Indian Journal of Dental Research

: 2019  |  Volume : 30  |  Issue : 4  |  Page : 639--642

Transient diplopia: A loco regional complication of inferior alveolar nerve block

Emmanuel Dhiravia Sargunam1, Anuradha Ganesan2, Deepak Chandrasekaran1, Pearlcid A Siroraj3,  
1 Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, Sri Ramachandra University, Chennai, Tamil Nadu, India
2 Department of Oral Medicine and Radiology, Madha Dental College, Chennai, Tamil Nadu, India
3 Consultant, Oral and Maxillofacial Surgeon, Siroraj Hospital, Thoothukudi, Tamil Nadu, India

Correspondence Address:
Dr. Emmanuel Dhiravia Sargunam
Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, Sri Ramachandra University, Porur, Chennai - 600 116, Tamil Nadu


A 34-year-old female patient required surgical removal of lower left third molar under local anesthesia. Two percent lignocaine with 1:80000 adrenaline was used for administrating inferior alveolar nerve block at dental clinic. Twenty five minutes after the surgical removal, patient developed diplopia on the left eye. This transient diplopia could be due to retro flow of local anesthetic agent through the inferior alveolar artery and indirectly to the ophthalmic artery paralyzing the lateral rectus muscle. Patient recovered after 60 minutes. This article discusses the possible etiologies of diplopia, the mechanism behind this ophthalmic complication, and the review of various reported literature.

How to cite this article:
Sargunam ED, Ganesan A, Chandrasekaran D, Siroraj PA. Transient diplopia: A loco regional complication of inferior alveolar nerve block.Indian J Dent Res 2019;30:639-642

How to cite this URL:
Sargunam ED, Ganesan A, Chandrasekaran D, Siroraj PA. Transient diplopia: A loco regional complication of inferior alveolar nerve block. Indian J Dent Res [serial online] 2019 [cited 2020 Nov 27 ];30:639-642
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Inferior alveolar nerve block is one of the most frequent and most useful injection technique for anesthetizing various surgical interventions in mandible.[1] Various injection techniques to block the inferior alveolar nerve are direct or indirect inferior alveolar technique, Gow – Gates technique, and Vazirani – Akinosi technique.[2] Direct injection technique is the most frequently used technique for anesthetizing the inferior alveolar nerve.[3],[4] This injection technique has a few complications like needle breakage, hematoma, transient facial nerve paralysis, lip biting, etc.[5]

Abducent nerve palsy can be multifactorial including trauma, infection, and rarely iatrogenic. Abducent nerve palsy following dental nerve blocks was first reported by Goodside and Weigneist in 1946.[6]

 Case Report

A 34-year-old female patient visited the dental clinic with the complaint of pain in the lower left posterior tooth region. A detailed case history was taken and systemic illness was ruled out. Intraoral examination revealed a carious tooth, which was tender on percussion in relation to 38 and it was found to be partially impacted. After a thorough clinical examination, a diagnosis of chronic irreversible pulpitis in left lower third molar region was made, intraoral periapical radiograph revealed an irregular coronal radiolucency involving pulp in relation to 38 and also the tooth was horizontally impacted [Figure 1]. Treatment was planned for a surgical removal under local anesthesia by an oral and maxillofacial surgeon. On the day of the surgery, 2% lignocaine with 1:80000 adrenaline was used to give an inferior alveolar nerve block (IANB) with a 2-ml syringe with 24-gauge needle. The direct technique was followed and after contacting the bone, aspiration was performed and 2 ml of local anesthetic (LA) solution was deposited.{Figure 1}

During subjective evaluation of anesthesia, five minutes following the IANB, the patient reported a feeling of numbness over the left malar region and left half of the tongue with no evidence of blanching. After eight minutes, the patient had complete anesthesia of the left inferior alveolar, lingual nerves, and long-buccal nerve. Buccal and distal bone guttering was done and the tooth 38 was delivered out of the socket without any complications and the wound was irrigated and closed with 3-0 silk sutures.

About 25 minutes after surgical removal, the patient complained of watery eyes and an abnormal gaze. On further examination, the patient felt that she was feeling dizzy due to double vision in the left eye. On clinical examination, the extra ocular movement was restricted with a left lateral gaze on the left eye [Figure 2].{Figure 2}

A temporary paralysis of the left lateral rectus was suspected and the patient was reassured and the eye was covered with an eye pad to prevent dizziness due to double vision. The patient was reevaluated after 30 minutes and after 1 hour. The extra ocular movement was totally restored with normal vision. So, a diagnosis of transient diplopia following IANB was confirmed and no further treatment was necessary. Patient was recalled after a week for suture removal and was normal.


Local complications of LA agents include burning sensation during injection, breakage of needles, soft tissue ulcers, trismus, prolonged anesthesia, and anesthesia of adjacent nerves.[5],[7]

Inadvertent anesthesia of adjacent nerves can result in either sensory loss as in infraorbital, mental nerves, or can have motor paralysis when it involves the facial nerve. Ocular complications like amurosis, paralysis of extra ocular muscles, and loss of accommodation have been reported.[8] [Table 1] lists the various possible etiologies for diplopia. Incidence of these ocular complications are more common in LA techniques that has been used for maxillary anesthesia and can be attributed to direct diffusion of the LA agents due to close proximity of the nerves of the orbit to the area of injection as in infiltration of posterior teeth or posterior superior alveolar nerve block.[8]{Table 1}

Ocular complications from IANB are seen more in females in the ratio of 4:1 (female: male). The average age of the affected patients with ocular complications was 34.2 years with a range of 4–73 years.[9] Following anesthesia, the time duration of onset of ocular complication was 8 ± 10 minutes and resolve without any sequelae within five hours.[10] Almost all of the complications were temporary, with an average recovery time of 68 minutes.[9] The most commonly suggested mechanism is the deposition of some of the drug under pressure into the inferior alveolar artery, which is explained in the flow chart [Flow chart 1]. This possible retrograde flow or diffusion of the anesthetic agent will most commonly affect III, IV, VI cranial nerves and can cause ophthalmoplegia and blanching of the malar region; however, blanching was not present in our patient.[10][INLINE:1]

The repeated occurrence of complications in some cases suggests a possibility of an anatomical anomaly or a vascular malformation, which can lead to the retrograde flow phenomenon.[9],[10] Other possible reasons include those based on spread by direct extension via venous, lymphatic, or neural routes. Diplopia, if due to LA, is a transient phenomenon. The patient is explained and reassured and the eye protected with a pad till the patient's symptoms are relieved. The patient is to be escorted home by a responsible adult. [Table 2] shows the occurrence of such ophthalmic complications following inferior alveolar nerve block. An important consideration is if the ocular complication lasts more than 6 hours, an ophthalmologist opinion is sought as the complication could lead to permanent damage.{Table 2}

Courtesy: Aguado-Gil JM et al. Occular complications following dental local anesthesia. Med Oral Patol Oral Cir Bucal. 2011 Aug 1;16 (5): e688-93.


The consequence of dental LA causing diplopia, though rare, should be taken into consideration and patient should be well informed about the complication that can arise due to IANB. Since the effect of ocular complication due to an IANB is more through the retrograde flow and not direct extension of the drug, and thus, it is a systemic complication of the LA agent, which every dental surgeon has to be aware of.


Informed consent has been obtained.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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