Soft Tissue Menton Research Articles

Facial asymmetry outcome of orthognathic surgery in mild craniofacial microsomia compared to non-syndromic class II asymmetry

ObjectivesTo compare the facial asymmetry after bimaxillary surgery between mild craniofacial microsomia (CFM) and non-syndromic class II asymmetry.Materials and methodsCone-beam computed tomography scans of adults with Pruzansky-Kaban types I and IIA CFM (CFM groups, n = 20), non-syndromic skeletal class II asymmetry (Class II group, n = 20), and normal controls (control group, n = 20) were compared. The area asymmetry of lower face and jaw bones was quantified. Landmark-based method was used to evaluate the lower facial asymmetry regarding midline, cants, and contour.ResultsThere were no significant postoperative differences in the hemi-facial and hemi-jaw area asymmetry between CFM and Class II groups, both of which were significantly larger than the control group. No significant difference was found in the midline deviation and lip and occlusal cants between CFM and Class II groups. The vertical contour asymmetry in CFM group became significantly larger than Class II group. Compared to the control group, the deviation of pronasale, subnasale, and soft-tissue menton, lip and occlusal cants, and sagittal and vertical contour asymmetry in CFM group were significantly larger, as were the deviation of subnasale and soft-tissue menton and vertical contour asymmetry in Class II group.ConclusionsThe vertical contour asymmetry of mild CFM was significantly larger than non-CFM class II after surgery, while the area asymmetry, midline deviation, cants, and sagittal contour asymmetry of lower face showed no significant difference.Clinical relevanceBe aware that correcting vertical asymmetry of contour, lip, and dentition in CFM is still challenging.

Reproducibility of Manual Transfer of the Clinical Natural Head Position: Influence on the Soft Tissue and Hard Tissue Position of 3-Dimensional Virtual Surgical Planning

The purpose of this study was to assess the reproducibility of manually transferring the clinical natural head position (NHP) to the 3-dimensional (3D) virtual surgical planning and its subsequent influence on the soft tissue and maxillary hard tissue position. A retrospective cohort study was set up. The study population consisted of subjects who underwent bimaxillary osteotomies between 2016 and 2020 at the Department of Oral and Maxillofacial Surgery in Radboud University Medical Centre (Nijmegen, the Netherlands). Cone beam computed tomography scans, dentition data, and clinical photographs were acquired 4weeks before surgery. Two attempts (NHP1 and NHP2) were performed by a single examiner to manually transfer the NHP. 3D transformation matrices were used to quantify the transferred NHP in 3 degrees of freedom (pitch, roll, and yaw). Landmarks and surface-based matching were used to quantify the influence on the soft tissue and hard tissue positions in 6 degrees of freedom. The primary outcome variable was the reproducibility of manually aligning the NHP. The secondary and tertiary outcome variables were the effect of the reproducibility of the manually aligned NHP on the soft tissue and hard tissue displacements in the 3D virtual surgical planning. The study population consisted of 109 subjects: 37 males (33.9%) and 72 females (66.1%) with a mean age of 29.1±10.3years (range, 17.0 to 59.0). The manual transfer of pitch alignment (2.24±1.64⁰; 95% confidence interval [CI], 1.93 to 2.55) was significantly less reproducible than the roll (0.56±0.44⁰; 95% CI, 0.48 to 0.64; P<.001) and yaw (0.67±0.92⁰; 95% CI, 0.50 to 0.85; P<.001). Subsequently, this alignment error influenced the position of the maxilla (incisal point) and soft tissue menton by 0.85±0.86mm and 1.01±1.00mm vertically and 0.78±1.10mm and 0.80±1.18mm sagittally. The present study demonstrated that the manual transfer of the NHP from the clinical situation to the virtual environment influenced the soft tissue and hard tissue position and that a more reproducible method of transferring the clinical NHP is recommended.

