Course and Distribution of the Lingual Nerve in the Ventral Tongue Region: Anatomical Considerations for Frenectomy

Yang, Hun-Mu,Woo, Yong-Je,Won, Sung-Yoon,Kim, Da-Hye,Hu, Kyung-Seok,Kim, Hee-Jin Mutaz B. Habal, MD 2009 JOURNAL OF CRANIOFACIAL SURGERY - Vol.20 No.5

The aim of this study was to elucidate the sublingual and intralingual courses of the lingual nerve (LN) in the ventral tongue region, providing a clinical guide for safe surgical procedures such as frenectomy. We evaluated 16 specimens (32 sides) by gross observation after detailed dissections, and a further 6 specimens were examined after Sihler staining. All specimens were harvested from embalmed Korean cadavers. We classified the innervation patterns of the LN into 5 types and confirmed the distribution of the LN in the tip of the tongue. The classification of the LN was made with reference to a line formed by the interlacing of the styloglossus and genioglossus muscles. Based on the course of LN and the presence of a tiny twig (twigs directly innervating the ventral mucosa of the tongue, TM) directly innervating the sublingual mucosa, the course of the LN was classified as being straight, curved, or vertical and with or without the TM. Straight, curved, and vertical courses without the TM were seen in 9.4%, 46.9%, and 18.8% of the cases, respectively. Straight and curved courses with the TM were observed in 6.3% and 18.8% of the cases, respectively. Sihler staining revealed that the tongue tip is innervated by the LN. These findings indicate that surgical manipulations at the ventral tongue region might damage the LN and result in numbness of the tongue tip, and provide a useful anatomic reference for various surgical procedures involving the ventral tongue region.

Innervation Patterns of the Canine Masticatory Muscles in Comparison to Human

Yang, Hun-Mu,Hu, Kyung-Seok,Song, Woo-Chul,Park, Jong-Tae,Kim, Heung-Joong,Koh, Ki-Seok,Kim, Hee-Jin Wiley (John WileySons) 2010 The anatomical record Vol.293 No.1

The Sihler Staining Study of the Infraorbital Nerve and Its Clinical Complication

Yang, Hun-Mu,Won, Sung-Yoon,Lee, Young-Il,Kim, Hee-Jin,Hu, Kyung-Seok by Mutaz B. Habal, MD. 2014 JOURNAL OF CRANIOFACIAL SURGERY - Vol.25 No.6

ABSTRACT: The infraorbital nerve (ION) is a cardinal cutaneous nerve that provides general sensation to the mid face. Its twigs are vulnerable to iatrogenic damage during medical and dental manipulations. The aims of this study were to elucidate the distribution pattern of the ION and thus help to prevent nerve damage during medical procedures and to enable accurate prognostic evaluation where complications do occur. This was achieved by treating 7 human hemifaces with the Sihler modified staining protocol, which enables clear visualization of the course and distribution of nerves without the accidental displacement of these structures that can occur during classic dissection. The twigs of the ION can be classified into the usual 5 groups: inferior palpebral, innervating the lower eyelid in a fan-shaped area; external and internal nasal, reaching the nosewing and philtrum including the septal area between the nostrils, respectively; as well as medial and lateral superior labial, supplying the superior labial area from the midline to the mouth corner. Of particular note, the superior labial twigs fully innervated the infraorbital triangle formed by the infraorbital foramen, the most lateral point of the nosewing, and the mouth corner. In the superior 3-quarter area, the ION twigs made anastomoses with the buccal branches of the facial nerve, forming an infraorbital nervous plexus. The infraorbital triangle may be considered a dangerous zone with respect to the risk for iatrogenic complications associated with the various medical interventions such as implant placement.

The Buccofacial Wall of Maxillary Sinus: An Anatomical Consideration for Sinus Augmentation

Yang, Hun-Mu,Kyong Bae, Hanna Eun,Won, Sung-Yoon,Hu, Kyung-Seok,Song, Woo-Chul,Paik, Doo-Jin,Kim, Hee-Jin Wiley (Blackwell Publishing) 2009 Clinical Implant Dentistry and Related Research Vol. No.

