The three layered structure of orbicularis oris and buccinator complex with partial connection at the modiolus and partial direct continuation.

PURPOSE: This study aimed to clarify the structural arrangement of the orbicularis oris (OOr), the buccinator, and the other perioral muscles around the modiolus. METHODS: The perioral muscles in seventeen cadavers fixed with formalin were dissected in situ and/or in isolated muscle specimens, and their layers were reconstructed schematically upon pantomographic view of the skeleton to evaluate their actions. RESULTS: The buccinator was composed of three parts including upper and lower oblique parts in its superficial layer and a middle transverse part in its deep layer. The superior and inferior OOr were composed of an inner marginal part (IM) and an outer labial part (OL) in each. The perioral muscles as a whole were arranged in three layers. The first layer consisted of the depressor anguli oris and the OL of superior OOr connected at the modiolus in a vertical direction. The second layer consisted of the upper and inner oblique part of buccinator and a part of the OL of inferior OOr connected at the modiolus in a horizontal direction. The third layer contained the middle transverse part of buccinator continuous with the IM of both OOr and a part of the OL of inferior OOr without connection to the modiolus. CONCLUSIONS: The different arrangement of the three layers of perioral muscles around the modiolus could serve as a good basis to predict the actions of the individual perioral muscles on the movement of lips in open/close of the oral fissure and widening/narrowing of the lip width.

Evaluation metric of smile classification by peri-oral tissue segmentation for the automation of digital smile design.

OBJECTIVES: This study aimed to develop and validate evaluation metric for an automated smile classification model termed the "smile index." This innovative model uses computational methods to numerically classify and analyze conventional smile types. METHODS: The datasets used in this study consisted of 300 images to verify, 150 images to validate, and 9 images to test the evaluation metric. Images were annotated using Labelme. Computational techniques were used to calculate smile index values for the study datasets, and the resulting values were evaluated in three stages. RESULTS: The smile index successfully classified smile types using cutoff values of 0.0285 and 0.193. High accuracy (0.933) was achieved, along with an F1 score greater than 0.09. The smile index successfully reclassified smiles into six types (low, low-to-medium, medium, medium-to-high, high, and extremely high smiles), thereby providing a clear distinction among different smile characteristics. CONCLUSION: The smile index is a novel dimensionless parameter for classifying smile types. The index acts as a robust evaluation tool for artificial intelligence models that automatically classify smile types, thereby providing a scientific basis for largely subjective aesthetic elements. CLINICAL SIGNIFICANCE: The computational approach employed by the smile index enables quantitative numerical classification of smile types. This fosters the application of computerized methods in quantifying and analyzing real smile characteristics observed in clinical practice, paving the way for a more objective evidence-based approach to aesthetic dentistry.

Image-based investigation of lip aging features in a large number of Korean women.

BACKGROUND: The lips play a significant role in shaping facial aesthetics. Due to the distinct attributes of lips in contrast to other facial skin, a unique approach is imperative for managing lip aging. We analyzed lip characteristics (morphology, wrinkles, and color) to investigate visual changes and distinctive attributes of aging lips. METHODS: By utilizing image data processing methods, including facial landmark detection, pattern recognition, and color quantification, we extracted 11 lip characteristic indices (four morphological indices, four wrinkle indices, and three color indices) from high-resolution images of 1000 Korean women aged 20-69. Correlation tests were conducted to assess the relationship between lip characteristic indices and age, and also between lip morphological and wrinkle indices. RESULTS: Lip height significantly decreased, while lip width and lip ratio (lip width divided by the sum of the upper and lower lip height) significantly increased with aging. Lip wrinkles significantly increased with aging, whereas lip colors (redness and yellowness) decreased. The lip wrinkle indices, which are segmented for the first time in this study, exhibited significant correlations with lip width, and three of them additionally were correlated with lip ratio (p < 0.05). The results imply such morphological changes can be associated with wrinkle formation of human lips. CONCLUSION: The indices suggested in this study can be used for assessing lip aging characteristics, and the study results can contribute to deeper understanding of lip aging.

Using a structured light scanner to evaluate 3-dimensional soft-tissue changes after extracting 4 premolars in young adult female patients.

