Soft Tissue Responses to Orthodontic Treatment: Impact of Premolar Extraction on Diverse Growth Patterns.

INTRODUCTION: Alteration in facial soft tissue plays an important role in the esthetics of an individual. The first thing a patient wants from orthodontic treatment is how well he/she looks. The degree of soft tissue changes brought about by the retraction of teeth can be influenced by factors such as extraction pattern, muscle function, age, gender, weight, etc. Aim: The aim of the study was to compare post-orthodontic soft tissue changes among different facial growth patterns in orthodontic patients undergoing extraction of first premolar teeth. METHODOLOGY: Pre-treatment and post-treatment lateral cephalograms of 45 orthodontic patients who underwent therapeutic extraction of the first premolars were included in the study. They were divided into three equal groups based on their facial growth pattern, that is, average, horizontal, and vertical. Eight soft tissue cephalometric measurements were done in all the lateral cephalograms. Paired Student t-tests and analysis of variance (ANOVA) were conducted to statistically analyze the results. The significance level was set as 0.05. RESULTS: The paired Student t-test showed a P-value > 0.05 for lower anterior facial height in all three groups and for facial angle in vertical growers alone. ANOVA comparing the mean soft tissue changes among the three groups resulted in a P-value > 0.05 for all the measured parameters. CONCLUSIONS: Facial growth patterns do not influence the extent of soft tissue profile changes in orthodontic patients treated with extraction of first premolars.

Evaluation of the External Soft Tissue Changes Following the Correction of Class II Skeletal Malocclusion in the Adolescence Period Using Removable and Fixed Functional Appliances: A Systematic Review and Meta-Analysis.

In this systematic review, we aimed to assess the current evidence regarding the effectiveness of functional treatment with both removable and fixed appliances to normalize the external soft tissue for skeletal class II adolescent individuals. We performed a broad electronic search to retrieve relevant studies from nine databases to identify randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that investigated soft tissue changes following functional treatment and evaluated the changes using 2D lateral cephalometric radiographs and 3D-optical surface laser scanning. A total of three RCTs and eight CCTs were included. Ages ranged from 11 to 16 years with the fixed functional appliances, and from eight to 12 years with the removable ones, including 689 skeletal class II patients. Version 2 of Cochran's risk-of-bias (RoB2), and the risk of bias in non-randomized studies of interventions (ROBIN-I) were used to assess the risk of bias for the included papers. Of the 11 eligible studies, three studies were included in the meta-analysis to assess the upper and lower lip position in relation to the E-line (Ricketts's aesthetic line) in addition to the nasolabial angle. The meta-analysis showed that the upper lip retracted after functional treatment with Twin-block in relation to E-line (mean difference (MD) = -1.93; 95% CI: -2.37, -1.50; p < 0.00001; χ² = 5.43; p = 0.07; I2 = 63%), while the lower lip position did not change after functional treatment with Twin-block in relation to E-line (MD = 0.03; 95% CI: -0.56, 0.61; p = 0.92; χ² = 1.74; p = 0.42; I2 = 0%). The nasolabial angle increased after Twin-block treatment (MD = 5.75; 95% CI: 4.57, 6.93; p < 0.00001; χ² = 6.77; p = 0.03; I2 = 70%). The mentolabial angle and Z-angle also increased after functional therapy, where the facial convexity angle decreased, regardless of the functional devices used. On the other hand, using the 3D-optical surface laser scanning showed that the upper lip length and the commissural width did not change following therapy, but the lower lip increased in length, as well as the total face height. More high-quality RCTs are required to obtain accurate evidence in this field.

Facial soft tissue changes and volumetric analysis of upper airways in patients undergoing surgically assisted rapid maxillary expansion using a transpalatal distractor.

