• The korean journal of orthodontics
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• v.48 no.5
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• pp.304-315
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• 2018

Objective: The purpose of this study was to analyze initial displacement and stress distribution of the maxillofacial complex during dentoskeletal maxillary protraction with various appliance designs placed on the palatal region by using three-dimensional finite element analysis. Methods: Six models of maxillary protraction were developed: conventional facemask (Type A), facemask with dentoskeletal hybrid anchorage (Type B), facemask with a palatal plate (Type C), intraoral traction using a Class III palatal plate (Type D), facemask with a palatal plate combined with rapid maxillary expansion (RME; Type E), and Class III palatal plate intraoral traction with RME (Type F). In Types A, B, C, and D, maxillary protraction alone was performed, whereas in Types E and F, transverse expansion was performed simultaneously with maxillary protraction. Results: Type C displayed the greatest amount of anterior dentoskeletal displacement in the sagittal plane. Types A and B resulted in similar amounts of anterior displacement of all the maxillofacial landmarks. Type D showed little movement, but Type E with expansion and the palatal plate displayed a larger range of movement of the maxillofacial landmarks in all directions. Conclusions: The palatal plate served as an effective skeletal anchor for use with the facemask in maxillary protraction. In contrast, the intraoral use of Class III palatal plates showed minimal skeletal and dental effects in maxillary protraction. In addition, palatal expansion with the protraction force showed minimal effect on the forward movement of the maxillary complex.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.111-120
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• 1995

This case report presents two maxillary anterior cases for clinical crown lengthening by forced eruption. In the first case, clinical crown of maxillary right lateral incisor was almost lost by fracture. Forced eruption using intracoronal splint and elastic thread accomplished vertical root movement successfully. Then, post & core was inserted and final restoration was harmonious with adjacent teeth. In the second case, the crown portion of maxillary right central incisor was almost mutilated by secondary caries. Forced eruption using removable Hawley appliance and elastic accomplished vertical root movement successfully. Then, post & core was inserted and final restoration was placed. In conclusion, clinical crown lengthening by vertical root movement can be accomplished by a simple appliance without any sacrifice of periodontal support in selected patients. A clinical crown so created can be restored to adequate function and arch integrity without compromising adjacent teeth. Therefore, forced eruption is preferred in the anterior region of the dentition where esthetics is of major concern.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.150-160
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• 2019

Objective: This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods: In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results: When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions: The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.761-776
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• 2005

The purpose of the present study was to examine the relationship between the form of the clinical crowns in the maxillary anterior segment and the clinical feature of gingiva such as morphological characteristics and the gingival thickness. Fifty periodontally healthy subjects were clinically examined regarding the probing depth, the thickness of the free gingiva, and the width of the keratinized gingiva. From study models of the maxillary anterior region, the width at cervical third(CW) and the length(CL) of the clinical crown, the papillary height, and the gingival angle of the 6 anterior teeth were measured. Each tooth was classified into 4 groups (longnarrow, NL; narrow, N; wide, W; short-wide, WS) according to CW/CL ratio and all the data were compared between groups NL and WS using independent t-test. Stepwise multiple regression analysis was performed for each tooth region with the gingival thickness at the level of sulcus bottom, the width of keratinized gingiva, and gingival angle as the dependent variables. As the results, the NL group of the upper anterior teeth displayed, higher papilla height, and narrower keratinized gingiva, more acute gingival angle resulting in pronounced "scalloped" contour of the gingival margin, compared to the WS group. There was no significant difference between groups NL and WS with respect to probing depth and the gingival thickness. The regression analyses demonstrated that the gingival thickness in central incisors was significantly associated to the mesio-distal width and bucco-lingual width of the crown, and labial probing depth. The width of keratinized gingiva was significantly associated with labial probing depth in central incisors and with proximal probing depth and gingival angle in lateral incisors, and with labial and proximal probing depth, and gingival angle in canines. The gingival angle was significantly associated with papillary height and CW/CL ratio and additionally with proximal probing depth in central incisors, with the width of keratinized gingiva in lateral incisors, and with labial probing depth and the width of keratinized gingiva in canines. These results indicate that the form of clinical crown in upper anterior region could influence the clinical feature of gingiva and the influencing factors might be different according to the tooth region.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.39.1-39.8
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• 2019

The present report presents a case of dens invaginatus (DI) in a patient with 4 maxillary incisors. A 24-year-old female complained of swelling of the maxillary left anterior region and discoloration of the maxillary left anterior tooth. The maxillary left lateral incisor (tooth #22) showed pulp necrosis and a chronic apical abscess, and a periapical X-ray demonstrated DI on bilateral maxillary central and lateral incisors. All teeth responded to a vitality test, except tooth #22. The anatomic form of tooth #22 was similar to that of tooth #12, and both teeth had lingual pits. In addition, panoramic and periapical X-rays demonstrated root canal calcification, such as pulp stones, in the maxillary canines, first and second premolars, and the mandibular incisors, canines, and first premolars bilaterally. The patient underwent root canal treatment of tooth #22 and non-vital tooth bleaching. After a temporary filling material was removed, the invaginated mass was removed using ultrasonic tips under an operating microscope. The working length was established, and the root canal was enlarged up to #50 apical size and obturated with gutta-percha and AH 26 sealer using the continuous wave of condensation technique. Finally, non-vital bleaching was performed, and the access cavity was filled with composite resin.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.77-82
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• 2011

