An injection of 1-1.5 ml of L-ascorbic acid, locally introduced in relation to the keratinized gingival tissues, with extension to the whole target region successively. The injected area will be massaged for equal distribution of the injected vitamin. Injections will be performed on the first day of retainer delivery (T0), after 1 month (T1), after 3 months (T2), and after 6 months (T3). Hence, a total of 4 local Vit-C injections will be performed over the study period.

Alginate impressions will be taken, and dental models will then be scanned using Sirona inEos X5 CAD/CAM lab scanner, producing 3D digital images of the dental models in the form of stereolithographic (STL) files, which will be subsequently imported into a computer software. Little's Irregularity Index (LII) will be employed for the measurement and the quantitative evaluation of the lower anterior segment alignment. The horizontal linear displacement of the anatomic contact points of each mandibular incisor from the adjacent anatomic point is measured, and the 5 displacements are then summed together. The summed value represents the degree of anterior irregularity as follows: 0 = Perfect alignment. 1-3 = Minimal irregularity. 4-6 = Moderate irregularity. 7-9 = Severe irregularity. 10 = Very severe irregularity.

Salivary samples will be collected and measured using chemical analysis. Rise in salivary alkaline phosphatase levels reflects inflammation and destruction of healthy tissues suggesting it as a clinical biomarker. The normal level of alkaline phosphatase is 20-140IU/L (international unit per liter) in adults.