INTRODUCTION: Facial esthetics have always received much attention in orthodontic treatment, especially in young adult female patients. Three-dimensional (3D) soft-tissue changes after orthodontic extraction have not been fully explained. This study evaluated the 3D morphologic changes after orthodontic extraction in young female patients using a structured light scanner. METHODS: Forty-five adult female patients aged 20-25 years were enrolled in our study. The treatment group consisted of patients who received orthodontic treatment with 4 premolar extractions, and the control group was composed of young female volunteers who had not undergone any orthodontic treatment. To monitor the soft-tissue changes, 9 morphologic regions and 12 landmarks were identified for the 3D deviation analyses. The spatial deviations of landmarks and regions in the x, y, and z directions were constructed for quantitative analysis. Color map images were constructed to visualize soft-tissue displacement as a qualitative evaluation. The paired sample test was used to compare differences at the beginning of the experiment (T0) and after 24 months (T1) in both groups. An independent t test with Bonferroni correction was performed to compare differences between the treatment and control groups. A linear regression test was performed between incisor retraction and changes in the perioral tissues. RESULTS: Subtracting the effect of aging from the lip changes in the control group, the treatment group showed a statistically significant difference in the displacement of labrale superius (-1.37 mm), labrale inferius (-1.89 mm), the upper lip region (-0.98 mm), and the lower lip region (-1.36 mm) along the z-axis. No significant differences were found between the treatment and control groups in the temporal, parotideomasseteric, and buccal regions. Pearson correlation tests indicated a positive correlation between incisor tip retraction and changes in soft tissues (two-dimensional cephalometric analysis, 3D landmark measurements, and 3D regional measurements). The correlation coefficient ranged between 0.45 and 0.55. CONCLUSIONS: Three-dimensional soft-tissue changes were mainly concentrated in the upper and lower lip regions in adult female patients after the 4 premolars were extracted. For female patients aged 20-25 years with 4 extracted premolars, soft-tissue changes in the temporal, parotideomasseteric, and buccal regions were not clinically significant.

3D Facial Changes Between Maximal Intercuspal Position and Physiologic Rest Position.

PURPOSE: To evaluate the soft tissue changes of the face between two positions of occlusion: maximal intercuspal position (MIP) and physiologic rest position (RP). MATERIALS AND METHODS: In this study, facial surface scans of 83 volunteers in two mandibular positions (MIP and RP) were obtained using a 3D optical scanner. On each 3D image, 21 cephalometric soft tissue landmarks were identified and then compared using t test for various facial parameters (widths, heights, depths, angles, and ratio). Additionally, a regional analysis of the facial surface differences in each patient between the two mandibular positions was performed using a whole scan shell best-fit method and the regional forehead best-fit method. RESULTS: In MIP, facial heights with the nasion-gnathion distance shortened by approximately 1.2 mm (due to the vertical shrinkage of both lips together by 0.8 mm), and the mouth width was significantly widened, while other facial widths displayed no change. The labiomental angle and the upper vermilion arch were altered correspondingly, and regional analysis confirmed the findings with evident changes in the mandibular and subnasal areas with deviations amplified toward the facial midline. CONCLUSIONS: By applying 3D facial-scanning technology, this study displayed changes of facial appearance in different mandibular positions (MIP and RP), highlighting the need to instruct and monitor the patient's mandibular position more consistently to achieve accurate and repeatable data in a 3D facial analysis.

Lip color measurement: A new hyperspectral imaging device.

INTRODUCTION: The lips are of significant interest among the facial features for self-perception and social interactions. Such perceptions could rely in part upon the contrast in color between the lips and the surrounding skin. In contrast to skin color, lip color ethnic diversity measurement provides a challenge and is less documented in the literature, most likely due primarily to challenges in measurement based upon the lip characteristics of size and contour. Accurate measurement and reproduction of lip color are essential to build strong cross-sectional knowledge about lip color. OBJECTIVE: This preliminary experiment of a large-scale project on lip and skin color was designed to assess accuracy in lip color measurement and recommend instruments and protocols for good measurement practice. METHODS: The study involved 19 healthy French Caucasian women. Their inferior and superior natural lip color was measured twice with three devices in order to extract the standard colorimetric parameters of lightness (L*), chroma (C*), and hue (h): the VISIA-CR® (high-resolution digital camera, Canfield Scientific Inc.); the spectrophotometer VS3200 (45°:0° spectrophotometer, MetaVue™ VS3200, X-Rite Inc.); and the SpectraFace® (new hyperspectral imaging system, Newtone Technologies). The intercomparison and color distribution between the different instruments and the measurement repeatability of each one were assessed. RESULTS: Our results showed a reliable and equivalent repeatability for the three tested instruments. Moreover, the three tools led to the same conclusion regarding lip color heterogeneity (lighter, redder, less yellow and more saturated inferior lip versus superior lip). Agreement between the SpectraFace® and the spectrophotometer measurements was higher, and the SpectraFace® allowed to identify three separated lip color typologies. CONCLUSION: In conclusion, the combination of imaging technology and hyperspectral measurement makes the SpectraFace® a useful tool to investigate lip color characterization and establish a large-scale cross-sectional knowledge study about lip color.