Effect of increasing occlusal vertical dimension on lower facial form and perceived facial esthetics: A digital evaluation

Statement of problemIncreasing occlusal vertical dimension (OVD) is often indicated in complex prosthodontic rehabilitations to gain restorative space and improve the occlusal relationship and esthetics. The effect of increasing occlusal vertical dimension on lower facial height (distance from subnasale to soft-tissue menton) and perceived facial esthetics is not well understood. PurposeThe purpose of this clinical study was to investigate the effect of incremental increases in the occlusal vertical dimension on lower facial height and perceived facial esthetics by using a digital approach. Material and methodsTwenty-five participants with Class I jaw relationship and no loss of OVD participated in the study. Custom mandibular devices were digitally designed and 3-dimensionally printed to increase the OVD by 3, 6, and 9 mm in each participant. Three-dimensional facial scans and frontal photographs were made with the participants wearing a specific device to achieve the desired OVD increase. The lower facial height, total facial height (distance between nasion to soft-tissue menton), nasolabial angle, lip width, and lip height were digitally measured on facial scans. All measurements were recorded in a computer-aided design (CAD) software program and were repeated 3 times. Subsequently, frontal photographs of 10 participants were randomly selected for survey. Three groups each of 10 prosthodontists, general dentists, or laypersons participated in the survey and were asked to detect OVD difference in 2 photographs of the same participant and to rank facial esthetics at varying OVDs. One-way repeated measures ANOVA (α=.05) for the facial measurements and descriptive statistics for the survey results were used. ResultsLower facial height, the ratio of lower facial height to total facial height, lip height, and nasolabial angle increased with an OVD increase, whereas lip width decreased (P<.001). Bonferroni corrected paired t tests revealed all groups of OVD increase to be significantly different from each other (P<.001) except for an OVD increase to 6 mm versus 9 mm in lip height (P=.540) and lip width (P=.019), respectively. Prosthodontists, general dentists, and laypersons could detect a +3 mm OVD increase 63.9%, 62.5%, and 56.5% of the time, respectively. The participants’ original OVD was considered the most esthetic (60.0%, 45.0%, and 68.0%) by prosthodontists, general dentists, and laypersons, respectively. ConclusionsIncreased OVD increases lower facial height, the ratio of lower facial height to total facial height, lip height, and nasolabial angle but decreases lip width. Prosthodontists are more sensitive to a smaller increase in OVD, closely followed by general dentists and then laypersons. In case of no loss of OVD, a vertical increase as small as 3 mm can be detected by both dentists and the general public and perceived as less esthetic. The larger the increase in OVD, the more detectable the difference and the less the faces are perceived as esthetic.

Accuracy of computer-aided prediction in soft tissue changes after orthodontic treatment

An accurate prediction in the soft tissue changes is of great importance for orthodontic treatment planning. Previous studies on the accuracy of the Dolphin visual treatment objective (VTO) in predicting treatment results were mainly focused on orthognathic treatment. The accuracy of Dolphin VTO prediction for orthodontic treatment is, however, poorly understood. The aim of this study was to evaluate the accuracy of Dolphin VTO prediction in soft tissue changes after orthodontic treatment by comparing the changes between predicted and actual values. A total of 157 patients were screened for eligibility, and 34 young adult patients (8 males, 26 females; mean age 24.8±3.9years) were finally included in the study based on the inclusion and exclusion criteria. The landmarks and parameters of the Holdaway soft tissue analysis were used for the cephalometric analyses. The cephalometric tracings of the actual treatment result and the Dolphin predicted treatment outcome were superimposed to calculate the prediction errors. Paired t test was used to compare the statistical differences between the predicted and actual treatment outcomes of the parameters used in the Holdaway soft tissue analysis. There were significant differences between the predicted and actual values in parameters of the Holdaway soft tissue analysis (P<0.05). The prediction of the landmarks in the lips region (ie, subnasale, soft tissue A-point, upper lip, lower lip, and soft tissue B-point) was inclined to be overestimated horizontally and underestimated vertically, whereas the prediction of the landmarks belonging to the chin region (ie, soft tissue pogonion, soft tissue gnathion, and soft tissue menton) was inclined to be underestimated horizontally and overestimated vertically. The most accurate prediction was found in the soft tissue A-point, whereas the least accurate one was found in the soft tissue in the chin region. The prediction was relatively more accurate in the vertical direction than in the horizontal direction. The Dolphin VTO prediction in soft tissue changes after the orthodontic treatment in patients with bimaxillary protrusion is the most accurate for the soft tissue A-point and the least accurate for the soft tissue chin region.