OBJECTIVE: To verify changes in facial soft tissue using the RadiANT-DICOM-viewer and Dolphin Imaging software, through linear measurements of tomographic points in a 3D reconstruction of the face and volumetric evaluation with three-dimensional measurements of the upper airways of patients with transverse maxillary discrepancy undergoing Surgically Assisted Rapid Maxillary Expansion (SARME). METHODS: Retrospective, transverse, and descriptive study, through the analysis of computed tomography scans of the face of patients with transverse maxillary discrepancy, treated from July 2019 to December 2022. The sample consisted of 15 patients of both sexes, aged 21-42 years old, who underwent surgically assisted rapid maxillary expansion using the transpalatal distractor. Analysis was performed through linear, angular, and three-dimensional measurements in millimeters, in the preoperative and late four-month postoperative period, in frontal 3D tomographic images of the face, in the region of the width of the nose and alar base and also angular measurement in the lateral tomography for the angle nasolabial and upper airways of rhinopharynx, oropharynx and hypopharynx. RESULTS: There was an increase in nasal width with an average of 1.3467mm and an increase in the alar base with an average of 1.7333mm. A significant difference was found in the pre- and postoperative assessments of the measurements of nasal width, alar base and nasolabial angle, as well as the upper airways in all their extension. The results favour a better understanding of the professional and the patient regarding the diagnosis and management of patients with transverse maxillary width discrepancies. CONCLUSION: Although our study shows an increase in soft tissues after SARME, no aesthetic changes are observed clinically, and all patients report significant respiratory improvement. SARME may therefore contribute to the improvement of professionals working in the field of oral and maxillofacial surgery and orthodontics. LEVEL OF EVIDENCE: Level 4.

Facial soft tissue changes and volumetric analysis of upper airways in patients undergoing surgically assisted rapid maxillary expansion using a transpalatal distractor

Abstract Objective To verify changes in facial soft tissue using the RadiANT-DICOM-viewer and Dolphin Imaging software, through linear measurements of tomographic points in a 3D reconstruction of the face and volumetric evaluation with three-dimensional measurements of the upper airways of patients with transverse maxillary discrepancy undergoing Surgically Assisted Rapid Maxillary Expansion (SARME). Methods Retrospective, transverse, and descriptive study, through the analysis of computed tomography scans of the face of patients with transverse maxillary discrepancy, treated from July 2019 to December 2022. The sample consisted of 15 patients of both sexes, aged 21-42 years old, who underwent surgically assisted rapid maxillary expansion using the transpalatal distractor. Analysis was performed through linear, angular, and three-dimensional measurements in millimeters, in the preoperative and late four-month postoperative period, in frontal 3D tomographic images of the face, in the region of the width of the nose and alar base and also angular measurement in the lateral tomography for the angle nasolabial and upper airways of rhinopharynx, oropharynx and hypopharynx. Results There was an increase in nasal width with an average of 1.3467 mm and an increase in the alar base with an average of 1.7333 mm. A significant difference was found in the pre- and postoperative assessments of the measurements of nasal width, alar base and nasolabial angle, as well as the upper airways in all their extension. The results favour a better understanding of the professional and the patient regarding the diagnosis and management of patients with transverse maxillary width discrepancies. Conclusion Although our study shows an increase in soft tissues after SARME, no aesthetic changes are observed clinically, and all patients report significant respiratory improvement. SARME may therefore contribute to the improvement of professionals working in the field of oral and maxillofacial surgery and orthodontics. Level of evidence: Level 4.

Comparison of three-dimensional soft tissue changes according to the split pattern after sagittal split osteotomy in patients with skeletal class III malocclusion.

