Effect of Pre-treatment Photographs on Oral Hygiene Maintenance in Orthodontic Patients
Phase: NA
Conditions: Oral Hygiene, Photographs
Sponsor: Rehmat Memorial Post Graduate Dental Teaching Hospital

 
 
 
 
 
 
 
 
 
TITLE     OF     RESEARCH: 
Effect of pre-treatment 
photographs 
on 
oral 
hygiene maintenance in 
orthodontic 
patients 
DESCRIPTION:         Study 
protocol and statistical 
analysis plan 
NCT number: NCT06010797 
DATE: 20-08-2023 
[Year] 

STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN 
 
MATERIAL AND METHODS 
 
1) Setting 
 
The study was carried out in Orthodontics department, Rehmat Memorial Dental Teaching 
Hospital, Abbottabad 
2) Duration of Study 
 
The study lasted from month of August 2020 to month of July 2021. 
 
3) Sample Size 
 
The sample size was calculated to be 60 patients (30 in each group) using the WHO software 
for sample size calculation in health studies using the formula for hypothesis tests for two 
population mean (one sided) with the following assumptions: Statistical significance=5%, 
Statistical Power=80%, Anticipated mean + SD PI score of Study group after 3 
months=1.68(0.40) and Anticipated mean + SD PI score of Control group after 3 
 
months=1.72(0.33). 
 
4) Sampling Technique 
 
The sampling technique used was non-probability consecutive sampling. Patients visiting 
Orthodontic Department of Rehmat Memorial Postgradute Dental Teaching Hospital to start 
their Orthodontic treatment were selected. 
5) Sample Selection 
 
Inclusion Criteria 
 
 Patients of both genders  
 Between age 13-25 years 

 
 
Exclusion criteria 
 
 Patients with previous orthodontic treatment  
 Handicapped patients 
 Patients with any systemic disease 
 Generalized periodontal disease 
 Congenital malformations 
6) Study Design 
 
The study design was a double blinded randomized controlled trial. 
 
7) Data Collection Procedure 
 
After taking approval (Annexure A) from ethical approval committee of Rehmat Memorial 
Dental Teaching Hospital an informed written consent (Annexure B) was taken from the 
patient. The oral hygiene maintenance of the patients were examined with the University of 
Michigan ‘O’ probe with Williams markings for the Plaque Index (PI) on the first visit (T0) 
and then 3 months after starting treatment (T1). Patients were divided into two groups using 
block randomization to remove confounding factor. 
 Measuring PI: 
 
For PI (Silness-Löe Index)1,2 plaque was assessed on buccal, lingual, mesial and distal surface 
of teeth number 16, 12, 24, 32, 36 and 44. Each surface was given a score from 0-3. The score 
from the four surfaces of the tooth were added and divided by four to get plaque index for 
individual tooth. The index for the patient was obtained by summing the indices for all six 
teeth and dividing by six. Scoring was recorded on form (Annexure C). 

 
 
 Camera settings for photographs: 
 
Patients’ pre-treatment photographs were taken with Nikon D3500 SLR camera with 18 – 
55mm kit lens. Settings for extra-oral photographs were aperture size of f/8, shutter speed of 
1/200, ISO 100 and magnification of 1:10.3 Extra-oral photographs were taken with white clear 
background. Camera settings for intra-oral photographs were aperture size of f/20, shutter 
speed of 1/125, ISO 200 and magnification of 1:2.3 To eliminate shadows Meike MK-14 EXT 
macro ring flash with twin tubes was attached to the camera. 
 Randomized Controlled Trial Design: 
 
(a) Participants: 
 
Orthodontic patients. 
 
(b) Intervention: 
 
Patients’ own pre-treatment dental photographs. 
 
(c) Study group: 
 
Orthodontic patients who are shown dental photographs. 
 
(d) Comparison group: 
 
Orthodontic patients who are not shown dental photographs. 
 
(e) Outcome: 
 
Good oral hygiene measured by plaque index. 
 
(f) Block randomization: 

To decrease selection or accidental bias, patients were assigned group A or B using 
block randomization technique. Blocks were created, size of each block was 4 with 
2 ‘A’s and 2 ‘B’s. For 2 groups there were 6 possible blocks. From random number 
table a random sequence of blocks was generated. Patients were then assigned 
groups according to blocks. 
(g) Subjects: 
 
I. 
Group 1: 
 
Included 30 patients and these patients were shown full extra-oral and intra-oral 
photographs. 
II. 
Group 2: 
 
Included 30 patients and these patients were not shown any photographs. 
 
All subjects received similar oral hygiene instructions. Those in group A were shown their 
photographs while those in B were not shown any photographs. 
8) Data Analysis Plan 
 
Statistical analysis was done on SPSS (version 26.0) software. Categorical variables like 
occupation, address and gender were described as frequencies or percentages. Quantitative 
variables like age and PI were described as mean + SD. The two groups were compared 
regarding gender, occupation and address distribution with chi-square test at 5% level of 
significance at p value<0.05. The two groups were compared with independent t test in the 
case of plaque index which showed a normal distribution and with Mann Whitney U Test in 
the case of age which showed a non-normal distribution. For intra-group comparison paired t- 

test was performed. All these were taken at 5 % level of significance at p value<0.05. Relative 
risk was also calculated at 95 % confidence interval. 

Annexure – A 
ETHICAL APPROVAL LETTER 
 

Annexure-B 
 
CONSENT FORM FOR RESEARCH 
 
 
 
 
 
 
I 
D/S/O 
 
assure the following that: 
o I have been informed and understand the procedure and protocol of this study. 
o I have been given the opportunity to ask questions. 
o I agree to take part in this study. 
o I understand that participation involves examination of my oral cavity. 
o I have been informed of the possible recall visits. 
o I understand that my participation is voluntary and that I can withdraw from research any 
time. 
o I understand that all information I provide for this study will be treated confidentially. 
o I agree to digital images during research. 
 
 
Signature of the participant: 
  
 
 
Date of interview: 
_  
 
 
Signature of investigator taking consent:     
 

Annexure-C 
QUESTIONNAIRE 
EFFECT OF PRE-TREATMENT PHOTOGRAPHS ON ORAL HYGIENE 
MAINTENANCE IN ORTHODONTIC PATIENTS 
SURVEY INFORMATION 
 
 
Date of Interview: 
 
T0 
T1 
 
 
 
 
 
DEMOGRAPHIC DETAILS: 
 
 
 
First Name: 
Father’s Name: 
Age: 
Gender: 
Male: 
Female: 
Occupation: 
Address: 
Group: 
 
SCORING CHART: 
 
 
 
Maxilla 
Tooth 
16 
12 
24 
PI 
score 
B 
L 
M 
D 
B 
L 
M 
D 
B 
L 
M 
D 
Mandible 
Tooth 
36 
32 
44 
PI 
score 
B 
L 
M 
D 
B 
L 
M 
D 
B 
L 
M 
D 
 
Average PI score:   
 
 
 
(B=Buccal,L=Lingual,M=Mesial,D=Distal,PI=Plaque index) 

 
 
REFERENCES: 
1. Hiremath S. Textbook of Public Health Dentistry. 3rd ed. India: Elsevier India; 2016;chapter 
17:pg 162-168 
2. Oral health database. Silness-Loe Index. [cited on 23rd April,2019]. Available 
from:http://www.mah.se/CAPP/Methods-and-Indices/Oral-Hygiene-Indices/Silness-Loe- 
Index/. 
 
3. Guide to Dental photography. Decisions in Dentistry. [cited on 5th August,2021]. Available 
from: http://www.decisionsindentistry.com/article/guide-to-dental-photography/.