Effects of Rapid Maxillary Expansion and Facemask Therapy on the Soft Tissue Profiles of Class III Patients at Different Growth Stages.

Objectives The aim of this study was to evaluate the effects of rapid maxillary expansion (RME) and facemask therapy on the soft tissue profiles of class III patients at different growth stages. Materials and Methods Forty-five subjects (23 females and 22 males) were divided into prepubertal, pubertal, and postpubertal groups. Bonded type RME appliances and Petit-type facemasks were fitted to each patient, and intraoral elastics were applied from the hooks of the RME appliance to the facemask. Statistical Analysis All measurements were statistically analyzed with SPSS version 18.0 (SPSS Inc., Chicago, IL, United States) for Windows. Repeated-measures of ANOVA and posthoc Tukey tests were used to compare the groups. Results The soft tissue nasion, pronasale, subnasale, soft tissue A point, and labrale superior landmarks were all displaced forward and downward, and the most dramatic changes were recorded in the pubertal group. The labrale inferior, soft tissue B point, soft tissue pogonion, and soft tissue menton landmarks moved backward and downward in all groups, and the greatest displacements were observed in the pubertal group. Conclusions The soft tissue profiles improved significantly and became more convex in all treatment groups. Although, the most favorable facial changes were observed in the pubertal growth stage, the treatments applied in the postpubertal stage also elicited significant changes and should thus be considered viable treatment options.

Hard- and soft-tissue symmetry comparison in patients with Class III malocclusion.

Our aim was to describe hard- and soft-tissue asymmetry in people who have a skeletal Class III malocclusion, and to compare with those without asymmetry. We also performed a regional analysis of a possible correlation between facial soft- and hard-tissue asymmetries. This retrospective study was performed with the use of the computed tomographic scans of 60 subjects. The skeletal Class III subjects were categorized into 2 subgroups: soft-tissue menton deviation≤4mm (n=20) versus>4mm (n=20). The Class III groups were compared with a Class I symmetry group (n=20). Hard and soft tissues were segmented into different morphologic areas and deviation calculated. Pearson correlation coefficients were obtained, and 1-way analysis of variance was conducted for statistical analysis. The highest deviation in the hard tissues of the Class III asymmetry group was in the corpus region (5.55±3.05mm), with the second highest in the angulus region (4.70±2.43mm). The highest average deviation in the soft tissues was seen in the lower cheek (7.04±3.46mm). In the different study groups, the amounts of asymmetry measured in anatomic structures on the mandible were found to be highly correlated between neighboring structures. Clinically and statistically significant differences were found in the anatomic regions located in the middle and lower thirds of the face. There was a medium or high correlation between condyle, coronoid process, ramus, and angulus regions. A low level of correlation was observed between middle face and mandibular asymmetries in hard-tissue upper cheek and lower cheek regions were correlated with different mandibular regions.

