• 대한치과교정학회지
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• 제16권1호
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• pp.119-131
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• 1986

The purpose of the study is to note the effects of the resection of the lateral pterygoid muscle on the mandibular growth in the growing rats. Twenty four female Wistar rats were used in the experiment. They were divided into three groups: group 1 ; bilateral sham operation group 2 ; bilateral resenction of the lateral pterygoid muscle group 3 ; unilateral resection of the lateral pterygoid muscle (The right lateral pterygoid muscle was resected and the left one was sham-operated.) Groups 1&2 were sacrificed eight weeks lateral and group 3, four weeks later. All specimens were measured with calipers, and stained with hematoxylin and eosin. Groups 1 & 2 were compared with each other. In group 3, the right side was compared with the left. The results were as follows: 1. In the growing rats, the resection of the lateral pterygoid muscle was followed by a decrease of the mandibular growth. After eight weeks, the condyle-mental foramen distance, the angular process-mental foramen distance, the size of the condylar head, the supradentale-first molar distance, and the diameter of the symphysis were significantly smaller than the control. 2. Resection of the lateral pterygoid muscle resulted in decrease of the thickness of the cartilage layer and the prechondroblastic-chondroblastic layer after four weeks. 3. After eight weeks, group 1 and group 2 were not different significantly in the histologic sections. 4. The condylar cartilage was stabilized eight weeks after the experiment.

• Anatomy and Cell Biology
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• 제49권2호
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• pp.143-150
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• 2016

Understanding of morphological structures such as the sphenoid spine and pterygoid processes is important during lateral transzygomatic infratemporal fossa approach. In addition, osseous variations such as pterygospinous and pterygoalar bridges are significant in clinical practice because they can produce various neurological disturbances or block the passage of a needle into the trigeminal ganglion through the foramen ovale. Two hundred and eighty-four sides of Korean adult dry skulls were observed to carry out morphometric analysis of the lateral plate of the pterygoid process, to investigate, for the first time among Koreans, the incidence of the pterygospinous and pterygoalar bony bridges, to compare the results with those available for other regional populations, and to discuss their clinical relevance as described on literatures. The mean of maximum widths of the left and right lateral plates of the pterygoid process were 15.99 mm and 16.27 mm, respectively. Also, the mean of maximum heights of the left and right lateral plates were 31.02 mm and 31.01 mm, respectively. The ossified pterygospinous ligament was observed in 51 sides of the skulls (28.0%). Ossification of the pterygospinous ligament was complete in four sides (1.4%). In 47 sides (16.6%), the pterygospinous bridge was incomplete. The ossified pterygoalar ligament was observed in 24 sides of the skulls (8.4%). Ossification was complete in eight sides (2.8%) and incomplete in 16 sides (5.6%). This detailed analysis of the lateral plate of the pterygoid process and related ossification of ligaments can improve the understanding of complex clinical neuralgias associated with this region.

• Journal of Dental Anesthesia and Pain Medicine
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• 제21권3호
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• pp.253-260
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• 2021

Therapeutic injections into the craniofacial region can be a complex procedure because of the nature of its anatomical structure. This technical note demonstrates a process for creating an extra-oral template to inject therapeutic substances into the temporomandibular joint and the lateral pterygoid muscle. The described process involves merging cone-beam computed tomography data and extra-oral facial scans obtained using a mobile device to establish a correlated data set for virtual planning. Virtual injection points were simulated using existing dental implant planning software to assist clinicians in precisely targeting specific anatomical structures. A template was designed and then 3D printed. The printed template showed adequate surface fit. This innovative process demonstrates a potential new clinical technique. However, further validation and in vivo trials are necessary to assess its full potential.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권5호
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• pp.292-296
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• 2022

Objectives: During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications. Materials and Methods: One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively. Results: Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not. Conclusion: Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

• 대한두개안면성형외과학회지
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• 제18권1호
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• pp.5-8
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• 2017

Among the classification of maxillary fracture, the Le Fort classification is the best-known categorization. Le Fort (1901) completed experiments that determined the maxilla areas of structural weakness which he designated as the "lines of weakness". According to these results, there are three basic fracture line patterns (transverse, pyramidal and craniofacial disjunction). A transverse fracture is a Le Fort I fracture that is above the level of the apices of the maxillary teeth section, including the entire alveolar process of the maxilla, vault of the palate and inferior ends of the pterygoid processes in a single block from the upper craniofacial skeleton. Le Fort fractures result in both a cosmetic and a functional deficit if treated inappropriately. In this article, authors review the management of a Le Fort I fracture with a case-based discussion.

• 한국수산과학회지
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• 제56권4호
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• pp.549-557
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• 2023

This study aimed to investigate taxonomic differences in the early life history characteristics of Rhodeus ocellatus and Rhodeus notatus through an interspecific hybridization experiment. The hatching rates of the cross-bred eggs were 50% for the ON cross (R. ocellatus ♀×R. notatus♂) and 67% for the NO cross (R. notatus♀×R. ocellatus♂). Interestingly, the hatching time of the hybrids was longer than that of their parents. The newly hatched larvae exhibited distinct differences in their physical characteristics. The head of the adult fish protruded forward more than that of the ON cross. The pterygoid process was 45° for the ON cross and 90° for the NO cross. Furthermore, the tail shape of the ON and NO crosses closely resembled that of R. notatus.

