OBJECTIVETo explore the treatment on teeth transposition of maxillary canine and lateral incisor in order to improve the clinical treatment effect.

METHODSEleven patients with transposition maxillary canine and lateral incisor were treated with the method: Expand space, artificial reverse occlusion of transpositional lateral incisor to give way, transpositional lateral canine distalization and controlling root, mesial movement of lateral incisor with tongue arch, interactive controlling roots and retention with tongue fixed retaining appliance.

RESULTSEleven patients had satisfactory treatment effect, with tidy dentition and parallel teeth roots of transpositional canine and lateral incisor.

CONCLUSIONSeries orthodontic treatment on teeth transposition of maxillary canine and lateral incisor can effectively improve the clinical treatment effect and shorten the treatment time.

Transmigration of an impacted tooth through the symphyseal suture is a rare and special developmental anomaly of unknown etiology that is unique to the mandibular canine. Maxillary canine transmigration is even rarer. Transmigrated canines are particularly significant due to the aesthetic and functional importance. A maxillary lateral incisor crossing the mid-palatal suture has never been reported in the literature. The aim of this report is to present the first case of simultaneous transmigration of a lateral incisor and canine in the maxilla. The paper also reports four unusual cases of unilateral canine transmigration in the maxilla and mandible and successful eruption of one of the transmigrated mandibular canines following orthodontic traction. Etiology of transmigration and its clinical considerations are also discussed.
Cuspid ; Incisor ; Mandible ; Maxilla ; Sutures ; Tooth Migration ; Tooth, Impacted ; Traction

The present study examines the effects of orthodontic treatment of surgically exposed impacted upper canines or ectopically erupted upper canines to periodontal condition and whether various opening procedures have significant difference in postoperative periodontal status. The subjects included 23 orthodontic patients(7 men, 16 women) with unilateral upper canine impaction treated either with closed eruption technique(group I), with apically positioned flap procedure(group II), and those with canines ectopically erupted through keratinized gingiva(group III). In each subject, the ectopic canine was orthodontically aligned, and changes in periodontal tissue were assessed by measuring keratinized gingival width, attached gingival width, probing depth and bone probing depth. In all three groups, the width of keratinized gingiva was preserved while showed no signs of detrimental periodontal condition such as gingival recession. In all three groups, no significant difference in periodontal pocket depth from control was observed. The width of attached gingiva was significantly greater in patients treated with apically positioned flap procedure(group II) than in patients on other groups.
Cuspid* ; Gingiva ; Gingival Recession ; Humans ; Male ; Periodontal Pocket

When the bones of a human being are excavated, the teeth in particular can be a great help in distinguishing the sex of the person because they remain unchanged in terms of physical and chemical characteristics. We measured mesiodistal diameters of the crown of teeth and faciolingual diameters of the crown of teeth of 215 adult dental casts (male 109; female 106) and teeth of the 166 cadavers (male 127; female 39). Among these samples, we made use of only measurement values with statistical significance to obtain discriminant functions by discriminant analysis and to verify this study. Fifty one discriminant functions are obtained through several combinations of independent variables so that they can be applied to the bones of human being found in archaeological excavations. Among them, only 34 functions have the statistical significance, showing the correct classification from 64.5 to 89.8%. The other 17 functions are excluded from the discriminant analysis on the basis of Box's M value and Wilks' Lambda value. Among these 34 functions, only 8 functions with high classification accuracy are tested. They show the correct classification from 62.8 to 84.6%. The highest classification accuracy can be achieved when all of the lower teeth (I1 to PM2) are used. The functions from the canine tooth of the lower jaw have high potential usefulness because they can be applied to a variety of materials.
Adult ; Cadaver ; Classification ; Crowns ; Cuspid ; Female ; Humans ; Jaw ; Tooth

The long distance displacement of canine is a rare phenomenon in orthodontic clinic. Its related clinical epidemiology, etiology, diagnosis and treatment methods are briefly summarized, and a case of mandibular canine displaced in chin is reported.
Ambulatory Care Facilities ; Cuspid ; Humans ; Mandible ; Tooth, Impacted

OBJECTIVETo investigate root canal curvature in maxillary anterior teeth.

METHODSAbout 400 human maxillary anterior teeth were examined by indirect digital radiography both from labiolingual and mesiodistal directions. The root canal curvature was analyzed.

RESULTSThe major sort of maxillary anterior teeth was type I. The proportion of maxillary center incisors, maxillary lateral incisors, maxillary canines curved in mesiodistal were 11.17%, 16.19% and 21.43%, in labio-lingual were 39.59%, 40.00% and 29.59%, both in labiolingual and mesiodistal directions were 4.60%, 35.24% and 24.49%. About 50% of maxillary anterior teeth were moderate curve, the degree of root canal curvature of maxillary canines was larger than that of maxillary incisors, and radius of curvature and length of the curved part of root canal of maxillary canines were smaller than that of maxillary incisors.