Soft tissue changes after a mandibular osteotomy for symmetric skeletal class III malocclusion

The soft tissue profile is crucial to esthetics after orthognathic surgery. The aim of this study was to assess the soft tissue changes of the subnasal and submental regions more than 1year after a sagittal split ramus osteotomy (SSRO) in patients with skeletal class III malocclusion. A total of 22 patients with mandibular prognathism were included in this study. Patients had lateral cephalograms before and more than 1year after they underwent an isolated SSRO. Soft and hard tissue changes were assessed using the lateral cephalograms. The lower lip, labiomenton, and soft tissue menton moved posteriorly by 85, 89, and 88% compared with the corresponding hard tissue, and the movement of the soft tissue B point and the top of the chin nearly reflected the displacement of the hard tissues, at 96 and 99%, respectively. The labiomenton, stomions, and naso-labial angles were changed after the mandibular set-back and the changes in these angles correlated with either the width of the soft tissue or skeletal displacement. The naso-labial angle could be altered even if an isolated mandibular osteotomy is performed. Changes to the stomions and naso-labial angles were affected by hard tissue movement, while changes to the labiomental angle were affected by the width of the soft tissue after the mandibular osteotomy. It is important to create an accurate preoperative prediction of the esthetic outcomes after a mandibular osteotomy by considering the interrelations between the hard and soft tissues.

Establishment of a new relationship between posed smile width and lower facial height: A cross-sectional study.

Objective:The present study is intended to add a new parameter that would be useful in orthodontic clinical evaluation, treatment planning, and determination of vertical dimension (at occlusion).Materials and Methods:Standardized videographic recording of 79 subjects during posed smile was captured. Each video was then cut into 30 photos using the free studio software. The widest commissure-to-commissure posed smile frame (posed smile width [SW]) was selected as one of 10 or more frames showing an identical smile. Lower third of the face is measured from subnasale to soft tissue menton using a digital vernier caliper. Two values were then compared. Ratio between lower facial height and posed SW was calculated.Results:The co-relation between smiling width and lower facial height was found to be statistically significant (P < 0.01). The ratio of lower facial height and smiling width was calculated as 1.0016 with a standard deviation (SD) = 0.04 in males and 1.0301 with an SD = 0.07 in females. The difference between the mean lower facial height in males and females was statistically significant with a t = 10.231 and P = 0.000. The difference between the mean smiling width in males and females was also statistically significant with a t = 5.653 and P = 0.000.Conclusion:In class I subjects with pleasing appearance, normal facial proportions, normal overjet and overbite, and average Frankfort mandibular angle, the lower facial height (subnasale to soft tissue menton) is equal to posed SW.

The influence of bilateral sagittal split ramus osteotomy on submental-cervical aesthetics.

The effect of orthodontic-surgical treatment on submental-cervical region was evaluated in a very limited number of studies. The aim of this study was to evaluate submental-cervical soft tissue contour changes following mandibular advancement and set-back procedures via bilateral sagittal split ramus osteotomy. Sixty-seven patients were included in this study. Group 1 consisted of 27 skeletal Class II patients who underwent mandibular advancement surgery, whereas Group 2 consisted of 40 skeletal Class III patients who underwent mandibular set-back surgery. Various linear and angular measurements were performed on pre-operative and sixth month post-operative cephalometric radiographs. A new method was used to evaluate the amount of sagging at submental region. The submental length did not change in Group 1; however, it decreased significantly in Group 2 (P < 0·05). The angle between submental plane and facial plane decreased to 95·9° from 98·8° in Group 1(P < 0·05), whereas it increased to 93·1° from 88·2° in Group2 (P < 0·05). The change of submental soft tissue sag was almost stable in Group 1, while 0·34 mm increase of sag was observed in Group 2. This increase was not statistically significant (P > 0·05). Mandibular set-back and advancement procedures do not remarkably change the submental sag following approximately 6 mm jaw movement. Although mandibular advancement did not significantly effect submental length, soft tissue followed mandibular set-back with a ratio of 1:1 at C-point to projection of soft tissue pogonion and 1:0·7 at C-point to soft tissue menton distances.

