Morphology and Variant Anatomy of the Mandibular Canal in a Kenyan Population: A Cone-Beam Computed Tomography Study

Descriptive cross-sectional study. The mandibular canal (MC) exhibits surgically significant anatomical variations in its course and terminal segment among different ethnic groups. The aim of this study was to document a surgically relevant position of the MC, its variants, and related anatomical structures in dentate patients from a select Kenyan population. 351 hemi mandibular cone-beam computed tomography (CBCT) scans from 202 patients were used to evaluate the MC and mental foramen (MF) for normal morphology, anatomical variations, and their linear relationship to various reference points. The most frequently encountered course of the MC was the progressive descent type seen in 241 (68.7%) scans. Accessory MC were observed in 15 (4.3%) scans. Accessory MF were observed in 29 (8.3%) scans. The mean diameter of the MC was 3.36 ± .39 mm. The orientation of the MC was more lingual towards the angle of the mandible and more buccal towards the MF. The most frequent position of the main MF in relation to the second premolar was anterior (53.3%). The average distance from the MF to the inferior border of the mandible was 12.17 ± 1.91 mm. The anterior loop of the mental nerve was observed in 18 (5.1%) scans and its mean length was 4.83 ± .89 mm. Our study revealed significant variations in the position, size, and course of the MC and MF. This knowledge should assist oral surgeons to avoid inadvertent injury to the inferior alveolar neurovascular bundle in the local population.

[1]  D. Mansur,et al.  Radiographic assessment of mandibular canal in Nepalese population: a study based on cone beam computed tomography images , 2019, Journal of Chitwan Medical College.

[2]  H. Chauhan,et al.  Study of Normal Anatomy of Mandibular Canal and its Variations in Indian Population Using CBCT , 2019, Journal of Maxillofacial and Oral Surgery.

[3]  I. Veli,et al.  Cone-beam computed tomography evaluation of bifid mandibular canal in a Turkish population , 2018, International Dental Research.

[4]  F. F. Lopes,et al.  Location of the course of the mandibular canal, anterior loop and accessory mental foramen through cone-beam computed tomography , 2018, Surgical and Radiologic Anatomy.

[5]  Elluru Venkatesh,et al.  Cone beam computed tomography: basics and applications in dentistry , 2017, Journal of Istanbul University Faculty of Dentistry.

[6]  T. Ahmad.  Bilateral bifid mandibular canal: A case report , 2017 .

[7]  M. Sheikhi,et al.  CBCT Assessment of Mental Foramen Position Relative to Anatomical Landmarks , 2016, International journal of dentistry.

[8]  K. Horner,et al.  Impact of cone beam computed tomography (CBCT) on diagnostic thinking in endodontics of posterior teeth: A before- after study. , 2016, Journal of dentistry.

[9]  L. Khojastepour,et al.  Evaluation of the Course of the Inferior Alveolar Canal: The First CBCT Study in an Iranian Population , 2016, Polish journal of radiology.

[10]  Seyedeh Tahereh Mohtavipour,et al.  An Analysis of Visibility and Anatomic Variations of Mandibular Canal in Digital Panoramic Radiographs of Dentulous and Edentulous Patients in Northern Iran Populations , 2016, Journal of dentistry.

[11]  Mahgoub Mashail Mahmoud.  Diameter of the Inferior Alveolar Canal - A Comparative CT and Macroscopic Study of Sudanese Cadaveric Mandibles , 2015, Journal of Evolution of Medical and Dental Sciences.

[12]  M. Bobat.  Clinical significance of the anterior loop of the mental nerve: anatomical dissection of a cadaver population at the University of the Witwatersrand , 2015 .

[13]  Heung-Joong Kim,et al.  Morphological assessment of the anterior loop of the mandibular canal in Koreans , 2015, Anatomy & cell biology.

[14]  F. Butt,et al.  The surgical relevance of the anatomic position of the extraosseous mental nerve in a Kenyan population , 2014, The Pan African medical journal.

[15]  T. Schneider,et al.  The inferior alveolar nerve's loop at the mental foramen and its implications for surgery. , 2014, Journal of the American Dental Association.

[16]  A. Sekerci,et al.  Cone Beam Computed Tomographic Analyses of the Position and Course of the Mandibular Canal: Relevance to the Sagittal Split Ramus Osteotomy , 2014, BioMed research international.

[17]  B. T. Suer,et al.  Harvesting Mandibular Ramus Bone Grafts Using Ultrasonic Surgical Device: Report of 20 Cases , 2014 .

