The clinical records (Fig 1) revealed that the patient had symmetrical face, convex profile and incompetent lips at rest with hyperactive mentalis muscle
. Intraoral photographs showed class I dental malocclusion with upper and lower right first molars in crossbite, upper lateral incisors in crossbite, increased overbite (50%) and increased overjet (3-4 mm).
* Retraining Muscles during Orthodontic Treatment: Botox can be used to prevent relapse of orthodontic treatment in patients with stronger muscle activity such as that of mentalis muscle
. It can also reduce the intensity of the muscle after treatment and the muscle may be retrained to a more physiological movement.
Examination was significant for right-sided VIIth cranial nerve findings that included facial symmetry at rest, mild forehead weakness, incomplete eye closure, positive Bell phenomenon, moderate midface weakness with asymmetry of the nasolabial fold, mild weakness of the marginal mandibular nerve with a nearly symmetric smile, normal platysma movement, and synkinetic twitching of the mentalis muscle
. Findings on the remainder of the cranial nerve examination as well as on the neurologic and head and neck examinations were within normal limits and symmetric.
Electromyograph (EMG) results showed excessive twitching in her chin (mentalis muscle
) and limbs during REM sleep (see the ChinEMG, LegEMG2, LegEMG3 tracings in Figure 1) but no epileptic features.
The physical aspects of the lips, tongue, and mentalis muscle
at rest were observed, as well as the characteristics of breathing, chewing, swallowing, and tongue movements, using visual inspection and palpation by a speech pathologist (R.A.P).