Detailed methodology including study design and outcome measures

A prospective randomized control trial will be conducted in Department of Dentistry at AIIMS, Jodhpur. The study will be conducted in accordance with ICH-GCP, ICMR guidelines and other regulatory guidelines and after getting approval from Institute Ethics Committee. Forty four patients requiring orthodontic treatment will be included in the study. Patients will be randomized into conventional NiTi and Cu NiTi arch wires groups in 1:1 ratio by block randomization. Block randomization code will be computer generated. Each block will consist of 4 patients. Randomization codes concealment will be done using sealed opaque envelopes.

Inclusion Criteria:

·         With age group of 12-30 years of age at the start of treatment,

·         Permanent dentition including the maxillary second molars.

·         Arch length deficiency with lower anterior crowding between 3 and 6 mm

·         Patients having no impacted teeth present in the dentition except third molars,

Exclusion Criteria:

·         Patients who had undergone previous active orthodontic treatment.

·         Patients having any orofacial pain prior to treatment.

·         Patients with spacing in the lower anterior region.

·         Patients with carious mandibular anterior teeth.

·         Patient whose treatment plans included extraction of a mandibular incisor.

·         Arch with a blocked-out tooth that did not allow for placement of the bracket at the initial bonding appointment.

·         Patient with missing or impacted teeth present in dentition other than third molars.

·         Patients with systemic diseases, cleft lip and palate or with any other craniofacial anomaly.

·         Patients under medications that interfere with bone metabolism and gingival tissue health.

·         Patients with poor oral hygiene or periodontally compromised teeth.

 

Intervention:

After getting an informed written consent, patients will be randomly allocated into two groups, each group consisting of 22 patients.

Group A: Conventional Nickel Titanium arch wire, Wire sequence (0.014 inch, 0.016 inch and 0.018 inch, 0.019X0.025)

Group B: Copper Nickel Titanium arch wires, Wire sequence (0.014 inch, 0.016 inch and .018 inch, 0.019X0.025)

Both the groups will end in same working archwire, a 0.019 x 0.025 inch stainless steel archwire to produce a common endpoint.

Outcome:

The primary outcome will be the alignment efficiency of two nickel titanium arch wire during orthodontic treatment in terms of time required to reach the working arch wire. Secondary outcome will be pain and discomfort experienced at each arch wire change in conventional and Cu NiTi arch wire group. In addition, root resorption before start of orthodontic treatment and at the end of initial alignment stage(5 months) in conventional and Cu NiTi arch wire group will also be evaluated with CBCT scan.

Alignment efficiency

To measure the alignment efficiency. Anterior mandibular alginate impressions will be taken for each patient at the following time-points:

Little’s irregularity index score after removal of the archwire will be determined. Little’s irregularity index was measured to quantify the degree of tooth alignment of the six anterior mandibular teeth. The study models will be measured with digital callipers (with accuracy up to 0.01 mm.)

Discomfort or Pain Perception

Discomfort levels will be recorded using questionnaires completed by the patients using a Visual analogue scale. The questionnaire recorded orthodontic pain immediately after, 4hours, 24hours, and 1 week after each archwire change by means of a 10-mm visual analogue scale (VAS) and discomfort assessment using the terms “not affected” and “moderately affected” and "severely affected".

External apical root resorption (EARR)

The index proposed by Malmgren et al will be used to assess the degree of root changes. Zero degree will be added to this index, as proposed by Levander et al in order to point out unaltered teeth in the root apex. Root contour of mandibular central incisors assessed before and after completion of alignment will be compared, positioning the long axis of the tooth/root parallel to the index image. The degree of EARR will be assessed according to the index using CBCT scans, using a 0-4 scale of severity as follows:

• Score 0: Absence of changes in the root apex;
• Score 1: Irregular root contour;
• Score 2: EARR of less than 2 mm;
• Score 3: EARR from 2 mm to one-third of the original root length;
• Score 4: EARR exceeding one-third of the original root length.

12.2 Data analysis plan

Sample Size Calculation:

Sample size was calculated based on the study of Serafim et. al. .Assuming a proportion of 0.73 and 1 in two groups with risk difference of 0.27 and absolute precision of 80% with clinically significance level of 0.05, a sample size of 19 patients per group has been calculated. With a dropout rate of about 10 %, 22 patients will be required to be included in each group.

Statistical Analysis:

Data will be expressed as mean ± standard deviation. Independent Student t-test will be used for comparison of numerical variables between two groups. Chi-square test will be used to compare categorical variables. Intragroup comparison of mean changes in outcomes will be evaluated by Paired t-test. Analysis will be done using SPSS version 21 (IBM Corp. Ltd, Newark, USA).

Any deviation from the above mentioned will be done in the best interest of study.