• The korean journal of orthodontics
• /
• v.31 no.2 s.85
• /
• pp.187-197
• /
• 2001

The change of the vertical dimension is of fundamental importance to the orthodontist. However, the choice between the two methods of treatment, extraction versus nonextraction, is not clear. It is not verified that the extraction method decreases vertical dimension, or nonextraction methods result in an increase in vertical dimension. The purpose of this study was to evaluate the changes of vertical dimension of face after the orthodontic treatment with standard edgewise technique, and to compare them in relation to facial types and bicuspid extraction. The subjects consisted of 165 orthodontic patients (77 of adolescents, 88 of adults), and was divided into vertical nonextraction (VN) group, vertical extraction (VE) group, horizontal nonextraction (HN) group, horizontal extraction (HE) group. Pre-and Post-treatment cephalograms were taken with standard method, traced, and digitized for each subject. The comparison of the measurements were statistically executed with Student's t-test. The results were as follows : 1. The facial height and molar height were increased after orthodontic treatment in the all groups. 2. No significant difference was found in the facial height change between the vertical and horizontal groups. 3. No significant difference was found in the facial height change between the extraction and nonextraction groups. 4. As the upper molars were extruded in adolescents group and lower molars were extruded in adults group, lower anterior facial height (LAFH) was increased. 5. None of the pretreatment variables correlates to the change of lower anterior facial height (LAFH).

• The korean journal of orthodontics
• /
• v.26 no.1 s.54
• /
• pp.105-111
• /
• 1996

Most of orthodontic cases are treated with extraction of certain teeth, which influence the pre-eruptive movement of the lower third molar The purpose of this study was to evaluate the positional change of lower third molar following orthodontic treatment. Pre- and post-treatment pantomograms of 163 orthodontic patients (77 nonextraction group, 78 first premolar- extraction group, 8 second molar- extraction group) were analyzed in terms of the mesiodistal and buccolingual angles of lower third molar. The results were as follows. 1. The change of the mesiodistal angle of lower third molar by orthodontic treatment was significant in second molar-extraction group. 2. The mesiodistal angle of lower third molar in pre-treatment was significantly correlated to the mesiodistal angle in post-treatment and/or the change of the mesiodistal angle by treatment. 3. The change of the buccolingual angle of lower third molar by orthodontic treatment was significant in non -extraction group or first premolar-extrction group. 4. The change of the buccolingual angle of lower third molar by treatment was significantly correlated to the mesiodistal angle in post-treatment, the change of the mesiodistal angle by treatment, the buccolingual angle in pre-treatment or the buccolingual angle in post-treatment.

• Restorative Dentistry and Endodontics
• /
• v.36 no.3
• /
• pp.211-218
• /
• 2011

Purpose: Intentional replantation (IR) is a suitable treatment option when nonsurgical retreatment and periradicular surgery are unfeasible. For successful IR, fracture-free safe extraction is crucial step. Recently, a new extraction method of atraumatic safe extraction (ASE) for IR has been introduced. Patients and Methods: Ninety-six patients with the following conditions who underwent IR at the Department of Conservative Dentistry, Seoul National University Bundang Hospital, in 2010 were enrolled in this study: failed nonsurgical retreatment and periradicular surgery not recommended because of anatomical limitations or when rejected by the patient. Preoperative orthodontic extrusive force was applied for 2-3 weeks to increase mobility and periodontal ligament volume. A Physics Forceps was used for extraction and the success rate of ASE was assessed. Results: Ninety-six premolars and molars were treated by IR. The complete success rate (no crown and root fracture) was 93% (n = 89); the limited success rates because of partial root tip fracture and partial osteotomy were 2% (n = 2) and 5% (n = 5), respectively. The clinical and overall success rates of ASE were 95% and 100%, respectively; no failure was observed. Conclusions: ASE can be regarded as a reproducible, predictable method of extraction for IR.

• Journal of dental hygiene science
• /
• v.11 no.3
• /
• pp.251-255
• /
• 2011

Objectives One aspect of undesirable outcomes in orthodontic treatment includes excessive resorption of dental roots with mechanotherapy. The purpose of this study was to examine the relationship between treatment duration, adult and adolescent, gender, extraction and non-extraction root resorption after orthodontic treatment. Methods The subjects consisted of 140 orthodontic patients(adult : 70, adolescent : 70) who treated by standard edgewise technique at the three orthodontic hospital and clinic in seoul. Pre-treatment and post-treatment periapical radiographs were examined. The amount of root resorption was assessed for six anterior teeth according to criteria modified from Lupi et al root resorption score. Results Treatment duration was 24.7 months in the adult group and 33.5 months in the adolescents group. Between adult and adolescents group were significantly difference of mean of root resorption score(p<0.05). Female group and extraction group usually had higher prevalence of root resorption, but were not significant differences between the each groups(p>0.05). Conclusions When viewing these results, a lot of root resorption in adult patients appears, especially the maxillary central incisor, lateral incisor root resorption during orthodontic treatment occurs, so be careful and do more research to be done is suggested.

• Journal of Oral Medicine and Pain
• /
• v.34 no.3
• /
• pp.277-294
• /
• 2009

The purpose of this study was to evaluate the soft tissue changes of class II adolescents and adults in respect to extraction or nonextraction. The study included 68 patients from Wonkwang Dental Hospital were categorized to adolescent extraction group, adolescent nonextraction group, adult extraction group, adult nonextraction group. Cephalometric tracing of each patient was done to compare pretreatment and posttreatment of each group, to compare the changes between groups. And among the variables that showed significancy, correlation analysis and simple linear regression were done. The results were as follows. 1. In both adolescents and adults after extraction treatment, nasolabial angle significantly increased and in both subjects after non extraction treatment, nasolabial angle significantly decreased. 2. In extraction subjects, there were positive correlation between the amount of treatment changes of vertical-U1 and E line-upper lip, the changes of vertical-L1 and E line-lower lip, the changes of vertical-L1 and vertical-Li. 3. In extraction subjects, simple regression equations of E line-upper lip, E line-lower lip, Li were calculated by regression analysis. According to the results above, it could be considered that the effect of the extraction or nonextraction treatment was greater than the effect of growth.