• Archives of Plastic Surgery
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• 제45권1호
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• pp.23-28
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• 2018

Background Condylar process fractures account for one-third of all mandibular fractures, and the distal fragment is prone to dislocate to the medial side due to the pulling of the lateral pterygoid muscle. Retromandibular approaches are commonly used, but the intraoperative view becomes limited in medially dislocated fractures. This study summarized a series of cases of retromandibular reduction for medially dislocated condylar process fractures and described our supplementary procedure to realign the dislocated condylar process. Methods Nine patients with medially dislocated condylar process fractures underwent surgical correction from January 2012 to December 2016. In 6 of them, it was possible to realign the fractures with a conventional retromandibular approach, but for 3 cases of severe dislocation to the middle cranial fossa, a supplementary transoral procedure was carried out. The angle difference between the ramus and condyle, ramus height, and maximal mouth opening (MMO) were evaluated. Results All 9 cases were restored to the proper anatomical alignment without any major complications, and postoperative images revealed successful union. The angle difference was $8.94^{\circ}{\pm}4.11^{\circ}$ preoperatively, and $0.99{\pm}0.49^{\circ}$ at the 6-month follow-up. The pretreatment ramus height difference was $6.12{\pm}6.09mm$, and the postoperative difference was $0.18{\pm}0.10mm$. These changes after surgery were statistically significant. The MMO before surgery was $11.44{\pm}3.0mm$, and the postoperative MMO was $37.2{\pm}2.9mm$, reflecting a significant increase after reduction. Conclusions Retromandibular reduction is a useful method in medially dislocated condylar process fractures, and additional transoral assistance should be considered to realign condylar processes that severely dislocate to the middle cranial fossa.

• 대한치과교정학회지
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• 제11권1호
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• pp.25-30
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• 1981

Fifteen young pigs were used in this study. The animals were divided into three groups 1. Group for removal of the temporal muscle, 2. Group for removal of the masseter muscle, 3, Group for removal of masseter and internal pterygoid muscles. The animals were anesthetized with $3.5\%$ chloral hydrate intraperitoneally. In the right side the head was shaved. The masticatory muscle was removed. The animals were sacrificed four months later. The head was separated from trunk and cleaned by boiling in a solution of potassium hydroxide. The results were as follows; 1. In the group for removal of the temporal muscle, the Coronoid process of the mandible was resorbed. 2. In the group for removal of the masseter muscle, there was produced asymmetrical growth of the mandible, attrition of the molar teeth in the control side, and resorption of the mandibular angle. 3. In the group for removal of the Masseter and Internal muscles, the changes were more severe than that of the group for removal of the masseter muscle. The mandibular angle was completely absent. 4. The growth of the bone seems definitely related to the presence of the muscular tissue actively pulling upon it.

• 구강회복응용과학지
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• 제23권4호
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• pp.373-384
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• 2007

The purpose of this study was to analyse the stress distribution on the craniofacial suture and cranium after application of RME. Twelve years and six months old boy and twenty years old adult male were chosen for taking computed-tomography for FEM. From DICOM visual information, it was processed by 3-dimensional image construction program Mimics 10.01. Hounsfield unit(HU) which shows gray scale of CT image is picked for revealing mechanical properties of each model. The models have been accomplished with various range of physical properties. After applying 5.0 mm expansion, the maxillary complex model was obeserved for analyzing displacement and stress distribution of the model. The amount of transverse expansion of child and adult maxilla is different according to its location. It appears that it decreases gradually with the distance from separation site. In child, maximum compressive stress located broad area in zygomatic buttress department and the ends of frontal process of maxilla, pterygoid plate, and bones surrounding orbit. However, in adult maximum compressive stress was located smaller area and the stres was higher than child.

• Journal of Oral Medicine and Pain
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• 제16권1호
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• pp.33-72
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• 1991

The purpose of this study was to investigate the stress distribution and the displacement in the temporomandibular joints following the teeth loss patterns. The three dimensional finite element method was used for a mathematical model. The finite element model was composed of 1,632 elements and 2,411 nodes in the mandible with articular disc and mandibular fossa of the temporal bone. The masseter, the temporal and the internal pterygoid muscle forces were applied at each insertion site, bisecting point of gonion and antegonion, tip of the coronoid process, and gonion at the ration of 2:2:1 respectively. The directions of muscles force were obtained from frontal and lateral cephalometric tracings using bony landmarks of the skull. The results were as follows : 1. In control model, the minimum principal stresses were concentrated on the region of anterosuperior part of the condyle head and articular disc, and maximum principal stresses on the anterior part of the condyle head and posterolateral part of the articular disc. 2. In case of unilateral teeth loss, the greater principal stress appeared at the teeth loss side and the principal stresses increased at the teeth loss side as the number of the posterior teeth loss went up. 3. In case of bilateral teeth loss, the principal stresses were greater than those of the control model and as the number of the posterior teeth loss increased, the grater principal stresses on the temporomandibular joints appeared at the both side. 4. When the posterior teeth existed bilateral, the principal stress patterns were similar to those of the control model. 5. The displacement ws directed mainly upward and backward in the upper part of the temporomandibular joints and upward and forward in the largest part of the condyle head. The displacement increased as the number of the posterior teeth loss went up.