[18]  D. He,et al.  Anatomic relationship between impacted third mandibular molar and the mandibular canal as the risk factor of inferior alveolar nerve injury. , 2013, The British journal of oral & maxillofacial surgery.

[19]  Sug-Joon Ahn,et al.  Position of the mental foramen on panoramic radiographs and its relation to the horizontal course of the mandibular canal: a computed tomographic analysis. , 2013, Clinical oral implants research.

[20]  C. Francischone,et al.  Retrospective study of the anterior loop of the inferior alveolar nerve and the incisive canal using cone beam computed tomography. , 2013, The International journal of oral & maxillofacial implants.

[21]  D. Apostolakis,et al.  The anterior loop of the inferior alveolar nerve: prevalence, measurement of its length and a recommendation for interforaminal implant installation based on cone beam CT imaging. , 2012, Clinical oral implants research.

[22]  A. R. Vieira,et al.  Position and course of the mandibular canal in skulls. , 2012, Oral surgery, oral medicine, oral pathology and oral radiology.

[23]  R. Jacobs,et al.  Assessment of variations of the mandibular canal through cone beam computed tomography , 2012, Clinical Oral Investigations.

[24]  E. Ariji,et al.  Demonstration of the accessory mental foramen using rotational panoramic radiography compared with cone-beam computed tomography. , 2011, Clinical oral implants research.

[25]  Kivanç Kamburoglu,et al.  Accuracy of CBCT Measurements of a Human Skull , 2011, Journal of Digital Imaging.

[26]  N. van Assche,et al.  Characterisation of additional mental foramina through cone beam computed tomography. , 2011, Journal of oral rehabilitation.

[27]  K. Orhan,et al.  Evaluation of bifid mandibular canals with cone-beam computed tomography in a Turkish adult population: a retrospective study , 2011, Surgical and Radiologic Anatomy.

[28]  T. Olson,et al.  Cone beam computed tomography and SimPlant materialize dental software versus direct measurement of the width and height of the posterior mandible: an anatomic study. , 2011, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[29]  Y. Seta,et al.  Relationship between inferior alveolar nerve canal position at mandibular second molar in patients with prognathism and possible occurrence of neurosensory disturbance after sagittal split ramus osteotomy. , 2010, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[30]  Flaviana Soares Rocha,et al.  Retrospective Study of Bone Grafting Procedures Before Implant Placement , 2010, Implant dentistry.

[31]  Reinhilde Jacobs,et al.  A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT) Part I. On subjective image quality. , 2010, European journal of radiology.

[32]  W. Ngeow.  Is there a "safety zone" in the mandibular premolar region where damage to the mental nerve can be avoided if periapical extrusion occurs? , 2010, Journal.

[33]  H. Hashemi.  Neurosensory function following mandibular nerve lateralization for placement of implants. , 2010, International journal of oral and maxillofacial surgery.

[34]  M. C. M. Wong,et al.  Incidence of neurosensory deficits and recovery after lower third molar surgery: a prospective clinical study of 4338 cases. , 2010, International journal of oral and maxillofacial surgery.

[35]  Sotirios Tetradis,et al.  Cone beam computed tomography in the diagnosis of dental disease. , 2010, Texas dental journal.

[36]  K. Gröndahl,et al.  Cone-beam CT for preoperative implant planning in the posterior mandible: visibility of anatomic landmarks. , 2009, Clinical implant dentistry and related research.

[37]  M Kortesniemi,et al.  Dosimetry and image quality of four dental cone beam computed tomography scanners compared with multislice computed tomography scanners. , 2009, Dento maxillo facial radiology.

[38]  F. Çağlayan,et al.  Bilateral bifid mandibular canal: a case report. , 2009, Medicina oral, patologia oral y cirugia bucal.

[39]  S. Shahidi,et al.  Bilateral bifid mandibular canal: report of two cases. , 2009, Indian journal of dental research : official publication of Indian Society for Dental Research.

[40]  E. Ariji,et al.  Accessory mental foramen assessment using cone-beam computed tomography. , 2009, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[41]  Christos Angelopoulos,et al.  Comparison between digital panoramic radiography and cone-beam computed tomography for the identification of the mandibular canal as part of presurgical dental implant assessment. , 2008, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[42]  M. Şençimen,et al.  Retrospective radiographic evaluation of the anterior loop of the mental nerve: comparison between panoramic radiography and spiral computerized tomography. , 2008, The International journal of oral & maxillofacial implants.

