Some patients might asked you this question before: “I don’t like my gingival display on smiling and I don’t want orthodontic treatment nor jaw surgery, what are my options?”
Gingival display on smiling (GDS) that exceeds 4mm considered unattractive especially among males (Kokich 1999).
The aetiology of increased GDS are multifactorial including but not limited to: short upper lip, short clinical crowns, dentoalveolar extrusion, vertical maxillary excess, hypermobile upper lip, passive eruption and combination of the above (Robbins 1999).
Several options, depending of the aetiologies, have been suggested including but not limited to LeFort I impaction, crown lengthening, V-Y closure, anterior teeth intrusion (Sahoo 2012) as well as Botulinum toxin (Botox) (Polo 2005).
Botox acts on the muscles that lift and elevate the upper lip during smile which are mainly the levator labii superioris alaeque nasi (LLSAN), levator labii superioris, zygomaticus minor, zygomaticus major, lower lip muscles and lower portion of the orbicularis oris (OO) muscle.
We do not know whether injecting Botox in the LLSAN is more effective than injecting OO muscle.
AJODO published a prospective controlled study in their September 2020 issue which answered this question. The study was undertaken by a Turkish team led by Dr Cengiz.
Their main findings were: •Botox is effective palliative temporarily option in managing increased GDS. • Injecting Botox in LLSAN muscle is more effective than injecting it into the OO muscle (mild non-significant difference, almost 0.5mm). • The maximum effect of Botox becomes visible on 15th day and last for at least 6 months with high patients satisfaction.
However, it should be noted that it is difficult to limit the diffusion of the Botox to one area which considered as one of the uncontrolled weaknesses of the study.
What do you think?
Link to the paper