• The korean journal of orthodontics
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• v.53 no.3
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• pp.205-216
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• 2023

Objective: To investigate changes in the immature teeth of Sprague-Dawley rats during orthodontic treatment and to explore the changes in the peri-radicular alveolar bone through micro-computed tomography (CT). Methods: Twenty-five 26-day-old male Sprague-Dawley rats were included. The maxillary left first molar was moved mesially under a continuous force of 30 cN, and the right first molar served as the control. After orthodontic treatment for 7, 14, 21, 28, and 42 days, the root length, tooth volume, and alveolar bone mineral density (BMD) around the mesial root were measured through micro-CT. Results: The immature teeth continued to elongate after application of orthodontic force. The root length on the force side was significantly smaller than that on the control side, whereas the differences in the volume change between both sides were not statistically significant. Alveolar bone in the coronal part of the compression and tension sides showed no difference in BMD between the experimental and control groups. The BMD of the experimental group decreased from day 14 to day 42 in the apical part of the compression side and increased from day 7 to day 42 in the apical part of the tension side. The BMD of the experimental group decreased in the root apex part on day 7. Conclusions: The root length and volume of immature teeth showed continued development under orthodontic forces. Alveolar bone resorption was observed on the compression side, and bone formation was observed on the tension side.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.495-499
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• 2008

For the successful placement of dental implants, adequate alveolar bone height and width are required. Alveolar distraction osteogenesis is an effective method that resolves insufficient alveolar bone height for dental implant placement, and thus has been clinically applied with satisfactory results. But, minor and major problems may occur during the treatment. In the following report, we studied for such problematic cases. The problems are as follows: 1) sharp edges of the transport segment, 2) infection, 3) soft tissue dehiscence, 4) limitation of distraction, 5) numbness, 6) insufficient bone formation. But, most of them were answered by simple solutions and did not jeopardize the final outcomes. Distraction osteogenesis can be considered a safe and predictable procedure for lengthening the alveolar bone.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.1
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• pp.35-44
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• 1997

The most critical factor in determining which type of implant to be used would be the available bone of the patient. Usually a minimum of 5mm in the bone width and 8mm in the bone height is necessary to ensure primary implant stability and maintain the integrity of bone contact surface. Placement of implant is limited by the several anatomic strutures such as maxillary sinus, floor of the nose, inferior alveolar neurovascular bundle and nasopalatine foramen, etc. When severe resorption of alveolar ridge is encountered, implant placement would be a problematic procedure. A number of techniques to improve the poor anatomic situations have been proposed. This article reports 4 cases of patients using surgical procedures such as blade implant technique, cortical split technique in the anterior maxillary area, sinus lifting and lateral repositioning of inferior alveolar nerve, We treated dental implant candidates with unfavorable alveolar ridge utilizing various surgical techniques, resulted in successful rehabilitation of edentulous ridge.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.601-610
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• 2001

The purpose of this retrospective study was to evaluate the level oi alveolar bone support of the erupted Permanent canine through the reconstructed cleft region compared to the contralateral canine on the non-cleft side. This study was limited to children with complete unilateral cleft lip and palate who underwent secondary alveolar iliac bone gvaft and the apices of the erupted canine roots were closed at the time of evaluation. With these criteria the study included 21 children whose average age at the time of bone graft reconstruction was 9.8 years, with a minimum of 12.4 years of age at the time of the evaluation. The study was limited to the use of iliac cancellous bone as the autograft material for reconstruction of the alveolar cleft. Cranial bone graft and other autogenous bone sources were excluded. The periapical radiographs were used to evaluate alveolar bone level of each canine. The percentages of root supported by the bone were established by dividing the amount of root covered with the bone by the anatomic root length. The canine oi the non-cleft side was used as an internal control and the canine on the cleft side was used as an experimental. There was a statistically significant difference in the alveolar bone support ratio between the control ($92.9\%$) and experimental canines ($8.7\%$). An average of $95\%$ level of alveolar bone support was achieved for the experimental canine in comparison to the control canine. Neither the presence of lateral incisor, nor the stage of root development of the canine at the time of the bone graft appeared to have affected the alveolar bone support ratio of the canine after the secondary bone graft.

• The Journal of the Korean dental association
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• v.19 no.3 s.142
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• pp.279-282
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• 1981

The authors observed the degree of alveolar bone resorption on the intraoral roentgenogram of 105 patients who were affected by periodontal disease, and following results were obtained. That is, the alveolar bone resorption due to the periodontal disease showed increased tendency as aging, and severe degree on the mandible in comparison with the maxilla, and revealed sere destruction on the area of mandibular incisors and maxillary molars.

• The korean journal of orthodontics
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• v.44 no.2
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• pp.54-61
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• 2014

Objective: This study aimed to propose clinical guidelines for placing miniscrew implants using the results obtained from 3-dimensional analysis of maxillary anterior interdental alveolar bone by cone-beam computed tomography (CBCT). Methods: By using CBCT data from 52 adult patients (17 men and 35 women; mean age, 27.9 years), alveolar bone were measured in 3 regions: between the maxillary central incisors (U1-U1), between the maxillary central incisor and maxillary lateral incisor (U1-U2), and between the maxillary lateral incisor and the canine (U2-U3). Cortical bone thickness, labio-palatal thickness, and interdental root distance were measured at 4 mm, 6 mm, and 8 mm apical to the interdental cementoenamel junction (ICEJ). Results: The cortical bone thickness significantly increased from the U1-U1 region to the U2-U3 region (p < 0.05). The labio-palatal thickness was significantly less in the U1-U1 region (p < 0.05), and the interdental root distance was significantly less in the U1-U2 region (p < 0.05). Conclusions: The results of this study suggest that the interdental root regions U2-U3 and U1-U1 are the best sites for placing miniscrew implants into maxillary anterior alveolar bone.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.461-471
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• 2006

