Evaluation of Oral Stereognosis in Completely Edentulous Patient With Maxillary Tori
Phase: NA
Conditions: Torus Palatinus and Torus Mandibularis
Sponsor: Segi University

          
                                                                                                   
 
Title of the Research Project:  
 
Evaluation of oral stereognosis in completely edentulous patients with maxillary 
tori. 
Document Date:  September 17, 2018 
Investigators : 
Name 
Email Id 
Dr Indumathi Sivakumar 
indumathisivakumar@segi.edu.my 
Nur Lyanna Mahfuzah binti Mohamad Johar 
lyanna1909@gmail.com 
Rachel Chua Hui Shien 
purplepeach.rachel@gmail.com 
Sham Wern Xuan  
wxuan1214@gmail.com 
Sin Pi Xian 
pixian1104@gmail.com 

          
                                                                                                   
 
 
Title of the Research Project 
Evaluation of oral stereognosis in completely edentulous patients with maxillary tori. 
 
Introduction  
 
Stereognosis has been defined as the appreciation of the form of objects by manual palpation 
without the use of eye-sight.1 The term was introduced by H. Hoffmann in 1883. Whilst this 
definition holds good for the manual exploration of objects, it is also possible to extend the 
tactile perception of objects intraorally which is referred  as Oral stereognosis (OS).1 It was first 
introduced by Berry and Mahood in 1966. Oral Stereognostic tests are performed using test 
specimens intraorally to determine the extent to which patients are able to distinguish shapes 
and surface structures. The OS testing is an indicator of overall sensory ability of the patient as 
the intraoral tactile sensation is conveyed through various cranial nerves including of 
trigeminal nerve, hypoglossal nerve and glossopharyngeal nerve. 2  
 
Various studies have been designed to assess the oral stereognosis ability (OSA) by using a 
variety of test pieces with different shapes, materials, sizes, etc. with the objects kept away 
from patient’s eyesight in order to evaluate the ability of patients to distinguish the shape and 
form of the test pieces.1, 3, 4, 5, 6  Several studies has proved that OSA decreases with age and 
completely edentulous patient had lower OSA when compared to dentate patients.3, 4,  6, 7   The 
level of oral stereognostic score demonstrated a definite relationship with denture 
performance, that is patients with poor stereognostic ability appeared more satisfied with 
their complete denture prosthesis than did those with better stereognostic ability.1,  Thus, 
evaluating OSA in edentulous patients who require rehabilitation with complete denture 
prosthesis may provide useful information about the sensory abilities of edentulous patients 
and aid in interpreting the role of adaptation and adjustment to the complete denture 
prosthesis. 

          
                                                                                                   
 
 
OSA was even evaluated in patients with palatal anomaly like cleft lip and palate where the 
palatal hard and soft tissues are compromised. OS levels of denture wearers with cleft lip and 
palate were lower than those observed in edentulous subjects without clefts. 8,9 However, 
there are no studies evaluating the effect of palatal tori on OSA. Torus palatinus (TP) are 
commonly found along the midline of the hard palate at the junction of the intermaxillary 
suture and the transverse palatine suture. Patients with TP may experience trauma or 
ulceration when masticating hard and sharp food since the soft tissue covering the bony 
protuberances is reported to be thinner than the surrounding mucosa. In addition, speech 
difficulties due to limited tongue movement, food lodgement resulting in malodour, difficulty 
in recording oral impressions and seating of dentures are the common problems. The 
prevalence of TP in Malaysian population was found to range between 12% to 65%.¹², ¹³ Hence, 
it is clear that Malaysian population carry a significant prevalence of TP and its effect on OSA 
has not been studied and this has been taken into consideration while designing this study. 
Thus, this research is designed to achieve a better understanding of the oral stereognosis in 
completely edentulous patients with maxillary tori. 
 
Aim and Objective  
Aim : To evaluate the oral stereognostic ability in completely edentulous patient with maxillary 
tori.     
 Objective : 
  1. To compare the oral stereognostic ability of the completely edentulous patient with 
maxillary tori and patient without maxillary tori.  
2. To compare the time duration taken for oral stereognosis of the completely edentulous 
patients with and without maxillary tori.   

          
                                                                                                   
 
 
Background of the study  
 
Mantecchini et al (1998)¹⁰ evaluated oral stereognosis in edentulous subjects rehabilitated 
with complete removable dentures Stereognosis was evaluated with and without the denture 
in place. The results showed that the older subjects had poorer stereognostic ability than the 
younger ones, whereas the duration of edentulism appeared not to influence this ability. The 
presence of a correct prosthetic rehabilitation appeared to improve stereognostic ability. 
Subjects with poorer stereognostic ability appeared more satisfied with their rehabilitation 
than did those with better stereognostic ability. 
 
