[Downloaded free from http://www.ijdr.in on Thursday, December 31, 2015, IP: 115.111.224.207] CASE REPORT Jaw ‑ winking phenomenon: Report of a case with review of literature Shobha Sundareswaran, Nipun CA, Vinay Kumar1 Department of Orthodontics, ABSTRACT Government Dental College (Affiliated to Kerala Jaw‑winking or the Marcus Gunn phenomenon (MGP), a congenital uncommon condition University of Health Sciences), characterized by involuntary elevation of a drooping upper eyelid concomitant with various Calicut, Kerala, 1Unit of Orthodontics, Oral Health movements of the mandible, is well‑documented in medical literature, but very little information Sciences Center, Post Graduate is available in dental literature. This is an interesting case report of a 17‑year‑old female with Institute of Medical Education MGP, who reported for orthodontic treatment of her proclined upper anterior teeth, severe lower and Research, Chandigarh, India crowding, and mandibular micrognathia. Review of the literature revealed only two reported cases of dental anomalies in conjunction with MGP. The patient also gave a positive family history of MGP with a maternal cousin having a similar problem. Dentists and other oral health professionals can play a significant role in detection and diagnosis of this rare condition and Received : 05‑01‑15 should take protective measures during dental and oral surgical procedures. Review completed : 09‑01‑15 Accepted : 14‑05‑15 Key words: Jaw winking, Marcus Gunn, ptosis The jaw‑winking phenomenon is a congenital clinical males[2,5] with the left eyelid being more frequently involved. entity characterized by involuntary elevation of a ptotic However, this has been refuted by Pratt et al., and Doucet upper eyelid concomitant with various movements of the and Crawford.[3,6] MGP is usually unilateral. Rarely, bilateral mandible. This was first described by Gunn in 1883[1] and is involvement has also been reported.[6] A rare case of bilateral also called Marcus Gunn phenomenon (MGP). This unilateral MGP in an 18‑year‑old male patient with asymmetric synkinetic reflex retraction of the upper eyelid occurs during bilateral ptosis and monocular elevation deficiency in mouth opening or lateral excursions of the mandible to the the right eye was recently reported.[7] Ophthalmologic contralateral side. Also called Pterygoid‑levator synkinesis, conditions accompanying the MGP have been extensively it is well‑documented in medical literature, but very little discussed in the literature. A high incidence of strabismus information is available in dental publications. and amblyopia is reported to be associated with MGP. Associated anisotropia, superior rectus muscle weakness, This condition is found in approximately 2–13% of all cases and double elevator palsy may also be seen. However, of congenital ptosis.[2,3] Recently, Carman et al.,[4] reported reports of dental abnormalities are not well‑documented. two cases of children who presented with ptosis and were Dental surgeons have every chance of being exposed to diagnosed with MGP. It is evident at birth and often, parents this condition during regular clinical practice. Hence, it is are the first to detect the jaw‑winking as their infants feed. certainly within the domain of the dental practitioner to Earlier studies have reported a greater predilection for establish a tentative diagnosis of MGP. Occurrence of cleft lip and palate as well as supernumerary incisors has been Address for correspondence: reported in cases of MGP.[5,8] Dr. Shobha Sundareswaran E‑mail: [email protected] CASE REPORT Videos available on: www.ijdr.in A 17‑year‑old female patient reported to the Department Access this article online of Orthodontics for the treatment of her severely proclined Quick Response Code: Website: upper anterior teeth. Growth and development were www.ijdr.in apparently normal. Medical history did not reveal any systemic disorder. No other family member was reported to have a similar malocclusion. DOI: Extraoral examination revealed a hyper leptoprosopic facial 10.4103/0970-9290.162895 form with mild facial asymmetry, increased lower anterior 320 Indian Journal of Dental Research, 26(3), 2015 [Downloaded free from http://www.ijdr.in on Thursday, December 31, 2015, IP: 115.111.224.207] Jaw ‑ winking phenomenon Sundareswaran, et al. face height, incompetent lips with excessive incisor display, a similar problem. As they lived in another state, we were convex profile, and steep mandibular plane. In rest position, unable to verify this. there was blepharoptosis of the left upper eyelid [Figure 1]. However, when the mouth was opened, the left upper Intraoral examination revealed a constricted maxillary arch eyelid retracted suddenly, revealing sclera above the with severely proclined upper anteriors, missing upper right limbus [Figure 2]. The same phenomenon occurred when lateral incisor, crowding of lower arch, and exaggerated curve the mandible was moved to the contralateral side [Figure 3]. of Spee. Molars were in Class II relationship with an excessive No