[43]  P. Monsour,et al.  Implant radiography and radiology. , 2008, Australian dental journal.

[44]  Y. Wong,et al.  Evaluation of mandibular anatomy related to sagittal split ramus osteotomy using 3-dimensional computed tomography scan images. , 2008, International journal of oral and maxillofacial surgery.

[45]  J. Bernard,et al.  Efficacy of panoramic radiographs in the preoperative planning of posterior mandibular implants: a prospective clinical study of 1527 consecutively treated patients. , 2007, Clinical oral implants research.

[46]  E. Whaites,et al.  The potential applications of cone beam computed tomography in the management of endodontic problems. , 2007, International endodontic journal.

[47]  K. Pai,et al.  Multiple mandibular nerve canals: radiographic observations and clinical relevance. Report of 6 cases. , 2007, Quintessence international.

[48]  L. Goldman.  Principles of CT and CT Technology* , 2007, Journal of Nuclear Medicine Technology.

[49]  P. Wadhwani,et al.  Mandibular canal variant: a case report. , 2007, Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology.

[50]  A. Farman,et al.  Cone beam computed tomographic findings in refractory chronic suppurative osteomyelitis of the mandible. , 2007, The British journal of oral & maxillofacial surgery.

[51]  R. Emery,et al.  Bisphosphonate-related osteonecrosis of the jaws: a report of three cases demonstrating variability in outcomes and morbidity. , 2007, Journal of the American Dental Association.

[52]  Max Heiland,et al.  Clinical indications and perspectives for intraoperative cone-beam computed tomography in oral and maxillofacial surgery. , 2007, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[53]  B. Jones,et al.  Osseous genioplasty in facial aesthetic surgery--a personal perspective reviewing 54 patients. , 2006, Journal of plastic, reconstructive & aesthetic surgery : JPRAS.

[54]  Y. Hayakawa,et al.  Cone-beam CT (CB Throne) applied to dentomaxillofacial region. , 2006, The Bulletin of Tokyo Dental College.

[55]  J. Barabás,et al.  Atypical Courses of the Mandibular Canal: Comparative Examination of Dry Mandibles and X-Rays , 2006, The Journal of craniofacial surgery.

[56]  P. Rouas,et al.  Pseudo multiple and enlarged mandibular canals: the evidence-based response of cone beam computed tomography. , 2006, Dento maxillo facial radiology.

[57]  W R Proffit,et al.  Superimposition of 3D cone-beam CT models of orthognathic surgery patients. , 2005, Dento maxillo facial radiology.

[58]  G. Rezvani,et al.  Enlargement of mandibular canal with tongue paresthesia caused by extranodal B-cell Lymphoma: A case report , 2005 .

[59]  T. Muto,et al.  Computed tomographic analysis of the position and course of the mandibular canal: relevance to the sagittal split ramus osteotomy. , 2005, International journal of oral and maxillofacial surgery.

[60]  Akira Mishima,et al.  Application of Limited Cone Beam Computed Tomography to Clinical Assessment of Alveolar Bone Grafting: A Preliminary Report , 2005, The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association.

[61]  R. Schmelzle,et al.  Postoperative imaging of zygomaticomaxillary complex fractures using digital volume tomography. , 2004, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[62]  Philip Worthington,et al.  Injury to the inferior alveolar nerve during implant placement: a formula for protection of the patient and clinician. , 2004, The International journal of oral & maxillofacial implants.

[63]  F. Dilberović,et al.  Clinical and anatomy study of the human mental foramen. , 2004, Bosnian journal of basic medical sciences.

[64]  Hom-lay Wang,et al.  Morphometric analysis of implant-related anatomy in Caucasian skulls. , 2004, Journal of periodontology.

[65]  S. Berrone,et al.  Vertical alveolar ridge augmentation by means of a titanium mesh and autogenous bone grafts. , 2004, Clinical oral implants research.

[66]  E. Seldin,et al.  Types, frequencies, and risk factors for complications after third molar extraction. , 2003, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[67]  T. Dodson,et al.  Inferior alveolar nerve canal position: a clinical and radiographic study. , 2003, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[68]  M. Peñarrocha,et al.  Bifid mandibular canal. , 2003, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[69]  M Cohnen,et al.  A comparison of conventional panoramic radiographs with volumetric computed tomography images in the preoperative assessment of impacted mandibular third molars. , 2002, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[70]  K. Michi,et al.  Relationship of the mandibular canal to the lateral cortex of the mandibular ramus as a factor in the development of neurosensory disturbance after bilateral sagittal split osteotomy. , 2002, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[71]  O. Oğuz,et al.  Evaluation of location of mandibular and mental foramina in dry, young, adult human male, dentulous mandibles. , 2002, The West Indian medical journal.