Pedreira A et al (2004)¹¹ evaluated oral stereognosis in dentate and edentulous subjects with 
and without cleft lip and palate before and after chewing. The results demonstrated that 
oral stereognosis levels of dentate subjects were higher than those observed in edentulous 
subjects. Oral stereognosis levels of denture wearers with cleft lip and palate were lower 
than those observed in edentulous subjects without clefts. Chewing did not influence the 
oral stereognosis levels in edentulous patients. 
Meenakshi S et al (2014)¹ evaluated the oral stereognostic ability after rehabilitating patients 
with complete dentures and concluded that covering the palatal mucosa with a denture 
does not reduce oral stereognostic ability. Oral stereognostic test is a reliable test to 
measure patients’ oral stereognostic perception which would enable the patient to 
appreciate the functional limitations of the denture. 
 
Bakhtiyari J et al (2014)⁸ evaluated oral stereognostic ability and response time in children 
with cleft palate and normal children and showed that there was a significant difference 
between oral stereognosis and response time of children with cleft palate and that of normal 

          
                                                                                                   
 
children (P < 0.05) The results can be used for developing intervention programs for children 
with cleft palate in the early years of their lives. 
 
Jin-Hyuck Park (2016)⁴ assessed the changes in oral stereognosis of healthy adults by age. 
This study investigated oral stereognosis in 184 healthy adults with normal eating and 
swallowing function. Results showed that oral stereognosis ability differ in age of the 
subjects and test pieces employed to test the OSA. The younger age group scored higher 
with short response time comparing to the older age group except for comparison between 
20s and 30s age groups suggesting that aging negatively impacts in OSA in terms of speed in 
which sensory information is responded. Response time was negative correlated with test 
scores (r= -0.956, P < 0.001) and these proved that OSA decreases with age. 
 
Materials and Methods 
Study will be conducted at Faculty of Dentistry SEGi Oral Health Center to evaluate oral 
stereognosis in completely edentulous patients with maxillary tori. 
Subject  
Inclusion Criteria : 
● Complete edentulous patient with maxillary tori and without maxillary tori 
● Complete edentulous patient who give consent and is willing to participate 
Exclusion Criteria: 
● Patients with swallow and mastication dysfunction  
● Patients with cognitive disturbances 
● Uncooperative patients. 
● Patients with oral lesions, pathologies and TMJ disorders. 
 

          
                                                                                                   
 
● Patients with systemic diseases 
● Patients allergic to acrylic resin 
 
The study group will comprise of 20 completely edentulous patients with maxillary tori and 20 
completely edentulous patients without maxillary tori who are willing to participate in this 
study. The patients who fulfill the above mentioned inclusion and exclusion criteria would be 
conveniently selected from among outpatients of the SEGi Oral Health Centre. Informed 
consent will be obtained from each patient following sufficient explanation of purpose and 
contents of the research.  
 
Fabrication of test samples  
The 6 test pieces were selected from the 20 shapes of test pieces from National Institute of 
Dental Research (figure 1). The test pieces comprises 6 shaped form which include circle, 
eclipse, square, rectangular, triangle and star shaped with 13mm length and 2mm thickness. 
2mm stainless steel wire will be used to fabricate as the test pieces mould. After fabrication of 
the test piece moulds by the stainless steel wire, the mould will be stamp on 2mm thickness of 
light cured acrylic resin, followed by curing of the resin for 30 seconds in light cure chamber. 
The test samples would be trimmed and polished to meet the standardized measurements.   A 
total of 240 test sample (6 samples for each patient) for 20 completely edentulous patients with 
maxillary tori and 20 completely edentulous patients without tori will be made for this study. 
The test pieces will attached with dental floss. The attaching dental floss would prevent any 
accidentally aspiration of the test pieces. 

          
                                                                                                   
 
 
 
     
 
Fig. 2 6 test pieces shape that are chosen  
 
   
 
Assessment of oral stereognostic test 
 
The OSA test will be conducted in Segi Oral Health Centre under quiet condition. All patients 
will be seated comfortably in upright position on dental chair. All the test pieces will be kept 
out of sight of patient before and during the test. Test pieces will be placed intraorally and 
patients will be instructed to identify the shape of test pieces with their tongue and palate. A 
visual representation chart of all 6 shaped forms will be provided to patient for identification 
purpose. Patients will be asked to identify the correct shape form by pointing out on the 

          
                                                                                                   
 
corresponding shape form on the chart. There will be no trial test held to avoid learning effect. 
The 6 test pieces will be presented randomly to the patients and correct answer will not be 
informed to the patients during the OSA.  
 
The duration time for recognition of each shaped form for each patient will be noted and 
answers will be recorded on an OSA evaluation form. A correct answer will recorded as one 
point and incorrect answer is zero point. A full 6 points will be scored if all answers were 
correct. The response time and the OSA scores will be recorded. The response time will be the 
time between the placements of test piece in the oral cavity until the identification of the test.  
 
