• 대한치과교정학회지
• /
• 제16권2호
• /
• pp.123-133
• /
• 1986

The purpose of this study was to collect the information of the straight-wire appliance and to determine the amount of second-order bends in clinical orthodontics. The author analysed the study model of 50 individuals with normal occlusion and results were obtained as follows. 1. The crown angulation was 4 degree in upper central incisor, 7 degree in upper lateral incisor, and 0 degree in lower central incisor and lateral incisor. 2. The crown angulation was 8 degree in upper cuspid and 2 degree in lower cuspid. 3. The crown angulations were 4 degree in upper first bicuspid, upper second bicuspid and lower second bicuspid and 1 degree in lower first bicuspid. 4. The crown angulation was 3 degree in upper first molar, 0 degree in upper second molar, 5 degree in lower first molar and 8 degree in lower second molar. 5. The crown angulations in lower arch were progressively increased from first premolar to second molar. 6. In upper arch, as the crown angulation of one tooth was increased, those of adjacent teeth were increased, too. 7. In the case of lower arch, the crown angulation of cuspid was increased as that of lateral incisor was increased, the crown angulation of second premolar was increased as that of first premolar was increased, and similarity the crown angulation of second molar was increased as that of first molar was increased.

• Imaging Science in Dentistry
• /
• 제49권2호
• /
• pp.123-130
• /
• 2019

Purpose: This study was conducted to characterize the relationship of the angulation between the tooth root axis and alveolar bone axis with anterior alveolar(AA) arch forms and sagittal root position (SRP) in the anterior esthetic region using cone-beam computed tomography (CBCT) images. Materials and Methods: CBCT images that met the inclusion and exclusion criteria were categorized using a recent classification of AA arch forms and a SRP classification. Then, the angulation of the root axis and the alveolar bone axis was measured using mid-sagittal CBCT images of each tooth. The relationships of the angulation with each AA arch form and SRP classification were evaluated using 1-way analysis of variance and a linear regression model. Results: Ninety-eight CBCT images were included in this study. SRP had a greater influence than the AA arch form on the angulation of the root axis and the alveolar bone axis(P<0.05). However, the combination of AA arch form and SRP was more predictive of the angulation of the root axis and the alveolar bone axis than either parameter individually. Conclusion: The angulation of the root axis and alveolar bone axis demonstrated a relationship with the AA arch form and SRP in teeth in the anterior esthetic region. The influence of SRP was greater, but the combination of both parameters was more predictive of root-to-bone angulation than either parameter individually, implying that clinicians should account for both the AA arch form and SRP when planning implant placement procedures in this region.

• 대한치과교정학회지
• /
• 제29권2호
• /
• pp.137-146
• /
• 1999

교합기에 거상된 모형 상에서 각 치아의 순, 협설측경사와 근원심경사를 적절하게 조절할 수 있도록 개발된 측정기구를 교정 치료의 마무리 단계에서 술자가 원하는 보다 정확하고 좋은 교합으로 유도하는 tooth Positioner의 제작을 위한 셋업 모형 제작에 이용하는 방법을 보여 주고자 한다.

• 대한치과기공학회지
• /
• 제35권4호
• /
• pp.415-424
• /
• 2013

Purpose: This study is to present a standard value for clinical crown angulation and inclination required in laboratory process and see if the value can be used for actual laboratory process. Methods: In order to find out a standard value for clinical crown angulation and inclination, this study made a study model of normal occlusion of 21 females in twenties. The clinical crown angulation and inclination of both six-maxillary and six-mandibular anterior teeth are measured by Set-up Model Checker. From the measured value above, the mean and standard deviation of the twelve teeth are obtained, and then the mean of the teeth between right and left side is calculated. Results: Each clinical crown angulation of maxillary central incisor, lateral incisor, and canine is like this; $1.0^{\circ}{\pm}1.3^{\circ}$, $3.0^{\circ}{\pm}1.3^{\circ}$, and $5.0^{\circ}{\pm}1.4^{\circ}$. In case of mandibular, each degree is like this; $0.6^{\circ}{\pm}1.1^{\circ}$, $1.5^{\circ}{\pm}1.1^{\circ}$, and $4.1^{\circ}{\pm}1.1^{\circ}$. Each clinical crown inclination of maxillary central incisor, lateral incisor, and canine is like this; $6.1^{\circ}{\pm}1.8^{\circ}$, $4.5^{\circ}{\pm}1.9^{\circ}$, and $-6.2^{\circ}{\pm}1.4^{\circ}$. In case of mandibular, each degree is like this; $0.3^{\circ}{\pm}1.5^{\circ}$, $0.3^{\circ}{\pm}1.8^{\circ}$, and $-7.5^{\circ}{\pm}1.8^{\circ}$. Conclusion: As the result, the mean value for clinical crown angulation and inclination can be referred to actual laboratory process. However, the mean value is different from those of the precedent study and an unsatisfied one for adopting the standard value.

