticatory function is of prime importance for complete denture wearers. This masticatory function is restored by proper occlusion, and complete dentures can be made with different types of occlusal schemes. Studies comparing various types of complete denture occlusal schemes have been conducted for years, on same patient or different patients and had explored outcomes such as masticatory efficiency, occlusal force, and patient preference.[2] To overcome bias resulting from individual variation between subjects, most studies have compared different types of occlusal schemes in the same patient in a crossover fashion.[3] The purpose of this study is to evaluate the masticatory efficiency of complete dentures with different occlusal schemes.

 Materials and Methods



Study design

The present study included 14 completely edentulous patients aged 50-70 years including both male and female who were selected to evaluate and compare the masticatory efficiencies of anatomic occlusion without balancing, anatomic occlusion with balancing, and lingualized occlusal schemes in subjects using complete dentures. The study's protocols and procedures were reviewed and approved by the college ethics committee. Prior to the start of the treatment, the treatment procedures were explained and a written informed consent was obtained from the patients.

Methodology

Initially primary impressions of patients were made in stock edentulous nonperforated trays (Jabbar, India) using type I impression compound material (Y-dents impression compound, MDM Corporation, Delhi) in to which type II Gypsum product (dental plaster, Kalabhai, Mumbai) were poured to obtain primary casts. Later custom trays were fabricated with Boucher's wax spacer design on these primary casts using self-cure acrylic (DPI-RR acrylic material, Mumbai) by dough method. Now these custom trays were checked for peripheral extensions in the patient and an active border molding technique was carried out in both maxillary and mandibular arches using low fusing impression compound (Green stick compound, DPI pinnacle tracing sticks, Mumbai), and later final impressions [Figure 1] were made using zinc oxide eugenol impression material (DPI Impression paste, Mumbai). These impressions were poured with type III Gypsum product (Dental stone, Kalabhai, Mumbai) to obtain master casts. Once maxillary and mandibular master casts were ready they were duplicated twice using silicone duplicating material (UniSil-Flow, Germany) in order to obtain the molds [Figure 2] for pouring the remaining two sets of casts, that were to be used for fabrication of bilateral balancing and lingualized occlusion (LO) teeth arrangements in the same patient. Upon these three sets of master casts, heat cure acrylic (DPI-RR acrylic repair material, Mumbai) denture bases were fabricated using conventional flasking method and occlusal rims were prepared using modeling wax (Hindustan Dental Products, Hyderabad). Orientation jaw relations were carried out using earpiece arbitrary type of facebow (Hanau spring bow) and facebow transfer was done on to a semi adjustable articulator (Hanau Wide-Vue). Vertical jaw relations were made using a combination of anatomic, phonetic, and swallowing methods. Bite registration was done by nick-and-notch method with Jet bite occlusal registration material (Coltene Whaledent, Switzerland) and the mounting was done. Now Height's Extra Oral Tracers were attached to the occlusal rims to perform extraoral tracings. The gothic arch tracings were done to record centric and protrusive movements of the patients. Interocclusal records [i.e. centric record (CR) and protrusive record (PR)] were made using jet bite occlusal registration material [Figure 3]. These interocclusal records were used for programing of the articulator. Now the tracers were detached and maxillary and mandibular occlusal rims were reconstructed to their previous original form. The putty indexes [Figure 4] of these reconstructed occlusal rims were made using putty material (Coltene Whaledent, Switzerland), in order to utilize them for fabrication of the remaining two sets of occlusal rims that were to be used for conventional and lingualized occlusal scheme teeth arrangements. This putty indexing was carried out in order to ensure the accurate maintenance of arch forms of that particular patient for the remaining two occlusal scheme teeth arrangements also. The vertical dimensions of patients were also maintained using the markings on the incisal rod of the articulator. For each patient, three sets of artificial teeth (Acry Rock teeth set, Ruthinium Group, India) were selected from the same mold and shade. Later teeth arrangements were carried out as followed.{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Anatomic occlusion without balancing teeth arrangement

In this scheme, the selected teeth were arranged [Figure 5] following the basic teeth arrangement principles with normal condylar guidance setting of 30°, lateral condylar guidance setting of 30°, and incisal guidance setting of 0° as suggested by the Hanau-Wide Vue articulator manufacturer.{Figure 5}

Anatomic occlusion with balancing teeth arrangement

Programming of the articulator was carried out individually for all the patients using the centric and protrusive records obtained from them [Figure 6]. Lateral condylar guidance was calculated using Hanau's formula{Figure 6}

L = H/8 + 12

To obtain balancing the functional maxillary palatal cusps of posterior teeth were set in the central groove of the mandibular teeth, and the maxillary buccal cusps were kept in contact with mandibular buccal cusps. The buccal cusps and palatal cusps were in articulation and functional in the bilateral and protrusive excursions.

