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Age  and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography
Age  and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography
Age  and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography
Age  and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography
Age  and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography
Age  and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography
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Age and gender-related differences in the position of the inferior alveolar nerve by using cone beam computed tomography

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  • 1. Clinical ResearchAge- and Gender-related Differences in the Position of theInferior Alveolar Nerve by Using Cone Beam ComputedTomographyJay D. Simonton, DDS,* Bruno Azevedo, DDS, MS,† William G. Schindler, DDS, MS,*and Kenneth M. Hargreaves, DDS, PhD*AbstractIntroduction: Surgical endodontic procedures requireprecise knowledge of anatomic structures that mightbe traumatized. The aim of this study was to evaluate T he most frequently treated tooth for endodontic procedures is the mandibular first molar (1, 2). This might be due to the complexity of the root system in the mandib- ular first molar and possibly because it is the most restored tooth (3). Even though therewhether differences in patient gender or age are predic- is a high success rate with nonsurgical root canal treatment, root-end surgery might betive of differences in the relative location of the inferior required in up to 26% of cases presenting with apical periodontitis (4). As new tech-alveolar nerve (IAN) compared with the roots of the nology increasingly becomes more available to endodontists, such as ultrasonics andmandibular first molar. Methods: We searched a data- microscopes, the success rate of root-end surgeries has increased dramaticallybase of 23,000 small-volume cone beam computed (5–9). However, the proximity of the inferior alveolar nerve (IAN) to root structurestomography scans and evaluated the first 200 patients is a critical anatomic issue for surgery on mandibular molars, even with advanced tech-that met the following inclusion criteria: (1) age nology. It has been reported that dentoalveolar and root-end surgery can cause persis-between 30–69 years; (2) known gender (n = 25 males tent neurosensory disturbances including paresthesia, dysesthesia, or anesthesia of theand 25 females for each 10-year age bin); and (3) scans IAN (10–14). In addition, it is possible that some practitioners have minimized surgerycontaining the mandibular first molar and IAN. Exclusion on mandibular molars because of the proximity of the IAN (15, 16). There have beencriteria consisted of any pathosis that might alter the a few recent studies showing changes in the craniofacial complex, including the dentalposition of the IAN. Anatomic measurements were arches, occurring throughout life and even into the sixth decade (17, 18), with differ-made by 2 observers with mutual agreement of any ences among men and women (19). A thorough knowledge of the relative 3-dimen-discordant measures. Fourteen measurements (in milli- sional (3-D) position of the IAN to the root apices of the mandibular molars as itmeters) were taken at the level of the IAN and mesial relates to gender and age is imperative for this procedure to be carried out with minimaland distal root apices. Data were analyzed by 2-way risk to the patient.(age, sex) analysis of variance with Bonferroni post Cone beam computed tomography (CBCT) has made considerable improvementshoc test at P <.05. Results: Regardless of age, females in dental imaging and has proved to be extremely accurate (20–23). Klinge et al (24)had significantly shorter vertical distances from the IAN demonstrated that CT is better than other radiographic techniques for locating theto the mesial (P < .01) and distal apices (P < .01) and mandibular canal before surgeries. CBCT allows for 3-D reconstruction of the dento-shorter horizontal distances for total width of mandib- maxillofacial complex in a true 1:1 anatomic representation. In other conventionalular bone at the mesial (P < .01) and distal apices radiographic techniques, there are distortion and magnification of the