Can Adjunctive Oral Magnesium Supplementation Prolong the Effect of Botulinum Toxin Type A in Excessive Gingival Display?

To evaluate and compare the effect of adjuvant oral magnesium supplementation combined with Botulinum Toxin Type A versus Botulinum Toxin Type A alone on the reduction of millimeter gingival display and the duration of clinical effectiveness in patients with excessive gingival display

Inclusion Criteria: 1. Male or female patients aged \>18 years. 2. Presence of neuromuscular Excessive Gingival Display \>3mm of gingival exposure from the inferior border of the upper lip to the gingival margin of maxillary central incisors during a maximum spontaneous smile). 3. Healthy systemic condition ( American Society of Anesthesiologists Physical Status Classification System Class I). 4. Complete maxillary anterior dentition with healthy periodontal tissues Exclusion Criteria: 2\. Pregnant or lactating females. 3. Patients with inflamed gingiva or gingival enlargement. 4. Inflammation or infection at the site of injection. 5. Patients with known allergy to any of the components of botulinum toxin type A or botulinum toxin type B (i.e. botulinum toxin , human albumin, saline, lactose and sodium succinate). 6\. Patients using anticholinesterase or other agents interfering with neuromuscular transmission. 7\. Psychologically unstable or who have questionable motives and unrealistic expectations.