JIAOMR CASE REPORT An Incidental Finding of Enlarged Genial Tubercles in a Case of Oral Carcinoma An Incidental Finding of Enlarged Genial Tubercles in a Case of Oral Carcinoma 1SC Selvamuthukumar, 2Nalini Aswath, 3B Karthika 1Professor and Head, Department of Oral Medicine Diagnosis and Radiology, Sree Balaji Dental College and Hospital Narayanapuram, Velachery Main Road, Chennai, Tamil Nadu, India 2Professor, Department of Oral Medicine Diagnosis and Radiology, Sree Balaji Dental College and Hospital Narayanapuram, Velachery Main Road, Chennai, Tamil Nadu, India 3 Postgraduate Student, Department of Oral Medicine Diagnosis and Radiology, Sree Balaji Dental College and Hospital Narayanapuram, Velachery Main Road, Chennai, Tamil Nadu, India Correspondence: SC Selvamuthukumar, Professor and Head, Department of Oral Medicine Diagnosis and Radiology Sree Balaji Dental College and Hospital, Narayanapuram, Velachery Main Road, Chennai: 601302, Tamil Nadu, India e-mail: [email protected]

Abstract The genial tubercles are a group of bony extensions that surround the bilaterally in the midway between the superior and inferior borders of the lingual surface of the . Enlargement of genial tubercle occurs very rarely due to hypertrophy. This article focuses on a rare case showing hypertrophy of the genial tubercles. Keywords: Genial tubercles, mental spine, hypertrophy, computed tomography.

INTRODUCTION The symphysis menti is a faint ridge in the median line where the right and left halves of the mandibular meet each other. There are four small elevations on the lingual surface of the symphysis menti which is called superior and inferior genial tubercles depending upon their position. Usually genial tubercles occurs as a rudimentary cortical elevation that gives attachment to the from inferior surface and to the muscle from superior surface. Very rarely hypertrophied genial tubercles occur as an anatomical variant.1 The genial tubercles are synonymously called as mental spine, genial apophysis, and spinae mentalis. This case report highlights the rare occurrence of genial tubercle hypertrophy which was identified incidentally during the process of investigating a case of oral carcinoma. Fig. 1: A ulceroproliferative lesion in the right alveolar mucosa CASE REPORT A 70 years old man reported to the department with history of swelling was noticed and it extends from the midline of the severe pain in a decayed right lower molar and a painful ulcer in lingual surface of the mandible posteriorly in the floor of the the same region since one month. His past medical history mouth. Tubular bony hard swelling was nontender and measures revealed that the patient was hypertensive but did not take the of about 18 mm in length and 7 mm in width. prescribed medication as he could not afford it. Orthopantomograph (Fig. 2) revealed a radiolucent lesion Extraoral examination revealed a dome shaped swelling in with irregular bony margins in the right body of the mandible. right side of the face over the body of the mandible. The right Axial CT of the mandible shows erosion in the right body of the submandibular lymph nodes were palpable, stony hard in mandible (Fig. 3). consistency and fixed to the underlying tissue. Mandibular occlusal radiograph (Fig. 4) revealed a Intraoral examination revealed an ulceroproliferative lesion radiopaque spike like projection with the radiodensity similar to in the alveolar mucosa in relation to premolar and molar regions the adjacent mandibular cortical bone that extends from the (Fig. 1). The ulceroproliferative lesion appears erythematous midline of the lingual surface of the mandible towards posteriorly and edematous with rolled and keratotic margin. On palpation, in the floor of the mouth. This radiopaque projection measures the ulceroproliferative lesion was tender and indurated. On of about 18 mm in length. 3D reconstruction computer bimanual palpation in sublingual region, a tubular bony hard tomography confirmed a hyperdense linear projection

Journal of Indian Academy of Oral Medicine and Radiology, April-June 2010;22(2):99-101 99 SC Selvamuthukumar et al

Fig. 2: OPG showing a radiolucent lesion with irregular bony margins in the right mandibular body

Fig. 5: 3D reconstruction in axial direction of the genial tubercles

Fig. 3: Axial CT of the mandible shows erosion in the right body of the mandible Fig. 6: Photomicrograph

diagnosed as moderately differentiated squamous cell carcinoma in right side of the mandible and hypertrophy of genial tubercle.