Statistical analysis plan 
The data collection will include the time duration and OSA scores for recognition of each 
shaped form and the answers recorded on an OSA evaluation form. All data analyses will be 
conducted using SPSS version 22. Descriptive statistic will be used to analyses the mean and 
standard deviation of the OSA test scores and the respond time for answering. Analysis of 
variants (ANOVA) will be applied to compare the test scores and respond time among the 
completely edentulous patient with maxillary tori and completely edentulous patient without 
maxillary tori. Spearman’s rank correlation coefficient would to be used to investigate the 
relationship between response time and OSA test score. 
 
References 
1) S.Meenakshi, Anil Kumar Gujjari, H.N Thippeswamy and N. Raghunath. Evaluation of Oral Stereognostic 
Ability After Rehabilitating Patients with Complete Dentures: In Vivo study. J Indian Prosthodont Soc 
2013;14(4):363-368 
2) Litvak H, Silverman SI, Garfinkel L. Oral stereognosis in dentulous and edentulous subjects. J Prostthet 
Dent 1971;25(2):139-150. 
3) Kawagishi S, Tanaka T, Shimodozono M, Yoshino K. Simplifying the Assessment of Stereognostic Ability 
of the Tongue in Elderly Subjects Using Six Selected Test Pieces. Aging Sci 2013;1:111 
4) Jin-Hyuck Park. Original Changes in oral stereognosis of healthy adults by age.Journal of Oral Science 
2017;59(1):71-76. 

          
                                                                                                   
 
5) Stephan Eitner, Manfred Wichmann, Andreas Schlegel, Stefan Helst. Clinical study on the correlation 
between psychogenic dental prosthesis incompatibility, oral stereognosis, and the psychogenic diagnostic 
tools. J Prosthodont 2007;20:538-545 
6) Reinhilde Jacobs · Charbel Bou Serhal Daniel van Steenberghe.Oral stereognosis: a review of the 
literature.Clin Oral Invest 1998;2:3–10  
7) K. Ikebe, M. Amemiya, K. Morii, K. Matsuda, M. Furuya-Yoshinaka, T. Nokubi. Comparison of oral 
stereognosis in relation to age and the use of complete dentures. J of Oral Rehabilitation 2007;34:345-
350 
8) J. Bakhtiyari, H. Dadgar, A. Sadolahi, A. R. Khatoonabadi. Oral Stereognosis in children with cleft palate 
and normal children. Middle East J Rehabil Health. 2014;1(1):e20840 
9) Hochberg I, Kabcanell J. Oral stereognosis in normal and cleft palate individuals.Cleft palate J1967;4:47-
57 
10) Mantecchini G, Bassi F, Pera P, Preti G. Oral stereognosis in edentulous subjects rehabilitated with 
complete removable dentures. J Oral Rehabil 1998;25:185–189 
11) Ana Paula Ribeiro do vale Pedreira, Wellington Cardoso Bonachela, Paulo Henrique Orlato Rossetti, 
Joao Henrique Nogueria Pinto. Oral stereognosis in dentate and edentulous subjects with and without 
cleft lip and palate before and after chewing. Ini J Oral – Med Sci 2004;3(1):61-65 
 
12) K Sathya, Sham Kishor Kanneppady, T Arishiya.Prevalence and clinical characteristics of oral tori 
among outpatients in Northern Malaysia. Journal of Oral Biology and Craniofacial Research 2012;2(1):15–
19  
13) Ashish Kumar Singh, Srinivas Sulugodu Ramachandra, Shelly Arora, Daniel Devaprakash Dicksit, C.G. 
Kalyan, Priyanshi Singh. Prevalence of oral tori and exostosis in Malaysian population- A cross-sectional 
study. J Oral Biol Craniofac Res 2017;7(3):158-160.  
 
14) Dr. Divya Dahiya , Dr. Harleen Thukral , Dr. Rangesing Rathwa. Oral Stereognostic Ability- Sensory 
Perception In Complete Denture Patients. International Journal of Enhanced Research in Medicines & 
Dental Care,2016 ;Vol. 3 Issue 3,69-71 
 
 
 

          
                                                                                                   
 
PARTICIPANT CONSENT FORM FOR ORAL 
STEREOGNOSTIC STUDY 
 
Title: Evaluation of oral stereognosis in completely edentulous patients with maxillary 
tori. 
 
Participant’s name: 
I.C / Passport No: 
 
 
The details of the study have been explained to me in my own language. I confirmed that I have 
understood the above study and had the opportunity to ask questions. I understand that my 
participation in the study is voluntary and that I am free to withdraw at any time, without giving 
any reason, without the medical care that will normally be provided by the hospital being 
affected. I agree not to restrict the use of any data or results that arise from this study provided 
and can be used in future studies.  However, such a use is only for scientific purpose(s). I fully 
consent to participate in the above study. 
 
 
 
 
 
 
 
 
Signature of the participant: ______________________ 
Date: _____________