• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.1
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• pp.3-10
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• 2015

Objectives: We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. Materials and Methods: This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Results: Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). Conclusion: The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.305-312
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• 2008

Crown-root fractures occur throughout both crown and root, and are defined as fractures involving enamel, dentin and cementum. The fractures may be grouped according to pulpal involvement into complicated and uncomplicated one. Crown-root fractures often occur on maxillary anterior teeth and comprise 5% of injuries affecting the permanent dentition and 2% in the primary dentition. To restore crown-root fractured tooth, biologic width must be maintained. For maintaining biologic width, such methods as gingivectomy following osteoplasty or orthodontic extrusion or surgical extrusion are available. Surgical extrusion is a method that extracts the tooth and replants the fractured tooth supragingivally. It is indicated when the length of the crown fragment is less than half the length of the clinical root. In these cases, root canal treatment and crown restoration using light-cured composite resin were performed after surgical extrusion. In following periodic examinations, favorable outcome was observed.

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.173-180
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• 2007

There was a great problem about the deposition between materials of a different kind at the beginnings of the introduction of porcelains, however, thereafter the deposition efficiency was settlded to the sufficient level of all user thanks to effort to have studied by many scholars and clinical authorities. But in a clinical process, as the difference of designs has an effect on fractures of porcelains, this researcher divided them into 4 groups of A: 1 mm, B: 2 mm, C: 3 mm, and D: 4 mm, and made 40 pieces to each 10 as the test samples to consider a length axis of tooth for studies in accordance with a position of a finishing line to meet between porcelain and metal at the contact point at the adjacent side to a metal porcelain. The sample materials are those to be use at the open market and the test samples wer completed by the same manufacturing technique to that of existent metal porcelain tube. s a result of the strength test on fractures, the average value is as in the following, A: 1 mm - 8.5bar, B: 2 mm - 10.5bar, C: 3 mm - 14.3bar, and D: 4 mm - 15.0bar. In case of the metal porcelain tube, the more faraway to process parts of metal and porcelain from the contact point of adjacent side has the stronger strength of fractures, Accordingly, the research shows that it had better to keep off more than 3 to consider a ledngth axis of tooth.

• Imaging Science in Dentistry
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• v.45 no.3
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• pp.147-151
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• 2015

Purpose: The aim of this study was to investigate the effects of metal artifacts on the accurate diagnosis of root fractures using cone-beam computed tomography (CBCT) images with large and small/limited fields of view (FOVs). Materials and Methods: Forty extracted molar and premolar teeth were collected. Access canals were made in all teeth using a rotary system. In half of the teeth, fractures were created by the application of mild pressure with a hammer. The teeth were then randomly put into a wax rim on an acryl base designed in the shape of a mandible. CBCT scans were obtained using a Newtom 5G system with FOVs of $18cm{\times}16cm$ and $6cm{\times}6cm$. A metal pin was then placed into each tooth, and CBCT imaging was again performed using the same fields of view. All scans were evaluated by two oral and maxillofacial radiologists. The specificity, sensitivity, positive predictive value, negative predictive value, and likelihood ratios (positive and negative) were calculated. Result: The maximum levels of sensitivity and specificity (100% and 100%, respectively) were observed in small-volume CBCT scans of teeth without pins. The highest negative predictive value was found in the small-volume group without pins, whereas the positive predictive value was 100% in all groups except the large-volume group with pins. Conclusion: The specificity of CBCT decreased with the presence of a pin in the large-volume group, but not in the small-volume group.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.1
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• pp.24-30
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• 2024

Complicated crown fractures of maxillary anterior teeth caused by trauma in adolescence can cause functional and aesthetic problems. For crown fractures with pulp exposure, various restorative methods can be considered depending on the amount of remaining tooth structure. Direct resin restorations are the most traditional and effective method, but they are likely to discolor and break over time. Fixed prosthesis have a high possibility of re-restoration due to marginal disharmony due to tooth movement during the growth period, and restorations using post which are mainly performed for extensive crown fractures increase the risk of root perforation and root fracture. However, endocrown is an integrated structure that gains retention force from the pulp space, enabling effective reconstruction from a biomechanical perspective and providing advantages in restoring function and aesthetics. Therefore, endocrown can be considered as a restoration method for complicated crown fractures caused by trauma in adolescence.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.376-381
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• 2019

Background: This study was conducted to determine the relationship between third molar (M3) and mandibular fracture. Methods: Patients with unilateral mandibular angle or condyle fractures between 2008 and 2018 were evaluated retrospectively. Medical records were reviewed regarding the location of fractures, and panoramic radiographs were reviewed to discern the presence and position of ipsilateral mandibular third molars (M3). We measured the bony area of the mandibular angle (area A) and the bony area occupied by the M3 (area B) to calculate the true mandibular angle bony area ratio (area A-B/area A×100). Results: The study consisted of 129 patients, of which 60 (46.5%) had angle fractures and 69 (53.5%) had condyle fractures. The risk of angle fracture was higher in the presence of M3 (odds ratio [OR], 2.2; p< 0.05) and the risk of condyle fracture was lower in the presence of M3 (OR, 0.45; p< 0.05), than in the absence of M3. The risk of angle fracture was higher in the presence of an impacted M3 (OR, 0.3; p< 0.001) and the risk of condyle fracture was lower in the presence of an impacted M3 (OR, 3.32; p< 0.001), than in the presence of a fully erupted M3. True mandibular angle bony area ratio was significantly lower in the angle fractures than in the condyle fractures (p= 0.003). Conclusion: Angle fractures had significantly lower true mandibular angle bony area ratios than condyle fractures. True mandibular angle bony area ratio, a simple and inexpensive method, could be an option to predict the mandibular fracture patterns.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.49-57
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• 2006