Three-dimensional Assessment of Facial Soft Tissue after Orthognathic Surgery in Patients with Skeletal Class III and Asymmetry

Purpose: The purpose of this study was to perform three-dimensional (3D) assessment of facial soft tissue in patients with skeletal Class III and mandibular asymmetry after orthognathic surgery. Methods: Samples consisted of 3D facial images obtained from five patients with A point-nasion-B point angle less than 2 degrees, and more than 5 mm of menton deviation. All patients had been treated at Gangneung-Wonju National University Dental Hospital from 2009 to 2012. They had undergone orthognathic surgery of Lefort I, and sagittal split osteotomy for correction of skeletal deformity, and orthodontic treatment. Facial scanning was performed before treatment (T1) and post-surgical orthodontic treatment (T2). Linear and angle variables of soft tissue landmarks, antero-posterior facial depth, and facial volume were measured. Results: No significant differences in width of the alar base, mouth width, and nasal canting were observed between T1 and T2. However, lip deviation, menton deviation, alar canting, lip canting, and menton deviation angle were significantly reduced at T2. Antero-posterior facial depth on the axial plane parallel to the left cheilion was significantly reduced on the deviated side and significantly increased on the non-deviated side at T2. Volume of the lower lateral and lower medial parts of the face was reduced on the deviated side, and volume of upper lateral and lower lateral parts on the non-deviated side was significantly increased at T2. Conclusion: After orthognathic surgery, facial asymmetry of soft tissue was improved following skeletal changes, especially the mandibular region. Although the length of the alar base and mouth width did not change, lip and soft tissue menton were displaced to the medial side after treatment. Facial depth also became symmetric after treatment. Facial volume showed a decrease on the lower part of the deviated side and that on lateral parts of the non-deviated side showed an increase after treatment.

Facial Symmetry: An Illusion?

Objective: To investigate the laterality of the normal asymmetry of the human face, examining differences in laterality in relation to sex, and skeletal classification. Materials and methods: A sample of 120 patients (60 males and 60 females; mean age, 15 years; range, 16-22 years) who had received orthodontic clinical examination at AME’s Dental College and Hospital were selected. Selection was made in such a way that following malocclusions with equal sexual distribution was possible from the patient database. Patients selected were classified into skeletal Class I (25 males and 25 females), Class II (25 males and 25 females) and Class III (10 males and 10 females) based on ANB angle. The number was predecided to be the same and also was based on the number of patients with following malocclusions reported to the department. Differences in length between distances from the points at which ear rods were inserted to the facial midline and the perpendicular distance from the softtissue menton to the facial midline were measured on a frontofacial photograph. Subjects with a discrepancy of more than three standard deviations of the measurement error were categorized as having left- or right-sided laterality. Results: Of subjects with facial asymmetry, 74.1% had a wider right hemiface, and 51.6% of those with chin deviation had left-sided laterality. These tendencies were independent of sex or skeletal jaw relationships. Conclusion: These results suggest that laterality in the normal asymmetry of the face, which is consistently found in humans, is likely to be a hereditary rather than an acquired trait.

Multidirectional lip-closing force in adults with mandibular deviation

The purpose of this study was to investigate the relationship between multidi-rectional lip-closing force and facial soft tissue morphology in adults with mandibular deviation. Fifteen Japanese adults with mandibular deviation participated in this study. The deviation value was defined as the horizontal distance between soft tissue menton and the facial midline. The side of the soft tissue menton relative to the facial midline was defined as the deviated side and the opposite side as the non-deviated side. The signals of directional lip-closing force (DLCF) were investigated in 8 directions. Total lip-closing force (TLCF) was calculated by adding DLCFs in 8 directions. Correlations and differences between the variables were analysed statistically. Significant positive correlations between TLCF and DLCFs were determined in six directions with the exception of the horizontal direction. Significant positive correlations for seven pairs of opposing DLCFs were found. The lower non-deviated DLCF was smaller than the three pairs of opposing lip-closing forces. Negative significant correlation was found between the deviation value and the upper deviated DLCF (P<0·05). In individuals with mandibular deviation, lip-closing force in the lower non-deviated direction was found to be smaller than the opposing lip-closing forces. When mandibular deviation was greater, the upper deviated lip-closing force was smaller.

