ABSTRACT
La región anterior de la mandíbula generalmente se considera un área quirúrgica segura, con pocos riesgos de daño a estructuras anatómicas importantes. Sin embargo, esta región contiene un canal intraóseo, el canal incisivo de la mandíbula (CIM), que es la continuación del canal mandibular mesial al foramen mental, donde se encuentra el nervio incisivo de la mandíbula acompañado de estructuras vasculares. Su presencia y el curso de la inervación mandibular anterior siguen siendo un tema de debate y algunos autores incluso niegan su existencia. Este reporte define el curso anatómico del CIM bilateralmente mediante tomografía computarizada, confirmando la presencia del nervio incisivo de la mandíbula mediante técnica microquirúrgica asistida por endoscopía. El conocimiento de la presencia, longitud y diámetro del CIM pueden jugar un rol importante en el éxito de la oseointegración de un implante y prevenir alteraciones sensoriales postoperatorias.
The anterior mandible region is generally considered a safe surgical area, involving few risks of damage to vital anatomic structures. However, this area has an intraosseous canal, the mandibular incisive canal (MIC), the continuation of the mandibular canal, mesial to the mental foramen where the mandibular incisive nerve along with vascular structures is located. The presence and course of the incisive nerve remains a matter of debate and some authors even neglect it. This case report defines the anatomic courses of the incisive mandibular canal bilaterally using cone-beam computed tomography and confirms the presence of the incisive nerve by endoscopically assisted surgical technique. The knowledge of the MIC presence, length and diameter may play an important role in successful implant osseointegration and prevention of postoperative sensory disturbances.
Subject(s)
Humans , Female , Middle Aged , Dental Implantation , Mandible/anatomy & histology , Mandible/surgery , Mandibular Nerve/anatomy & histology , Tomography, X-Ray Computed , Mandible/innervation , Mandible/diagnostic imaging , MicrosurgeryABSTRACT
BACKGROUND: When surgeons plan mandible ortho surgery for patients with skeletal class III facial asymmetry, they must be consider the exact method of surgery for correction of the facial asymmetry. Three-dimensional (3D) CT imaging is efficient in depicting specific structures in the craniofacial area. It reproduces actual measurements by minimizing errors from patient movement and allows for image magnification. Due to the rapid development of digital image technology and the expansion of treatment range, rapid progress has been made in the study of three-dimensional facial skeleton analysis. The purpose of this study was to conduct 3D CT image comparisons of mandible changes after mandibular surgery in facial asymmetry patients. MATERIALS & METHODS: This study included 7 patients who underwent 3D CT before and after correction of facial asymmetry in the oral and maxillofacial surgery department of Yeungnam University Hospital between August 2002 and November 2005. Patients included 2 males and 5 females, with ages ranging from 16 years to 30 years (average 21.4 years). Frontal CT images were obtained before and after surgery, and changes in mandible angle and length were measured. RESULTS: When we compared the measurements obtained before and after mandibular surgery in facial asymmetry patients, correction of facial asymmetry was identified on the "after" images. The mean difference between the right and left mandibular angles before mandibular surgery was 7degrees, whereas after mandibular surgery it was 1.5degrees. The right and left mandibular length ratios subtracted from 1 was 0.114 before mandibular surgery, while it was 0.036 after mandibular surgery. The differences were analyzed using the nonparametric test and the Wilcoxon signed ranks test (p<0.05). CONCLUSION: The system that has been developed produces an accurate three-dimensional representation of the skull, upon which individualized surgery of the skull and jaws is easily performed. The system also permits accurate measurement and monitoring of postsurgical changes to the face and jaws through reproducible and noninvasive means.