J Korean Assoc Oral Maxillofac Surg.  2006 Dec;32(6):566-574.

The study by using the computerized tomography imaging in order to access to mandibular foramen while inferior alveolar nerve anesthesia

• Kim JK
• Gu H
• An JS
• Kook MS
• Park HJ
• Oh HK
• Cho JH

Abstract

PURPOSE: This study was performed to provide an anatomical information of the mandibular ramus for the successful inferior alveolar nerve block. Three dimensional images were reconstructed from the computerized tomography (CT) and the anatomical evaluation of the mandibular ramus was done.
MATERIALS AND METHODS
Sixty-four patients who had been taken the facial CT scans from 2000, Jan to 2003, June was selected. The patients who had the anterior or posterior teeth misssing, edentulous ridge, and jaw fracture were excepted. In the occulusal plane, the lingual surface angle (LSA) between the mid-sagittal plane and the mandibular molar lingual surface from the 2nd premolar to the 2nd molar, the inner ramal surface angle (IRSA), the maximum inner ramal surface angle (MxIRSA), and the outer ramal surface angle (ORSA) to the-mid sagittal plane were MEASURED: The inner ramal surface angle in the ligular tip level (IRSA-L) and the outer ramal surface angle in the ligular tip level (ORSA-L), the ramal length (RL), and the anterior ramal length (ARL) were also measured in the lingular tip level.
RESULTS
In the lingular tip level, the mean IRSA-L and ORSA-L were 28.6+/-6.3 degrees and 17.9+/-4.9 degrees respectively. The larger was the IRSA, the larger was the ORSA. In the lingular tip level, the mean ramal length was 35.8+/-3.4 mm. The larger was the IRSA-L, the shorter was the ramal length. On the lingular tip level, the mean anterior ramal length from anterior ramus to lingular tip was 19.6+/-3.3 mm. when the ramal length was longer, the anterior ramal length was also longer. On the lingular tip level, there was positive correlation vetween the IRSA and the ORSA, negative correlation between the IRSA and the ramal length, and positive correlation between the ramal length and the lingular tip level to the anterior ramus. There was no statistical meaning of data between sex and age.
CONCLUSION
In the clinical view of the results so far achieved, if the direction of needle is closer to posterior it is able to contact bone on lingular tip when the internal surface of ramus is wided outer.

Keyword

Computerized tomography (CT); ORSA; IRSA; LSA; RL; ARL

MeSH Terms

Anesthesia*
Bicuspid
Humans
Jaw Fractures
Mandibular Nerve*
Molar
Needles
Tomography, X-Ray Computed
Tooth