CONCLUSIONRoot canal curvature in maxillary anterior is complex, especially in maxillary canine. In order to improve quality of root canal therapy, we need to understand types of root canal, degree of root canal curvature and radius of curvature completely.

STATEMENT OF PROBLEM: There have been a few studies about unsplinted implant retainted maxillary overdenture. PURPOSE: The purpose of this study was to examine the effect of different position of implant for 2 implants-retained maxillary overdenture. MATERIALS AND METHODS: Three-dimensional finite element models were used to reproduce an edentulous human maxilla with an implant-retained overdenture. Two implants in the canine tooth positions on both side and in the second premolar tooth positions on both side models were examined. Axial loads of 100 N were applied to the occlusal surface at the right first molar tooth positions. Maximum stress at the implant-bone interface and stress at the cortical bone surface just under the loading point were observed. RESULTS AND CONCLUSION: Within the limits of this study, maximum stresses were concentrated around implant of canine position at loading side. The second premolar area was thought to be more favorable to distribution of stress on mucosa, alveolar bone and implants than canine area for maxillary overdenture.
Bicuspid ; Cuspid ; Denture, Overlay ; Humans ; Maxilla ; Molar ; Mucous Membrane ; Tooth

OBJECTIVETo analyze the practical effect of distalization of lower cuspiud by light-segmented archwire.

METHODS17 cases were selected. In all cases, two lower first bicuspids were extracted and lower molars were designed as reinforced anchorage. In the first half year, lower cuspids were distalized with light-segmented archwire, and lower incisors were in the physiologic drift stage. Before the treatment, three months and six months after the treatment, cephalograms and study models were recorded respectively. The data were analyzed with SPSS 10.0.

RESULTSThe distance of mesiolization of the first lower molar was 1.14 mm in half a year. The distance of distalization of the lower cuspid was 5.02 mm in half a year. No significant difference was found in LM-MP and SN-MP angle. LI-NB angle was decreased by 9.57 degrees. Crowding of lower incisors was transferred from -2.55 mm to 1.08 mm.

CONCLUSIONDuring distalization of lower cuspid by light-segmented archwire, anchorage tooth was stable, lower cuspids were distalized effectively, and lower incisors drifted towards the ideal position automatically.

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 m 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.
Bicuspid ; Crowns* ; Cuspid ; Decompression Sickness ; Incisor ; Molar ; Orthodontics ; Tooth

OBJECTIVE: The relationship between the orthodontic tooth movement and the change of keratinized gingival width was analyzed by measuring the keratinized gingival width and position of the teeth before and after 28 orthodontic treatments. METHODS: The photos were matched to the model and the width of the keratinized gingival was obtained by measuring the length of the crown, and the keratinized gingiva. The pre- and post-treatment models were overlapped on rapidform 2006 and the change of tooth position before and after orthodontic movement could be accurately measured, and the relationship between tooth intrusion and extrusion, retraction and forward movement, torque variation and keratinized gingival width was statistically investigated. RESULTS: Analysis of the correlation between data before and after treatments for 213 teeth in 28 patients revealed a strong correlation between changes in tooth torque angle and changes in keratinized gingiva width (r=-0.47, P<0.001). In the multi-level linear regression analysis, the correlation between them was verified (regression coefficient<0, P<0.001), and there was no significant correlation between the intrusion and retraction of the teeth and the change of the width of keratinized gingiva (P>0.05). Regression coefficient was negatively relative to the reference incisor between the teeth for the canines and premolars (canine regression coefficient=-0.35, premolar regression coefficient=-0.38, P<0.05). Therefore, the study found that there was a strong negative correlation between the changes in tooth torque angle and width of keratinized gingival (r=-0.41, P<0.001), that is, an increase in positive torque led to the reduction of width of keratinized gingiva, and on the contrary the increase of negative torque would cause the width of keratinized gingiva increase. There was no significant correlation between the intrusion and extrusion of the teeth for the width of keratinized gingiva. The sensitivity of different teeth for the width of keratinized gingiva differed, with incisor compared with canines and premolars that were more prone to keratinized gingiva width changes. CONCLUSION Tooth movement during orthodontics affected the width of the keratinized gingiva width, and the increase in positive torque was more likely to cause a reduction in the width of keratinized gingiva. There was no significant correlation between the intrusion and retraction of the teeth and the change in the width of keratinized gingiva. Incisors were more prone to changes in the width of keratinized gingiva relative to the cuspids and premolars during tooth movement. In the orthodontic process, it is possible to predict the effect of changes in the position of the teeth on the keratinized gingiva width, and attention shoud be to the changes in the keratinized gingiva width.
Bicuspid ; Cuspid ; Gingiva ; Humans ; Incisor ; Tooth Movement Techniques