Visualization of Inferior Alveolar and Lingual Nerve Pathology by 3D Double-Echo Steady-State MRI: Two Case Reports with Literature Review

Abstract

Injury to the peripheral branches of the trigeminal nerve, particularly the lingual nerve (LN) and the inferior alveolar nerve (IAN), is a rare but serious complication that can occur during oral and maxillofacial surgery. Mandibular third molar surgery, one of the most common surgical procedures in dentistry, is most often associated with such a nerve injury. Proper preoperative radiologic assessment is hence key to avoiding neurosensory dysfunction. In addition to the well-established conventional X-ray-based imaging modalities, such as panoramic radiography and cone-beam computed tomography, radiation-free magnetic resonance imaging (MRI) with the recently introduced black-bone MRI sequences offers the possibility to simultaneously visualize osseous structures and neural tissue in the oral cavity with high spatial resolution and excellent soft-tissue contrast. Fortunately, most LN and IAN injuries recover spontaneously within six months. However, permanent damage may cause significant loss of quality of life for affected patients. Therefore, therapy should be initiated early in indicated cases, despite the inconsistency in the literature regarding the therapeutic time window. In this report, we present the visualization of two cases of nerve pathology using 3D double-echo steady-state MRI and evaluate evidence-based decision-making for iatrogenic nerve injury regarding a wait-and-see strategy, conservative drug treatment, or surgical re-intervention.

The complete anatomy of the lingual nerve: A meta‐analysis with implications for oral and maxillofacial surgery

“…Most of the time, the damaged nerve recovers spontaneously within 3-6 months (Al-Haj Husain et al, 2022;Chossegros et al, 2002).…”

“…Usually, they manifest with lack or alteration of sensation and taste, neuropathic pain from two‐thirds of the anterior tongue, problems with proprioception being revealed by inadvertent tongue biting, decreased salivation, and problems with speaking (Atkins & Kyriakidou, 2021; Nakanishi et al, 2019; Wang et al, 2019). Most of the time, the damaged nerve recovers spontaneously within 3–6 months (Al‐Haj Husain et al, 2022; Chossegros et al, 2002). However, if there is no improvement after this time, it may suggest that the damage will remain permanent.…”

Dental MRI of Oral Soft-Tissue Tumors—Optimized Use of Black Bone MRI Sequences and a 15-Channel Mandibular Coil

“…The use of higher field strengths of 3 Tesla and coils designed explicitly for dental imaging, such as radiofrequency coils [ 23 ], wireless intraoral coils [ 24 ], or mandibular coils [ 25 ], enabled excellent image quality with a high spatial resolution of the alveolar ridge and teeth with the surrounding soft-tissues [ 31 ]. Refinement of the MR sequences using ultrashort echo times was successfully implemented in various dental tasks [ 19 , 21 , 30 , 32 ]. Recently, the implementation of black bone MRI sequences with the combined use of mandibular coils has enabled improved characterization and staging of benign and malignant changes of soft and hard tissues, such as accurate depth extension of clinically suspicious lesions and providing information on other clinically unsuspected changes [ 25 ].…”

“…Dental MRI with the recently introduced black bone MRI sequences is another step towards simultaneous radiation-free imaging of soft and hard tissues in the oral and maxillofacial region [ 14 , 15 , 16 , 17 ]. It allows for better characterization and staging of benign and malignant oral changes, providing the clinician with surgically relevant information such as the exact depth extent of clinically suspicious lesions, or information on other, clinically unsuspected, changes [ 18 , 19 , 20 , 21 ]. To overcome the remaining limitations of MRI in the oral cavity, such as motion artifacts and artifacts due to field inhomogeneities caused by metallic reconstructions [ 22 ], indication-specific MRI protocols in combination with novel imaging tools, such as radiofrequency coils [ 23 ], wireless intraoral coils [ 24 ] or mandibular coils [ 25 ], are implemented in the image acquisition process to achieve better image quality with shorter acquisition times.…”

Bilateral supernumerary maxillary fourth and fifth molars: A clinical case report and literature review

“…17 18 19 Considering the efforts to minimize or even eliminate radiation exposure in biomedical imaging, several promising imaging modalities such as low-dose CBCT 20 or radiation-free magnetic resonance imaging have recently been implemented in dental imaging workflows, 21 providing high-quality diagnostic information with an improved risk-benefit ratio in oral and maxillofacial surgery. 22 23 24 25 In addition, CT or CBCT data can be combined with novel volume-rendering techniques such as cinematic rendering, which provides more photorealistic visualization with a better depiction of image findings than conventional reconstructions ( Fig. 4 ).…”