Accuracy in predicting soft tissue changes of orthodontic class III cases using Dolphin® software.

OBJECTIVES: The prediction of posttreatment outcomes is conducive to the final determination of ideal therapeutic options. However, the prediction accuracy in orthodontic class III cases is unclear. Therefore, this study conducted exploration on prediction accuracy in orthodontic class III patients using the Dolphin® software. MATERIALS AND METHODS: In this retrospective study, lateral cephalometric radiographs of pre- and posttreatment were collected from 28 angle class III adults who received completed non-orthognathic orthodontic therapy (8 males, 20 females; mean age = 20.89 ± 4.26 years). The values of 7 posttreatment parameters were recorded and inserted into the Dolphin® Imaging software to generate a predicted outcome, and then the prediction radiograph and actual posttreatment radiograph were superimposed and compared in terms of soft tissue parameters and landmarks. RESULTS: The prediction showed significant differences with the actual outcomes in nasal prominence (the difference between the prediction and the actual value was - 0.78 ± 1.82 mm), the distance from the lower lip to the H line (0.55 ± 1.11 mm), and the distance from the lower lip to the E line (0.77 ± 1.62 mm) (p < 0.05). Point subnasale (Sn) (an accuracy of 92.86% in the horizontal direction and 100% in the vertical direction in 2 mm) and point soft tissue A (ST A) (an accuracy of 92.86% in the horizontal direction and 85.71% in the vertical direction in 2 mm) were proven to be the most accurate landmarks, while the predictions in the chin region were relatively inaccurate. Furthermore, the predictions in the vertical direction were of higher accuracy compared to the horizontal direction except for the points around the chin. CONCLUSIONS: The Dolphin® software demonstrated acceptable prediction accuracy in midfacial changes in class III patients. However, there were still limitations for changes in the chin and lower lip prominence. CLINICAL RELEVANCE: Clarifying the accuracy of Dolphin® software in predicting soft tissue changes of orthodontic class III cases will facilitate physician-patient communication and clinical treatment.

Differences in the 3-dimensional aging changes of the lips among female adults with skeletal Class I, II, and III malocclusion.

INTRODUCTION: The objective of this study was to evaluate and compare the 3-dimensional (3D) aging changes of the lips among adult skeletal Class I, II, and III malocclusion. METHODS: Female adult orthodontic patients aged 20-50 years with pretreatment cone-beam computed tomography scans were retrospectively classified according to age (20s [20-29 years], 30s [30-39 years], and 40s [40-49 years]) and then subclassified by malocclusion into skeletal Class I, II, and III relationship (9 groups; n = 30 per group). Positional differences in midsagittal and parasagittal soft-tissue landmarks and 3D morphologic aging changes of the lips were evaluated using cone-beam computed tomography scans. RESULTS: Labiale superius and cheilion for patients in their 40s indicated a significant downward and backward position compared with those in their 20s, regardless of skeletal classifications (P <0.05). Accordingly, the upper lip height decreased, and the mouth width increased significantly (P <0.05). For Class III malocclusion, the upper lip vermilion angle was greater for patients in their 40s than those in their 20s (P <0.05), whereas the lower lip vermilion angle was only lower for patients with Class II malocclusion (P <0.05). CONCLUSIONS: Middle-aged adult females (40-49 years) had a lower upper lip height and greater mouth width than those in their 20s, regardless of skeletal malocclusion. However, prominent morphologic aging changes of the lips were noted on the upper lip for skeletal Class III malocclusion and the lower lip for skeletal Class II malocclusion, implying that the underlying skeletal features (or malocclusion) may influence 3D aging changes of the lips.