retraction of the left upper eyelid was observed when overjet of 15 mm, overbite of 1.5 mm, crossbite of 14.15 and the mandible was moved to the ipsilateral side [Figure 4]. marked deviation of upper midline to right by 2.5 mm and The affected eyelid remained elevated while the mouth lower midline to left by 2 mm. Cephalometric analysis revealed was held open or mandible moved to the opposite side and a Class II skeletal base, with dimensionally small, retrognathic returned to its normal position only when the mouth was mandible, vertical growth pattern, and deficient chin button. closed (the video file attached to this article shows ptosis and retraction of left upper eyelid with various mandibular DISCUSSION movements – [Video File 1]). There was a full range of conjugate eye movements and visual acuity was 6/6 in The Marcus Gunn jaw‑winking syndrome is a rare problem both eyes. varying in severity from a mild disorder to a significant cosmetic disability. Her mother reported that the condition had been present since birth and there was neither improvement nor One of the characteristic signs of this phenomenon is worsening with age. She also reported that her nephew had blepharoptosis, which is present in the above case. There Figure 1: Ptosis of the left upper eyelid in rest position Figure 2: Retraction of the left upper eyelid during mouth opening Figure 3: Retraction of the left upper eyelid during movement of the Figure 4: Left upper eyelid remains ptotic during movement of the mandible to the contralateral side (Revelation of sclera above the limbus) mandible to the ipsilateral side Indian Journal of Dental Research, 26(3), 2015 321 [Downloaded free from http://www.ijdr.in on Thursday, December 31, 2015, IP: 115.111.224.207] Jaw ‑ winking phenomenon Sundareswaran, et al. are reports in the literature indicating a tendency for mandibular movements.[17] Simultaneous occurrence of improvement of the disorder with age. However, the patient MGP in one eye and inverted MGP in the other have also described here did not report any such improvement. been reported (“see‑saw Marcus Gunn syndrome”).[18,19] Although most cases of MGP are said to be congenital, Family history of myasthenia gravis with ptosis, congenital acquired forms of this condition are also known to exist. nasal sinus tract, cleft lip and palate, congenital ptosis, MGP is said to have developed after eye surgery, syphilis, and convergent strabismus in a case of MGP has been trauma, pontine tumors, etc.[9,10] The congenital forms of reported earlier.[11] This may be a variation of the MGP trait. this condition will usually be present throughout life unless Disabling of the involved levator muscle and unilateral or corrective surgery is done. bilateral frontalis suspension are stated to be effective in the treatment of MGP. Eyelash ptosis and loss of eyelid crease Various theories have been proposed regarding the etiology were the most commonly reported complications, each of this disorder. Dual innervation of the levator palpebrae occurring in 10% of the patients.[20] superioris muscle from both the occulomotor nucleus and external pterygoid portion of the trigeminal nucleus[1] is one CLINICAL IMPLICATIONS FOR THE DENTAL such theory. Normally, levator muscle is innervated by the SURGEON occulomotor nucleus. Any type of dental treatment for these patients would The second theory on innervation states that there is a reflex require the exercising of utmost care to prevent the potential arc arising from the motor division of the trigeminal nerve risk of ocular damage, because mouth opening will lead to to the gasserian ganglion, propagated along intraneuronal simultaneous lid retraction. connections to the occulomotor nucleus and finally to [2] levator muscle. This theory is based on embryologic Protective eye shield wear is mandatory during routine evidence as the motor nucleus of the two cranial nerves dental procedures like cavity preparation, use of prophylactic [11] appear at the same time and are located in close proximity. paste, amalgam removal, etc. Special care and precaution Kinematic and MRI findings point to a brainstem structural must be exercised during orthodontic procedures using abnormality in familial MGP patients thus supporting the sharp instruments, while cutting wires, using fine ligatures, hypothesis of a neural misdirection of trigeminal motor brackets, pins, and halogen/LED curing light as protective [12] axons to the elevator palpebralis muscle. reflex closure of the eyelid is not possible for these patients. Furthermore, short appointments are preferable to reduce The third phylogenetic theory of atavism relates this the problems due to prolonged exposure to the halogen/LED phenomenon to lower animals and fish, where retraction of lights of the dental unit. the upper eyelid is associated with opening of the mouth. In general, these related movements become inhibited through CONCLUSION an evolutionary process.[11] Patients with MGP may be more vulnerable to eye injuries Systemic anomalies in association with MGP are rare.