Incidence, types and clinical implications of a non-metrical variant - mylohyoid bridging in human mandibles

• Autorzy: Narayana K , Narayan P. , Ashwin K. , Prabhu L.V.
• Języki publikacji: EN

Abstrakty

EN

Mylohyoid bridging (MB) is a non-metrical variant of the human mandible. The incidence and types of MB were investigated in 264 mandibles (edentulous 116, semi-dentulous 90 and dentulous 58). No mandible showed a complete type of MB, although 19 (7.2%) mandibles had a partial type. These were classified into two subtypes: distal partial (DP; Type I) and proximal partial (PP; Type II), depending on their location over the mylohyoid groove. The MB was present unilaterally in 7.76% of edentulous mandibles: right side 5.17% (3.45% PP type and 1.72% DP type) and left side 2.59% (1.72% PP type and 0.86% DP type). Of the semi-dentulous mandibles 3.33% had DP type of MB, 1.11% on the right side and 2.22% on the left side, and of the dentulous mandibles 1.72% had DP type of MB on the right side. A total of 13 mandibles out of 264 (4.92%) had unilateral MB. No dentulous mandible had bilateral MB, but 3.45% of edentulous and 2.22% of semi-dentulous mandibles did have. In total, 6 mandibles out of 264 bones (2.27%) had bilateral MB. Of the bilateral incidences 1.72% of edentulous mandibles had a DP-DP combination and the remaining 1.72% had a PP-DP combination. However, both instances of bilateral MB in semi-dentulous mandibles were of PP-DP combination. The incidence or types of MB showed no statistically significant differences between the groups or sides (p > 0.5; χ² test). In conclusion, the complete type of MB is a rare occurrence. The incidence increases with age, as edentulous mandibles had a higher incidence of MB than the other two groups. Clinically, MB may compress the mylohyoid neurovascular bundle, leading to neurological or vascular disorders.

Słowa kluczowe

EN

human mandible; inferior alveolar nerve; non-metrical variant; mylohyoid nerve; man; anatomy; mylohyoid muscle; mandibular tooth; mylohyoid bridging; mandibular foramen

• Wydawca: -
• Czasopismo: Folia Morphologica
• Rocznik: 2007
• Tom: 66
• Numer: 1
• Opis fizyczny: p.20-24,fig.,ref.

Twórcy

autor

Narayana K

• Kuwait University, P.O.Box No.24923, Safat 13110, Kuwait

autor

Narayan P.

autor

Ashwin K.

autor

Prabhu L.V.

Bibliografia

• 1. Arensburg B, Nathan H (1979) Anatomical observations on the mylohyoid groove, and the course of the mylohyoid nerve and vessels. J Oral Surg, 37: 93–96.
• 2. Asami Y, Kawai K, Kanoh T, Koizumi M, Honma S, Tokiyoshi A, Kodama K (2006) Double innervation of the anterior belly of the digastric muscle. Anat Sci Int, 81: 130–133.
• 3. Corrucini RS (1974) An examination of the meaning of cranial discrete traits for human skeletal biological studies. Am J Phys Anthropol, 40: 425–445.
• 4. Gopinathan K, Chhabra S, Dhall U (1995) Mylohyoid bridging in north Indian population. J Anat Soc India, 44: 110–125.
• 5. Hanihara T, Ishida H (2001) Frequency variations of discrete cranial traits in major human populations. III. Hyperostotic variations. J Anat, 199: 251–272.
• 6. Jidoi K, Nara T, Dodo Y (2000) Bony bridging of the mylohyoid groove of the human mandible. Anthropol Sci, 108: 345–370.
• 7. Kaul SS, Pathak RK (1984) The mylohyoid bridge in four population samples from India, with observations on its suitability as a genetic marker. Am J Phys Anthropol, 65: 213–218.
• 8. Lundy JK (1980) The mylohyoid bridge in the Khoisan of Southern Africa and its unsuitability as a mongoloid genetic marker. Am J Phys Anthropol, 53: 43–48.
• 9. Manjunath KY (2003) Mylohyoid bridging in south Indian mandibles. Indian J Dent Res, 14: 206–209.
• 10. Narayana K, Nayak UA, Ahmed WN, Bhat JG, Devaiah BA (2002) The retromolar foramen and canal in south Indian dry mandibles. Eur J Anat, 6: 141–146.
• 11. Narayana K, Prashanthi N (2003) Incidence of large accessory mandibular foramen in human mandibles. Eur J Anat, 7: 139–142.
• 12. Narayana K, Vasudha S (2004) Intraosseous course of the inferior alveolar (dental) nerve and its relative position in the mandible. Indian J Dent Res, 15: 99–102.
• 13. Narayana K, Nayak SR, Prashanthi N, Prabhu LV (2005) The location of the mandibular foramen maintains absolute bilateral symmetry in mandibles of different age groups. Hong Kong Dent J, 2: 35–37.
• 14. Ossenburg NS (1974) The mylohyoid bridge: an anomalous derivative of Meckel’s cartilage. J Dent Res, 53: 72–82.
• 15. Sato I, Sunohara M, Ueno R, Yoshida S (2004) Branch of mylohyoid and lingual nerves on submandibular and submental triangles. Okajimas Folia Anat Jpn, 81 (2–3): 45–48.
• 16. Sawyer DR, Gianfortune V, Kiely ML, Allison MJ (1990) Mylohyoid and jugular foramen bridging in pre-Columbian Chileans. Am J Phys Anthropol, 82: 179–181.
• 17. Sawyer DR, Kiely ML (1987) Jugular foramen and mylohyoid bridging in an Asian Indian population. Am J Phys Anthropol, 72: 473–477.
• 18. Soames RW (1995) Skeletal system. In: Williams PL, Banister LH, Berry MM, Collins P, Dyson M, Dussek JE, Ferguson MW (eds). Gray’s anatomy. 38th Ed., Churchill Livingstone, London, pp. 556–557.
• 19. Turan-Ozdemir S, Sendemir E (2006) Incidence of mylohyoid bridging in 13th century Byzantine mandibles. Anat Sci Int, 81: 126–129.