Complications of fillers in the lips and perioral area: Prevention, assessment, and management focusing on ultrasound guidance.

An ever-increasing interest in perioral rejuvenation with dermal fillers reflects the esthetic importance of this region. However, filler injections in the lips and perioral area have been associated with various complications. Such complications are classified according to severity (mild, moderate, severe) or by the time of onset: immediate (within 24 h after injection), early (24 h to 4 weeks post-procedure), and late or delayed (>4 weeks after injection). While most complications are mild and manageable, vascular compromise, infections, and the development of delayed-onset nodules may significantly undermine the ultimate esthetic outcome and cause substantial morbidity. These more serious complications often require more invasive treatment modalities. This article details the prevention and management of such adverse events and discusses safe filler injection principles, including safety recommendations for the lips. Lastly, we highlight the use of ultrasound guidance in complication prevention (vascular mapping, filler identification, location, and extent), assessment (identification of intravascular embolus or external vascular compression by the filler implant), and management (real-time imaging of hyaluronidase or other drug injection in the affected area). Esthetic practitioners should be versed in injection anatomy, and the prevention, recognition, and management of filler complications in the perioral area.

Enhanced Lip-Contour During Facial Scan for 3D DSD and Implant Planning: A Blue Screen Approach.

When obtaining 3-dimensional (3D) facial images for digital smile design (DSD) and dental implant planning, inaccuracies may frequently be introduced by distortion in the region between the lips' vermilion border and the teeth. The present clinical technique aimed to reduce such deformation during face scanning, thereby facilitating 3D DSD. This is also essential to plan bone reduction with precision for implant reconstructions. A custom-made silicone matrix acting as a blue screen provided reliable support for 3D visualization of facial images in a patient requiring a new maxillary screw-retained implant-supported fixed complete denture. Imperceptible volumetric changes were registered in the facial tissues when the silicone matrix was added. The usual deformation of the lip vermilion border originating in face scans was overcome by applying blue-screen technology with a silicone matrix. Reproducing the vermilion border of the lip contour accurately may offer improved communication and visualization for 3D DSD. The silicone matrix was a practical approach that acted as a blue screen to display the transition from lips to teeth with satisfactory precision. Implementing blue-screen technology in reconstructive dentistry might increase predictability by reducing errors when scanning objects with challenging-to-capture surfaces.

Three-dimensional soft tissue landmark detection with marching cube algorithm.

Current method of analyzing three-dimensional soft tissue data, especially in the frontal view, is subjective and has poor reliability. To overcome this limitation, the present study aimed to introduce a new method of analyzing soft tissue data reconstructed by marching cube algorithm (Program S) and compare it with a commercially available program (Program A). Cone-beam computed tomography images of 42 patients were included. Two orthodontists digitized six landmarks (pronasale, columella, upper and lower lip, right and left cheek) twice using both programs in two-week intervals, and the reliability was compared. Furthermore, computer-calculated point (CC point) was developed to evaluate whether human error could be reduced. The results showed that the intra- and inter-examiner reliability of Program S (99.7-100% and 99.9-100%, respectively) were higher than that of Program A (64.0-99.9% and 76.1-99.9%, respectively). Moreover, the inter-examiner difference of coordinate values and distances for all six landmarks in Program S was lower than Program A. Lastly, CC point was provided as a consistent single point. Therefore, it was validated that this new methodology can increase the intra- and inter-examiner reliability of soft tissue landmark digitation and CC point can be used as a landmark to reduce human error.

Visualising trends in dentition to lip mouth morphology using geometric morphometrics.