Lingualized occlusal scheme arrangement

In this scheme, the teeth were arranged following the basic arrangement principles with normal condylar guidance setting of 30°, lateral condylar guidance setting of 30°, and incisal guidance setting of 0° as suggested by the Hanau-Wide Vue articulator manufacturer.

The complete dentures with LO arrangement were done as follows.

The functional maxillary lingual cusps of the posterior teeth were set in the central groove of the opposing mandibular posterior teeth. The maxillary buccal cusps were elevated and had no contact with the opposing mandibular teeth [Figure 7].{Figure 7}

The try-in of these three sets of dentures were done on the same day and were evaluated for occlusion, esthetics, and phonetics. After obtaining the patient's written approval of the try-in procedure denture processing were carried out following conventional procedure and were lab remounted. Later occlusal corrections were done and dentures were trimmed, finished, and polished. These dentures were stored in distilled water till the date of denture insertion.

After insertion of dentures, for the first 24 h the patients were instructed to wear dentures throughout the day except during meals. For the next 2-7days, the patients were asked to chew with dentures. Seven days following the denture insertion, the patients were recalled and masticatory efficiency test was carried out.

Masticatory efficiency test

Masticatory efficiency was tested using boiled peanuts and by an internationally accepted standard sieve system [Figure 8]. Three grams of boiled peanuts were used for the chewing test and the patients were asked to complete twenty masticatory strokes. Later, the patients were asked to expectorate the chewed test portion into paper cup and thereafter to rinse their mouth thrice with water so as to ensure complete collection of remnants and spit the remnants into the same cup. The same procedure was repeated for two more times and samples were collected into two more cups. Averages of these three values were taken for calculating the average masticatory efficiency index (R). Later, these particles were dried in an incubator at 60°C for 24 h and then weighed (T). Now these dried particles were placed in a sieve system, which had a stack of three sieves with coarsest (2.8 mm), medium (2.0 mm), and finest (1.4 mm) apertures. The particles were made to pass through the sieves, which was kept on a dental vibrator (Unident, India) set at half speed for 2 min. After the completion of this process the weight of the material in the coarsest fraction (x) was measured and the material in medium fraction (y) was measured. Then masticatory efficiency index (R) was calculated using the following formula:{Figure 8}

[INLINE:1]

x = Weight of material in coarsest fraction sieve in grams.

y = Weight of material in medium fraction sieve in grams.

T = Weight of expectorated material after drying in grams.

The values were noted, evaluated, and analyzed using one-way ANOVA test and unpaired “t” test.

 Results



The masticatory efficiency of the dentures fabricated using anatomic occlusion with balancing was higher than dentures with anatomic occlusion without balancing (P< 0.01) [Table 1]. When the efficiency was compared between balanced occlusal and lingualized occlusal schemes, lingualized surpassed the previous scheme (P< 0.01) [Table 2]. Later, anatomic occlusion without balancing and lingualized were compared, and lingualized scheme gave superior results (P< 0.01) [Table 3]. Finally all the three groups were analyzed statistically, and lingualized scheme outshined [Table 4].{Table 1}{Table 2}{Table 3}{Table 4}

 Discussion



Formulation of the treatment plan aims at the well-being of the patient as well as his satisfaction. In case of complete denture fabrication, it is attained by the chewing efficiency. Occlusion is one of the important criteria that dictate masticatory efficiency. Studies comparing various types of complete denture occlusal schemes have been conducted for years and have explored outcomes such as masticatory efficiency, occlusal force, and patient preference.

Several studies have been reported for the effect of occlusal schemes on chewing ability. There are two specific methods used for evaluating chewing ability. One is the subjective method that uses questionnaire for evaluating the chewing ability and other is the objective method that uses the laboratory method such as masticatory efficiency measurement by internationally accepted standard sieve method presented by Manly and Braley.[4] Kapur and Soman [5] reported no positive correlation when the subjective evaluation of masticatory efficiency was compared with the objective test results. In the dental literature, many reports were published regarding that professionally assessed quality of complete dentures do not agree with patient's subjective judgments.[6] Many people with poor masticatory efficiency, as judged from objective test methods, will still judge their masticatory function as “good”. It is concluded that self-assessment of chewing ability is in general, too optimistic when compared with the results of functional tests. Therefore, the focus of this study was on the patient's chewing efficiency as the main outcome.