anatomic struc-(P < .01). In addition, the overall width of the mandib- tures ranging from 3.4% for periapical radiographs to more than 14% for panoramicular bone decreased in both genders from the 3rd–6th radiographs (25). In addition, the conventional methods for evaluating the location ofdecade of life (P < .01). Conclusions: Collectively, the roots and IAN only allow for a 2-D position and do not give information in the buc-these data indicate that both gender and age are predic- colingual dimension in the mandible (26, 27).tive of surgical endodontic anatomic relationships and Before CBCT, only cadaver studies could be used to obtain similar informationshould be considered in presurgical planning. (J Endod (28). However, these studies did not allow for sufficient sample sizes to give a normal2009;35:944–949) distribution of the data (29). Moreover, cadaver studies are usually inadequate to provide sufficient numbers of specimens to calculate gender and age differencesKey Words (20, 28). As the use of CBCT becomes more commonplace, information can beAge differences, cone beam, endodontic surgery, gender obtained and studied in sufficient quantity that was previously unavailable by otherdifferences, inferior alveolar nerve, mandibular canal, methods. Many such emerging studies provide a new source of reliable anatomic infor-paresthesia mation (27, 30–32). From the *Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas; and †Department of Oral Maxillofacial Radi-ology, Western University College of Dental Medicine at Pomona, Pomona, California. Address requests for reprints to Dr William G. Schindler, Department of Endodontics, UTHSCSA School of Dentistry, 7703 Floyd Curl Dr, Mail Code 7892, San Antonio,TX 78229-3900. E-mail address: Schindler@uthscsa.edu.0099-2399/$0 - see front matter Copyright ª 2009 American Association of Endodontists.doi:10.1016/j.joen.2009.04.032944 Simonton et al. JOE — Volume 35, Number 7, July 2009
  • 2. Clinical ResearchFigure 1. (A) Examples of the 7 different measurements taken for both the mesial and distal roots of the mandibular first molar. (B) Showing the coronal view withall 7 measurements on the mesial root, similar measurements were also taken for the distal root. (C) Showing the axial view measurements of the mesial root at thelevel 3 mm coronal to the root apex, measurements were also taken for the distal root and again at the level of the IAN for both the mesial and distal roots. (D)Showing the sagittal view measurements of the distance of the mesial root apex to the IAN, a measurement was taken again for the distal root to the IAN. To our knowledge, no published study has used CBCT in sufficient isotropic voxel size of 0.125 mm3. The scans were viewed and measuredquantities to evaluate whether gender or age is associated with alter- by using the Morita I-viewer software supplied by the manufacturer andations in the relative location of the IAN to the roots of the mandibular viewed on a VGA monitor (Model ET7V76 M; Exorvision, Seattle,first molar. The purposes of this study were to (1) provide normative WA) with the following specifications: screen size19-inch diagonal,information that would reduce the risk for damage to the IAN during 1280 Â 1024 pixel screen resolution, pixel dot size 0.264 mm, andendodontic surgical procedures and (2) evaluate whether patient contrast ratio 500:1. The volumes were displayed with a 0.125-mmdifferences in gender or age are predictive of differences in the relative thickness and 1-mm intervals. All volumes were standardized in thelocation of the IAN to the roots of the mandibular first molar. same orientation, with the sagittal plane parallel to the inferior alveolar canal and the coronal plane perpendicular to the inferior alveolar canal. A database of more than 23,000 CBCT scans was searched, and the Materials and Methods first 200 patients that conformed to the following inclusion and exclu- High-resolution small-volume CBCT scans were obtained from the sion criteria were selected for the study: (1) known age between 30–69radiology database at the University of Texas Health Science Center at years; (2) known gender (n = 25 males and 25 females were collectedSan Antonio and a private practice in Brasilia D.C., Brazil. The images for each 10-year age bin); and (3) CBCT scans contained the mandib-were taken between January 1, 2006 and November 1, 2007. All scans at ular first molar and IAN. Exclusion criteria consisted of any pathosis thatboth sites were acquired by using the Accuitomo 3DX Morita CBCT might alter the relationship of the mandibular first molar and the IAN.