Mandibular fractures have higher incidence rate compared to facial bone fractures because of relatively prominent form. Specially, mandibular angle fractures were known as common fracture site because of morphological anatomic structure. The mandibular third molar appears to be the most frequent impacted tooth. The mandibular third molar have influence on mandibular angle fractures according to it's eruption state. Also, the mandibular angle fracture including the third molar may influence on post operative infection whether the third molar is in impacted or extracted state when reduction of fracture site is operated. The presence or absence and degree of impaction of the mandibular third molar were assessed for each patient and were related to the occurrence of the mandibular angle fracture. The extraction or non extraction of the mandibular third molar were related to the occurrence of the post operative infection in the reduction of mandibular angle fractures. In the presence of mandibular third molar, the possibility of mandibular angle fractures were relatively common. When viewing the mandibular third molar at occlusal plane, the possibility of mandibular angle fractures were high in the class C group. The possibility of mandibular angle fractures were high in the mesial angulation and partial impaction. There was a statistically significant difference(P<0.05). In complete erupted mandibular third molar, the possibility of post operative infection occurs quite often, but there was no statistical significant difference(P>0.05). In the extracted or non extracted of mandibular third molar, the post operative infection showed no statistical significant difference(P>0.05). With the results mentioned above, mandibular third molar was significantly more susceptible to mandibular angle fracture. In the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.155-160
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• 2011

Purpose: Fibrillar collagens like type I collagen, are the major constituent of the extracellular matrix and structural protein of bone. Also, it can be a scaffold for osteoblast migration. The purpose of this study is to estimate the effects of absorbable atelo-collagen sponge (Teruplug$^{(R)}$, Terumo biomaterials Co., Tokyo, Japan) insertion in tooth extraction sites on periodontal healing of the second molar, healing of the fractured mandibular bone and new bone formation of third molar socket after the extraction of the impacted third molar with mandibular angle fracture. Methods: In our study of six cases of mandibular angle fractures, all of them underwent the extraction of the third molar tooth & absorbable atelo-collagen sponge insertion in tooth extraction site. Three of them had a intraoral infection & oral opening to fracture site, two of the six had dental caries, and only one had reduction problem due to third molar position. Six consecutive patients with noncomminuted fractures of the mandibular angle were treated by open reduction and internal fixation using one noncompression miniplates and screws placed through a transoral incision. Results: All of the patients have showed good postoperative functions and have not experienced complications requiring second surgical intervention. There was well healing of the mandibular bone and the most new bone formation of third molar socket after the extraction of the impacted third molar with mandibular angle fracture. Conclusion: The results of this study suggest that absorbable atelo-collagen sponge is relatively favorable bone void filler with prevention of tissue collapse, food packing, and enhance periodontal healing. Thus, the use of atelo-collagen sponge and one noncompression miniplate seems to be relatively easy, safe, and effective for the treatment of fractures of the mandibular angle and third molar extraction.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.27.1-27.8
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• 2018

Purpose: Various complications occur when a maxillofacial fracture is malunionized or improperly resolved. Malocclusion is the most common complication, followed by facial deformity, temporomandibular joint disorder (TMD), and neurological symptoms. The purpose of this study was to evaluate the dental treatment of postoperative complications after maxillofacial fracture. Materials and methods: In this study, nine patients with a postoperative complication after maxillofacial fracture who had been performed the initial operation from other units and were referred to the authors' department had been included. Of the nine patients, six had mandibular fractures, one had maxillary fractures, one had maxillary and mandibular complex fractures, and one had multiple facial fractures. All the patients had tooth fractures, dislocations, displacements, and alveolar bone fractures at the time of trauma, but complications occurred because none of the patients underwent preoperative and postoperative dental treatment. Malocclusion and TMD are the most common complications, followed by dental problems (pulp necrosis, tooth extrusion, osteomyelitis, etc.) due to improper treatment of teeth and alveolar bone injuries. The patients were referred to the department of dentistry to undergo treatment for the complications. One of the nine patients underwent orthognathic surgery for a severe open bite. Another patient underwent bone reconstruction using an iliac bone graft and vestibuloplasty with extensive bone loss. The other patients, who complained of moderate occlusal abnormalities and TMDs such as mouth-opening limitation, underwent occlusal treatment by prosthodontic repair and temporomandibular joint treatment instead of surgery. Results: One patient who underwent orthognathic surgery had complete loss of open bite and TMD after surgery. One patient who underwent reconstruction using an iliac bone graft had a good healing process. Other patients were treated with splint, injection, and physical therapy for mouth-opening limitation and temporomandibular joint pain. After treatment, the TMDs were resolved, but the remaining occlusal abnormalities were resolved with prosthetic restoration. Conclusions: Considering the severity of malocclusion and TMJ symptom and the feasibillity of reoperation, nonsurgical methods such as orthodontic and prosthodontic treatments and splint therapy can be used to manage the dental and TMD complication after the trauma surgery. However, reoperation needs to be strongly considered for severe malocclusion and TMD problem.

• The Journal of the Korean dental association
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• v.51 no.11
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• pp.604-609
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• 2013

Crown fractures are relatively common trauma to anterior teeth, and should be restored immediately in most cases. For those who suffer from unfortunate traumatic episode, the best treatment option should be minimally invasive approach. In the presence of fractured tooth fragment, reattachment procedure creates positive emotional response in the patient and simplifies the procedure and maintenance of the patient's original tooth anatomy and occlusion. Without fractured tooth fragment, next conservative option could be direct composite restoration which is based on minimal invasion concept. This article proposes simple and very conservative techniques that anyone can do in daily practice.