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<\/p>\nMs. Manal Ahmed Mohammed Abdullah was awarded a Master’s degree with an average of Excellent and a grade of 90% in Clinical Periodontology, for her thesis titled: “Comparing the Efficacy of Botulinum Toxin Type-A Injection versus Placebo in the Management of Gummy Smile Among Qat Chewers and Non-Qat Chewers: A Randomized Clinical Trial,” which was submitted to Department of Oral Medicine, Periodontology, Diagnosis, and Oral Radiology at Faculty of Dentistry – Sana’a University.<\/p>\n
The MA defense took place on Saturday, September 20, 2025 corresponding to Rabi’ Al-Awwal 28, 1447 Hijri.<\/p>\n
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The MA Viva-voce Committee, which was formed based on a resolution issued by the Post-Graduate Studies and Scientific Research Council, consisted of the following members:<\/p>\n
– Assoc. Prof. Baleegh Abdulra’ouf Ahmed Al-Qadasi, External Examiner and Chair.<\/p>\n
– Assoc. Prof. Manal Mohammed Al-Hajri, Main Supervisor and Member.<\/p>\n
– Assist. Prof. Abeer Hasan Ahmed Sharafuddin, Internal Examiner and Member.<\/p>\n
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The thesis aimed to evaluate the effectiveness of Botulinum Toxin Type-A injection when compared to a placebo in correcting a gummy smile among individuals who engage in khat chewing and those who do not.<\/p>\n
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The thesis\u00a0 yielded several significant findings, including:<\/p>\n
– The thesis confirmed that Botulinum Toxin Type-A injection is an effective and non-surgical therapeutic intervention for the correction of a gummy smile.<\/p>\n
– Results showed that the habit of khat chewing has a negative impact on the continuity and duration of the gummy smile treatment’s efficacy using Botulinum Toxin Type-A.<\/p>\n
– A clear correlation was found between the number of daily Qat chewing hours and the accelerated breakdown of Botulinum Toxin Type-A, leading to a reduction in its duration of effect, particularly when chewing exceeds five hours per day.<\/p>\n
– The frequency of Qat chewing throughout the week was also shown to significantly influence the duration of the treatment’s effectiveness.<\/p>\n
– It was observed that the effect caused by khat chewing was more pronounced on the side of the mouth where the chewing is habitually practiced.<\/p>\n
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The researcher presented several key recommendations, notably:<\/p>\n
– The necessity for subsequent research with a larger sample size and a long-term follow-up period to fully confirm the results obtained to date.<\/p>\n
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The thesis was examined and recommended by the Viva-Voce Committee for acceptance and approval. The defense was attended by a number of academics, researchers, interested individuals, in addition to the candidate\u2019s colleagues and family members.<\/p>\n
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