Linear measurements taken from bony landmarks are often utilised in facial approximation (FA) to estimate and plan the placement of overlying soft tissue features. This process similarly guides craniofacial superimposition (CFS) practices. Knowledge of how hard and soft tissue features spatially relate around the mouth region is, however, limited. Geometric morphometric techniques have thus been used to investigate size and shape variation in dentition-to-lip mouth morphology in a South African population. Twenty landmarks (twelve dentition, eight lips) were digitised, using cone-beam CT images of the anterior craniofacial complex in a Frankfurt/Frankfort position, for 147 individuals aged between 20 and 75 years. Principal Component Analysis and Canonical Variate Analysis established that much shape variation exists. A two-way ANOVA identified significant (p < 0.0001) population and sex variation with mouth shape. Black individuals presented with thicker lips, with the oral fissure aligning closely to the dental occlusion. Oral fissure position for white individuals corresponded to the inferior one-quarter (females) or one-sixth (males) of the maxillary central incisor crowns. Males presented larger dimensions than females, but females had a greater lip-to-teeth height ratio than their male counterparts. A pooled within-group regression analysis assessed the effect of age on the dentition and lips and found that it had a significant (p < 0.0001) impact on mouth shape. Ageing was associated with a reduced lip and teeth height, increased mouth width, and a lowered oral fissure and cheilion placement. The generated mean shape data, with metric guides, offer a visual and numerical guide that builds on existing FA and CFS standards, enhancing our understanding of hard and soft tissue relationships.

A cone beam computed tomography study based on three-dimensional cephalometric analysis of relationships between the lip-line and jaw deformity.

OBJECTIVE: The aim of this study was to use the cone beam computed tomography (CBCT) to study the relationships between the lip-line and mandible deformity. DESIGN: CBCT data of 20 patients with jaw deformity (experimental group) and 20 patients without mandible deformity (control group) were selected. Use three-dimensional cephalometry to measure the reconstructed images of CBCT data simulated by the Materialise Interactive Medical Image Control System (Mimics), mark the related points, lines and planes of the three-dimensional craniomaxillofacial structure, and measure relevant distances and angles. The T-test, Pearson correlation analysis and Linear regression were used to analyze the characteristics of the lip-line and jaw deformity. RESULTS: There was a significant difference in the lip-line between mandible deformity group and control group. Significant positive correlations could been found among the lip-line cant, the occlusal plane cant, the mandibular plane cant and the degree of mandible deformity (r=0.964, 0.942, 0.611, P < 0.01). A linear relationship was found between the left lip-line cant Y and the menton deviation X [the mandible deflection to the right was defined as positive, and the left lip-line below frankfort horizontal was viewed as positive] as Y= 0.340 + 0.505X. CONCLUSIONS: The lip-line of patients with jaw deformity was inclined, and the lip-line cant was positively correlated with the degree of mandible deformity, and there was a certain linear relationship between the two, which could provide a theoretical reference for clinicians to diagnose and treat patients with mandible deformity.

Beyond the Edge: Markerless Pose Estimation of Speech Articulators from Ultrasound and Camera Images Using DeepLabCut.

Automatic feature extraction from images of speech articulators is currently achieved by detecting edges. Here, we investigate the use of pose estimation deep neural nets with transfer learning to perform markerless estimation of speech articulator keypoints using only a few hundred hand-labelled images as training input. Midsagittal ultrasound images of the tongue, jaw, and hyoid and camera images of the lips were hand-labelled with keypoints, trained using DeepLabCut and evaluated on unseen speakers and systems. Tongue surface contours interpolated from estimated and hand-labelled keypoints produced an average mean sum of distances (MSD) of 0.93, s.d. 0.46 mm, compared with 0.96, s.d. 0.39 mm, for two human labellers, and 2.3, s.d. 1.5 mm, for the best performing edge detection algorithm. A pilot set of simultaneous electromagnetic articulography (EMA) and ultrasound recordings demonstrated partial correlation among three physical sensor positions and the corresponding estimated keypoints and requires further investigation. The accuracy of the estimating lip aperture from a camera video was high, with a mean MSD of 0.70, s.d. 0.56 mm compared with 0.57, s.d. 0.48 mm for two human labellers. DeepLabCut was found to be a fast, accurate and fully automatic method of providing unique kinematic data for tongue, hyoid, jaw, and lips.

Improved lip esthetics in patients with skeletal Class III malocclusion and facial asymmetry after isolated mandibular orthognathic surgery.