<P>PURPOSE: This study aimed to quantify the thickness of the buccofacial wall of the maxillary sinus where sinus augmentations are often performed. MATERIALS AND METHODS: Fourteen sites located 15 and 20 mm superior to the anatomical cervical line (named as groups H15 and H20, respectively) and along the long axes of the mid and the interproximal of two premolars and two molars were measured from 74 Korean hemiface cadavers. RESULTS: The buccofacial wall of the maxillary sinus was thinnest at the area between the maxillary second premolar and first molar in groups H15 and H20. The lowest mean thickness was 1.2 mm in both groups. The walls were thicker in males than in females, with statistically significant gender differences found at four and two sites on the anterior horizontal reference in groups H15 and H20, respectively. However, the thickness did not differ significantly with age or laterality. Incomplete septa were found in seven of the 74 specimens, and they were present in the area between the first and second molars in six (86%) of these cases. CONCLUSIONS: These observations indicate that anatomical characteristics of the buccofacial wall thickness of the maxillary sinus need to be considered when performing a window opening procedure for sinus augmentation.</P>

Distributing pattern of the mandibular nerve innervations to temporalis, zygomaticomandibularis and masster muscles of dog

Hun-Mu YANG,Jong-Tae PARK,Kyung-Seok HU,Heung-Joong KIM,Hee-Jin KIM 대한체질인류학회 2008 대한체질인류학회 학술대회 연제 초록 Vol.51 No.-

Phylogenic Oto-stomatognathic Connection of the Mammalian Jaw

Hun-Mu Yang(양헌무),Kyung-Seok Hu(허경석),Hee-Jin Kim(김희진) 대한체질인류학회 2015 해부·생물인류학 (Anat Biol Anthropol) Vol.28 No.2

