OBJECTIVETo observe the results of surgical crown lengthening procedure and the factors which affected the success of the surgery.

METHODSCrown lengthening surgery was performed on 27 teeth. The distance between margin of tooth and bone crest (MT-B) was obtained greater than 4 mm during the surgeries on 10 teeth which were considered as satisfying group. The other 17 teeth were as temporized group with MT-B < or = 3 mm. The position of the tooth margin was evaluated before surgery, immediately after suturing, and at 4 - 6 weeks after surgery. The occlusal force and tooth mobility were measured immediately after restoration, at 3 and 6 months after surgery.

RESULTSMT-B was obtained > or = 4 mm and all margins and sites of the teeth were exposed in satisfying group (10/10). At least 1 site with MT-B < 3 mm in temporized group in which there still were 11 sites (16%) in 5 teeth (29%) with subgingival tooth margin at 4 - 6 weeks after surgery. There were more teeth showing increased mobility in temporized group (12/17) than in satisfying group (1/10) after surgery (P < 0.05). The occlusal force of the teeth after surgery and restoration in temporized group was significantly lower than that of their counterpart teeth (P < 0.01), but it was not the case in satisfying group (P > 0.05).

CONCLUSIONSIt is suggested that ideal exposure of tooth margin could be obtained if 4 mm from tooth margin to alveolar crest could be created during the crown lengthening surgery. The teeth both with 4 - 5 mm subgingival margin sites and factors limiting surgical performance are not the suitable indications for the surgical crown lengthening.

Alveolectomy ; Crown Lengthening ; methods ; Follow-Up Studies ; Gingiva ; anatomy & histology ; Humans ; Periodontium ; anatomy & histology ; physiology ; Prospective Studies ; Tooth Crown ; pathology

OBJECTIVETo evaluate Beijing college students' concern and preference for maxillary anterior tooth esthetic factors.

METHODSSeveral images about lip and tooth were made through computer. A questionnaire was sent out to students in ten colleges and then collected. There were five factors to be evaluated: relationship of maxillary incisors and lower lip, numbers of tooth exposed, shape of centric incisor, crown width-length ratio, gingival margin. Concern of the beauty of anterior tooth, ie. tooth shape, tooth arrangement, shape of gingiva and so on, were then analyzed.

RESULTSThere were 408 responses collected, and 47.5% (194/408) of them preferred light contact between upper incisors and lower lip; 49.5% (202/408) preferred 8 tooth exposed when smile; 69.1% (282/408) preferred oval crown shape; 52.5% (214/408) preferred 0.85 as a crown width-length ratio; 49.5% (202/408)of responses chose the curve of gingiva runs horizontal. The average score of concern for male was 52.6% (100/190), for female was 59.6% (130/218).

CONCLUSIONSMost results from this study accord with the classical principles of tooth esthetics. Sex affects the concern and preferences of maxillary anterior tooth esthetics factors.

Adult ; China ; Esthetics, Dental ; Female ; Gingiva ; anatomy & histology ; Humans ; Incisor ; anatomy & histology ; Lip ; anatomy & histology ; Male ; Maxilla ; anatomy & histology ; Odontometry ; methods ; Patient Preference ; Sex Factors ; Smiling ; Surveys and Questionnaires ; Tooth Crown ; anatomy & histology ; Young Adult

During smile evaluation and anterior esthetic construction, the anatomic and racial variations should be considered in order to achieve better matching results. The aims of this study were to validate an objective method for recording spontaneous smile process and to categorize the smile and upper lip curvature of Chinese Han-nationality youth. One hundred and eighty-eight Chinese Han-nationality youths (88 males and 100 females) ranged from 20 to 35 years of age were selected. Spontaneous smiles were elicited by watching comical movies and the dynamics of the spontaneous smile were captured continuously with a digital video camera. All subjects' smiles were categorized into three types: commissure, cuspid and gummy smile based on video editing software and final images. Subjects' upper lip curvatures were also measured and divided into three groups: upward, straight and downward. Reliability analysis was conducted to obtain intra-rater reliabilities on twice measurements. The Pearson Chi-square test was used to compare differences for each parameters (α=0.05). In smile classification, 60.6% commissure smile, 33.5% cuspid smile and 5.9% gummy smile were obtained. In upper lip measurement, 26.1% upward, 39.9% straight and 34.0% downward upper lip curvature were determined. The commissure smile group showed statistically significant higher percentage of straight (46.5%) and upward (40.4%) in upper lip curvatures (P<0.05), while cuspid smile group (65.1%) and gummy smile group (72.7%) showed statistically significant higher frequency in downward upper lip curvature (P<0.05). It is evident that differences in upper lip curvature and smile classification exist based on race, when comparing Chinese subjects with those of Caucasian descent, and gender.
Adult ; Cephalometry ; methods ; China ; ethnology ; Cuspid ; anatomy & histology ; Ethnic Groups ; Female ; Gingiva ; anatomy & histology ; Humans ; Image Processing, Computer-Assisted ; methods ; Lip ; anatomy & histology ; Male ; Smiling ; Video Recording ; methods ; Young Adult