Effect of orthodontic treatment on lip position

Does an advanced or retracted position of the upper and lower incisors lead to modifications in lip position? The aim of our study was to evaluate modifications in lip position following orthodontic treatments. This study concerned 100 patients who underwent treatment in the dento-facial orthopedic unit in Casablanca. Profile headfilms at the start and at the end of orthodontic treatment were compared using Frapier's analysis. The Student test was applied to evaluate the variations in the cephalometric measurements. We noted a non-significant increase in the nasolabial angle (P = 0.274), a significant decrease in the sagittal position of the lower vermillion border (PsVei) (P < 0.001) and the sagittal position of the soft-tissue supramentale (PsSmc) (P < 0.001), and a significant increase in the vertical position of the soft-tissue menton (PvMec) (P = 0.035). The results of this study demonstrate marked improvements in the situation of soft tissues. We suggest further investigation to throw light on the relationship between tooth movement and soft tissue, increasing the size of the sample and taking growth into account.

Residents' journal review

Residents' journal review

Effects of intra-space injection of Twin mix versus intraoral-submucosal, intramuscular, intravenous and per-oral administration of dexamethasone on post-operative sequelae after mandibular impacted third molar surgery: a preliminary clinical comparative study

A prospective randomised double-blind study was undertaken to compare the effects of intra-space injection of 'Twin mix' versus intraoral-submucosal, intramuscular, intravenous and per-oral administration of dexamethasone on post-operative sequelae after mandibular impacted third molar surgery. A randomised double-blind clinical trial was conducted on 60 patients with class II position B impaction of mandibular third molars. Sixty transalveolar extractions were performed prospectively with ten patients randomly allocated to each of the six study groups (group T: intra-space injection of Twin mix; group S: submucosal dexamethasone; group M: intramuscular dexamethasone; group V: intravenous dexamethasone; group O: per-oral dexamethasone; group C: control group, no dexamethasone). A ten-point visual analogue scale was used to assess the overall pain intensity/patient discomfort, and specific facial measurements were recorded to assess the post-operative facial swelling. Maximal mouth opening was compared pre and post-operatively to assess the trismus. Mean operative visual analogue scale scores did not show statistical variation, and post-operative visual scores indicated better patient comfort in the steroid groups with statistically significant difference between group T and the control group on the first, third and the seventh post-operative day. Mean increase in distances between tragus and soft tissue menton to assess facial swelling showed strong statistically significant difference between the first and the third post-operative day between the control group and group T (p value <0.0001). Association of trismus was found less with the steroid treatment groups when compared to the control group. Steroid groups had a better clinical outcome with improved quality of life post-operatively when compared to the nonsteroid study group. Intra-space injection of dexamethasone in pterigomandibular space as Twin mix was found to have similar clinical effects as conventional methods of administering steroids via intraoral-submucosal, intramuscular, intravenous and per-oral routes. This, however, is a small study which would now benefit from larger numbers.

Sagittal Soft-Tissue Changes of the Lower Lip and Chin Associated with Surgical Maxillary Impaction and Consequent Mandibular Autorotation