(J. Morita Corp, Kyoto Japan). The image acquisition protocol consisted Anatomic measurements were made by 2 observers, with mutual agree-of 360-degree rotation of the C-arm armed with an x-ray tube and a flat ment of any discordant measures. Fourteen measurements (in millime-panel detector. A full scan acquires 540 base images that are loaded into ters) were taken at the level of the IAN and mesial and distal root apicesthe native reconstruction software i-dixel (J. Morita Corp). The volume (Fig. 1). These measurements included (1) the distance from the buccalwas displayed in all 3 planes, XYZ (axial, coronal, and sagittal). The cortical plate to the most buccal aspect of the root at a level 3 mmresolution of this scanner is >2 line pairs per millimeter and has an coronal to the apex, (2) the distance from the most lingual aspect ofJOE — Volume 35, Number 7, July 2009 Age- and Gender-related Differences in the Position of the IAN 945
  • 3. Clinical ResearchTABLE 1. Measured Distance of the IAN to the Root Apices of the Mandibular 11.3 Æ 1.7 mm for females; the 3-mm distance was selected as a resultFirst Molar (in mm) of its common location for root-end resection. This difference was Males (n = 100) Females (n = 100) statistically significant (P < .01). The range was 8.6–20.7 mm for males and 7.4–15.2 mm for females. In addition to gender differences, age- Age Mesial Distal Mesial Distal related differences were also found to be significant for the overall hori- 30–39 5.1† 4.8 4.8 4.6 zontal mandibular bone width at the mesial and distal roots of the first 40–49 6.5 5.9 5.6 5.3 molar regardless of gender. Generally, the overall horizontal bone width 50–59 7.0† 6.6 5.3 4.9 decreased in both genders from the 3rd–6th decade of life (P < .01). 60–69 6.3 6.2 4.1 4.0 Secondary findings of this study were also observed. Eight patients Total 6.2 Æ 2.6* 5.8 Æ 2.5** 4.9 Æ 2.2* 4.7 Æ 2.2** (4%) had a radix entomolaris, and 2 patients (1%) had a bifurcatedMeasurements correspond to landmark 7 in Fig. 1. IAN. When this occurred, the closest root or IAN to the cortical plates*P < .01 comparing males and females for the mesial root. was used for measurements #1–6, and the closest portion of the root**P < .01 comparing males and females for the distal root. to the closest IAN was used for measurement #7 (see Fig. 1 for land-† P < .05 comparing age for the mesial root only. marks). Twelve patients (6%) were found to have accessory mental foramina. No portion of the accessory mental foramen was considered for analysis in this study.the root to the lingual cortical plate 3 mm coronal to the apex, (3) thetotal buccolingual dimension of the mandibular bone at a level 3 mmcoronal to the apex, (4) the distance from the buccal plate to the Discussionmost buccal aspect of the inferior alveolar canal at the point perpendic- The IAN is a critical anatomic structure whose location can oftenular to the long axis of the root, (5) the distance from the most lingual influence the surgical planning of root-end surgery on mandibularaspect of the mandibular canal to the lingual cortical plate, (6) the total molars. Even though the success rate of root-end surgery has beenbuccolingual width of the mandible at the level of the inferior alveolar reported recently at levels $ 90% (9, 15), dentists are increasinglycanal, and (7) the distance from the closest aspect of the root to closest electing to place artificial prosthesis such as implants instead of refer-portion of the inferior alveolar canal. Measuring the thickness of bone at ring for root-end surgery on mandibular molars to avoid potentiala level 3 mm coronal to the anatomic apex minimized variation in root complications. Therefore, it is critical for endodontists to understandanatomy in the apical portion of the root and is the point to which many the anatomy of the IAN and its relationship to the roots of mandibularroots are resected. All measurements were verified by using coronal, molars. Awareness of the relationships