Masticatory function in complete denture wearers is influenced by many factors. It is possible to divide the factors into two main categories — the first factor is related to proper design and fit of the prosthesis and the second factor was related to morphologic, physiologic, and psychologic parameters. The former has to do with the fit of the denture, the shape of the denture base, and occlusion relating mainly to performance of clinicians. The latter biologic category has to do with the oral motor behavior, mandibular and/or tongue movement, shape of the residual ridge including size and/or height, salivary secretion rate, relating mainly to aging of the patient.[7]

Various occlusal schemes that are commonly used in complete denture are as follows: anatomic occlusal scheme without balancing, anatomic occlusal scheme with balancing, and lingualized occlusal schemes.

LO gives the patient improved comfort, function and appearance, and quality of life goals sought by the clinician and patient alike. The principle of LO aims at stabilizing the prosthesis. It is based on maxillary palatal cusps functioning as the main supporting cusp in harmony with the occlusal surfaces of the mandibular teeth.

For the present study, 14 completely edentulous patients were selected. Each patient received three sets of dentures with three different teeth arrangement occlusal schemes as follows: anatomic occlusion without balancing, anatomic occlusion with balancing, and LO, and after 1 week's usage of dentures each occlusal scheme's masticatory efficiency was carried out using an internationally accepted standard sieve system. The obtained values were statistically analyzed and compared. The masticatory efficiency that was obtained for lingualized, anatomic occlusion with balancing, and anatomic occlusion without balancing were 63.66%, 50.35%, and 38.53%, respectively.

Several reports have been published regarding the effect of occlusal scheme on masticatory efficiency. These reports were compared between two or three occlusal schemes in either same or in different patients.

Sutton et al.[8] have compared the levels of subject's satisfaction with three types of posterior occlusal forms, i.e., zero-degree, anatomic, and lingualized. The subjective data was collected according to the visual analogue scale results after 8 weeks of denture wearing. They noted that usage of lingualized and anatomic occlusal forms dominated superior results in terms of chewing ability, when compared with zero-degree posterior occlusal surfaces.

In the present study, lingualized occlusal scheme showed superior results of 63.66% than other schemes.

Clough et al.[9] conducted a study to compare the significance of LO and monoplane occlusion in complete dentures of the same patient. All the patients were asked to observe the chewing efficiency, comfort, and appearance of the dentures during the 3 weeks usage of dentures with first occlusal scheme and later with the second occlusal scheme after 3 weeks. They have noted that 67% of the patients preferred the lingualized occlusal scheme over other schemes because of the improved masticatory ability, comfort, and esthetics.

Masticatory efficiency of lingualized occlusal scheme in the present study was 63.66%.

Kimoto et al.[10] documented significantly poorer masticatory efficiency of complete denture wearers in a low-bone-height group versus middle and high bone height groups.

In the studies that were mentioned earlier, there was discrimination in explaining which occlusal form is superior both subjectively and objectively. In the objective assessment, bilateral balanced occlusion (BBO) was found to be superior to LO, whereas subjectively LO was superior to BBO. The reason behind this was related to the alveolar ridge height as pointed out by Kimoto et al.[10] In the present study, only the high ridge cases were taken as inclusion criteria and masticatory efficiency was evaluated.

The above study showed masticatory efficiency of 63.66% using lingualized occlusal scheme, which is higher than that using anatomic occlusion with balancing scheme (50.35%) and that using anatomic occlusion without balancing scheme (38.53%). The statistically significant results proved that masticatory efficiency was better with complete dentures fabricated using lingualized occlusal scheme when compared to those fabricated using anatomic occlusion with balancing and anatomic occlusion without balancing schemes.

 Conclusion



Within the limited scope of this study, it can be concluded that the masticatory efficiency will generally be higher in patients provided with complete dentures fabricated using the lingualized occlusal scheme than in the patients who receive complete dentures using either anatomic occlusion without balancing or anatomic occlusion with balancing. In addition to this, more research work needs to be carried out in population to assess the benefits of lingualized occlusal scheme in the fabrication of partial dentures and other prostheses as well.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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