• The korean journal of orthodontics
• /
• v.27 no.4 s.63
• /
• pp.661-668
• /
• 1997

There is a variation in the range of normal occlusion, and we must fit our treatment to the needs of each patient. If the upper or lower incisors are congenital)y missing, malformed, or crowded, the extraction of the incisor has some advantages over the extraction of premolars and nonextractions. The advantages are 1)simple mechanics, 2)reduced treatment time, 3)less relapse tendency, and 4)fewer facial profile changes. In order to decide which incisor should be extracted, we must consider certain factors 1)discrepancies in anterior arch length, 2)anterior tooth ratio, 3)periodontal and tooth health condition, and 4)the relationship between the upper and lower midline. Diagnostic set-up can be helpful to plan the treatment and show us the post treatment result.

• The korean journal of orthodontics
• /
• v.27 no.1
• /
• pp.79-89
• /
• 1997

One of the strenuous problems in orthodontic procedures is postretention stability and retention against relapse. Many investigative trial had been done to disclose the factors associated with relapse and effective prescription to stave off, however, the nature of these jeopardies remained obscure. The objective was to investigate the long-term stability and quantitative changes of dental arches subsequently after Class I nonextraction treatment. Study models,cephalometric headfilms of 26 samples which were taken before, after teatment and postretention were employed to measure the interdental width of corresponding buccal teeth,overbite,overjet and the inclination of incisors and molars. Statistical analysis was carried to compare each measurements across the time period, and followings were brought around. 1. The quantitative amount of relapse in overbite presented positive correlation with the amount of changes through the treatment. 2. Stability of intercanine width was so far secure in the case the expansion had been done through. 3. The amount of changes in intercanine width of the lower regardless of expansion or contraction manifested less than the upper, however, the relapse ratio got high. 4. The upper and lower incisors were likely to be labioversive, and remained stable after retention. 5. The first molars of the upper and lower were conceivably tipped back immediately after treatment and returned to the original angulation. The expansion of intermolar width stayed stable across the time scheme after treatment It was suggested that the maintenance of intercanine width of lower was pertinent to perform the postretention stabilityv and the expansion of dental arch shoed be confined within physiologic boundaries of the patients.

• 대한치과교정학회:학술대회논문집
• /
• 2002.11a
• /
• pp.35.1-35.1
• /
• 2002

• The Journal of Korean Academy of Prosthodontics
• /
• v.50 no.3
• /
• pp.191-197
• /
• 2012

Esthetics is important in restoring maxillary anterior area. Alveolar bone resorption and loss of interdental papilla may be minimized by immediate implantation. Previous studies showed successful results with the immediate implantation in healthy extraction socket, while many of these studies objected the immediate implantation into extraction sites with periapical lesions. Recent studies, however, reported successful results of the immediate implantation into extraction sites with periapical lesions with careful debridement of extraction sockets and general medication of antibiotics prior to implantation. A 73-year-old female visited the department of Prosthodontics in ${\bigcirc}{\bigcirc}$ University Dental Hospital with the chief complaint of fallen post-core and crown on left maxillary incisor. Although the incisor was with vertical root fracture and periapical lesion, the immediate implantation following the extraction of tooth was planned. Thorough socket debridement, irrigation with chlorhexidine, and tetracycline soaking were followed by immediate implantation. The general medication of antibiotics (Moxicle Tab.$^{(R)}$, 375 mg) was prescribed before and after the surgery. Immediate provisional restoration was delivered two days after the surgery, and the definitive metal-ceramic restoration was placed about six months later after reproducing the emergence profile from the provisional restoration. This case presents satisfying result esthetically and functionally upto two years after the placement of prosthesis with the harmonious gingival line and no loss of marginal bone.

• The korean journal of orthodontics
• /
• v.40 no.5
• /
• pp.349-357
• /
• 2010

Objective: The purpose of this study was to evaluate the dentoskeletal and soft tissue profile changes after extraction of two lower first or second premolars in "borderline" adult skeletal Class III cases. Methods: Twenty-eight patients with "borderline" skeletal Class III malocclusion were studied. All of them were treated by extraction of two lower first or second premolars. Lateral cephalometric radiographs taken at the start and end of treatment were analysed. Twenty-five cephalometric variables were calculated and paired $t$-tests were performed. Results: After treatment, no significant changes were noted in the skeletal parameters ($p{\geq}0.05$). Regarding the dental parameters, the L1-MP angle decreased by $8.1^{\circ}$, the U1-L1 angle increased by $7.7^{\circ}$ ($p$ < 0.01), the overjet distance increased by 5.7 mm ($p$ < 0.01), the L1-NB angle decreased by $7.3^{\circ}$ and the L1-NB distance decreased by 4.8 mm ($p$ < 0.01). The soft tissue parameters of Li-E, Li-H and Li-RL2 distance decreased by 3.2 mm, 3.4 mm and 4.1 mm respectively ($p$ < 0.01). Conclusions: Orthodontic camouflage treatment by extraction of two lower first or second premolars provides a viable treatment alternative for "borderline" skeletal Class III cases to achieve a good occlusal relationship.