## 4 Discussion
The localization of the fragment can be achieved using two- or three-dimensional image approaches such as image-guided navigation using computed tomography (CT); magnetic resonance angiography (MRI); ultrasound examination [39; 48; 68; 69; 70]. Since iron was removed from the iron alloy used to make dental needles to enhance its mechanical qualities, electromagnets can no longer be utilized to locate dental needles [65; 66; 71]. For pinpointing the needle position, two plain film radiographs--a panoramic or lateral cephalometric radiograph combined with a postero-anterior (PA) radiograph with 2-3 needle locations--may be useful. However, radiographs do not present the same level of accuracy as a CT scan [72]. Another proposed possibility is stereotactic imaging with two localizing needles. It has been recommended to employ intraoperative ultrasound imaging to locate foreign things in the neck, but sadly, its application in a tiny mouth cavity may be restricted [62]. For removing the foreign body, an intraoperative navigation system can also be used for an image-guided surgery as successfully shown by [PERSON] et al., [PERSON] et al. and [PERSON] et al. [50; 67; 73]. Two unusual cases of [PERSON] et al. and [PERSON] et al. show dental needles that migrated in the carotid space and were removed with coronal angiogram and CT [49; 52]. As described by these case reports, tenderness, dysphagia, discomfort, and trismus are among the symptoms that patients may mention, while some may be wholly asymptomatic [39; 49; 74]. Complications such as anesthesia are not described in the literature, and in the most of case series presented in this review, the fragment was successfully removed [39; 40; 43; 44; 45; 46; 47; 48; 49; 50; 51; 52; 53; 54; 53; 56; 74] (Table 1). By being diligent and knowledgeable about all the factors that enhance the likelihood of needle breakage, practitioners can lower the occurrence of needle breakage providing an injection only with the patient's complete agreement and involvement, considering that quick movements have been linked to needle breakage [26; 62; 75]. Risk for needle fracture increases in noncooperative patients, as in the case described by [PERSON] et al., where a sudden movement of a 6-year-old autistic patient occurred during the injection with a computer-controlled local anesthesia device [51]. The same occurred in the case of [PERSON] et al. during the treatment of a patient affected by KBG syndrome [68]. Multiple injections should not be performed using the same needle. The needles become blunter with usage, increasing the discomfort of each consecutive injection for the patient and necessitating greater force to puncture the tissue; the chance of the needle breaking rises with higher pressure [55; 62]. Smaller needles are believed by some clinicians to be more prone to breaking. Since most breaking happens with 30-gauge or smaller needles, some authors advise using at least a 27-gauge needle for all blocks [55; 62; 64; 65; 76]. Also to be noted is that most patients are unable to distinguish between a 27-gauge and 30-gauge needle [17; 77]. Any benefit from puncturing the tissue with a smaller needle is lost due to the fact that injection pressure is frequently more uncomfortable with a 30-gauge needle [17; 78]. The needle-hub junction is a needle's weakest point [72; 79]. In order to prevent being buried to the hub, a needle must be long enough [55]. A needle should never be put into the tissue past a bend or up to the hub since this creates an additional point of vulnerability to the needle and the vulnerable hub [17]. By following this guideline, it may be ensured that if a needle does break, it will be simple to remove because part of it will be poking out of the tissue. [PERSON] et al. recommend avoiding soft tissue palpation as it may cause migration of the needle if it disappears under the mucosa. In addition, the dentists should advise the patient the importance of avoiding mouth opening and closing maneuvers to minimize needle migration [80].