• The Journal of Advanced Prosthodontics
• /
• 제15권6호
• /
• pp.290-301
• /
• 2023

PURPOSE. The study aimed to determine the influence of implant angulation on the trueness of multi-unit implant impressions taken through different techniques and strategies. MATERIALS AND METHODS. As reference models, three partially edentulous mandibular models (Model 1: No angulation; Model 2: No angulation for #33, 15-degree distal angulation for #35 and #37; Model 3: No angulation for #33, 25-degree distal angulation for #35 and #37) were created by modifying the angulations of implant analogues. Using a lab scanner, these reference models were scanned. The obtained data were preserved and utilized as virtual references. Three intraoral scanning (IOS) strategies: IOS-Omnicam, ISO-Quadrant, and IOS-Consecutive, as well as two traaditional techniques: splinted open tray (OT) and closed tray (CT), were used to create impressions from each reference model. The best-fit alignment approach was used to sequentially superimpose the reference and test scan data. Computations and statistical analysis of angular (AD), linear (LD), and 3D deviations (RMS) were performed. RESULTS. Model type, impression technique, as well as interaction factor, all demonstrated a significant influence on AD and LD values for all implant locations (P < .05). The Model 1 and SOT techniques displayed the lowest mean AD and LD values across all implant locations. When considering interaction factors, CT-Model 3 and SOT-Model 1 exhibited the highest and lowest mean AD and LD values, respectively. Model type, impression technique, and interaction factor all revealed significant effects on RMS values (P ≤ .001). CT-Model 3 and SOT-Model 1 presented the highest and lowest mean RMS values, respectively. CONCLUSION. Splinted-OT and IOS-Omnicam are recommended for multi-unit implant impressions to enhance trueness, potentially benefiting subsequent manufacturing stages.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제26권2호
• /
• pp.115-131
• /
• 2000

In the study of craniofacial deformity, it is very important that identifying the factor which can affect the morphology and which is closely related to the morphology, because it can not only improve the comprehension of growth and developmental process but also be applied in growth prediction and treatment modality. Several investigators have already mentioned the characterstics of head posture and airway space in relations to morphologic difference. But it is very meaningful work in clarifying the correlation between morphology, head posture and airway space that observing the change of head posture after morplologic change caused by operation and the change of airway space after same procedure. To investigate above correlation, I selected normal group which is consisted of 43 adults and mandibular prognathism group which is consisted of 47 adults who had been operated by sagittal split ramus osteotomy and were followed up more than 1 year. With their lateral skull radiograghs, reference lines which can evaluate each measuring points and areas without effect of postural change were first determined. And using above reference lines, change of airway space, positional change of tongue and hyoid, change of cranial and cervical angulations were measured. The results obtained from the study were as follows 1. In the change of head posture, the position of tongue and hyoid neighboring to pharynx is more closely related to the reference line of cervical column than to reference line of cranium. 2. After mandibular setback operation, the airway dimension was decreased to 81.6% of preoperative state at 1 month postoperatively and was slightly increased to 89.7% at 1 year postoperatively. 3. Posterior movement of tongue plays important role in decrease of airway dimension and inferior movement of hyoid was closely correlated with posterior movement of tongue. 4. Postoperative anterior movement of mandible, namely, morphologic relapse had correlation with relapse phenomenon of airway dimension. 5. Craniocervical angulation increased postoperatively. Especially in the postoperative early state, there was increased foreward inclination of cervical angulation rather than increase of cranial angulation. But at postoperative 1 year it was observed that cervical inclination was returned to preoperative state and cranial angulation was increased gradually. 6. Increase rate of airway dimension was correlated with the increase of cranial angulation from postoperative 1 month to 1 year. In conclusion, relapse tendency of airway dimension following increase of cranial angulation was found after mandibular setback operation and it is considered that increase of cranial angulation is one of compensatory mechanism in airway maintenance.