OBJECTIVETo investigate the smile esthetic elements of Chinese Han-nationality female based on high definition (HD) digital camera with computer-image measuring technique.

METHODSHD digital camera was used to capture spontaneous smile process combined with computer-image measuring technique to establish the analysis method of smile. Ninety-nine Han-nationality female with normal gingiva, aged from 20 to 30 years were recruited. The lip-incisor edge distance, gingival display were measured. The data was statistically analyzed.

RESULTSA standard and objective method to analyze spontaneous smile was established. Forty-three percent (43/99) of the subjects studied were classified as having a high smile and average smile respectively, 13% (13/99) as having a low smile. Gingival display accounted for (1.34 ± 0.98) mm in high smile type.

CONCLUSIONSAverage smile and high smile type were most common in the Chinese Han-nationality female studied.

Adult ; Analysis of Variance ; Asian Continental Ancestry Group ; Cephalometry ; methods ; Esthetics, Dental ; Female ; Gingiva ; anatomy & histology ; Humans ; Image Processing, Computer-Assisted ; methods ; Incisor ; anatomy & histology ; Lip ; anatomy & histology ; Smiling ; Young Adult

OBJECTIVETo establish a convenient, objective and applicable method to assess gingival biotype using periodontal probing.

METHODSA total of 66 maxillary anterior teeth from 14 volunteers (6 males, 8 females) with healthy gingiva, aged from 20 to 30 years, were recruited in this study. The gingival biotypes were evaluated by whether or not the outline of the periodontal probe was clear inside the gingiva. Gingival thickness of the cemento-enamel junction (CEJ) in upper anterior teeth was measured by cone-beam CT (CBCT).

RESULTSThe method of periodontal probing-assessed gingival biotype had good consistency and repeatability. The result of probing-assessed gingival biotype was consistent with that obtained by CBCT. The mean thickness of gingiva in thin, compromised and thick gingival biotype was (1.02 ± 0.20), (1.28 ± 0.25) and (1.46 ± 0.25) mm. These differences were significant for all three comparisons (P = 0.001, respectively).

CONCLUSIONSPeriodontal probing-assessed gingival biotype is a simple, relatively objective and suitable method for clinical examination.

Adult ; Cone-Beam Computed Tomography ; Female ; Gingiva ; anatomy & histology ; diagnostic imaging ; Humans ; Male ; Periodontal Index ; Periodontics ; instrumentation ; Tooth Cervix ; diagnostic imaging ; Young Adult

OBJECTIVETo analyze and find factors affecting the height of adjacent gingival papilla of maxillary central incisor single implant in human in order to promote the esthetic result of dental implants.

METHODSSixteen maxillary central incisor single implants of 16 patients and 30 sites of adjacent tissues and prosthesis were evaluated. Data on the height of adjacent gingival papilla of dental implant and relative factors were obtained from clinical parameters, photographs, research models, and X radiographs.

RESULTSThe mean and standard deviation of adjacent gingival papilla height of maxillary central incisor single implant were (4.01 +/- 1.85) mm. Statistical analysis revealed that factors affecting the height of adjacent gingival papilla of implant were as following from strong to weak: vertical distance between contact point and gingival margin, vertical distance between proximal bone level of natural tooth and implant abutment, vertical distance between proximal bone level of natural tooth and contact point, proximal protruding degree of crown, horizontal distance between abutment and root, length ratio of the crown and fixture, vertical distance between proximal bone level of implant and abutment, lip-side protruding degree of crown, probing depth.

CONCLUSIONSMultiple factors affected the height of adjacent gingival papilla of maxillary central incisor single implant in human.

