Biomedical subjects

Dae Kwang Lee

Publications and source records attributed to Dae Kwang Lee.

3 recordsLinked to original sources

PubMed2005

Zygomaticomandibularis muscle.

The aim of this study was to elucidate the precise anatomy of the zygomaticomandibularis muscle through cadaveric dissection and magnetic resonance imaging (MRI). Five fresh human cadavers and 10 fixed cadavers were dissected. Nine preserved human cadavers were used for the MRI study. Four volunteers took MRIs of their head as well. Zygomaticomandibularis muscle was found in all the cadaveric specimens. It is a fan shaped muscle. The length of the muscle is 25.1 +/- 4.6 mm, and the width at the zygomatic arch is 16.6 +/- 4.2 mm. The thickness is approximately 4.8 +/- 1.9 mm. It originates from the deep layer of the deep temporal fascia approximately 1 cm above the zygomatic arch and is inserted into the superior border and outer surface of the mandible between the coronoid process and mandibular notch. The deepest layer of the masseter muscle covers the lateral surface of zygomaticomandibularis. We believe that this muscle functions as coordinator of the temporalis and masseter in mammals with strong masticatory power but is a degraded or rudimentary muscle in humans.

Cadaver↗

PubMed2004

A split ostectomy of mandibular body and angle reduction.

Combined mandibular angle resection with angle-splitting ostectomy (ASO) is more effective than conventional simple or multistaged ostectomy. Removal of the outer cortex of the mandibular body by ASO lessens the protuberance of the masseter muscle. In this study, the anatomy of the mandibular canals in seven human cadavers was studied in detail, and a guideline for ASO and mandibular angle ostectomy was set up so as to avoid injury to the inferior alveolar nerve. The most vulnerable area of the inferior alveolar nerve is the line from the gonion (G) to the junction (O) of the intersecting vertical line along the anterior border of the ramus and the horizontal line on the alveolar crest because of the thin anterior distance (AD) between the buccal surface of the mandible and the outer wall of the mandibular canal. The resection line should not be above 17.5 mm at the GO line to ensure a safe inferior distance, the distance between the inferior border of the mandible and the floor of the mandibular canal (21.6 +/- 4.1 mm). The body of the mandible was less vulnerable to injury to the inferior alveolar nerve in ASO because of the relatively thicker AD at the second molar (8.3 mm) and first molar (6.8 mm). Pilot surgery was performed in five cadavers. The lateral cortex was safely split off, avoiding injury to the inferior alveolar nerve, and angle ostectomy was then done. This method was applied in two clinical cases without any complications. The "split ostectomy of mandibular body and angle reduction" is a new and safe method of avoiding the injury to the inferior alveolar nerve.

Adult↗

PubMed2002

Roberts syndrome, normal cell division, and normal intelligence.

Roberts-SC phocomelia syndrome (RS) is an autosomal recessive disorder of symmetric limb defects, craniofacial abnormalities, pre- and postnatal growth retardation, and mental retardation. Patients with RS have been reported to have premature separation of heterochromatin of many chromosomes and abnormalities in the cell-division cycle. No case has been reported who had normal intelligence and normal cell division with typical clinical features of the RS. We report a case of a six-year-old male of clinical and radiologic findings of typical RS with normal cell division and normal intelligence. Although he showed growth retardation, his intelligence was normal. Van Den Berg and Francke later reported that 79 out of 100 cases of Roberts syndrome had premature cell separation (PCS). We think that this case may demonstrate severe expression of the Roberts syndrome even though PCS is not exhibited. The limb involvement of this case was symmetrical, and he showed phocomelia of upper limbs, equinus valgus deformity of ankle, aplasia of fibula, and shortness of fifth toes while his hands and feet were normal with 5 rays each. Craniofacial abnormalities of this case were typical; he showed scaphocephaly, mild hypertelorism, mandibular hypoplasia, dysplastic helix of ear, narrowing of external auditory canal, and cleft palate with wide gap. This report supports the theory that normal intelligence can make social-personal adjustment possible even if all of the stigmata of Roberts syndrome is present.

Arm↗