萎縮した下顎の解剖学的特徴1.萎縮下顎における下顎管の位置

[Anatomy of the atrophic mandible. 1. The location of the mandibular canal in the atrophic mandible].

• C Ulm
• U Pechmann
• L Ertl
• H Gruber
• P Solar
• M Matejka

抄録

43名の萎縮した左半身の大顎を、心窩部と第三大臼歯の間に6本のノコギリで切断して分割し、下顎管の位置を解析しました。Atwoodの分類を用いて歯槽膿漏の重症度で大顎を分類し，下顎体の上縁と下縁からの下顎管の距離の変化を萎縮の程度と相関させた。測定はデジタイザーとコンピュータを用いて行い、結果を統計的に分析した。その結果、以下のような統計的に有意な結果が得られた。下顎管と外リンガおよび頬側皮質層との距離は、萎縮度の増加に伴って変化せず、ほぼ一定であった。対照的に、下顎体の距離には非常に大きな変化が見られた。この変化は、下縁よりも上縁でより顕著であった。この変化は、第一大臼歯のレベルで一貫して最も深刻であった。萎縮した下顎を対象とした外科手術を行う前には、下腹神経の損傷を避け、法医学的な結果を排除するために、オルソパントモグラフィー、テレメトリックX線、断層撮影、CT、MRIなどの画像技術を用いて、下顎管の位置を必ず確認する必要があります。

43 atrophic left hemimandibles were divided by 6 saw cuts made between the mental foramen and the third molar to analyze the location of the mandibular canal. Mandibles were classified by the severity of alveolar absorption using Atwood's classification and changes in the distances of the mandibular canal from the superior and inferior borders of the mandibular body were correlated wit the degree of atrophy. Measurements were obtained with a digitizer and a computer and results were analyzed statistically. The following statistically significant observations were made: The distance of the mandibular canal to the external lingua and buccal cortical layers did not change with increasing atrophy, but remained remarkably constant. By contrast, highly significant changes in the distance of the mandibular body were found to be present. These were more pronounced at the superior than at the inferior border. The changes seen were consistently most severe at the level of the first molar. Prior to surgical interventions involving an atrophic mandible the location of the mandibular canal should invariably be identified by imaging techniques such as orthopantomography, telemetric X-rays, tomographies, CT and MRI, if indicated, in order to avoid injuries of the inferior alveloar nerve and preclude forensic consequences.