[72]  E. Valmaseda-Castellón,et al.  Inferior alveolar nerve damage after lower third molar surgical extraction: a prospective study of 1117 surgical extractions. , 2001, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[73]  P. Louis.  Inferior alveolar nerve repositioning. , 2001, Atlas of the oral and maxillofacial surgery clinics of North America.

[74]  R Jacobs,et al.  Localisation of the mandibular canal using conventional spiral tomography: a human cadaver study. , 2001, Clinical oral implants research.

[75]  J. Walton.  Altered sensation associated with implants in the anterior mandible: a prospective study. , 2000, The Journal of prosthetic dentistry.

[76]  R A Kraut,et al.  The incidence of altered sensation of the mental nerve after mandibular implant placement. , 1999, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[77]  M. Pogrel,et al.  The etiology of altered sensation in the inferior alveolar, lingual, and mental nerves as a result of dental treatment. , 1999, Journal of the California Dental Association.

[78]  E Tammisalo,et al.  Development of a compact computed tomographic apparatus for dental use. , 1999, Dento maxillo facial radiology.

[79]  P. Nocini,et al.  Clinical and electrophysiological assessment of inferior alveolar nerve function after lateral nerve transposition. , 1999, Clinical oral implants research.

[80]  I. Kjaer,et al.  Prenatal Development of the Alveolar Bone of Human Deciduous Incisors and Canines , 1999, Journal of dental research.

[81]  L. Kaban,et al.  Neurosensory deficit and functional impairment after sagittal ramus osteotomy: a long-term follow-up study. , 1998, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[82]  T. Dao,et al.  Sensory disturbances associated with implant surgery. , 1998, The International journal of prosthodontics.

[83]  M. Pyle,et al.  The frequency of accessory mental foramina in four ethnic groups. , 1998, Archives of oral biology.

[84]  J. Moiseiwitsch.  Position of the mental foramen in a North American, white population. , 1998, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[85]  S. Asala,et al.  Position of the mental foramen in adult black Zimbabwean mandibles: a clinical anatomical study. , 1998, The Central African journal of medicine.

[86]  C. Goodacre,et al.  Mandibular fracture after endosseous implant placement in conjunction with inferior alveolar nerve transposition: a patient treatment report. , 1997, The International journal of oral & maxillofacial implants.

[87]  D. Wismeijer,et al.  Patients' perception of sensory disturbances of the mental nerve before and after implant surgery: a prospective study of 110 patients. , 1997, The British journal of oral & maxillofacial surgery.

[88]  A. Smith,et al.  Inferior alveolar nerve damage following removal of mandibular third molar teeth. A prospective study using panoramic radiography. , 1997, Australian dental journal.

[89]  B H Nowicki,et al.  Multiplanar MR and anatomic study of the mandibular canal. , 1996, AJNR. American journal of neuroradiology.

[90]  C. Misch,et al.  Ridge augmentation using mandibular ramus bone grafts for the placement of dental implants: presentation of a technique. , 1996, Practical periodontics and aesthetic dentistry : PPAD.

[91]  H. Toh,et al.  Anatomical study of the accessory mental foramen and the distribution of its nerve. , 1992, Okajimas folia anatomica Japonica.

[92]  J. Hassanali,et al.  The position of mandibular and mental foramina in Kenyan African mandibles. , 1992, East African medical journal.

[93]  M. Torabinejad,et al.  Anatomical relationship of the mandibular canal to its surrounding structures in mature mandibles. , 1992, Journal of endodontics.

[94]  B. R. Smith,et al.  Mandibular ramus anatomy as it relates to the medial osteotomy of the sagittal split ramus osteotomy. , 1991, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[95]  R. Langlais,et al.  Cross-sectional tomography. A diagnostic technique for determining the buccolingual relationship of impacted mandibular third molars and the inferior alveolar neurovascular bundle. , 1990, Oral surgery, oral medicine, and oral pathology.

[96]  O. Jensen,et al.  Inferior alveolar nerve repositioning in conjunction with placement of osseointegrated implants: a case report. , 1987, Oral surgery, oral medicine, and oral pathology.