A retrospective cephalometric study was undertaken to assess the sagittal soft-tissue changes of the lower lip and chin in 22 patients who exhibited autorotation of the mandible after surgical vertical impaction of the maxilla. Lateral cephalometric radiographs were taken immediately before surgery and on average 15 months after surgery. Sixteen cephalometric landmarks were digitized by the use of a Kontron Videoplan Image Analysis System (Kontron Messgerate, GmbH, Image-analysis-systems, Eching/München, West Germany). The comparison between those cases that received maxillary elevation only and 6 cases that had additional advancement genioplasties revealed statistically significant proportional differences in the changes in the chin area, but not in the lower lip response, between the 2 groups. Therefore, when studying the lower lip changes, the 2 groups were pooled, but when changes in the area of the chin were considered, the 6 advancement cases were omitted from the study. In the horizontal plane, soft-tissue contours of the chin responded to changes to the underlying hard tissue at a ratio of 0.9:1. In the vertical dimension, soft-tissue gnathion also followed hard-tissue gnathion at a ratio of 0.9:1, whereas soft-tissue menton responded to hard-tissue menton at a ratio of 1:1. The lower lip in the horizontal dimension responded at a ratio of 1:1 with the lower incisor tip and lower incisor anterius at a ratio of 1:1, the associated correlation being strong (<i>r</i> = 0.84). In the vertical dimension, stomion inferius followed lower incisor tip at 1:1 and lower incisor anterius in a ratio of 1.3:1, whereas labrale inferius followed lower incisor anterius in a ratio of 1.5:1. Multiple regression analyses revealed that presurgical tissue thickness exerted no influence on the strength of the relationships between changes expressed at corresponding soft- and hard-tissue landmarks.

Asymmetry of the Face in Orthodontic Patients

To investigate the laterality of the normal asymmetry of the human face, examining differences in laterality in relation to sex, growth stage, and skeletal classification. A total of 1800 Japanese subjects (651 males and 1149 females; mean age, 15 years 3 months; range, 4 years 2 months to 59 years 11 months) were selected. Individuals in the sample were categorized according to sex, one of three growth stages, and one of three skeletal patterns. Differences in length between distances from the points at which ear rods were inserted to the facial midline and the perpendicular distance from the soft-tissue menton to the facial midline were measured on a frontal facial photograph. Subjects with a discrepancy of more than 3 standard deviations of the measurement error were categorized as having left- or right-sided laterality. Of subjects with facial asymmetry, 79.7% had a wider right hemiface, and 79.3% of those with chin deviation had left-sided laterality. These tendencies were independent of sex, age, or skeletal jaw relationships. In this regard, during pubertal growth, the proportion of subjects with wider right hemiface decreased (P < .0001), whereas the proportion of those with a wider left hemiface increased (P < .01), despite a consistent tendency for right-sided dominance. These results suggest that laterality in the normal asymmetry of the face, which is consistently found in humans, is likely to be a hereditary rather than an acquired trait.

Which Hard and Soft Tissue Factors Relate with the Amount of Buccal Corridor Space during Smiling?

To investigate which hard and soft tissue factors relate with the amount of buccal corridor area (BCA) during posed smiling. The samples consisted of 92 adult patients (19 men and 73 women; 56 four first bicuspids extraction and 36 nonextraction treatment cases; mean age = 23.5 years), who were treated only with a fixed appliance and finished with Angle Class I canine and molar relationships. To eliminate the crowding effect on the buccal corridor area, lateral cephalograms, dental casts, and standardized frontal posed smile photographs were obtained at debonding stage and 28 variables were measured. Pearson correlation analysis, multiple linear regression analysis, and independent t-test were used to find variables that were related with buccal corridor area ratio (BCAR). Among the lateral cephalometric and dental cast variables, FMA, lower anterior facial height, upper incisor (U1) exposure, U1 to facial plane, lower incisor (L1) to mandibular plane, L1 to N-B, Sn (subnasale) to soft tissue menton (Me'), Sn to stomodium superius (stms), stms to Me', and interpremolar width were significantly negatively correlated with BCAR. Occlusal plane inclination and buccal corridor linear ratio did not show any significant correlation with BCAR. Multiple linear regression analysis generated a three-variable model: Sn to Me', U1 exposure, and sum of tooth material (STM) (R(2) = 0.324). There was no significant difference in BCAR between extraction and nonextraction groups. To control the amount of BCA for achieving a better esthetic smile, it is necessary to observe the vertical pattern of the face, amount of upper incisor exposure, and sum of the tooth material.

