Master’s Degree Awarded to Mr. Manal Ahmed Mohammed Abdullah from Faculty of Dentistry
Ms. 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.
The MA defense took place on Saturday, September 20, 2025 corresponding to Rabi’ Al-Awwal 28, 1447 Hijri.
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:
– Assoc. Prof. Baleegh Abdulra’ouf Ahmed Al-Qadasi, External Examiner and Chair.
– Assoc. Prof. Manal Mohammed Al-Hajri, Main Supervisor and Member.
– Assist. Prof. Abeer Hasan Ahmed Sharafuddin, Internal Examiner and Member.
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.
The thesis yielded several significant findings, including:
– The thesis confirmed that Botulinum Toxin Type-A injection is an effective and non-surgical therapeutic intervention for the correction of a gummy smile.
– 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.
– 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.
– The frequency of Qat chewing throughout the week was also shown to significantly influence the duration of the treatment’s effectiveness.
– 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.
The researcher presented several key recommendations, notably:
– 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.
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’s colleagues and family members.