OBJECTIVES: This study aimed to analyse the changes in soft tissue and hard tissue stability associated with the split pattern, i.e. long split (LS) or short split (SS), after sagittal split osteotomy. MATERIALS AND METHODS: Patients who underwent sagittal split ramus osteotomy were classified into LS or SS groups according to postoperative computed tomography images. They were examined via lateral cephalography and three-dimensional (3D) optical scanning before surgery (T0) and 1 (T1), 3 (T2), and 12 (T3) months after surgery. Six standard angles (SNA, SNB, ANB, FMA, FMIA, and IMPA) were used as measures of hard tissue change. The two sets of 3D data were superimposed, and the volumetric differences were calculated as the soft tissue change. The areas evaluated were delimited by 10 × 20-mm rectangles in the frontal aspect and a 25 × 25-mm square in the lateral aspect. RESULTS: A total of 42 sides (26 patients) were analysed, including 20 (16 patients) in the SS group and 22 (16 patients) in the LS group. We found no significant differences in cephalographic angle or soft tissue changes in the frontal aspect between the SS and LS groups. We found significant differences in the subauricular region from T0-T1 (p = 0.02), T0-T2 (p = 0.03), and T0-T3 (p = 0.037) in terms of soft tissue changes in the lateral aspect. The volume increase associated with posterior mandibular movement was greater in the LS group. CONCLUSIONS: We found that LS patients with mandibular prognathism exhibited increased subauricular volumes following mandibular setback. CLINICAL RELEVANCE: It is essential to predict the postoperative facial profile before surgery. The split pattern after sagittal split osteotomy affects the postoperative profile of patients with mandibular prognathism.

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Artificial intelligence (AI) has been utilized in soft-tissue analysis and prediction in orthodontic treatment planning, although its reliability has not been systematically assessed. This scoping review was conducted to outline the development of AI in terms of predicting soft-tissue changes after orthodontic treatment, as well as to comprehensively evaluate its prediction accuracy. Six electronic databases (PubMed, EBSCOhost, Web of Science, Embase, Cochrane Library, and Scopus) were searched up to March 14, 2023. Clinical studies investigating the performance of AI-based systems in predicting post-orthodontic soft-tissue alterations were included. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and Joanna Briggs Institute (JBI) appraisal checklist for diagnostic test accuracy studies were applied to assess risk of bias, while the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) assessment was conducted to evaluate the certainty of outcomes. After screening 2500 studies, four non-randomized clinical trials were finally included for full-text evaluation. We found a low level of evidence indicating an estimated high overall accuracy of AI-generated prediction, whereas the lower lip and chin seemed to be the least predictable regions. Furthermore, the facial morphology simulated by AI via the fusion of multimodality images was considered to be reasonably true. Since all of the included studies that were not randomized clinical trials (non-RCTs) showed a moderate to high risk of bias, more well-designed clinical trials with sufficient sample size are needed in future work.

Development and accuracy of artificial intelligence-generated prediction of facial changes in orthodontic treatment: a scoping review. / äººå·¥æ™ºèƒ½é¢„æµ‹æ­£ç•¸é¢éƒ¨å˜åŒ–çš„ç ”ç©¶è¿›å±•å’Œå‡†ç¡®åº¦ï¼šæ¦‚å†µæ€§ç³»ç»Ÿç»¼è¿°.

Artificial intelligence (AI) has been utilized in soft-tissue analysis and prediction in orthodontic treatment planning, although its reliability has not been systematically assessed. This scoping review was conducted to outline the development of AI in terms of predicting soft-tissue changes after orthodontic treatment, as well as to comprehensively evaluate its prediction accuracy. Six electronic databases (PubMed, EBSCOhost, Web of Science, Embase, Cochrane Library, and Scopus) were searched up to March 14, 2023. Clinical studies investigating the performance of AI-based systems in predicting post-orthodontic soft-tissue alterations were included. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and Joanna Briggs Institute (JBI) appraisal checklist for diagnostic test accuracy studies were applied to assess risk of bias, while the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) assessment was conducted to evaluate the certainty of outcomes. After screening 2500 studies, four non-randomized clinical trials were finally included for full-text evaluation. We found a low level of evidence indicating an estimated high overall accuracy of AI-generated prediction, whereas the lower lip and chin seemed to be the least predictable regions. Furthermore, the facial morphology simulated by AI via the fusion of multimodality images was considered to be reasonably true. Since all of the included studies that were not randomized clinical trials (non-RCTs) showed a moderate to high risk of bias, more well-designed clinical trials with sufficient sample size are needed in future work.

