{"id":1058,"date":"2015-06-18T06:56:56","date_gmt":"2015-06-18T06:56:56","guid":{"rendered":"http:\/\/biomedpharmajournal.org\/?p=1058"},"modified":"2020-04-25T02:38:48","modified_gmt":"2020-04-25T02:38:48","slug":"a-novel-approach-for-inferior-alveolar-nerve-ian-injury-identification-using-panoramic-radiographic-image","status":"publish","type":"post","link":"https:\/\/biomedpharmajournal.org\/staging\/vol8no1\/a-novel-approach-for-inferior-alveolar-nerve-ian-injury-identification-using-panoramic-radiographic-image\/","title":{"rendered":"A Novel Approach for Inferior Alveolar Nerve (IAN) Injury Identification Using Panoramic Radiographic Image"},"content":{"rendered":"

Introduction<\/strong><\/p>\n

Medical demands have driven the fast growth of medical image processing methods, which in turn have significantly promoted the level of the therapeutic process. They have become essential tools for diagnosis, treatment planning, and verification of administered treatment. Therefore, the technology of medical image processing has long attracted attention of relevant experts. \u00a0\u00a0 Nowadays, panoramic radiography is regularly used in dental practice, because it provides visibility of anatomical structures in pathological changes of the teeth, jaws and temporo-mandibular joints. Inferior alveolar nerve injury is one of the most severe complications in implant dentistry. This nerve injury can occur during local anesthesia, implant osteotomy or implant placement.<\/p>\n

Inferior Alveolar Nerve (IAN) <\/strong><\/p>\n

Inferior Alveolar Nerve (IAN) is the core sensory nerve that provides sensory innervations to the lower teeth as well as the lower lip and some skin on the lower face. The IAN traverses the mandibular bone (lower jawbone) through a mandibular canal, or the inferior alveolar canal (IAC). As the IAN is to be found inside the IAC, it can be ultimately evaluated throughout radiographic evaluation of the IAC in Figure.1.<\/p>\n

The IAC has a hollow tubular shape but is difficult to detect because its structure is not well defined and because it is frequently connected to nearby hollow spaces. Hence, accurate and automatic identification of the IAN canal is a challenging issue. Thus, the majority of earlier researches on the IAN canal detection [1] require users\u2019 intervention such as a manual trace or the uses of the initial points of the IAN canal.<\/p>\n

Inferior Alveolar Nerve injury (IANI) is the main problematical significance of dental surgical procedures and has major medico-legal implications [2]. These injuries results in partial or complete loss of sensation from the ipsilateral skin of the lower lip and chin, the buccal oral mucosa in this region, and the lower teeth. Causes of IANI include placement of dental implants, local anesthetic injections, third molar surgery, endodontic, trauma and orthognathic surgery.<\/p>\n

Lingual Nerve (LN) and IAN injuries are considered to be suitable to mechanical irritations from surgical interference and are inclined by numerous demographic, anatomic and treatment-related factors [3]. Most patients who extend an IAN injury gradually get back to normal sensation over the course of a few weeks or months, depending upon the severity of the injury. However, after the most severe injuries, where part or all of the nerve has been sectioned and the site may have been compromised by infection, recovery will be incomplete. Fig. 2 shows some of the OPG images with and without visibility of IAC.<\/p>\n\n\n\n
\"Fig.1.<\/td>\nFigure 1: Anatomy of IAN<\/strong><\/p>\n

Click here to View figure<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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\"Fig.<\/td>\nFigure 2: Sample OPG Images<\/strong><\/p>\n

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Panoramic radiograph<\/strong><\/p>\n

Panoramic radiograph is one of the types of dental radiograph. It is also called as orthopantomography (OPG) Image. Nevertheless, the fact that panoramic radiograph imaging is extensively used for assessment of the jaws, justifies the interest in determining the visibility of anatomical structures on these films. Number of radiologic technique had been applied to demonstrate different anatomical structures, the Oblique lateral demonstrates large areas of mandible, is the projection that produces an image of both jaws and their respective dentitions on a single extra oral film [4]. During the treatment planning, we can use OPG as a primary resource because it allows measurement of the two-dimensional association among the tooth and the IAC.<\/p>\n

Panoramic equipment is based upon simultaneous rotation movement of the tube head and film cassette carriage in equal but opposite directions around the patient\u2019s head which remains stationary. The patients were in erect position and were placed accurately within the machines using the various head positioning devices and light beam marker positioning guides. Patients were instructed not to move throughout the exposure [5]. Radiological prediction of injury to the IAN depends on the relationship of the root to the canal discussed in table 1[6].<\/p>\n

Rood and Shebab[7] has defined seven vital recommendations that can be taken from OPG images in table 1. There have been several OPG assessement researches which maintain the effectiveness of these seven findings [8, 9]. It must be renowned, even if, that the statistical results from these analysis had various levels of specificity and sensitivity in table 2. Nowadays, research decided that high-risk signs were known by OPG in particular; darkening of the root is closely related to cortical bone loss and\/or grooving of the root [9].<\/p>\n

Table 1: Specificity and sensitivity for predicting IAN injury with third molar surgery in OPG image [8, 9]<\/strong><\/p>\n\n\n\n\n\n\n
OPG Imaging <\/strong>p<\/strong>rocedure<\/strong><\/td>\nSensitivity (%)<\/strong><\/td>\nSpecificity (%)<\/strong><\/td>\n<\/tr>\n
Darkening of the root<\/td>\n32-71<\/td>\n73-96<\/td>\n<\/tr>\n
Interruption of the canal<\/td>\n22-80<\/td>\n47-97<\/td>\n<\/tr>\n
Diversion of the canal<\/td>\n3-50<\/td>\n82-100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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\"Fig.<\/td>\nFigure 3: Proposed Methodology<\/strong><\/p>\n

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A general framework for this fully segmentation system in accordance with the block diagram shown in Fig. 3 is as follows:<\/p>\n