**4.6 Parathyroid hormone injection**

*Periodontal Disease - Diagnostic and Adjunctive Non-surgical Considerations*

*Pre- and postoperative local vitamin C injection in physiologic gingival hyperpigmentation [29].*

Platelet-rich plasma (PRP) is defined as a portion of the plasma element of autologous blood having a platelet concentration above baseline [56, 57]. It is considered as a growth factor agonist [58] with both mitogenic and chemotactic

*Pre- and postoperative local vitamin C injection in gingival inflammation [45].*

Black triangles or insufficient interdental papillae are considered a serious

Hyaluronic acid is an important component of the extracellular matrix, which has great role in maintaining the health of the oral tissues and healing and repair process. The mechanism of its action depends mainly on stimulating the cellular proliferation, migration, and vasculature and restoring the integrity of epidermal and dermal layer. It is also effective in stimulating collagen formation through enhancing the proliferation of fibroblasts. In dentistry, it is recently used

esthetic problem especially in patients with high lip line [62, 63].

It was found that intralesional injection is a newly described method for application of PRP and represents an effective therapeutic option when dealing with nonhealing wounds [59]. These findings open the door for using intralesional PRP in oral chronic ulcers. In 2015, El-K*omy* and his colleagues conducted a pilot study on seven patients suffering from resistant chronic oral pemphigus vulgaris (PV). All patients reported improvement in pain scores, ability to eat, and healing score [60]. In orthodontic therapy, significant improvement was reported following the introduction of local submucosal PRP injection in the pressure side. A single injection of PRP was enough during active orthodontic treatment (just 2 injections; pre and after 6 months). Acceleration of orthodontic tooth movement was reported 1.7-fold when compared to the conventional traction technique [61] (**Figure 8**).

**4.4 Autogenous blood products**

properties [56].

**Figure 6.**

**Figure 7.**

**4.5 Hyaluronic acid**

**76**

Parathyroid hormone is one of the essential hormones that affect the bone metabolism. It was found that its local injection provides acceleration of the orthodontic tooth movement 1.6 times faster than the normal movement range. A daily local injection of parathyroid hormone (PTH) was also used to induce local bone resorption by reducing the concentration of the gel medium using saline [69, 70].
