Abstract
The retromolar region is a triangular area bounded by temporal crest on the medial side, anterior border of ramus on the lateral side, and the posterior portion of the third molar area. The deeper fibers of the temporalis muscle attach to the upper two-thirds of the medial boundary of the retromolar fossa. The superficial fibers of the temporalis muscle attach to the upper one-third of the lateral boundary of the retromolar triangle. The buccal nerve and artery cross the middle portion of the medial border, while the lingual nerve crosses the inferior portion. The retromolar foramen also consists of clinically relevant vessels and nerves. The posterior portion of the third molar attaches to the pterygomandibular raphe, where the buccinator and superior pharyngeal constrictor muscle attach anteriorly and posteriorly. It is implicated clinically in procedures such as third molar extractions, periodontal distal wedge procedures, and sagittal split osteotomy. Furthermore, the retromolar trigone marks an aggressive type of oral cancer.
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References
Al-Amery SM, Nambiar P, Naidu M et al (2016) Variation in lingual nerve course: a human cadaveric study. PLoS One 11:e0162773. https://doi.org/10.1371/journal.pone.0162773
Alves N, Deana NF (2015) Anatomical and radiographical study of the retromolar canal and retromolar foramen in macerated mandibles. Int J Clin Exp Med 8:4292–4296
Behnia H, Kheradvar A, Shahrokhi M (2000) An anatomic study of the lingual nerve in the third molar region. J Oral Maxillofac Surg 58:649–651. –653
Benninger B, Lee B-I (2012) Clinical importance of morphology and nomenclature of distal attachment of temporalis tendon. J Oral Maxillofac Surg 70:557–561. https://doi.org/10.1016/j.joms.2011.02.047
Bilecenoglu B, Tuncer N (2006) Clinical and anatomical study of retromolar foramen and canal. J Oral Maxillofac Surg 64:1493–1497. https://doi.org/10.1016/j.joms.2006.05.043
Capote TS d O, Gonçalves M d A, Campos JÁDB (2015) Retromolar canal associated with age, side, sex, bifid mandibular canal, and accessory mental foramen in panoramic radiographs of Brazilians. Anat Res Int 2015:434083. https://doi.org/10.1155/2015/434083
Castelli WA, Nasjleti CE, Díaz-Pérez R (1975) Interruption of the arterial inferior alveolar flow and its effects on mandibular collateral circulation and dental tissues. J Dent Res 54:708–715. https://doi.org/10.1177/00220345750540040301
Celebić A, Valentić-Peruzović M, Kraljević K et al (1995) A study of the occlusal plane orientation by intra-oral method (retromolar pad). J Oral Rehabil 22:233–236
Chan H-L, Leong DJM, Fu J-H et al (2010) The significance of the lingual nerve during periodontal/implant surgery. J Periodontol 81:372–377. https://doi.org/10.1902/jop.2009.090506
Chávez-Lomeli ME, Mansilla Lory J, Pompa JA et al (1996) The human mandibular canal arises from three separate canals innervating different tooth groups. J Dent Res 75:1540–1544. https://doi.org/10.1177/00220345960750080401
Cohen ES (2007) Atlas of cosmetic and reconstructive periodontal surgery. PMPH-USA
Di Bari R, Coronelli R, Cicconetti A (2013) Radiographic evaluation of the symphysis menti as a donor site for an autologous bone graft in pre-implant surgery. Imaging Sci Dent 43:135–143. https://doi.org/10.5624/isd.2013.43.3.135
Di Bari R, Coronelli R, Cicconetti A (2014) An anatomical radiographic evaluation of the posterior portion of the mandible in relation to autologous bone harvest procedures. J Craniofac Surg 25:e475–e483. https://doi.org/10.1097/SCS.0000000000000598
Filo K, Schneider T, Kruse AL et al (2015) Frequency and anatomy of the retromolar canal—implications for the dental practice. Swiss Dent J 125:278–292
Fukami K, Shiozaki K, Mishima A et al (2012) Bifid mandibular canal: confirmation of limited cone beam CT findings by gross anatomical and histological investigations. Dento Maxillo Facial Radiol 41:460–465. https://doi.org/10.1259/dmfr/60245722
Galdames I (2012) Lower Third Molar Region [WWW Document]. URL/paper/Lower-Third-Molar-Region-Tercer-Galdames/279fe6c8550ee7b53f12472968a5f28b4d0f29d9. Accessed 20 Nov 17
Gamieldien MY, Van Schoor A (2016) Retromolar foramen: an anatomical study with clinical considerations. Br J Oral Maxillofac Surg 54:784–787. https://doi.org/10.1016/j.bjoms.2016.05.011
Haas DA (2011) Alternative mandibular nerve block techniques: a review of the Gow-Gates and Akinosi-Vazirani closed-mouth mandibular nerve block techniques. J Am Dent Assoc 142:8S–12S