The influence of tissue redraping after Le Fort I type osteotomy.

Elongation of the upper lip, in particular the philtrum, and nose widening are common postoperative changes after a Le Fort I osteotomy. These changes can be induced by the transection of soft tissue and loosening of the underlying musculature. A methodology for soft tissue redraping was developed to limit these undesirable nasolabial changes. This study evaluates the effectiveness of the technique and influence of maxillary translocation on the nasolabial form. Anthropometric measurements, lip, philtrum length, and nose width, were taken two weeks prior to, and one year after, surgery. The mean postoperative changes were minimised to less than 1mm except for lip length in the extrusion groups, which was less than 1.5mm. Statistical analysis showed a stable result for lip length after maxillary advancement and/or intrusion as limited lengthening mainly occurred at the vermilion. Conversely, lip lengthening after extrusion mainly occurred at the philtrum. The mean nose width was maintained after maxillary advancement, decreased after extrusion, and increased after intrusion. The type of maxillary translocation only influenced the nasolabial soft tissue in case of intrusion and extrusion, not after advancement.

Immediate implant positioning using tooth-derived bone substitute material for alveolar ridge preservation: Preliminary results at 6 months.

OBJECTIVES: In the present study we evaluated the effectiveness of the use of a novel autologous bone substitute derived directly from processing the extracted tooth in the upper premolar area to preserve a suitable esthetic score and functionality. MATERIAL AND METHODS: Fourteen bone-level implants with platform switching were inserted in 12 patients immediately after atraumatic extraction of premolars for restorative or endodontic reasons. The implant buccal bone gap was filled using autologous tooth extracted-derived material. Clinical and radiographic parameters, including Pink Esthetic Score (PES) were evaluated at 6 months. RESULTS: A total of 10 patients accounting for 11 implants were included. PES showed a suitable esthetic result, and all the implant-prosthetic rehabilitation reported full satisfaction for masticatory function, phonetics, and aesthetics. Bone levels were stable and not affected by implant location, lesion type, or bone quality. CONCLUSION: Radiographically the autologous bone substitute used appears stable in the surgical site and there is good continuity between the autologous bone and the graft. No adverse effects such as periodontal inflammation, infection, or graft rejection was reported.

Development and accuracy of artificial intelligence-generated prediction of facial changes in orthodontic treatment: a scoping review / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Artificial intelligence (AI) has been utilized in soft-tissue analysis and prediction in orthodontic treatment planning, although its reliability has not been systematically assessed. This scoping review was conducted to outline the development of AI in terms of predicting soft-tissue changes after orthodontic treatment, as well as to comprehensively evaluate its prediction accuracy. Six electronic databases (PubMed, EBSCOhost, Web of Science, Embase, Cochrane Library, and Scopus) were searched up to March 14, 2023. Clinical studies investigating the performance of AI-based systems in predicting post-orthodontic soft-tissue alterations were included. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and Joanna Briggs Institute (JBI) appraisal checklist for diagnostic test accuracy studies were applied to assess risk of bias, while the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) assessment was conducted to evaluate the certainty of outcomes. After screening 2500 studies, four non-randomized clinical trials were finally included for full-text evaluation. We found a low level of evidence indicating an estimated high overall accuracy of AI-generated prediction, whereas the lower lip and chin seemed to be the least predictable regions. Furthermore, the facial morphology simulated by AI via the fusion of multimodality images was considered to be reasonably true. Since all of the included studies that were not randomized clinical trials (non-RCTs) showed a moderate to high risk of bias, more well-designed clinical trials with sufficient sample size are needed in future work.

Evaluation of Soft and Hard Tissue Changes Following the Use of Rapid Molar Intruder for the Management of Skeletal Anterior Open Bite in Mixed Dentition: A Randomized Controlled Trial.

