Anatomical Study of the Lingual Nerve and Inferior Alveolar Nerve in the Pterygomandibular Space: Complications of the Inferior Alveolar Nerve Block

Abstract

The inferior alveolar nerve block (IANB) procedure delivers anesthetics to the pterygomandibular space through which the lingual nerve (LN) and inferior alveolar nerve (IAN) travel. Injury to the LN has been reported more often than injury to the IAN. However, the number of anatomical studies of LN injury is limited. We aimed to establish evidence by investigating LN and IAN anatomy at the level of the mandibular foramen (MF). Forty-four sides from 22 Caucasian cadaveric heads (16 fresh-frozen and six formalin-fixed cadavers) were used in this study. The LN and IAN were laterally dissected, and the diameter and the distance between the two nerves were measured at the level of the MF. The mean diameters of the LN and IAN were 2.57 mm and 2.53 mm in fresh-frozen specimens and 2.97 mm and 2.93 mm in formalin-fixed specimens, respectively. The mean diameters of the LN and IAN in all the specimens were 2.65 mm and 2.64 mm. The distance between the posterior edge of the LN and anterior edge of the IAN at the level of the MF ranged from 1.62 to 8.36 mm with a mean of 5.33 ± 1.88 mm. These findings could elucidate the risk of LN injury during the IANB procedure.

An anatomical study of the lingual nerve in the lower third molar area

“…However, Hölzle and Wolff [14] concluded that the influence of formalin fixation on the shape of the LN was minimal by comparing its shape between formalin fixed and fresh cadavers. By contrast, Iwanaga et al [16] reported that the mean diameter of the LN had a statistically significant difference between fresh-frozen and formalin-fixed cadavers. Despite some discrepancy between these studies, there is no doubt that the LN is a risk factor during oral surgery.…”

“…At the horizontal plane of needle placement, the mean diameter of the LN in formalin-fixed cadavers was 3.42±0.38 mm (range, 2.55–4.15) [15]. At the pterygomandibular space, the mean diameter of the LN was 2.57±0.44 mm in fresh frozen cadavers and 2.97±0.48 mm in formalin fixed cadavers [16]. There is a discrepancy in the mean diameter of the LN in the literature (Table 1).…”

Comprehensive review of lower third molar management: A guide for improved informed consent

“…Lingual nerve (LN) injury during wisdom tooth removal could result in loss of general sensation and taste of the anterior two‐thirds of the tongue. The LN runs anteromedial to the IAN at the level of the mandibular foramen, passes under the inferior border of the superior pharyngeal constrictor muscle, and finally enters the floor of the oral cavity (Iwanaga, Choi, et al, 2018; Iwanaga, Nakamura, et al, 2018; Kikuta, Iwanaga, Kusukawa, & Tubbs, 2019). The course of the LN in the retromolar area is medial to the lingual plate, with a distance of 2 and 3 mm from the lingual plate horizontally and lingual alveolar crest vertically, respectively (Behnia et al, 2000).…”

Inferior Alveolar Nerve Block by Injection Into the Pterygomandibular Space Using Guiding Devices: A Systematic Review

“…This is due the pain not only during treatment, but also during an anesthetic injection (Ushnitsky et al, 2018). According to Iwanaga et al, 2018 andBhat et al, 2020, the most common mandible local anesthesia method is the inferior alveolar nerve blockage (IANB) (Iwanaga et al, 2018), (Bhat et al, 2020). A study by Rajvanshi, 2016 and Howait and Basunbul, 2019 showed a high efficiency of this method -85% (Rajvanshi H., Ernest S., Hafsa Effendi H., Afridi S., Chhabra M., 2016), (Howait M., Basunbul, 2019).…”

“…et al, 2020). The injection point is located in the once center on the mucosa formed by the protrusion of the anterior inferior alveolar nerve branch edge (outside) and the medial part of the pterygoid muscle (inside) (Iwanaga et al, 2018). There are some intraoral landmarks described for IANB, which may vary depending on an inverted triangle of the individual' s anatomy.…”