In order to achieve a satisfactory esthetic result of periodontal surgery or implant in maxillary anterior area, periodontists must be aware of normal alveolar bone anatomy. The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 78(mean age : 25 yrs) periodontally healthy volunteers participated in this study. Two maxillary central incisor and one lateral incisor were selected to study. With minimal local anesthesia, gutta-percha cone inserted to labial gingival sulcus of selected teeth just after bone sounding with periodontal probe. Metal ball (4mm diameter) attached to palatal fossa of central incisor. Then, periapical radiograph was taken according to long cone paralleling technique. After film scan, labial alveolar bone profile reproduced along interproximal bone and apical ends of gutta-percha cones on computer screen. By utilizing computer program, the distance from height of interproximal bone to the labial bone crest in central incisor-central incisor and central incisor-lateral incisor area was measured and converted to real distance by using vertical length of metal ball on film. After measuring crown length & width of central incisor, the 10 individuals ranked lowest GW/L ratio (crown width/length ratio) and the 10 ranked highest were selected as having a long-narrow(group N), or a short-wide(group W) form of the central incisors. Means of the distance from height of interproximal bone to the labial bone crest of group N, W were calculated and compared by means of independent t-test. The results were as follows: 1. Mean distance from the height of the interproximal bone to the labial bone crest was $3.5{\pm}0.7mm$ between two central incisor, and $2.8{\pm}0.6mm$ between central and lateral incisor. 2. Mean GW/L ratio of group N was 0.57, and group W was 0.8. Mean distance from the height of the interproximal bone to the labial bone crest of group N was higher than group W in both measured area(measurements of group N, W were $3.9{\pm0.2mm$ and $3.5{\pm}0.2mm$ between two central incisor, $3.0{\pm}0.2mm$ and $2.8{\pm}0.2mm$ between central and lateral incisor), but there were no statistically significant differences when the groups were compared. Within the limits of the present study, there was a tendency that subjects with long-narrow teeth have more scalloped alveolar bone profile than subjects with short-wide teeth in upper anterior area, but no statistically significant differences were found.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.41-46
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• 1976

The purpose of the current study was to investigate histologic changes in the alveolar bone of the lower molar region subsequent to the loss of their opposite molars, and to characterize chemical alterations by utilization of histochemical procedures. Twenty five rats(Sprague Dawley), approximately 150-200gm body weight, were used in this experiment. In the treated animals, upper molars were removed. The animals were decapitated by groups at the following intervals after teeth removals: 10th, 20th, 50th, 70th and 100th day. The normal, untreated rats were used as controls. The molar region of lower jaw, including the intact alvelar bone and teeth was dissected and specimens were decalcified in 3% formic acid. After the tissues were fully decalcified, the specimens were embedded in celloidin and sectioned in mesiodistal plane. These sections were stained in the following staining methods. Mallory azan stain and hematoxylin-eosin stain were utilized for structural evaluation. Polysaccharides were demonstrated by means of the PAS reaction. Acidmucopolysaccharides were studied by means of the colloidal iron stain. Alloxan-Schiff reaction was used for protein. The results were as follows: 1) In the control animals, bone resorption was noted in the distal alveolar bone proper and bone apposition was shown in the mesial alveolar bone proper. But in the treated animals, bone apposition was observed on the mesial and distal walls of the alveolus and osteoclastic activity was not noted in any walls. 2) Bone apposition was most prominent from the 10th to 20th day after treatment. 3) Appositional growth of cementum along the surface of root was prominent from the 50th to 70th day after treatment. 4) In the area where osteoblastic activity was apparent, osteoblasts were stained strongly in the PAS and alloxan-Schiff reaction. A plastic resorption line showed strong alloxan-Schiff reaction. 5) In the colloidal iron stain, the alveolar wall adjacent to the cementum apposition area was stained more strongly than the other areas.

• The korean journal of orthodontics
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• v.53 no.4
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• pp.264-275
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• 2023

Objective: To investigate the effects of maxillary orthodontic expansion on the alveolar bone tissue in adult patients treated with aligners by using cone-beam computed tomography. Methods: Thirty patients (22 females and 8 males; mean age: 36.3 years) were treated with Invisalign^® aligners. Cone-beam computed tomography and digital models were obtained before (T0) and after (T1) upper arch expansion. The bone thicknesses in the cervical, middle, and apical areas of the incisors, canines, premolar, and first molars were buccally and palatally measured, totaling 96 areas and 2,880 measurements. The buccolingual inclinations and transverse measurements of the teeth were obtained from digital models to correlate them with the bone changes. The statistical tests used were Student's t-test, analysis of variance, and Pearson's correlation tests (p < 0.05). Results: From the 96 areas evaluated, 84 revealed an increase or stability in the alveolar bone thickness and twelve displayed significant bone loss. Bone changes did not correlate with the tooth inclination and transverse measurements. Conclusions: Within the limitation of the present study, mild levels of upper arch expansion obtained with Invisalign^® aligners in adult patients did not result in any clinically significant loss of alveolar bone thickness.

• The korean journal of orthodontics
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• v.47 no.6
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• pp.394-400
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• 2017

Assessing the condition of the alveolar bone before and after orthodontic treatment is important. Recently, cone-beam computed tomography has been widely accepted as a useful tool for orthodontic treatment. Moreover, using a three-dimensional (3D) structural analysis software enables gathering detailed information and quantifying data. The aim of this study was to introduce various quantitative analyses performed before and after orthodontic treatment by using a 3D structural analysis software for evaluating the morphological condition of the alveolar bone of a patient with gingival recession around the canines.