Haas LF, Dutra K, Porporatti AL et al (2016) Anatomical variations of mandibular canal detected by panoramic radiography and CT: a systematic review and meta-analysis. Dento Maxillo Facial Radiol 45:20150310. https://doi.org/10.1259/dmfr.20150310
Han S-S, Hwang Y-S (2014) Cone beam CT findings of retromolar canals in a Korean population. Surg Radiol Anat SRA 36:871–876. https://doi.org/10.1007/s00276-014-1262-1
Han S-S, Park C-S (2013) Cone beam CT findings of retromolar canals: report of cases and literature review. Imaging Sci Dent 43:309–312. https://doi.org/10.5624/isd.2013.43.4.309
He P, Iwanaga J, Matsushita Y et al (2017) A comparative review of mandibular orthognathic surgeries with a focus on intraoral Vertico-sagittal ramus osteotomy. Cureus 9
He P, Iwanaga J, Truong MK et al (2017) First report of tripled retromolar foramina. Cureus 9:e1440. https://doi.org/10.7759/cureus.1440
Hölzle FW, Wolff KD (2001) Anatomic position of the lingual nerve in the mandibular third molar region with special consideration of an atrophied mandibular crest: an anatomical study. Int J Oral Maxillofac Surg 30:333–338. https://doi.org/10.1054/ijom.2001.0064
Horta R, Nascimento R, Silva A et al (2016) The Retromolar Trigone: anatomy, cancer treatment modalities, reconstruction, and a classification system. J Craniofac Surg 27:1070–1076. https://doi.org/10.1097/SCS.0000000000002625
Iwanaga J (2017) The clinical view for dissection of the lingual nerve with application to minimizing iatrogenic injury. Clin Anat N Y N 30:467–469. https://doi.org/10.1002/ca.22877
Iwanaga J, Watanabe K, Saga T et al (2017) A novel method for observation of the mandibular foramen: application to a better understanding of dental anatomy. Anat Rec 300:1875–1880
Kalantar Motamedi MH, Navi F, Sarabi N (2015) Bifid mandibular canals: prevalence and implications. J Oral Maxillofac Surg 73:387–390. https://doi.org/10.1016/j.joms.2014.09.011
Kang J-H, Lee K-S, Oh M-G et al (2014) The incidence and configuration of the bifid mandibular canal in Koreans by using cone-beam computed tomography. Imaging Sci Dent 44:53–60. https://doi.org/10.5624/isd.2014.44.1.53
Kawai T, Sato I, Yosue T et al (2006) Anastomosis between the inferior alveolar artery branches and submental artery in human mandible. Surg Radiol Anat SRA 28:308–310. https://doi.org/10.1007/s00276-006-0097-9
Kiesselbach JE, Chamberlain JG (1984) Clinical and anatomic observations on the relationship of the lingual nerve to the mandibular third molar region. J Oral Maxillofac Surg 42:565–567
Kikuta S, Iwanaga J, Nakamura K et al (2018) The retromolar canals and foramina: radiographic observation and application to oral surgery. Surg Radiol Anat 40:647–652. (submitted to J Craniofac Surg)
Kodera H, Hashimoto I (1995) A case of mandibular retromolar canal: elements of nerves and arteries in this canal. Kaibogaku Zasshi 70:23–30
Lizio G, Pelliccioni GA, Ghigi G et al (2013) Radiographic assessment of the mandibular retromolar canal using cone-beam computed tomography. Acta Odontol Scand 71:650–655. https://doi.org/10.3109/00016357.2012.704393
Lopez FB, Cantin LM, Sandoval MC (2008) Biomethrics study of the retromolar pad. Int J Odontostomat 2:39–42
Luaces Rey R, Lorenzo Franco F, Gómez Oliveira G et al (2007) Oral leiomyoma in retromolar trigone: A case report. Medicina Oral, Patología Oral y Cirugía Bucal (Internet), 12:53–55
Mccrorie JW, Hall DC (1965) A histological investigation of the retromolar and pear-shaped pad. Dent Pract Dent Rec 15:237–239
Monson LA (2013) Bilateral sagittal split osteotomy. Semin Plast Surg 27:145–148. https://doi.org/10.1055/s-0033-1357111
Motamedi MHK, Gharedaghi J, Mehralizadeh S et al (2016) Anthropomorphic assessment of the retromolar foramen and retromolar nerve: anomaly or variation of normal anatomy? Int J Oral Maxillofac Surg 45:241–244. https://doi.org/10.1016/j.ijom.2015.10.017
Muinelo-Lorenzo J, Suárez-Quintanilla JA, Fernández-Alonso A et al (2014) Descriptive study of the bifid mandibular canals and retromolar foramina: cone beam CT vs panoramic radiography. Dento Maxillo Facial Radiol 43:20140090. https://doi.org/10.1259/dmfr.20140090
Naitoh M, Hiraiwa Y, Aimiya H et al (2009) Observation of bifid mandibular canal using cone-beam computerized tomography. Int J Oral Maxillofac Implants 24:155–159
Obwegeser HL (2007) Orthognathic surgery and a tale of how three procedures came to be: a letter to the next generations of surgeons. Clin Plast Surg 34:331–355. https://doi.org/10.1016/j.cps.2007.05.014