Soft tissue changes inconclusive in Class II division 1 patients treated with Activator and Bionator appliances

Medline, Medline In-Process and other non-indexed citations, Lilacs, PubMed, Embase, Web of Science and all evidence-based medicine reviews were searched. The reference lists of the retrieved articles were also searched by hand for possible missing articles. Authors were contacted to obtain additional information if necessary. For inclusion, an article had to satisfy the following criteria: they should be clinical trials with a comparable untreated control group; facial soft tissue changes were evaluated through lateral cephalograms; Activator and/or Bionator functional appliances were used to correct Class II division 1 malocclusions; no syndromic or medically compromised patients were included; none were individual case-reports or series of cases; there was no surgical intervention; and only a removable functional appliance was used. Screening of eligible studies was independently made by both authors and their results were compared: discrepancies were settled through discussion. In the case of the Lilacs database, evaluation was by one author alone because of language limitation. Eligible studies were independently evaluated by both authors using a methodological scoring process which was developed to identify which selected studies would be most valuable. The search identified 30 articles, of which 11 met the inclusion criteria. Only one of these was a randomised controlled trial. Five studies evaluated the soft tissue changes after use of an Activator appliance. No changes in the naso-labial and labio-mental angles were observed, but a mild protrusion of menton was reported. Neither the tip nor the base of the nose underwent any change. Contradictory results were found regarding the position of the upper lip, the lower lip and menton. Contradictory changes in upper lip thickness and length were also reported, but no changes in the lower lip or soft tissue menton were noted. Six studies evaluated the soft tissue changes using a Bionator. Contradictory results were reported for the facial angles. No studies reported a significant naso-labial angle change. Total face height and lower face thirds were augmented. Contradictory results were found for the antero-posterior position of the upper lip, lower lip and soft-tissue pogonion. A vertical increase was reported for upper lip, lower lip and soft tissue menton measurements. Based on the available evidence, a significant amount of controversy regarding the soft tissue changes produced by the Activator and the Bionator exists. Soft tissue changes that were reported as being statistically significant were of questionable clinical significance.

Facial soft-tissue analysis of Korean adults with normal occlusion using a 3-dimensional laser scanner

Developments in computer technology have made the 3-dimensional (3D) diagnosis of facial soft tissues possible, opening the window for 3D soft-tissue evaluation in orthodontic treatment planning and posttreatment results. Korean adults (30 men, 30 women) with normal occlusion were scanned with a 3D laser scanner, and 3D facial images were made with the Rapidform 2004 program (Inus Technology, Seoul, Korea). Reference planes in the facial soft tissues of the 3D image were established, and a 3D coordinate system (X-axis, left/right; Y-axis, superior/inferior; Z-axis, anterior/posterior) was established; 29 measurement points were assigned on the 3D image, and 39 linear measurements, 8 angular measurements, and 29 linear distance ratios were obtained. Significant differences between the sexes were found in nasofrontal angle (men, 142 degrees; women, 147 degrees) and transverse nasal prominence (men, 112 degrees; women, 116 degrees) (P <.05). Transverse upper lip prominence was 107 degrees in the men and 106 degrees in the women, and transverse mandibular prominence was 76 degrees in both sexes. The distance between lower lip vermilion border (Li) and Me' was 0.4 times mandibular body length (Me' - Go'), and mouth height was also 0.4 times the mouth width. The linear distance ratios from the coronal reference plane to fronto-temporal point, zygomatic point, pronasale, upper lip point, labrale inferior, and soft-tissue menton were -1, -1, 1, 0.5, 0.5, and -0.6, respectively. These data could be guidelines for the 3D evaluation of the facial image, because the 3D facial model constructed by the averaged coordinate values could be a template for orthodontic diagnosis and treatment planning.