Vol 66, No 1 (2007)
Original article
Submitted: 2012-02-06
Published online: 2006-12-14
Incidence, types and clinical implications of a non-metrical variant - mylohyoid bridging in human mandibles
K. Narayana, P. Narayan, K. Ashwin, L.V. Prabhu
Folia Morphol 2007;66(1):20-24.
Vol 66, No 1 (2007)
ORIGINAL ARTICLES
Submitted: 2012-02-06
Published online: 2006-12-14
Abstract
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.
Abstract
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.
Keywords
mandibular foramen; mylohyoid nerve; inferior alveolar nerve; mandibular teeth; mylohyoid muscle; Meckel`s cartilage
Title
Incidence, types and clinical implications of a non-metrical variant - mylohyoid bridging in human mandibles
Journal
Folia Morphologica
Issue
Vol 66, No 1 (2007)
Article type
Original article
Pages
20-24
Published online
2006-12-14
Page views
566
Article views/downloads
1475
Bibliographic record
Folia Morphol 2007;66(1):20-24.
Keywords
mandibular foramen
mylohyoid nerve
inferior alveolar nerve
mandibular teeth
mylohyoid muscle
Meckel`s cartilage
Authors
K. Narayana
P. Narayan
K. Ashwin
L.V. Prabhu