DISCUSSION Thomson, in 1915, examined 1,670 from anthropoids and concluded that the genial tubercles may be absent, replaced by pits, and in some cases well-developed.1 In 1955 Monheimer has reported an unusual case of exostosis of the genial tubercles in Maori man that measures of about 13 mm wide and 9 mm heigh.2 Murphy's study in 1957 reported female prediction in occurrence of hypertrophied genial tubercle.3 In 1970 Fig. 4: Occlusal radiograph showing enlarged genital tubercle Wiesenbaugh et al reported enlargement of the genial tubercles on patients, but the length was not mentioned.4 Oda LS et al in originating from the genial tubercular region. The Hounsfield 1977 concluded that the tubercles seem to diminish with age, unit of this projection is similar to the adjacent mandibular cortical especially in complete edentulous individuals.5 Later in 1992 bone. Thus 3D reconstruction image confirms the enlarged MacLeod et al also reported enlargement of the genial tubercles genial tubercle (Fig. 5). on patients.6 In other mandible specimens, the tubercles Photomicrograph (Fig. 6) of histopathology showing measured 10 mm in length.7 In 2003, Izhar Shohat et al has evidence of moderately differentiated squamous cell carcinoma. reported that enlarged genial tubercle acts as a frequent site of From the clinical examination and investigations this case was fracture in patients wearing a complete mandibular denture, 100 JAYPEE An Incidental Finding of Enlarged Genial Tubercles in a Case of Oral Carcinoma when the mandible is atrophied and the genial tubercles are 4. Wiesenbaugh JM, Bingham C. Sialolithiasis and enlarged genial hypertrophied.8 In 2006 Yassutaka Faria Yaedú et al reported tubercles. Oral Surg Oral Med Oral Pathol 1970;30:506-07. that spontaneous fracture of genial tubercle occur in edentulous 5. Oda LS, Iyomasa MM, Watanabe IS. Morphologic analysis of the 9 "spina mentalis" in adult mandibles of Brazilian whites and Negroes. mandible. Later numerous researchers analyzed the genial Rev Bras Pesqui Med Biol 1977;10:357-60. tubercles concerning size, site and association with adjacent 6. MacLeod SP, MacIntyre DR. Case report: CalciWcation of structure has been reported.10 In 2007 Hueman et al has proven genioglossus-a painful radiographic Wedding. Clin Radiol 1992; accuracy of cone beam in determining the location of the genial 46:137-38. 11 7. Greyling LM, Le Grange F, Meiring JH. Mandibular spine: A case tubercle. Izabel Rubira et al in 2009 reported that enlarged report. Clin Anat 1997;10:416-18. genial tubercles produced a painful hard swelling on the floor 8. Izhar Shohat, Yitzhak Shoshani, Shlomo Taicher. Fracture of the of the mouth in a completely edentulous mandible due to severe genial tubercles associated with a mandibular denture: A clinical resorption of the alveolar Ridge.12 In our case enlarged genial report. J Prosthet Dent 2003;89:232-33. tubercle measures of about 18 mm in length and 7 mm in width, 9. Yassutaka Faria Yaedú R, Regina Fisher Rubira-Bullen I, Sant'Ana E. Spontaneous fracture of genial tubercles: Case report. Quintessence which from our current knowledge appears to be the longest Int 2006;37:737-39. reported so far in the literature. Figures 4 and 5 shows the image 10. Yin SK, Yi HL, Lu WY, Guan J, Wu HM, Cao ZY, Yu DZ, Huang of the mandible showing enlarged genial tubercle. YY, Wu CG. Anatomic and spiral computed tomography study of the genial tubercles and genioglossus advancement. Otolaryngol REFERENCES Head Neck Surg 2007;136:632-37. 11. Hueman EM, Noujeim ME, Langlais RP, Prihoda TJ, Miller FR. 1. Thomson A. On the presence of genial tubercles on the mandible Accuracy of cone beam computed tomography in determining the of man, and their suggested association with the faculty of speech. location of the genial tubercle. Otolaryngol Head Neck Surg 2007; J Anat Physiol 1915;50:43-74. 137:115-18. 2. Monheimer BM. Exostosis of the genial tubercles of the mandible. 12. Izabel Rubira-Bullen, Eduardo Sant_Ana, Renato Faria Yaedú, Elen NZ Med J 1957;56:576-79. Sousa Tolentino, Evandro Borgo (Springer-Verlag 2009) Rare 3. Murphy T. The region of the Australian aboriginal mandible. enlargement of the genial tubercles. Surg Radiol Anat DOI 10.1007/ Is J Phys Anthropol 1957;15:517-35. s00276-009-0581-0.

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