Objective The aim of the study was to evaluate skeletal, dentoalveolar, and soft tissue changes following early anterior open bite (AOB) treatment using a rapid molar intruder (RMI). Materials and methods A two-arm, parallel-group, randomized controlled trial was conducted on 40 patients aged 8-12 years with anterior open bites. They were randomly allocated to the RMI group and the untreated control group (UCG) with a 1:1 allocation ratio. At the beginning of the treatment (T1) and after nine months of treatment (T2), lateral cephalometric images were taken of each patient. The primary outcome measures were skeletal, dentoalveolar, and soft tissue changes. A two-sample t-test was used in the intergroup comparisons of the cephalometric measurement. Results The findings showed that the overbite increased significantly in the RMI group compared to the control group (x = 4.44 mm, x = 0.19 mm, respectively; p<0.001). A statistically significant intrusion of the upper and lower first molars was observed in the RMI group (x = 2.9 mm, x = 1.54 mm, respectively) compared to a slight extrusion in the control group. The differences between the two groups were significant (p<0.001). The SN: GoMe angle and the sum of Bjork decreased significantly in the RMI group compared to an increase observed in the control group. The differences between the two groups were significant (p<0.001). Conclusion The rapid molar intruder is an effective appliance for correcting anterior open bites in mixed dentition, inducing favorable skeletal, dentoalveolar, and soft tissue changes.

Three-dimensional image study of accelerated maxillary expansion in oral breathing kids

Abstract Objective: To evaluate, by a three-dimensional study, the volumetric and integumentary effects of rapid maxillary expansion on the nose, in mouth breathing kids with maxillary hypoplasia, in the short term, assessing the possible interference of gender, growth and age on the results achieved. Methods: 120 mouth breathing patients with maxilla hypoplasia were divided into an Experimental Group treated by rapid maxillary expansion (n = 104, 62 males and 42 females, mean age 10.1 years, SD = 2.10, ranging from 5.1 to 13.9 years); and Control Group, constituted by 16 patients (9 males and 7 females, mean age 9.3 years, SD = 2.1 years, ranging from 6.1 to 13.2 years). Patients in the experimental group underwent multislice computed tomography examinations at two different times: (T1) pre-expansion and (T2) post-expansion. The control group was submitted to the same tests at the same time intervals. Six soft tissue variables of the nose were studied, besides the volume and area of the nasal cavity, and the measurement and comparison of data between T1 and T2 were performed using the Dolphin Imaging 11.7 Premium software. Results: The experimental group showed significant mean increases in all soft tissue variables studied (p < 0.005), yet there were no significant changes in the control group. In the comparison between groups, only inclination of the nasal dorsum did not present any significant change. Conclusion: Rapid maxillary expansion may alter the nasal shape and physiology, by anatomical changes in the nose soft tissues, making it an important aid in the treatment of mouth breathing in childhood. Level of evidence: The soft tissues of the nose play an important role in nasal shape and physiology and facial esthetics, and since they are directly related to the nasal valves, they are fundamental for maintenance and stability of the nasal breathing pattern.

Facial soft-tissue changes after anterior maxillary osteotomy: A prospective study.

Aims: The aim of this study was to analyze and assess the soft-tissue response in patients treated by anterior maxillary osteotomy (AMO) in the postoperative period at 3, 6, and 9 months and to qualitatively assess the outcome of the surgery by the patients. Patients and Methods: The study included twenty adult healthy patients between 18 and 25 years with skeletal Class II malocclusion and requiring AMO setback for the correction of facial deformity. Preoperative and postoperative lateral cephalograms were taken and soft-tissue changes that occurred following AMO were compared at 3, 6, and 9 months postoperatively. The stability and acceptance of the soft-tissue changes were analyzed, and the patient's acceptance for the soft-tissue changes was measured on the surgical rating scale (SRS). Results: All the soft-tissue parameters showed noticeable changes following AMO. Statistically significant difference was observed with nasolabial angle, upper lip, and lower lip inclination. All the patients were moderately satisfied with the outcome of the surgery. Conclusion: This study aims in quantifying the soft-tissue changes following the AMO and the quality of the changes were recorded based on the SRS by the patients. Although there are changes associated with all the parameters assessed, significant differences was observed in nasolabial angle, upper lip, and lower lip inclination. The surgeon must be aware of the soft-tissue adaptation following the surgery for better outcomes.