• 대한방사선기술학회지:방사선기술과학
• /
• 제20권1호
• /
• pp.51-54
• /
• 1997

This study is to evaluate the individual angulation on maxlliary sinus projection and establishing angulation in children by new geometrical method. There were two groups, which are 60 cases in children (ranged from 1yr to 3yrs, 3yrs to 8yrs, 8yrs to 12yrs) and 50 cases in adults. We analyzed the true lateral maxillary sinus film of total 110 patients using new geometrical method. We demonstrated an angle of maxillary sinus projection. Arithmetical average angulation in adults is 36.56 degrees that accord with Waters. Whereas it is not valid during development of facial bone in childhood. The individual range of angulation according to age was that 1yr to 3yrs is 50-47 degrees, 3yrs to 8yrs is 47-40 degrees, 8yrs to 12yrs is 40-38 degrees. This geomatrical method will be useful in establishing angulation for maxillary sinus profection.

• Imaging Science in Dentistry
• /
• 제37권3호
• /
• pp.127-131
• /
• 2007

Purpose: To measure the differences of the splint pin angulation and the position of the planned implant site after conventional tomographic analysis. Materials and Methods: The angulation and the location of the metal splint pin retained in acrylic stent were compared with the corrected angulation and the location of the implant fixture on the 331 tomographic images. Results: The stent pins were located buccal in 40%, lingual in 10% to the corrected implant site after analysis of the conventional tomographic image. The angle and the location of the maxillary splint pin were mainly directed buccal on incisor and canine regions. The angle and the location of the splint pins in premolar and molar regions needed less corrections in both maxilla and mandible. Conclusions: This study demonstrated that the use of tomographs was essential for successful dental implant planning.

• 구강회복응용과학지
• /
• 제20권2호
• /
• pp.135-141
• /
• 2004

Statement of problem: Arrangement and angulation of clinical crown is very important for esthetic restoration in the upper anterior dentition. However, there was no clinical criteria to mesial angulation of the crown for Korean. Purpose: This study was undertaken to estimate the mesial angulation of the crown of the anterior teeth and the Oh's E-triangle made of the inter-pupillary line and the mesial inclination lines of the canines. Material and Method: 270 portraits of Korean were used for this study. The mesial angulation of the upper anterior teeth and the relationship of the inter-pupillary line and the mesial inclination lines of the canines were measured with the tools of PhotoShop software on the scanned images. Results: The angulation between the clinical crowns having a same name in the upper anterior dentition were $3.6^{\circ}$ between the central incisors, $8.6^{\circ}$ between the lateral incisors, and $13.6^{\circ}$ between the canines. There was no significance according to occupation and gender( P > 0.05). The ratio of height to base line of Oh's E-triangle was 4.47. 81.6% of the subjects showed the mesial inclination line of the canine passed by mesial border area of pupil. Conclusion: These data for Korean would be useful clinically to give the esthetic arrangement and to make the contour of upper anterior teeth.

• 대한치과교정학회지
• /
• 제28권5호
• /
• pp.791-802
• /
• 1998

교합기에 거상된 정상교합자 31명의 진단모형에서 치아 FACC의 경사도를 측정하기 위해 약간 변형시킨 T.A.R.G.를 이용하여 안이평면에 대한 각 치아 FACC의 순, 협설측경사와 근원심경사를 측정하여 분석한 결과 다음과 같은 결론을 얻었다. $\cdot$상, 하악 각 치아의 FACC의 순, 협설측경사와 근원심경사를 측정하여 각각의 기준치를 얻었다. $\cdot$치아 FACC의 순, 협설측경사는 상, 하악 치열 모두에서 전방치아에서 후방치아로 갈수록 점점 설측으로 경사되는 경향을 보였다. $\cdot$치아 FACC의 근원심경사는 상악치열에서 중절치와 측절치는 거의 비슷한 경사도를 가지고 견치부위에서 후방치아로 갈수록 점점 원심으로 경사되는 양상을 보였고, 하악 치열에서는 전방치아에서 후방치아로 갈수록 점점 근심으로 경사되는 경향을 보였다. $\cdot$상, 하악 모든 치아에서 어느 한 치아의 치관 근원심 경사와 순, 협설측경사는 인접치아들의 치관 근원심경사와 순, 협설측경사와 높은 순상관관계를 보였다.