INTRODUCTION: Asymmetry of the lips severely affects facial esthetics and is often one of the chief complaints of orthognathic patients, especially those with Class III malocclusion. The objectives of this study were to investigate the changes in lip symmetry in patients with mandibular prognathism and deviation and the relationships between jaw hard tissue and lip soft-tissue changes. METHODS: Three-dimensional facial scan and cone-beam computed tomography scan data of 30 orthodontic-orthognathic patients treated with bilateral sagittal split ramus osteotomy were combined to conduct the research. Paired-sample t test and Pearson correlation coefficient were applied to compare the differences in the same variable before and after the orthognathic surgery and the potential correlations between the changes in hard and soft variables. To explore the important hard tissue variables influencing the lip soft-tissue changes, linear regression analysis was performed. RESULTS: Although there was significant upper lip asymmetry presurgery, the upper lip asymmetry was corrected postsurgery. Surgical correction of the mandibular deviation was also accompanied by lengthening of the bilateral philtrum crests. Improvement in lip asymmetry and lengthening of the philtrum crests were primarily related to the transverse correction of the mandible rather than sagittal changes. The corresponding prediction formulas were established. CONCLUSIONS: The isolated mandibular bilateral sagittal split ramus osteotomy surgery can substantially improve the upper and lower lip asymmetry in patients with mandibular prognathism and deviation, but one should be wary of the unesthetic effects associated with lengthening of the philtrum crests.

Clinical and dermatoscopic predictors of squamous cell carcinoma of the lips: a case-control, multicentric study.

BACKGROUND: Squamous cell carcinoma of the lip accounts for 20% of all oral carcinomas. Its diagnosis may be challenging because it clinically resembles actinic cheilitis and inflammatory lesions of the lips. OBJECTIVES: To determine clinical and dermatoscopic predictors of squamous cell carcinoma of the lip vs. other lip lesions. METHODS: Multicentre retrospective morphological study, including histologically confirmed cases of squamous cell carcinoma of the lip and controls consisting of actinic cheilitis and inflammatory lesions of the lips. Clinical and dermatoscopic images were evaluated for the presence of predefined criteria. Crude and adjusted odds ratios and corresponding 95% confidence intervals were calculated by univariate and multivariate logistic regression respectively. RESULTS: A total of 177 lip lesions were evaluated, 107 (60.5%) were squamous cell carcinomas and 70 (39.5%) were controls. The most frequent dermatoscopic criteria of lip squamous cell carcinoma were scales (100%), white halos (87.3%) and ulceration (79.4%). The majority of squamous cell carcinomas displayed polymorphic vessels (60.8%), with linear (68.6%) and hairpin (67.6%) being the most frequent types. Multivariate logistic regression analysis showed that clinical predictors of lip squamous cell carcinoma were exophytic appearance and clinical hyperkeratosis, with 43-fold and 6-fold higher probability respectively. White clods and ulceration in dermoscopy presented a 6-fold and 4-fold increased risk for squamous cell carcinoma respectively. CONCLUSIONS: A scaly lesion with exophytic growth, dermatoscopically displaying white clods, ulceration and linear and hairpin vessels is very likely a squamous cell carcinoma of the lip.

Evaluation by 3D stereophotogrammetry of facial changes in edentulous patients after rehabilitation.

OBJECTIVE: To assess facial changes after oral rehabilitation with complete dentures (CDs) by 3D technology allows understanding the results of a treatment that changes facial proportions. Precise outcome parameters can improve decision making. This descriptive observational research aimed to assess facial changes in completely edentulous patients after oral rehabilitation with a CD by a 3D stereophotogrammetry system. METHODOLOGY: 30 edentulous patients (7 men and 23 women), aged 50 to 75, were analyzed with stereophotogrammetry at 28 previously determined anthropometric landmarks, at 2 different times: T1, before treatment, and T2, after inserting the CDs. Images were analyzed with a specific software for linear and angular measurements. The paired t-test was used to compare timestamps (α=0.05). RESULTS: Major changes were observed in 7 of the 13 linear measures and 7 of the 9 angular measures. The following linear measurements had an increase: Sn-Gn (lower third of the face), Ls-Li (height of the vermilion lip), and ChL-ChR (mouth width). Sn-Ls (nasal philtrum height) decreased. For angular measurements, Sn-St-Pg (lower facial convexity) angles increased, and the Prn-Sn-Ls (nasolabial angle) and GoR-Pg-GoL (mandible convexity) angles decreased. CONCLUSIONS: Major facial changes in newly rehabilitated edentulous patients with CDs included an increase of the lower third of the face, of the vermilion lip, of mouth width, and of the lower facial convexity, and a decrease of the nasolabial angle and mandible convexity.