between the mean averageaxial, and sagittal views, and the measurement landmarks are defined distance of the mandibular roots to the IAN and with variations amongin Fig. 1. age and gender is essential to minimize risks. To our knowledge, there Scans were randomly selected as to whether the right side or the have been no studies with this new technology, CBCT, in sufficient pop-left side was used from a single patient. This allowed for statistical inde- ulation of patients to determine the position of the IAN as it relates to thependence of observations, because analysis that included both sides of roots of mandibular molars and the buccal and lingual cortical platesthe mandible would produce correlated observations confounding the and compare the norm between age groups and gender to determinestatistical tests used in this study. Data were analyzed by 2-way (age, sex) whether a significant difference exists.analysis of variance with Bonferroni post hoc test at P <.05 to determine This study found that the distance between the IAN and the rootthe effect of age and gender on the position of the IAN within the bone apices of mandibular first molars is significantly shorter in femalesand with respect to the apex of the mesial and distal roots of the mandib- than in males. In addition, age-related differences were also found toular first molar. be statistically significant for the distance of the IAN to the mesial root apex. It appeared that the distance generally increased to a certain Results age group and then began to decrease again. The peak increase in the Details of the results are presented in Tables 1 and 2 and Fig. 2. distance of the IAN to the root apices was in the 50-year age group inThere are 3 major findings in this study that have a direct impact on treat- males and the 40-year age group in females. After this peak, we foundment planning for surgical endodontic procedures involving the mandib- a decrease in the distance of the apices to the IAN. This finding could beular first molar: (1) regardless of age, females had significantly shorter explained by continued mandibular growth up to age 40 in females andvertical distances from the IAN to the mesial and distal apices; (2) females age 50 in males and then a decrease as a result of hormonal changes orhad shorter horizontal distances for total width of mandibular bone at an overall decrease in bone mass in older persons. Another possibilitymesial and distal apices; and (3) the overall width of the mandibular might be due to continued tooth eruption throughout life as a result ofbone decreased in both genders from the 3rd–6th decade of life. attrition and wear. It is noteworthy that several studies have now shown For the mesial root, the average distance to the IAN was 6.2 Æ 2.6 that the craniofacial complex continues to change and adapt throughoutmm for males and 4.9 Æ 2.2 mm for females. For the distal root to the life and into the sixth decade (17–20).IAN, the average distance was 5.8 Æ 2.5 mm for males and 4.7 Æ 2.2 In 6 patients, the IAN was in direct contact with the root, and in 2 ofmm for females. Overall, females had significantly shorter vertical these patients, the IAN was coronal to the distal root apex of the firstdistances from the IAN to the mesial (P < .01) and distal root apices molar. When this occurred, it was on the lingual side of the root in(P < .01). The range was 0–13.9 mm for males and 0–11.3 mm for both cases. According to the present results, 3% of patients can havefemales. For the mesial root only, age was also found to be a statistically the IAN directly contacting 1 or both of the roots of the mandibular firstsignificant predictor (P < .05) for the distance of the IAN to the root molar. In 3 patients, the distal root was the only root contacting the IAN,apex overall. Subdividing the data according to gender, only males in 2 patients had both the mesial and distal roots in contact with the IAN,the third decade of life had a significantly shorter distance of the mesial and 1 patient had just the mesial root contacting the IAN. In the last case,root apex to the IAN than males in the fifth decade of life (P < .05). The the tooth was tipped mesially as a result of a missing second premolar.total horizontal bone width from buccal to lingual cortical plates at 3 The average horizontal bone width is also important to knowmm coronal to the root apices for males was 12.2 Æ 1.9 mm versus during surgical procedures. As a surgery is started, it is valuable946 Simonton et al. JOE — Volume 35, Number 7, July 2009
