3-dimensional reconstruction of mandibular canal at the interforaminal region using micro-computed tomography in Korean

PURPOSE: The purpose of this study was to identify the complex course of the mandibular canal using 3D reconstruction of microCT images and to provide the diagram for clinicians to help them understand at the interforaminal region in Korean. MATERIALS AND METHODS: Twenty-six hemimandibles obtained from cadavers were examined using microCT, and the images were reconstructed. At both the midpoint of mental foramen and the tip of anterior loop, the bucco-lingual position, the height from the mandibular inferior border, the horizontal distance between two points, and position relative to tooth site on the mandibular canal were measured. The angle that the mental canal diverges from the mandibular canal was measured in posteriorsuperior and lateral-superior direction. RESULTS: The buccal distance from the mandibular canal was significantly much shorter than lingual distance at both the mental foramen and the tip of anterior loop. The mandibular canal at the tip of anterior loop was significantly located closer to buccal side and higher than at the mental foramen. And the mental canal most commonly diverged from the mandibular canal below the first premolar by approximately 50° posterior-superior and 41° lateral-superior direction, which had with a mean length of 5.19 mm in front of the mental foramen, and exited to the mental foramen below the second premolar. CONCLUSION: These results suggest that it could form a hazardous tetrahedron space at the interforaminal region, thus, the clinician need to pay attention to the width of a premolar tooth from the mental foramen during dental implant placement.

Morphometric Analysis of the Facial Artery in Perioral Region / 체질인류학회지

The facial artery is the largest and main arterial supply of the face, and the inferior and superior labial arteries supply blood to the lower and upper lips and intersect on the opposite site. The aim of this study was to provide quantitative data on the course of facial artery and the distribution of inferior and superior labial artery in perioral region. The location, distance, course, and diameter of the facial artery, inferior labial artery, and superior labial artery were measured directly on 50 hemifacial cadavers of Koreans and statistically analyzed using oneway ANOVA. The facial artery was located 18.50 mm lateral to the mouth corners (Cheilions). The inferior labial artery at its origin was located 15.11 mm inferior and 19.63 mm lateral to the Cheilions. The superior labial artery at its origin was located 5.83 mm superior and 11.28 mm lateral to the Cheilions. The diameter of facial artery, inferior labial artery, and superior labial artery was 2.19, 1.56, and 1.48 mm, respectively. The courses of the facial artery and it's branches showed no significant differences on laterality except for the diameter of the superior labial artery (p=0.026). The buccal branch of facial artery was showed in 44% of the cases in the deep layer of perioral region. In conclusion, this study provides that the data will be useful in predicting the courses of the facial artery and helpful for reconstructive surgery in perioral region.

Cortical Neuronal Loss after Chronic Prenatal Hypoxia: A Comparative Laboratory Study

OBJECTIVE: The purpose of this study was to investigate the prenatal hypoxic effect on the fetal brain development. METHODS: We used the guinea pig chronic placental insufficiency model to investigate the effect of hypoxia on fetal brain development. We ligated unilateral uterine artery at 30-32 days of gestation (dg : with term defined as -67 dg). At 50 dg, 60 dg, fetuses were sacrificed and assigned to either the growth-restricted (GR) or control (no ligation) group. After fixation, dissection, and sectioning of cerebral tissue from these animals, immunohistochemistry was performed with NeuN antibody, which is a mature neuronal marker in the cerebral cortex. RESULTS: The number of NeuN-immunoreactive (IR) cells in the cerebral cortex did not differ between the GR and control groups at 50 dg. However, the number of NeuN-IR cells was lesser in GR fetuses than in controls at 60 dg (p<0.05). CONCLUSION: These findings show that chronic prenatal hypoxia affect the number of neuron in the cerebral cortex of guinea pig fetus at 60 dg. The approach used in this study is helpful for extending our understanding of neurogenesis in the cerebral cortex, and the findings may be useful for elucidating the brain injury caused by prenatal hypoxia.

Serious Penetrating Craniocerebral Injury Caused by a Nail Gun

Penetrating cerebral injuries caused by foreign bodies occur rarely due to the substantial mechanical protection offered by the skull. Throughout most of history, the brain, residing in a "closed box" of bone, has not been vulnerable to external aggression. Recently, we encountered a serious penetrating craniocerebral injury caused by a nail gun. Total excision of the offending nail via emergency craniotomy was performed, but the patient's neurologic status was not improved in spite of aggressive rehabilitative treatment. Here, we report on this troublesome case in light of a review of the relevant literature.

Arthroscopic Meniscectomy in Bucket Handle Tear of the Meniscus / 대한정형외과학회잡지

Recently, the frequency of meniscal injury of knee has been increasing due to increase of sports activities. It has been known that bucket handle tear is the most common type of the entire injuries of the meniscus. We found 127 cases of meniscal tears and experienced 42 cases of bucket handle tears in the arthroscopic findings from Jan. 1991 to April 1994 in our hospital. We analysed 31 cases which were followed up for at least 1 year. The purpose of this study is to analyse the locking history and frequency, to discuss the several types of bucket handle tear in arthroscopic view, to introduce three portal techniques using posteormedial or posterolateral portal to resect the meniscus, and to analyse our clinical results. So we concluded as follows. 1. Among the 31 cases, 23 cases(74%) had an episode of locking. 2. We found many different types of bucket handle tears in arthroscopic view and the most common type was complete tear in a classic type(11 cases). 3. We were able to resect the meniscal fragment very easily using posteromedial or posterolateral portal. 4. We obtained satisfactory results in 24 cases(77%).