Electrical stimulation to the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle induces involuntary reflex contraction of the frontalis muscles.

The levator and frontalis muscles lack interior muscle spindles, despite consisting of slow-twitch fibres that involuntarily sustain eyelid-opening and eyebrow-raising against gravity. To compensate for this anatomical defect, this study hypothetically proposes that initial voluntary contraction of the levator fast-twitch muscle fibres stretches the mechanoreceptors in Müller's muscle and evokes proprioception, which continuously induces reflex contraction of slow-twitch fibres of the levator and frontalis muscles. This study sought to determine whether unilateral transcutaneous electrical stimulation to the trigeminal proprioceptive fibres that innervate the mechanoreceptors in Müller's muscle could induce electromyographic responses in the frontalis muscles, with monitoring responses in the orbicularis oculi muscles. The study population included 27 normal subjects and 23 subjects with aponeurotic blepharoptosis, who displayed persistently raised eyebrows on primary gaze and light eyelid closure. The stimulation induced a short-latency response in the ipsilateral frontalis muscle of all subjects and long-latency responses in the bilateral frontalis muscles of normal subjects. However, it did not induce long-latency responses in the bilateral frontalis muscles of subjects with aponeurotic blepharoptosis. The orbicularis oculi muscles showed R1 and/or R2 responses. The stimulation might reach not only the proprioceptive fibres, but also other sensory fibres related to the blink or corneal reflex. The experimental system can provoke a monosynaptic short-latency response in the ipsilateral frontalis muscle, probably through the mesencephalic trigeminal proprioceptive neuron and the frontalis motor neuron, and polysynaptic long-latency responses in the bilateral frontalis muscles through an unknown pathway. The latter neural circuit appeared to be engaged by the circumstances of aponeurotic blepharoptosis.

Full-thickness chest-wall resection followed by thorax reconstruction for recurrent malignant phyllodes tumor.

We present a case of a 39-year-old woman with a giant recurrent malignant phyllodes tumor accompanied with bleeding and infection. She underwent full-thickness chest-wall resection. Bony thorax reconstruction and stabilization was accomplished using a Composix mesh™, and soft tissue reconstruction was performed with a musculocutaneous flap of latissimus dorsi muscle. The patient had a good postoperative outcome, and the surgical treatment remarkably improved her quality of life. Because chemotherapy and radiation are not established for treating malignant phyllodes tumors, an aggressive surgical approach should be considered for patients with a locally advanced malignant phyllodes tumor.

Reflexive contraction of the levator palpebrae superioris muscle to involuntarily sustain the effective eyelid retraction through the transverse trigeminal proprioceptive nerve on the proximal Mueller's muscle: verification with evoked electromyography.

We have proposed a hypothetical mechanism to involuntarily sustain the effective eyelid retraction, which consists of not only voluntary but also reflexive contractions of the levator palpebrae superior muscle (LPSM). Voluntary contraction of fast-twitch fibres of the LPSM stretches the mechanoreceptors in Mueller's muscle to evoke trigeminal proprioception, which induces continuous reflexive contraction of slow-twitch fibres of the LPSM through the trigeminal proprioceptive nerve fibres innervating the mechanoreceptors in Mueller's muscle via the oculomotor neurons, as a tonic trigemino-oculomotor reflex. In the common skeletal mixed muscles, electrical stimulation of the proprioceptive nerve, which apparently connects the mechanoreceptors in muscle spindles to the motoneurons, induces the electromyographic response as the Hoffmann reflex. To verify the presence of the trigemino-oculomotor reflex, we confirmed whether intra-operative electrical simulation of the transverse trigeminal proprioceptive nerve on the proximal Mueller's muscle evokes an electromyographic response in the LPSM under general anaesthesia in 12 patients. An ipsilateral, phasic, short-latency response (latency: 2.8+/-0.3 ms) was induced in the ipsilateral LPSM in 10 of 12 subjects. As successful induction of the short-latency response in the ipsilateral LPSM corresponds to the Hoffmann reflex in the common skeletal mixed muscles, the present study is the first electromyographic verification of the presence of the monosynaptic trigemino-oculomotor reflex to induce reflexive contraction of the LPSM. The presence of the trigemino-oculomotor reflex may elucidate the unexplainable blepharoptosis due to surgery, trauma and tumour, all of which may damage the trigeminal proprioceptive nerve fibres to impair the trigemino-oculomotor reflex.

Use of image-guiding template for contouring surgery of midfacial fibrous dysplasia.

Simulation surgery using a 3-dimensional model is common in treatment of the craniofacial region. However, designing the reduction volume on the affected region and precise contouring according to a simulation model are still difficult. We developed a template composed of a thin clear dental plastic plate, which fits on the reduction model obtained from simulation surgery. We made several holes on the reduction model covered with the template and measured the depth of each hole without the template, which represents the thickness to be contoured at each point. This template was a mold of the reduction model and guided contouring of deformed bones intraoperatively. We applied the template to the affected region and marked the outline of the template and points of the holes. With the image designed with this template, we could contour the deformity of midfacial fibrous dysplasia symmetrically and easily.

Reconstruction of an inner layer defect of the upper eyelid with avulsion of the superior levator palpebrae muscle and orbital fat.

The authors report a successful reconstruction of the total upper eyelid in conjunction with the gliding surface of the extraocular muscles. A 21-year-old woman sustained an inner layer defect of her right upper eyelid together with avulsions of the superior levator palpebrae muscle and the superior orbital fat. Her right superior rectus muscle was exposed, and no orbital fat was seen in the space between the muscle and the orbital roof. To preserve eye movement, a gliding surface between the superior rectus muscle and the orbital roof had to be reconstructed. Total upper lid reconstruction was performed using a radial forearm flap with a hard palate mucosal graft. The gliding surface was reconstructed with an adipofascial flap obtained from the forearm. Despite lack of levator function, the patient could raise her eyelid approximately 5 mm by using only the superior rectus muscle without frontalis suspension.