  • 4. JOE — Volume 35, Number 7, July 2009 TABLE 2. Measured Distances of Horizontal Bone Width Bone Bone Bone Bone Buccal Lingual width @ IAN-buccal IAN-lingual width Buccal Lingual width @ IAN-buccal IAN-lingual width plate-root plate-root 3 mm*† plate† plate @ IAN plate-root plate-root* 3 mm*† plate† plate @ IAN Measurement from Fig. 1 1 2 3 4 5 6 1 2 3 4 5 6 Mesial root, all males Distal root, all males Mean 1.6 4.1 12.2 4.7 2.4 10.0 2.5 4.4 13.0 5.3 1.9 10.0 SD 1.1 1.4 1.9 1.5 1.7 1.8 1.4 1.4 2.2 1.4 1.1 1.8 Low range 0.0 1.2 8.6 1.0 0.0 5.6 0.0 0.8 3.0 1.5 0.1 2.8 High range 6.6 10.5 20.7 10.0 12.9 15.6 7.0 9.0 19.9 9.9 5.6 14.9 n 100 100 100 100 100 100 100 100 100 100 100 100 Mesial root, all females Distal root, all females Mean 1.5 3.8 11.3 4.3 2.4 9.6 2.5 4.0 12.2 5.1 2.0 9.9 SD 1.0 1.2 1.7 1.2 0.9 1.5 1.5 1.3 1.9 1.3 0.8 1.5 Low range 0.0 0.0 7.4 2.0 0.6 3.5 0.0 0.0 8.4 1.9 0.3 5.5 High range 4.6 6.4 15.2 7.3 5.9 14.2 8.0 7.3 16.9 8.5 5.0 13.7 n 100 100 100 100 100 100 100 100 100 100 100 100 Summary: mesial root, all patients Summary: distal root, all patients Mean 1.5 4.0 11.8 4.5 2.4 9.8 2.5 4.2 12.6 5.2 2.0 10.0Age- and Gender-related Differences in the Position of the IAN SD 1.1 1.3 1.9 1.4 1.4 1.7 1.4 1.4 2.1 1.4 1.0 1.7 Low range 0.0 0.0 7.4 1.0 0.0 3.5 0.0 0.0 3.0 1.5 0.1 2.8 High range 6.6 10.5 20.7 9.9 12.9 15.6 8.0 9.0 19.9 9.9 5.6 14.9 n 200 200 200 200 200 200 200 200 200 200 200 200 Measurement from Fig. 1 refers to landmarks 1–6 illustrated in Fig. 1. SD, standard deviation. *P < .01 comparing males and females only (not applicable to Summary data). † P < .05 comparing age only (not applicable to Summary data). *†P < .01 comparing both males and females and age (not applicable to Summary data). Clinical Research 947
  • 5. Clinical ResearchFigure 2. Data were analyzed by 2-way (age, sex) analysis of variance with Bonferroni post hoc test at P <.05 to determine the effect of age and gender on theposition of the IAN within the bone and with respect to the apex of the mesial and distal roots of the mandibular first molar. (A) The total horizontal bone width at3 mm coronal to the mesial root apex (in mm) according to age and gender, (B) the total horizontal bone width at 3 mm coronal to the distal root apex (in mm)according to age and gender, (C) the distance of the mesial root apex to the closest portion of the IAN (in mm) according to age and gender, and (D) the distance ofthe distal root apex to the closest portion of the IAN (in mm) according to age and gender.information to know the thickness of the bone to the roots on both the terminated beyond the examined area. One patient had 2 mentalbuccal and lingual aspects of the tooth. It was shown in this study that the foramina that were comparable in size located 2 mm apart, both ante-average horizontal bone width was related to both gender and age. The rior to the second bicuspid. Two patients exhibited a bifurcated IAN;overall mandibular horizontal bone width is significantly less in females one terminated at the apex of the mesial root of the first molar.than in males, and as a patient ages from the 3rd–6th decade of life, Another important consideration for surgical procedures onregardless of gender, the horizontal bone width also decreases. mandibular molars is the presence of a radix entomolaris. It has The general course of the nerve within the mandible, however, been reported in the literature that radix entomolaris occurs up toseems to remain similar between both males and females and does 4.2% of the time in whites (34). We found 8 patients (4%) with a radixnot seem to be age-related. The IAN was most often located near the entomolaris in our study. In these patients, the distance of the IAN waslingual cortical plate and lingual to the root apices of the mandibular measured to the closest root.first molar. In many patients, the IAN created a ‘‘half-moon–shaped’’ The results of the present study indicated that females have a signif-(ie, concave) invagination into the lingual cortical pate. However, as icantly