Three-dimensional image study of accelerated maxillary expansion in oral breathing kids.

OBJECTIVE: To evaluate, by a three-dimensional study, the volumetric and integumentary effects of rapid maxillary expansion on the nose, in mouth breathing kids with maxillary hypoplasia, in the short term, assessing the possible interference of gender, growth and age on the results achieved. METHODS: 120 mouth breathing patients with maxilla hypoplasia were divided into an Experimental Group treated by rapid maxillary expansion (n = 104, 62 males and 42 females, mean age 10.1 years, SD = 2.10, ranging from 5.1 to 13.9 years); and Control Group, constituted by 16 patients (9 males and 7 females, mean age 9.3 years, SD = 2.1 years, ranging from 6.1 to 13.2 years). Patients in the experimental group underwent multislice computed tomography examinations at two different times: (T1) pre-expansion and (T2) post-expansion. The control group was submitted to the same tests at the same time intervals. Six soft tissue variables of the nose were studied, besides the volume and area of the nasal cavity, and the measurement and comparison of data between T1 and T2 were performed using the Dolphin Imaging 11.7 Premium software. RESULTS: The experimental group showed significant mean increases in all soft tissue variables studied (p < 0.005), yet there were no significant changes in the control group. In the comparison between groups, only inclination of the nasal dorsum did not present any significant change. CONCLUSION: Rapid maxillary expansion may alter the nasal shape and physiology, by anatomical changes in the nose soft tissues, making it an important aid in the treatment of mouth breathing in childhood. LEVEL OF EVIDENCE: The soft tissues of the nose play an important role in nasal shape and physiology and facial esthetics, and since they are directly related to the nasal valves, they are fundamental for maintenance and stability of the nasal breathing pattern.

Three-Dimensional Digital Image Analysis of Skeletal and Soft Tissue Points A and B after Orthodontic Treatment with Premolar Extraction in Bimaxillary Protrusive Patients.

Aim. To investigate the effect of changes in incisor tip, apex movement, and inclination on skeletal points A and B and characterize changes in skeletal points A and B to the soft tissue points A and B after incisor retraction in Angle Class I bimaxillary dentoalveolar protrusion. Methods. Twenty-two patients with Angle Class I bimaxillary dentoalveolar protrusion treated with four first premolar extractions were included in this study. The displacement of skeletal and soft tissue points A and B was measured using cone-beam computed tomography (CBCT) using a three-dimensional coordinate system. The movement of the upper and lower incisors was also measured using CBCT-synthesized lateral cephalograms. Results. Changes in the incisal tip, apex, and inclination after retraction did not significantly affect the position of points A and B in any direction (x, y, z). Linear regression analysis showed a statistically significant relationship between skeletal point A and soft tissue point A on the anteroposterior axis (z). Skeletal point A moved forward by 0.07 mm, and soft tissue point A moved forward by 0.38 mm, establishing a ratio of 0.18: 1 (r = 0.554, p < 0.01). Conclusion. The positional complexion of the skeletal points A and B was not directly influenced by changes in the incisor tip, apex, and inclination. Although the results suggest that soft tissue point A follows the anteroposterior position of skeletal point A, its clinical significance is suspected. Thus, hard and soft tissue analysis should be considered in treatment planning.

Improving lip aesthetics in the face profile after treatment of class II, division 2 malocclusion.

