Biomedical subjects

Hoon Jin

Publications and source records attributed to Hoon Jin.

5 recordsLinked to original sources

PubMed2004

Mandibular angle reduction versus mandible reduction.

The terms "mandibular angle reduction" and "reduction angleplasty" refer to operations to reduce the width of the lower face and change a square face to an oval one. Because the terms emphasize the word angle, however, they imply that the operations apply to the mandibular angle. The most frequent complaint after these operations is that the change in the lateral appearance is clear but that the change in the frontal appearance is not noticeable. Such a result is related to the fact that bone resection is performed mainly in the mandibular angle area and is focused particularly on resection of the posterior projection through curved ostectomy. That is, because operations limited to the mandibular angle area cannot properly satisfy patients' requirements, the operation must be applied to a larger area. Therefore, it seems reasonable to change the terms "mandibular angle reduction" and "reduction angleplasty" to "mandible reduction" and "reduction mandibuloplasty." In addition, the most important technique in the operation is the resection of the outer cortex of the mandible. In particular, the corticectomy technique using a reciprocating saw is quite safe and effective for the maximum resection of lateral flaring within a very short time.

Adult↗

PubMedDate not supplied

Mandibular osteotomies after drawing out the inferior alveolar nerve along the canal.

In some cases, the inferior alveolar nerve runs through a lower course than usual. In such cases, osteotomy of the mandible can injure the inferior alveolar nerves. In other instances, the course of the mandibular osteotomy can meet that of the inferior alveolar nerve. In these cases, a useful method may be excavating the canal and drawing the nerve out through it. With this technique, we can make the osteotomy as initially planned with minimal damage to the inferior alveolar nerve.

Adult↗

PubMedDate not supplied

Unexpected bleeding caused by arterial variation inferolateral to levator palpebrae.

When incisional or nonincisional double-eyelid operations are in process, unexpected bleeding adjacent to the lateral canthal area is often encountered. The unexpected bleeding may result in intraoperative hematoma and swelling. It may also cause temporary intraoperative ptosis. The intraoperative swelling along the designed double-eyelid line or temporary ptosis may prevent surgeons from taking an accurate measurement of the height of fold. Therefore, surgeons might have difficulties making symmetrical double-eyelid lines. Among the detailed dissections of 230 eyelids along the orbital septum and levator palpebrae during incisional double-eyelid operations, 25 cases of noticeable arterial variation were found adjacent to the inferolateral end of levator palpebrae. The artery is located 4-5 mm medial from the lateral canthus, at the inferior margin of levator palpebrae. During the dissections, the artery was found to be superficial to the orbital septum and it could be traced down into a deeper layer along the inferior end of levator palpebrae. It connects to the lateral canthal artery behind the levator palpebrae. During double-eyelid operations, accidental tearing of this artery, even at the superficial layer of orbital septum, might cause the retraction of the cleaved arterial end down into the levator palpebrae. The bleeding from the retracted arterial end rapidly makes a large hematoma posterior to the levator palpebrae, causing temporary intraoperative ptosis and an asymmetric double fold, and possibly retrobulbar hematoma and blindness. We should bear in mind the possibility of presence of this artery. Once bleeding of this artery begins, clamping this artery and the inferolateral portion of levator palpebrae with a hemostat is effective in preventing massive hematoma posterior to levator palpebrae and ptosis, but electocoagulation is not effective. A cadaver dissection study, with red colored latex injection into the ophthalmic artery, is in progress.

Arteries↗

PubMedDate not supplied

Misconceptions about mandible reduction procedures.

Mandible reduction procedures are currently very popular in Asian countries. But many misconceptions or differences in concepts about these procedures still exist, mainly because of preconceived ideas and restriction in communication. The author reviewed articles and found some misconceptions about these procedures. Also, the author added some opinions regarding new ideas about these procedures (i.e., minimal incision technique and botulinum toxin), as well as logical backgrounds of associated concepts. The intraoral approach is the safest and most effective procedure. The sagittal split ostectomy is the most important procedure for mandible reduction.

Asian People↗

PubMedDate not supplied

Three-dimensional mandible reduction: correction of occlusal class I in skeletal class III cases.

BACKGROUND: The human face is a three-dimensional structure. However, many studies on mandible reduction procedures are based on a two-dimensional concept, with a particular focus on one dimension: the width of the lower face. Many Korean individuals have class I occlusion with a skeletal class III pattern. When a conventional mandible reduction procedure is used on such individuals to reduce the width of the lower face, an unsatisfactory facial outcome may result because the changes in the other two dimensions of the lower face, vertical height and anteroposterior distance, are disregarded. This is true because the skeleton of the lower face is well developed in all three dimensions. METHODS: Bimaxillary surgery that reduces all three dimensions of the lower face was planned and conducted by the authors. This mandible reduction procedure reduced the protrusion of both the maxilla and the mandible and, at the same time, shortened the lower face height. The procedure consisted of a Le Fort I osteotomy for superior and/or posterior repositioning of the maxilla, followed by mandibular counterclockwise rotation and setback via a bilateral sagittal split osteotomy. Genioplasty was performed as necessary. RESULTS: With this procedure, the entire lower face volume is reduced, and the overall profile is improved. CONCLUSIONS: Three-dimensional mandible reduction greatly enhances the aesthetic outcome by improving the skeletal characteristics of the face common in the Korean population so that the facial measurements more closely approach normal values.

Adult↗