Ogawa A, Fukuta Y, Nakasato H et al (2016) Evaluation by dental cone-beam computed tomography of the incidence and sites of branches of the inferior dental canal that supply mandibular third molars. Br J Oral Maxillofac Surg. https://doi.org/10.1016/j.bjoms.2016.08.007
Ossenberg NS (1987) Retromolar foramen of the human mandible. Am J Phys Anthropol 73:119–128. https://doi.org/10.1002/ajpa.1330730112
Patil S, Matsuda Y, Nakajima K et al (2013) Retromolar canals as observed on cone-beam computed tomography: their incidence, course, and characteristics. Oral Surg Oral Med Oral Pathol Oral Radiol 115:692–699. https://doi.org/10.1016/j.oooo.2013.02.012
Pogrel MA, Renaut A, Schmidt B et al (1995) The relationship of the lingual nerve to the mandibular third molar region: an anatomic study. J Oral Maxillofac Surg 53:1178–1181. https://doi.org/10.1016/0278-2391(95)90630-4
Potu BK, Kumar V, Salem A-H et al (2014a) Occurrence of the retromolar foramen in dry mandibles of South-eastern part of India: a morphological study with review of the literature. Anat Res Int 2014:296717. https://doi.org/10.1155/2014/296717
Potu BK, Kumar V, Salem A-H, et al (2014b) Occurrence of the retromolar foramen in dry mandibles of south-eastern part of India: a morphological study with review of the literature [WWW Document]. Anat Res Int. https://www.hindawi.com/journals/ari/2014/296717/. Accessed 10 Dec 17
Pyle MA, Jasinevicius TR, Lalumandier JA et al (1999) Prevalence and implications of accessory retromolar foramina in clinical dentistry. Gen Dent 47:500–503. 505
Robinson RE (1966) The distal wedge operation. Periodontics 4:256–264
Schejtman R, Devoto FC, Arias NH (1967) The origin and distribution of the elements of the human mandibular retromolar canal. Arch Oral Biol 12:1261–1268
Singh S (1981) Aberrant buccal nerve encountered at third molar surgery. Oral Surg Oral Med Oral Pathol 52:142. https://doi.org/10.1016/0030-4220(81)90310-8
Sisman Y, Ercan-Sekerci A, Payveren-Arikan M et al (2015) Diagnostic accuracy of cone-beam CT compared with panoramic images in predicting retromolar canal during extraction of impacted mandibular third molars. Med Oral Patol Oral Cir Bucal 20:e74–e81
Sittitavornwong S, Babston M, Denson D et al (2017) Clinical anatomy of the lingual nerve: a review. J Oral Maxillofac Surg 75:926.e1–926.e9. https://doi.org/10.1016/j.joms.2017.01.009
Suazo Galdames I (2012) Lower third molar region. Int J Morphol 30:970–978. https://doi.org/10.4067/S0717-95022012000300034
Suazo Galdames IC, Cantín López MG, Zavando Matamala DA (2008) Inferior alveolar nerve block anesthesia via the retromolar triangle, an alternative for patients with blood dyscrasias. Med Oral Patol Oral Cirugia Bucal 13:E43–E47
Suazo GIC, Zavando MDA, Cantin LM (2008) Retromolar canal and foramen prevalence in dried mandibles and clinical implications. Int J Odontostomat 2:183–187
Taíeb F, Carpentier P (1989) Anatomy of the maxillary and mandibular retromolar area: effect on complete dentures. 2. The mandibular retromolar region. Cah Prothese 67:112–119
Takezawa K, Ghabriel M, Townsend G (2017) The course and distribution of the buccal nerve: clinical relevance in dentistry. Aust Dent J 63:66–71. https://doi.org/10.1111/adj.12543
Truong MK, He P, Adeeb N et al (2017) Clinical anatomy and significance of the retromolar foramina and their canals: a literature review. Cureus 9:e1781
Tubbs RS, Johnson PC, Loukas M et al (2010) Anatomical landmarks for localizing the buccal branch of the trigeminal nerve on the face. Surg Radiol Anat 32:933–935. https://doi.org/10.1007/s00276-010-0656-y
von Arx T, Hänni A, Sendi P et al (2011) Radiographic study of the mandibular retromolar canal: an anatomic structure with clinical importance. J Endod 37:1630–1635. https://doi.org/10.1016/j.joen.2011.09.007
Woelfel JB, Scheid RC, Weiss G (2012) Woelfel’s dental anatomy. Wolters Kluwer/Lippincott Williams & Wilkins, Philadelphia
Yamamoto N, Watabe Y, Iwamoto M et al (2014) A case of mucoepidermoid carcinoma with clear cell components occurring in retromolar region. The Bulletin of Tokyo Dental College 55:25–31
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He, P., Truong, M.K., Kikuta, S. (2019). Anatomy and Variations of the Retromolar Fossa. In: Iwanaga, J., Tubbs, R. (eds) Anatomical Variations in Clinical Dentistry. Springer, Cham. https://doi.org/10.1007/978-3-319-97961-8_5
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