AIM: The aims of our research were as follows: 1) Description of changes in the position of the upper and lower lips, as a result of the change in the position of upper and lower incisors after orthodontic treatment of malocclusion of Class II, division 2 type. 2) Determination of correlation between changes in the position of lips and incisors in the profile of the face after orthodontic treatment of malocclusion of Class II, division 2 type.MATERIALS AND METHODS: Our study analyses the documentation of 115 patients with malocclusion of Class II, division 2 type treated with a fixed orthodontic appliance in the upper and lower dental arches at the Orthodontic Department of the Clinic of Dentistry in Olomouc from January 1, 1996 to December 31, 2017. There were 78 women and 37 men aged 11 to 36 years included in the database. Cephalometric images of patients from the group taken before and after the treatment were used for the purpose of cephalometric analysis according to Kamínek (1) and Burstone's analysis (2) of soft tissues. Subsequently, all output data were processed statistically. RESULTS: While the protrusion of the incisors after treatment of malocclusion of Class II, division 2 type was 3 mm, the facial profile showed statistically significant changes in soft tissues in the ventral direction by 1 mm on average just in the area of the upper and lower lips, which means a shift corresponding to one third of teeth movement. CONCLUSION: A statistically significant change in the position of incisors, soft tissues as well as correlation between changes in hard and soft tissues in the face profile after orthodontic treatment of malocclusion of Class II, division 2 type were demonstrated. The more the incisors were inclined, the more the lips moved forward, and the patient's profile turned out to be aesthetically improved (Tab. 2, Fig. 3, Ref. 39).

Le Fort I osteotomy and soft tissue response: A retrospective cohort study comparing three different techniques.

The aim of this study was to evaluate the nasolabial soft tissues effects in three different Le Fort I osteotomy techniques using cone beam computed tomography (CBCT) evaluation of three-dimensional (3D) volume surfaces. A retrospective study was designed, and three groups were evaluated: group 1, patients who underwent conventional Le Fort I osteotomy; group 2, patients who underwent subspinal Le Fort I osteotomy; and group 3, patients who underwent conventional Le Fort I osteotomy with ANS recontouring or removal. CBCT evaluation was performed at two time points: T0, 1 week before surgery; T1, 6 months after surgery. A total of 90 patients were enrolled in this study (group 1: 30; group 2: 30; group 3: 30). Mean maxillary advancement was 4.26 mm. For group 1, mean change in inter-alar width was 2.29 ± 1.57 mm (minimum -2mm; maximum 6.1 mm; for group 2 it was 1.20 ± 1.56 mm (minimum -1.7 mm; maximum 5.9 mm), and for group 3 was 1.84 ± 1.76 mm (minimum -2.3 mm; maximum 5.9 mm). For group 1, mean change in alar base width was 1.69 ± 2.32 mm (minimum -4.8 mm; maximum 6,1 mm); in group 2 it was 0.85 ± 2.08 mm (minimum -4mm; maximum 6 mm), and group 3 was 1.21 ± 1.83 mm (minimum -2mm; maximum 5 mm). Results showed statistically significant differences in nasolabial area (P < 0.001). Within the limitations of the study it seems that subspinal Le Fort I osteotomy should be preferred when the priority is to avoid changes to the nasolabial region.

Baseline selection for evaluation of peri-implant soft tissue changes: a clinical trial.

BACKGROUND: To select the optimal baseline for evaluation of peri-implant soft tissue changes among 1, 2, and 3 weeks after definitive crown insertion. METHODS: A total of 22 individuals who required implant restoration were recruited to this study. Each participant received a screw-retained conventional implant restoration. Peri-implant soft tissue was captured by an intraoral scanner and analyzed by 3D analysis software. Soft tissue changes [mucosal margin (MM) and soft tissue thickness (STT)] on the buccal side of implant sites were evaluated at 1, 2, and 3 weeks after definitive crown insertion. One-way analysis of variance (ANOVA) for repeated measurement and Tukey's test were used to analyze significant differences between the 3 time points (α=0.05). RESULTS: An increased volume of peri-implant soft tissue was observed shortly after definitive crown insertion. Based on the findings of peri-implant soft tissue changes, significant differences were observed between weeks 1 and 2 (P<0.01), and weeks 1 and 3 (P<0.01), while there was no significant difference between weeks 2 and 3 (P>0.05). CONCLUSIONS: Minimal peri-implant soft tissue changes occurred in this study. The time point of 2 weeks after definitive crown insertion was preliminarily selected as the baseline. The small sample size and few time points must be taken into consideration when interpreting these findings. TRIAL REGISTRATION: This study was retrospectively registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2000037954; Date of registration: 6 September 2020).