closer distance of the root apices to the IAN and significantlythe mental foramen became more distally positioned, the IAN became decreased horizontal mandibular bone width than males. Also, as agemore buccally located within the mandible and in relation to the roots increased from the 3rd–6th decade of life, bone width significantlyof the mandibular first molar. In 3 patients, the mental foramen was decreased regardless of gender. One logical explanation would bepositioned directly apical to the mesial root of the first molar. We that females and older patients in their 5th–6th decade of life, inalso observed 12 accessory foramina in 12 different patients. These general, have less bone mass than males and patients in their 3rdaccessory foramina usually terminated apical to the mandibular first decade of life. This finding is important in both surgical and nonsurgicalmolar. This was recently reported in the literature by Katakami et al root canal treatment. Interestingly, a study done by Sandstedt et al (35)(33). Because of the high-resolution limited field-of-view scans (3 Â concluded that mainly women and older persons have the most severe4 mm) used in this study, the percentage might be higher than we discomfort after oral nerve damage. This might be due to the closerobserved because the accessory foramen could have originated or proximity of the nerve to the roots of mandibular molars and less overall948 Simonton et al. JOE — Volume 35, Number 7, July 2009
  • 6. Clinical Researchbone width, allowing more chance to receive greater trauma. We did not 13. Libersa P, Savignat M, Tonnel A. Neurosensory disturbances of the inferior alveolarevaluate patients younger than the age of 30 years because of limitations nerve: a retrospective study of complaints in a 10-year period. J Oral Maxillofac Surg 2007;65:1486–9.in the number of CBCT scans taken for younger patients and the relative 14. Schultze-Mosgau S, Reich RH. Assessment of inferior alveolar and lingual nerveinfrequency of this population to undergo endodontic surgical proce- disturbances after dentoalveolar surgery, and of recovery of sensitivity. Int J Oraldures. It might be interesting to evaluate whether the horizontal bone Maxillofac Surg 1993;22:214–7.width increases as the patient ages up to a certain decade of life and 15. Kim S, Kratchman S. Modern endodontic surgery concepts and practice: a review.then begins to decrease again, as was shown in this study between J Endod 2006;32:601–23. 16. Moiseiwitsch JR. Avoiding the mental foramen during periapical surgery. J Endodthe 3rd and 6th decade of life. Swasty et al (17) showed that subjects 1995;21:340–2.who are 10–19 years old have thinner cortical bone and decreased 17. Swasty D, Lee JS, Huang JC, et al. Anthropometric analysis of the human mandibularmandibular height compared with all other age groups, with peak thick- cortical bone as assessed by cone-beam computed tomography. J Oral Maxillofacness in subjects 40–49 years old followed by a decrease in thickness Surg 2009;67:491–500. 18. Dager MM, McNamara JA, Baccetti T, Franchi L. Aging in the craniofacial complex.after this period. We found a peak mandibular bone width at 30–39 Angle Orthod 2008;78:440–4.years old and then a decrease in overall horizontal mandibular bone 19. Pecora NG, Baccetti T. McNamara JA Jr. The aging craniofacial complex: a longitu-width in both genders. dinal cephalometric study from late adolescence to late adulthood. Am J Orthod According to this study, an important consideration in presurgical Dentofacial Orthop 2008;134:496–505.planning is that the measurements obtained from a CBCT scan will not 20. Agbaje JO, Jacobs R, Maes F, Michiels K, van Steenberghe D. Volumetric analysis of extraction sockets using cone beam computed tomography: a pilot study on ex vivostay constant throughout a person’s lifetime, and a current CBCT might jaw bone. J Clin Periodontol 2007;34:985–90.be recommended, when appropriate, before surgical treatment. Collec- 21. Ludlow JB, Laster WS, See M, Bailey LJ, Hershey HG. Accuracy of measurements oftively, these data indicate that both gender and age impact surgical mandibular anatomy in cone beam computed tomography images. Oral Surg Oralendodontic anatomic relationships and should be considered in pre- Med Oral Pathol Oral Radiol Endod 2007;103:534–42. 