1Assistant Professor, Department of Prosthodontics, School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran
2Assistant Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
4Assistant Professor, Health Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran
Background & Aims: Before the surgery of lower impacted third molars, it is essential to evaluate the relationship of the roots to mandibular canal using radiographies in order to avoid postoperative complications. The purpose of this study was to evaluate the reliability of panoramic radiographs in assessing this relationship. Methods: This was a prospective study. The study population consisted of 103 candidates for impacted lower third molar surgery. Before surgery, panoramic radiographs were taken and the relationship between mandibular canal and the root of impacted lower third molar was determined. Subsequently, a comparison was made between radiographic findings and postoperative complications 1 week after surgery (gold standard) and the compatibility between them was determined. Results: Based on panoramic findings, 36 (35%) patients had mandibular canal involvement. Moreover, complications after surgery were observed in 12 (11.7%) patients. Fisher's exact test showed that postoperative complications had a significant relationship with radiographic findings. In 70.9% of the patients, there was compatibility between radiographic findings and the results of the gold standard. Conclusion: Considering the limitations of this technique, this method is proposed as a primary technique for evaluating the involvement of the third molar and mandibular canal, and if the involvement is suspected, using advanced techniques such as computed tomography scan (CT-scan) is indicated.
Anderson M. Removal of asymptomatic third molars: indications, contraindications, risks and benefits. J Indiana Dent Assoc 1998; 77(1): 41-6.
Saglam AA, Tuzum MS. Clinical and radiologic investigation of the incidence, complications, and suitable removal times for fully impacted teeth in the Turkish population. Quintessence Int 2003; 34(1): 53-9.
Smith AC, Barry SE, Chiong AY, Hadzakis D, Kha SL, Mok SC, et al. Inferior alveolar nerve damage following removal of mandibular third molar teeth. A prospective study using panoramic radiography. Aust Dent J 1997; 42(3): 149-52.
Valmaseda-Castellon E, Berini-Aytes L, Gay-Escoda C. Inferior alveolar nerve damage after lower third molar surgical extraction: a prospective study of 1117 surgical extractions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001; 92(4): 377-83.
Monaco G, Montevecchi M, Bonetti GA, Gatto MR, Checchi L. Reliability of panoramic radiography in evaluating the topographic relationship between the mandibular canal and impacted third molars. J Am Dent Assoc 2004; 135(3): 312-8.
Pawelzik J, Cohnen M, Willers R, Becker J. A comparison of conventional panoramic radiographs with volumetric computed tomography images in the preoperative assessment of impacted mandibular third molars. J Oral Maxillofac Surg 2002; 60(9): 979-84.
Drage NA, Renton T. Inferior alveolar nerve injury related to mandibular third molar surgery: an unusual case presentation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002; 93(3): 358-61.
Mahasantipiya PM, Savage NW, Monsour PA, Wilson RJ. Narrowing of the inferior dental canal in relation to the lower third molars. Dentomaxillofac Radiol 2005; 34(3): 154-63.
Ohman A, Kivijarvi K, Blomback U, Flygare L. Pre-operative radiographic evaluation of lower third molars with computed tomography. Dentomaxillofac Radiol 2006; 35(1): 30-5.
Blaeser BF, August MA, Donoff RB, Kaban LB, Dodson TB. Panoramic radiographic risk factors for inferior alveolar nerve injury after third molar extraction. J Oral Maxillofac Surg 2003; 61(4): 417-21.
de Melo Albert DG, Gomes AC, do Egito Vasconcelos BC, de Oliveira e Silva ED, Holanda GZ. Comparison of orthopantomographs and conventional tomography images for assessing the relationship between impacted lower third molars and the mandibular canal. J Oral Maxillofac Surg 2006; 64(7): 1030-7.
Gomes AC, Vasconcelos BC, Silva ED, Caldas AF, Jr., Pita Neto IC. Sensitivity and specificity of pantomography to predict inferior alveolar nerve damage during extraction of impacted lower third molars. J Oral Maxillofac Surg 2008; 66(2): 256-9.
Nakagawa Y, Ishii H, Nomura Y, Watanabe NY, Hoshiba D, Kobayashi K, et al. Third molar position: reliability of panoramic radiography. J Oral Maxillofac Surg 2007; 65(7): 1303-8.
Jerjes W, El-Maaytah M, Swinson B, Upile T, Thompson G, Gittelmon S, et al. Inferior alveolar nerve injury and surgical difficulty prediction in third molar surgery: the role of dental panoramic tomography. J Clin Dent 2006; 17(5): 122-30.
Tantanapornkul W, Okouchi K, Fujiwara Y, Yamashiro M, Maruoka Y, Ohbayashi N, et al. A comparative study of cone-beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 103(2): 253-9.
Tetsch P, Wagner W. Operative extraction of wisdom teeth. London, UK: Wolfe Medical Publications; 1990. p. 158-69.
Cilasun U, Yildirim T, Guzeldemir E, Pektas ZO. Coronectomy in patients with high risk of inferior alveolar nerve injury diagnosed by computed tomography. J Oral Maxillofac Surg 2011; 69(6): 1557-61.
Juodzbalys G, Wang H, Sabalys G. Injury of the Inferior Alveolar Nerve during Implant Placement: a Literature Review. J Oral Maxillofac Res 2011; 2(1): e1.
Juodzbalys G, Wang HL, Sabalys G, Sidlauskas A, Galindo-Moreno P. Inferior alveolar nerve injury associated with implant surgery. Clin Oral Implants Res 2013; 24(2): 183-90.
Schultze-Mosgau S, Reich RH. Assessment of inferior alveolar and lingual nerve disturbances after dentoalveolar surgery, and of recovery of sensitivity. Int J Oral Maxillofac Surg 1993; 22(4): 214-7.
Miller C, Palenik CJ. Infection control and management of hazardous materials for the dental team. 2nd ed. St. Louis: Mosby; 1998. p. 9.
Venta I, Lindqvist C, Ylipaavalniemi P. Malpractice claims for permanent nerve injuries related to third molar removals. Acta Odontol Scand 1998; 56(4): 193-6.
Kaeppler G. Conventional cross-sectional tomographic evaluation of mandibular third molars. Quintessence Int 2000; 31(1): 49-56.
Tammisalo T, Happonen RP, Tammisalo EH. Stereographic assessment of mandibular canal in relation to the roots of impacted lower third molar using multiprojection narrow beam radiography. Int J Oral Maxillofac Surg 1992; 21(2): 85-9.
Wenzel A, Aagaard E, Sindet-Pedersen S. Evaluation of a new radiographic technique: diagnostic accuracy for mandibular third molars. Dentomaxillofac Radiol 1998; 27(5): 255-63.
Dharmar S. Locating the mandibular canal in panoramic radiographs. Int J Oral Maxillofac Implants 1997; 12(1): 113-7.
Diaz Torres MJ, Guisado Moya BF, Vega Del Barrio JM, Calatayud Sierra J, Carrillo Baracaldo JS. Factores clinicos Y radiologicos de "verdadera relacion" entre el nervio dentario y el tercer molar. Revista Española de Cirugía Oral y Maxilofacial 1990; 12(2): 103-9. [In Spanish].
Bell GW, Rodgers JM, Grime RJ, Edwards KL, Hahn MR, Dorman ML, et al. The accuracy of dental panoramic tomographs in determining the root morphology of mandibular third molar teeth before surgery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003; 95(1): 119-25.
Sedaghatfar M, August MA, Dodson TB. Panoramic radiographic findings as predictors of inferior alveolar nerve exposure following third molar extraction. J Oral Maxillofac Surg 2005; 63(1): 3-7.