Adult ; Aged ; Dental Implants, Single-Tooth ; Esthetics, Dental ; Female ; Gingiva ; anatomy & histology ; Humans ; Incisor ; surgery ; Linear Models ; Male ; Maxilla ; surgery ; Middle Aged ; Young Adult

Objective: To explore and analyze the correlation between labial gingival morphology and alveolar bone morphology of maxillary anterior teeth in patients with posterior dental implant, so as to provide reference basis for restoration design and esthetic reconstruction of anterior teeth. Methods: Sixty-four patients [24 males, 40 females (25.6±3.3) years old] who planned to receive posterior dental implant restoration were recruited randomly with the inclusion and exclusion criteria in Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University from May 2020 to May 2021. According to the visibility of periodontal probe through gingival margin, the subjects were divided into thin and thick gingival biotypes, including 29 cases of thin biotype and 35 cases of thick biotype. The 3Shape software was used to perform oral scanning, and cone beam CT (CBCT) was taken for each patient. Geomagic and Mimics software were used to measure and record the labial crown width and length, gingival papilla height, gingival angle, bone papilla height and bone margin angle of maxillary anterior teeth. Results: The crown width length ratios of maxillary central incisors, lateral incisors and canines were 0.85±0.08, 0.80±0.08 and 0.86±0.09 (F=10.71, P<0.01). The height of gingival papilla between maxillary central incisors, between central incisors and lateral incisors, between lateral incisors and canines were (3.93±0.86), (3.47±0.84) and (3.38±0.91) mm respectively (F=7.44, P<0.01), and the height of corresponding bone papilla were (3.44±0.88), (3.12±0.75) and (2.72±0.63) mm respectively (F=14.26, P<0.01). The gingival margin angles of maxillary central incisors, lateral incisors and canines were 88.3°±7.7°, 84.7°±8.9° and 81.2°±6.6° (F=13.15, P<0.01), and the bone margin angles were 103.2°±13.1°, 99.5°±11.2° and 110.6°±13.0° (F=13.25, P<0.01). The crown width length ratio (0.81±0.08), gingival margin angle (82.2°±7.4°) and bone margin angle (99.4°±12.9°) of thin gingival subjects were significantly lower than those of thick gingival subjects (0.85±0.09, 86.5°±8.6°, 108.5°±11.4°) (t=-2.79, 3.63, 5.20, P<0.01). The height of gingival papilla [(3.93±0.81) mm] and bone papilla [(3.43±0.80) mm] in thin gingival subjects were significantly lower than those in thick gingival subjects [(3.34±0.84) and (2.85±0.71) mm, respectively] (t=-4.89, -5.36, P<0.01). The height of labial gingival papilla of upper anterior teeth was positively correlated with that of bone papilla in all patients (r=0.66, P<0.01); the ratio of crown width to length of upper anterior teeth was positively correlated with the angle of bone margin (r=0.42, P<0.01); the height of anterior gingival papilla was negatively correlated with the angle of bone margin (r=-0.58, P<0.01), and the height of bone papilla was negatively correlated with the angle of bone margin (r=-0.82, P<0.01). Conclusions: The crown shape, gingival shape and alveolar bone shape of maxillary anterior teeth were different in different tooth positions. Patients with different periodontal phenotypes had different crown width length ratio, gingival papilla height, bone papilla height, gingival margin angle, and bone margin angle.
Adult ; Cone-Beam Computed Tomography ; Dental Implants ; Esthetics, Dental ; Female ; Gingiva/anatomy & histology* ; Humans ; Male ; Maxilla/diagnostic imaging* ; Tooth Crown ; Young Adult

To evaluate the papilla alterations around single-implant restorations in the anterior maxillae after crown attachment and to study the influence of soft tissue thickness on the papilla fill alteration. According to the inclusion criteria, 32 patients subjected to implant-supported single-tooth restorations in anterior maxillae were included. The patients were assigned to two groups according to the mucosal thickness: (i) group 1, 1.5 mm s mucosal thickness 3 mm; and (ii) group 2, 3 mm Adult ; Crowns ; Dental Implantation, Endosseous ; methods ; Dental Implants, Single-Tooth ; Dental Prosthesis Design ; Dental Prosthesis, Implant-Supported ; Esthetics, Dental ; Female ; Follow-Up Studies ; Gingiva ; anatomy & histology ; Humans ; Male ; Maxilla ; Middle Aged ; Outcome Assessment (Health Care) ; Prospective Studies ; Tooth Cervix ; anatomy & histology ; Young Adult