[97]  P. M. Fuller,et al.  The inferior alveolar and mylohyoid nerves: an anatomic study and relationship to local anesthesia of the anterior mandibular teeth. , 1984, Journal of the American Dental Association.

[98]  L. Lorton,et al.  Bifid mandibular nerve as a possible cause of inadequate anesthesia in the mandible. , 1983, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[99]  H. Obwegeser,et al.  The surgical correction of mandibular prognathism and retrognathia with consideration of genioplasty. I. Surgical procedures to correct mandibular prognathism and reshaping of the chin. , 1957, Oral surgery, oral medicine, and oral pathology.

[100]  J. Gakonyo.  Double inferior alveolar nerve canals and mental foramina in the mandible : a computed tomography study at a private dental clinic in Kenya , 2017 .

[101]  Anna Gerber,et al.  Oral Radiology Principles And Interpretation , 2016 .

[102]  Moni Thakur,et al.  Gender Determination by Mental Foramen and Height of the Body of the Mandible in Dentulous Patients A Radiographic Study , 2014 .

[103]  Anil Singh,et al.  Determination of sex by radiographic analysis of mental foramen in North Indian population , 2013, Journal of forensic dental sciences.

[104]  Z. Mohammadi.  Endodontics-related paresthesia of the mental and inferior alveolar nerves: an updated review. , 2010, Journal.

[105]  K. Patil,et al.  Mental foramen for gender determination: A panoramic radiographic study , 2009 .

[106]  Munetaka Naitoh,et al.  Observation of bifid mandibular canal using cone-beam computerized tomography. , 2009, The International journal of oral & maxillofacial implants.

[107]  Deng-Gao Liu,et al.  Localization of impacted maxillary canines and observation of adjacent incisor resorption with cone-beam computed tomography. , 2008, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[108]  M. Chamorro Pons,et al.  Repositioning of the inferior alveolar nerve in cases of severe mandibular atrophy. a clinical case. , 2008, Medicina oral, patologia oral y cirugia bucal.

[109]  P Rouas,et al.  Identification of double mandibular canals: literature review and three case reports with CT scans and cone beam CT. , 2007, Dento maxillo facial radiology.

[110]  D.M.D. Ph.D. Johannes Franz Hoenig M.D..  Sliding Osteotomy Genioplasty for Facial Aesthetic Balance: 10 Years of Experience , 2006, Aesthetic Plastic Surgery.

[111]  V. Claeys,et al.  Bifid mandibular canal: literature review and case report. , 2005, Dento maxillo facial radiology.

[112]  V. Gedrimas,et al.  Traumatic Damage to the Inferior Alveolar Nerve Sustained in Course of Dental Implantation. Possibility of Prevention , 2004 .

[113]  L. J. Dario,et al.  Implant placement above a bifurcated mandibular canal: a case report. , 2002, Implant dentistry.

[114]  A. Morrison,et al.  Mental nerve function after inferior alveolar nerve transposition for placement of dental implants. , 2002, Journal.

[115]  N. Serman,et al.  Bilateral mandibular accessory foramina and canals: a case report and review of the literature. , 2000, Dento maxillo facial radiology.

[116]  C. Misch.  Use of the mandibular ramus as a donor site for onlay bone grafting. , 2000, The Journal of oral implantology.

[117]  P. Mozzo,et al.  A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results , 1998, European Radiology.

[118]  L. Todorović,et al.  Anatomical considerations relevant to implant procedures in the mandible. , 1995, Bulletin du Groupement international pour la recherche scientifique en stomatologie & odontologie.

[119]  W. Shankland.  The position of the mental foramen in Asian Indians. , 1994, The Journal of oral implantology.

[120]  L. Ellies,et al.  The prevalence of altered sensation associated with implant surgery. , 1993, The International journal of oral & maxillofacial implants.

[121]  P. Mentag,et al.  A review of the intraosseous course of the nerves of the mandible. , 1991, The Journal of oral implantology.

[122]  B. Epker.  Modifications in the sagittal osteotomy of the mandible. , 1977, Journal of oral surgery.

[123]  J. Jordan,et al.  Duplication of the mandibular canal. , 1973, Oral surgery, oral medicine, and oral pathology.

[124]  E. E. Hunsuck.  A modified intraoral sagittal splitting technic for correction of mandibular prognathism. , 1968, Journal of oral surgery.

[125]  G. Dal Pont.  Retromolar osteotomy for the correction of prognathism. , 1961, Journal of oral surgery, anesthesia, and hospital dental service.