22. Greenstein G, Tarnow D. The mental foramen and nerve: clinical and anatomicalsurgical planning. factors related to dental implant placement: a literature review. J Periodontol 2006;77:1933–43. Acknowledgments 23. Pinsky HM, Dyda S, Pinsky RW, Misch KA, Sarment DP. Accuracy of three-dimen- sional measurements using cone-beam CT. Dentomaxillofac Radiol 2006;35:410–6. We thank the IORB Instituto OdontoRadiologico de Brasilia– 24. Klinge B, Petersson A, Maly P. Location of the mandibular canal: comparison ofBrazil for providing images used in this analysis. macroscopic findings, conventional radiography, and computed tomography. Int J Oral Maxillofac Implants 1989;4:327–32. 25. Lazzerini F, Minorati D, Nessi R, Gagliani M, Uslenghi CM. The measurement param- References eters in dental radiography: a comparison between traditional and digital tech- 1. Wayman BE, Patten JA, Dazey SE. Relative frequency of teeth needing endodontic niques. Radiol Med 1996;91:364–9. treatment in 3350 consecutive endodontic patients. J Endod 1994;20:399–401. 26. Garg AK. Dental implant imaging: TeraRecon’s Dental 3D Cone Beam Computed 2. Serene T, Spolsky V. Frequency of endodontic therapy in a dental school setting. Tomography System. Dent Implantol Update 2007;18:41–5. J Endod 1981;7:385–7. 27. Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler WG. Endodontic appli- 3. Jung IY, Seo MA, Fouad AF, et al. Apical anatomy in mesial and mesiobuccal roots of cations of cone-beam volumetric tomography. J Endod 2007;33:1121–32. permanent first molars. J Endod 2005;31:364–8. 28. Sato I, Ueno R, Kawai T, Yosue T. Rare courses of the mandibular canal in the molar 4. Friedman S, Mor C. The success of endodontic therapy-healing and functionality. regions of the human mandible: a cadaveric study. Okajimas Folia Anat Jpn 2005;82: J Calif Dent Assoc 2004;32:493–503. 95–101. 5. de Lange J, Putters T, Baas EM, van Ingen JM. Ultrasonic root-end preparation in 29. Narayana K, Vasudha S. Intraosseous course of the inferior alveolar (dental) apical surgery: a prospective randomized study. Oral Surg Oral Med Oral Pathol nerve and its relative position in the mandible. Indian J Dent Res 2004;15: Oral Radiol Endod 2007;104:841–5. 99–102. 6. Plotino G, Pameijer CH, Grande NM, Somma F. Ultrasonics in endodontics: a review 30. Frankle KT, Seibel W, Dumsha TC. Anatomical study of the position of the mesial of the literature. J Endod 2007;33:81–95. roots of mandibular molars. J Endod 1990;16:480–5. 7. Tsesis I, Rosen E, Schwartz-Arad D, Fuss Z. Retrospective evaluation of surgical 31. Levine MH, Goddard AL, Dodson TB. Inferior alveolar nerve canal position: a clinical endodontic treatment: traditional versus modern technique. J Endod 2006;32:412–6. and radiographic study. J Oral Maxillofac Surg 2007;65:470–4. 8. Kim S. Modern endodontic practice: instruments and techniques. Dent Clin North 32. Patel S, Dawood A, Ford TP, Whaites E. The potential applications of cone beam Am 2004;48:1–9. computed tomography in the management of endodontic problems. Int Endod 9. Rubinstein RA, Kim S. Long-term follow-up of cases considered healed one year J 2007;40:818–30. after apical microsurgery. J Endod 2002;28:378–83. 33. Katakami K, Mishima A, Shiozaki K, Shimoda S, Hamada Y, Kobayashi K. Character-10. Dempf R, Hausamen JE. Lesions of the inferior alveolar nerve arising from istics of accessory mental foramina observed on limited cone-beam computed endodontic treatment. Aust Endod J 2000;26:67–71. tomography images. J Endod 2008;34:1441–5.11. Pogrel MA, Thamby S. The etiology of altered sensation in the inferior alveolar, 34. De Moor R, Deroose C, Calberson F. The radix entomolaris in mandibular first lingual, and mental nerves as a result of dental treatment. J Calif Dent Assoc molars: an endodontic challenge. Int Endod J 2004;37:789–99. 1999;27:531–8. 35. Sandstedt P, Sorensen S. Neurosensory disturbances of the trigeminal nerve:12. Pogrel MA, Kaban LB. Injuries to the inferior alveolar and lingual nerves. J Calif Dent a long-term follow-up of traumatic injuries. J Oral Maxillofac Surg 1995;53: Assoc 1993;21:50–4. 498–505.JOE — Volume 35, Number 7, July 2009 Age- and Gender-related Differences in the Position of the IAN 949

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