턱관절장애는 귀통증, 귀울림, 어지러움 및 청각 손실 등과 같은 귀의 이상증상과 관련이 있다. 씹기근육, 가운데귀공간 및 턱관절의 밀접한 해부학적 관련성을 바탕으로 턱관절장애-귀관련질환에 대한 다양한 가설이 제시되고 있다. 특히 고막긴장근 (tensor tympani muscle)은 턱관절장애 관련 귀질환 (TMD-related otologic complications)을 이해하는 데 중요한 근육이다. 삼차신경이 분포하는 고막긴장근은 망치뼈자루에 붙어 귓속뼈의 소리전달조절 기능을 한다. 병적인 고막긴장근의 자발적 수축 (voluntary eardrum movement)은 다양한 귀질환의 원인으로 여겨지고 있다. 따라서 고막긴장근이 씹기근육과 공동수축을 하는 것은 턱관절장애 관련 귀질환을 이해하는 데 중요한 현상이다. 본 연구는 기존의 문헌을 바탕으로 귀와 씹기계통의 계통발생학적 연관성을 고찰하고, 고막긴장근과 씹기구조의 계통발생학적 연관성이 턱관절장애 관련 귀질환에 중요한 역할을 할 것이라는 가설을 제시하고자 한다. 등자근 (stapedius muscle)이 청각반사 (acoustic reflex)와 관련되어 소리전달조절 역할을 하는 것과는 달리, 고막긴장근은 청각반사와는 별개로 수축하는 것으로 알려져 있다. 이는 고막긴장근이 삼차신경감각핵 (trigeminal sensory nucleus)에서 들어온 고유감각에 의해 조절되기 때문으로 여겨진다. 계통해부학적으로 포유류의 망치뼈, 모루뼈 및 등자뼈를 포함한 가운데귀 구조는 포유류가 아닌 턱뼈 척추동물 (non-mammlian jawed vertebrate)과는 달리 씹기에는 관여하지 않는다. 포유류가 아닌 턱뼈 척추동물에서 포유류로의 진화과정에서 이러한 기능적 분리가 이루어졌으나, 포유류에서 고막긴장근과 씹기근육의 신경연결은 일부 남아 있다. 따라서 이러한 계통발생학적 흔적은 귀-씹기계통의 병적 연관성과 관련이 있다고 볼 수 있다. 본 연구는 이러한 계통발생학적 배경을 바탕으로 씹기근육의 비정상적 수축 시 고막긴장근이 귀-씹기계통 계통발생학적 흔적을 통해 과도한 공동수축을 일으켜 다양한 귀의 이상질환이 나타날 수 있다는 가설을 제시한다. Otologic complaints, including otalgia, tinnitus, vertigo, and hearing loss, are known to be related to temporomandibular disorders (TMDs). There have been several hypotheses regarding the clinical correlation between otologic complaints and TMDs, based on clinical phenomena with corresponding symptoms, the close neurological relationship between otic and masticatory structures, and anatomical features of the tympanic cavity and jaw joint. Function of the tensor tympani muscle seems to be crucial to understanding TMD-related otologic symptoms. The tensor tympani inserts into the handle of the malleus and it modulates sound transduction in situations of excessive noise. This muscle is innervated by the trigeminal nerve, like the masticatory muscles. Voluntary eardrum movement by pathological tensor tympani contraction results in various otologic symptoms. Thus, co-contraction of the tensor tympani with the masticatory muscle could be a possible cause of TMD-related otologic symptoms. The tensor tympani is rather unrelated to the acoustic reflex, in which the stapedius is strongly involved. The tensor tympani seem to be controlled by proprioceptive information from the trigeminal sensory nucleus. The peripheral innervation pattern of the tensor tympani and masticatory muscles is also supposed to be interconnected. The middle ear structure, including the malleus, incus, and tensor tympani, of mammals had been adapted for acoustic function and lacks the masticatory role seen in non-mammalian jawed vertebrates. The tensor tympani in non-mammals is one of the masticatory muscles and plays a role in the modulation of sound transduction and mastication. After the functional differentiation of the mammalian middle ear, the nervous connection of the tensor tympani with other masticatory apparatus still remains. Through this oto-stomatognathic vestige, the tensor tympani seems to contract unnecessarily in some pathological conditions of the TMD in which the masticatory muscles contract excessively. We hypothesized that the phylogenic relationship between the tensor tympani and masticatory apparatus is a significant and logical reason for TMD-related otologic complaints.

New Anatomical Insights on the Course and Branching Patterns of the Facial Artery: Clinical Implications of Injectable Treatments to the Nasolabial Fold and Nasojugal Groove

Yang, Hun-Mu,Lee, Jae-Gi,Hu, Kyung-Seok,Gil, Young-Chun,Choi, You-Jin,Lee, Hong-Ki,Kim, Hee-Jin American Society of Plastic Surgeons 2014 Plastic and reconstructive surgery Vol.133 No.5

BACKGROUND:: Improper manipulation of injectable treatments to the face can result in disastrous vascular complications. The aim of the present study was to elucidate the detoured course of the facial artery and to provide detailed metric data regarding facial artery location with a view to helping physicians avoid iatrogenic vascular accidents during injectable treatments. METHODS:: Sixty specimens from 35 embalmed cadavers (24 male and 11 female cadavers; mean age, 70.0 years) and one fresh male cadaver (age, 62 years) were used for this study. RESULTS:: In 56 cases (93.3 percent), the branches of the facial artery were observed at the vicinity of the nasolabial fold. The facial artery was located 3.2 ± 4.5 mm (mean ± SD) lateral to the ala of the nose and 13.5 ± 5.4 mm lateral to the oral commissure. It crossed the nasolabial fold in 33.9 percent of cases, and ascended within 5 mm of the nasolabial fold in 42.9 percent. The facial artery and detoured branches were found in 18 cases (30.0 percent). In the cases with detoured branches, the facial artery turned medially over the infraorbital area at 39.2 ± 5.8 mm lateral to the facial midsagittal line and 35.2 ± 8.2 mm inferior to the plane connecting the medial epicanthi of both sides. The nasojugal portion of the detoured branch traveled along the inferior border of the orbicularis oculi and then ascended toward the forehead, forming the angular artery. CONCLUSION:: This detailed vascular anatomy of the facial artery will promote safe clinical manipulations during injectable treatments to the nasolabial fold and nasojugal groove.