Upper-lip laser frenectomy with a diode laser in a pediatric patient: a case report.

The case report aims to describe the parameters of performing upper labial frenectomy with the use of diode laser beams without infiltrated local anaesthesia. A 6-year-old patient was referred by the orthodontist for assessment of the upper anterior labial frenum. The dental treatment plan reported only the presence of caries on deciduous teeth and seals on the first permanent molars. The clinical examination reported the presence of a high attachments of labial frenum with a pathologically attachment and the presence of a diastema supports this theory. The laser used to remove the frenulum was a diode laser used with a wavelength of 980 nm with 320 microns of fiber in contact with a power of 2.0 W in continuous wave mode. The clinical examination showed an acceptable healing by secondary intention of the wound and the initial functional recovery of a physiological upper lip movements. The patient reported that the procedure was well tolerated. The diode laser can be used with good result for the removal of pathological frenum. The diode laser can be used in pediatric dentistry because of its application, adequate coagulation, no need for sutures and less inflammation and pain.

Three-dimensional analysis of lip soft tissue changes and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry.

OBJECTIVE: To investigate three-dimensional soft tissue changes of lips and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry using cone-beam computerized tomography (CBCT). METHOD: This study included 46 CBCT scans of patients with aforementioned character before (T1) and 6-12 months after orthognathic surgery (T2). Subjects were divided into 2 groups according to two types of orthognathic surgery namely, the one-jaw surgery group who underwent bilateral sagittal splint ramus osteotomy (BSSRO) and the two-jaw surgery group who underwent Le Fort I osteotomy and BSSRO. Mimics 19.0 software are used for model reconstruction, landmark location and three-dimensional cephalometric analysis. Descriptive statistics and correlation analyses are used to investigate jaw hard tissue and lip soft tissue changes. RESULTS: In one-jaw group, the mandible shows changes in contour and position (p < 0.05), and the surgery causes changes of lip structure on the deviated side. While in two-jaw group, jaws only show changes in spatial position, and surgery changes contour of bilateral lips and nasolabial angle (p < 0.05). At the same time, lip symmetry increases significantly in both groups postoperatively. CONCLUSIONS: Orthognathic surgery can improve lip aesthetics in patients with skeletal class III malocclusion and facial asymmetry. However, changes induced by two surgical approaches are different. Surgeons should have a clear acquaintance with this difference to deal with different situations.

Revisiting the unrepaired unilateral cleft lip and nasal deformity using 3D surface image analysis: A data-driven model and its implications.

BACKGROUND: Current descriptions of the unilateral cleft lip and nasal deformity (uCLND) are based upon limited sample sets and subjective observations. While those descriptions are inconsistent and contradictory, theoretical models, including Hogan's "tilted tripod" and Fisher's "nasal arch forms", have never been tested. Given that favorable outcomes of treatment remain elusive, detailed study of the deformity is critical in devising better treatments. The purpose of this study was to develop a data-driven three-dimensional (3D) model of uCLND that spans the spectrum of presentation and involves a pervasive underlying mechanism. METHODS: We studied 3D images of 100 infants with unrepaired cleft lip at 6 months of age. Objective assessment included the landmark positions, anthropometric dimensions, and shape-based measures. Cleft severity was stratified by the lateral displacement of subnasale, so that a model could be developed using linear regression. RESULTS: With progressive deviation of subnasale, the non-cleft alar base moved lateral, the cleft alar base was left posterior, and the nasal dorsum followed the caudal septum (deviating towards the non-cleft side). The "twist" resulted in opposing cleft alar dome collapse, non-cleft alar ring constriction (the non-cleft nasal sill narrowed, lateral genu rose, and alar-cheek junction became more acute), and displacement of the philtrum from midline. CONCLUSIONS: Our study not only supports theoretical models of uCLND but also clarifies vectors of change and reveals significant non-cleft side alterations. On the basis of our findings, the objectives of treatment should involve centralization of the columella and philtrum and rebalancing the nose by untwisting the orthogonal displacement of the alar bases.