Effect of free gingival graft before implant placement on peri-implant health and soft tissue changes: a randomized controlled trial.

BACKGROUND: To evaluate the clinical outcome and changes in posterior buccal soft tissue following implant restoration in groups with and without a free gingival graft (FGG) before implant placement. METHODS: Twenty-six individuals who required implant restoration and displayed lack of keratinized mucosa (KM) were recruited and assigned to the FGG group (with FGG before implant placement) or Control group (without FGG before implant placement) randomly. A screw-retained conventional implant restoration was performed for each patient. Peri-implant soft tissue was captured by an intraoral scanner and analyzed by an image processing software. Clinical parameters (plaque index, gingival index, probing depth, and bleeding on probing) were assessed at baseline and 1, 3, 6, and 12 months. Buccal soft tissue changes (mucosal margin, soft tissue thickness, and width of keratinized mucosa) on the buccal side of implant site were assessed at 1, 3, 6, and 12 months. Two-way ANOVA and Bonferroni test were used to analyze significant difference between groups at each time point (α = 0.05). RESULTS: The clinical parameters were lower in the FGG group than that in the Control group, although there were no significant differences between the two groups (P > 0.05). Peri-implant soft tissue collapsed and the changes (mucosal margin and soft tissue thickness) were significantly greater in the Control group than the FGG group (P < 0.05). Width of KM was larger in the FGG group than the Control group, although there was no significant difference between the two groups (P > 0.05). CONCLUSIONS: Minimal peri-implant soft tissue changes occurred in two groups. Performing FGG before implant placement is a viable procedure to maintain peri-implant soft tissue but might not affect peri-implant health during 12 months follow-up. However, small sample size must be considered. Trial registration This study was retrospectively registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2000037954; Date of registration: 6 September 2020).

The effect of immediate implant placement on alveolar ridge preservation compared to spontaneous healing after tooth extraction: Soft tissue findings from a randomized controlled clinical trial.

AIM: To compare soft tissue dimensional changes and relative differences in soft and hard tissue volumes 4 months after single-tooth extraction and three different treatment modalities: spontaneous healing (SH) and alveolar ridge preservation by means of a deproteinized bovine bone mineral and a collagen matrix, with (IMPL/DBBM/CM) or without (DBBM/CM) immediate implant placement. MATERIALS AND METHODS: STL files from study casts obtained at baseline and after 4 months were matched to calculate buccal soft tissue linear and volumetric changes. DICOM files from CBCTs were superimposed to STL files allowing the evaluation of soft tissue thickness at baseline and 4 months. RESULTS: Mean horizontal reduction accounted for 1.46 ± 0.20 (SH), 0.85 ± 0.38 (DBBM-CM) and 0.84 ± 0.30 IMPL/DBBM-CM, with no statistical differences. Soft tissue thickness had a significant mean increase of 0.95 for SH group, compared to a non-significant mean decrease for DBBM-CM (0.20) and IMPL/DBBM-CM groups (0.07). CONCLUSION: A preservation technique with DBBM-CM, with or without immediate implant placement, did not reduce the horizontal linear and volumetric changes at the buccal soft tissue profile significantly at 4 months after tooth extraction when compared to spontaneous healing. This is due to a significant increase in soft tissue thickness in spontaneously healing sites.