A long-term follow-up study of a case of impacted teeth associated with a large dentigerous cyst in the left maxilla is presented. The patient was a 30-year-old man who had a large dentigerous cyst in the premaxilla and left posterior maxilla, which impacted the canine and supernumerary tooth. This is one of the most prevalent types of odontogenic cysts associated with an erupted or developing tooth, particularly the mandibular third molars. The other teeth commonly affected in order of frequency are the maxillary canines, maxillary third molars and rarely, the central incisor. Radiographically, the cyst appears as huge ovoid well-demarcated unilocular radiolucency with a sclerotic border and causes ectopic displacement of the inferior border of the maxillary sinus without destruction. Dentigerous cysts may grow unnoticed to such extensive sizes as to occupy a considerable portion of the maxillary sinus. These cysts appear to be associated with a supernumerary tooth in the maxillary anterior incisors region called the mesiodens and impacted canine. The present case report describes the surgical enucleation of a dentigerous cyst involving the permanent maxillary left canine and mesioden. After surgery, left maxillary sinus recovered their normal size and apposition of bone was observed around the apex of the posterior teeth. During the subsequent years, there was no recurrence of the cystic lesion but the inflammation was evoked in the anterior maxilla after 42 months. This complication appeared to have correlated with bony healing in the enucleation site of the cyst. We report the healing status of a huge dentigerous cyst in the maxilla for 5 years with a review of the relevant literature.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.6
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• pp.387-395
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• 2020

Background: The anterior-middle superior alveolar (AMSA) anesthetic technique has been reported to be a less traumatic alternative to several conventional nerve blocks and local infiltration for anesthesia of the maxillary teeth, their periodontium, and the palate. However, its anatomic basis remains controversial. The present study aimed to determine if the pattern of cortical and cancellous bone density in the maxillary premolar region can provide a rationale for the success of the AMSA anesthetic technique. Method: Cone-beam computed tomography scans of 66 maxillary quadrants from 34 patients (16 men and 18 women) were evaluated using a volumetric imaging software for cortical and cancellous bone densities in three interdental regions between the canine and first molar. Bone density was measured in Hounsfield units (HU) separately for the buccal cortical, palatal cortical, buccal cancellous, and palatal cancellous bones. Mean HU values were compared using the Mann-Whitney U test and one-way ANOVA with post-hoc analysis. Results: Cancellous bone density was significantly lower (P ≤ 0.001) in the palatal half than in the buccal half across all three interdental regions. However, there was no significant difference (P = 0.106) between the buccal and palatal cortical bone densities at the site of AMSA injection. No significant difference was observed between the two genders for any of the evaluated parameters. Conclusions: The palatal half of the cancellous bone had a significantly lower density than the buccal half, which could be a reason for the effective diffusion of the anesthetic solution following a palatal injection during the AMSA anesthetic technique.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.429-434
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• 2022

Supernumerary teeth that are present in the molar region may be evident based on crowding and impaction, but most cases are asymptomatic and discovered as incidental findings during routine radiological examinations. This article reports the case of a 29-year-old woman who presented with a severe feeling of pressure in the region of the maxillary third molars that had been increasing in intensity for weeks. A clinical examination revealed crowding of the maxillary anterior teeth despite the completion of orthodontic treatment and an erupted third molar with localized gingivitis in the second quadrant. A radiographic examination revealed bilateral supernumerary maxillary fourth and fifth molars, so cone-beam computed tomography was performed to locate the supernumerary teeth precisely for a preoperative diagnosis and comprehensive treatment planning. This report presents the radiological and surgical case management of a rare case of bilateral supernumerary molars and reviews the literature regarding epidemiology and treatment options.

• Journal of Periodontal and Implant Science
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• v.28 no.3
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• pp.507-517
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• 1998

This study was performed to investigate the soft tissue changes around single implant-supported crowns during followup periods. Twenty patients(31 implants) whose single missing tooth in the maxillary anterior region had been replaced with an single implant-supported crown were recruited for the study. Crown length, soft tissue level and papilla height at the single implant-supported crowns were measured at follow-up examination and calculated from the slides taken at time of crown placement. as well Papilla index was scored from the slides taken at the time of crown placement and follow-up examination. A very little amount of recession occurred and the soft tissue level moved more apically and the papilla height increased significantly (p<0.01). Especially, both mesial and distal papilla index at single implant-supported crowns increased significantly during follow-up periods (p<0.001). When the two slides taken at the time of crown placement and follow-up were compared simultaneously, except one site, papillae size increased at all sites. From the results of the study, the interdental papillae at the single implant-supported crowns seemed to regenerate significantly and their crown margins were stable during follow-up periods. Hence it is indicated that various surgical interventions at on early stage to enhance soft tissue esthetics arourd single implants may be unnecessary.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.163-169
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• 1989

The purpose of this study is to investigate on the clinical and radiographic patterns of residual cyst of the jaw for early diagnosis and treatment. The auther studied 87 cases of residual cyst with regard to age, sex distribution, the site of the lesion and several radiographic features. The results were as follows: 1. The average age was found to be 42.6 years, with a range of 15 to 84 years. The incidence was highest in the third and fourth decades(50.6%) and total 87 cases consist of 47 males and 38 females. 2. The common clinical symptoms were pus discharge, swelling, pain and no symptoms was presented in 5 cases(12.5%). 3. Residual cysts were found to be 46.0% maxillary anterior region, 18.4% maxillary molar region, 17.2% mandibular molar region and to be more common in the maxilla(70.1%) than in the mandible(29.9%) 4. Most of residual cysts were unilocular type(86 cases, 98.8%), showing distinct border(62 cases, 71.3%) with smooth margin(78 cases, 89.7%). 5. The adjacent teeth showed root resorption in 13 cases(14.9%), and root divergence in 16 cases(18.4%). 6. The residual cysts extended to the nasal fossa(22 cases, 22.5%), the maxillary sinus(19 cases, 19.4%) and caused the displacement of the mandibular canal wall (11 cases, 11.2%)