Three-dimensional finite element analysis of unilateral mastication in malocclusion cases using cone-beam computed tomography and a motion capture system

Yang, Hun-Mu,Cha, Jung-Yul,Hong, Ki-Seok,Park, Jong-Tae Korean Academy of Periodontology 2016 Journal of Periodontal & Implant Science Vol.46 No.2

Purpose: Stress distribution and mandible distortion during lateral movements are known to be closely linked to bruxism, dental implant placement, and temporomandibular joint disorder. The present study was performed to determine stress distribution and distortion patterns of the mandible during lateral movements in Class I, II, and III relationships. Methods: Five Korean volunteers (one normal, two Class II, and two Class III occlusion cases) were selected. Finite element (FE) modeling was performed using information from cone-beam computed tomographic (CBCT) scans of the subjects' skulls, scanned images of dental casts, and incisor movement captured by an optical motion-capture system. Results: In the Class I and II cases, maximum stress load occurred at the condyle of the balancing side, but, in the Class III cases, the maximum stress was loaded on the condyle of the working side. Maximum distortion was observed on the menton at the midline in every case, regardless of loading force. The distortion was greatest in Class III cases and smallest in Class II cases. Conclusions: The stress distribution along and accompanying distortion of a mandible seems to be affected by the anteroposterior position of the mandible. Additionally, 3-D modeling of the craniofacial skeleton using CBCT and an optical laser scanner and reproduction of mandibular movement by way of the optical motion-capture technique used in this study are reliable techniques for investigating the masticatory system.

Neurovascular structures of the mandibular angle and condyle: a comprehensive anatomical review

Yang, Hun-Mu,Won, Sung-Yoon,Kim, Hee-Jin,Hu, Kyung-Seok Springer-Verlag 2015 Surgical and radiologic anatomy Vol.37 No.9

Cadaveric Evaluation of Different Approaches for Quadratus Lumborum Blocks

Yang, Hun-Mu,Park, Sang Jun,Yoon, Kyung Bong,Park, Kyoungun,Kim, Shin Hyung Hindawi 2018 Pain research & management : the journal of the Ca Vol.2018 No.-

<P><B>Background</B></P><P> A quadratus lumborum (QL) block is an abdominal truncal block technique that primarily provides analgesia and anaesthesia to the abdominal wall. This cadaveric study was undertaken to compare the dye spread between different needle approaches for ultrasound-guided QL blocks in soft-embalmed cadavers. </P><P><B>Methods</B></P><P> After randomization, an experienced anesthesiologist performed two lateral, three posterior, and five alternative QL blocks on the left or right sides of five cadavers. The target injection point for the alternative approach was the lumbar interfascial triangle, same as that of conventional posterior QL block, with a different needle trajectory. For each block, 20 ml of dye solution was injected. The lumbar region and abdominal flank were dissected. </P><P><B>Results</B></P><P> Ten blocks were successfully performed. Regardless of the approach used, the middle thoracolumbar fascia was deeply stained in all blocks, but the anterior layer was less stained. The alternative approach was more associated with spread of injectate to the transversus abdominis and transversalis fascia plane. Despite accurate needle placement, all lateral QL blocks were associated with a certain amount of intramuscular or subcutaneous infiltration. Two posterior QL blocks showed a deeply stained posterior thoracolumbar fascia, and one of them was associated with obvious subcutaneous staining. The subcostal, iliohypogastric, and ilioinguinal nerves were mostly involved, but the thoracic paravertebral space and lumbar plexus were not affected in all blocks. </P><P><B>Conclusions</B></P><P> The alternative approach for QL blocks was able to achieve a comparable extent when compared to the conventional approach.</P>