Hard Tissue Changes Research Articles

Hard tissue dimensional changes following implant removal due to peri-implantitis: A retrospective study.

The current evidence regarding the alterations experienced by the alveolar ridge (hard tissue changes) after implant removal due to peri-implantitis is limited. To assess the hard tissue dimensional changes following implant removal due to peri-implantitis. Clinical records were examined to identify patients with implants that had to be removed due to a hopeless prognosis secondary to peri-implantitis due to expendability of peri-implantitis implants for functional reasons. Patients with preoperative and postoperative cone-beam computed tomography (CBCT) scans were included. Patient-related, implant-related, and surgery-related factors were assessed based on the clinical records. Linear measurements were made to evaluate the influence of bone plate thickness (BPT), ridge width (RW), and ridge height (RH) at various levels upon the outcome of implant removal. A descriptive statistical analysis of the quantitative and qualitative variables was performed. Correlations of the variables with the primary outcome (dimensional changes) were tested using univariate and multivariate analyses (multinomial random intercept mixed model linear regressions). A total of 26 patients (nimplants = 79) met the eligibility criteria. The mean decrease in RW at 1 and 3 mm below the crest was 11.3% and 4.4%, respectively (P < 0.001). Buccal and lingual RH was significantly reduced by 2.2% and 6.3%, respectively (P < 0.001). Few patient-related, implant-related, and surgery-related factors appeared to have an impact upon the hard tissue dimensional changes. Bone regeneration simultaneous to implant removal minimized the dimensional changes of the ridge both vertically (5% lesser buccal RH reduction) and horizontally (12% lesser RW reduction) when compared with spontaneous healing. The use of a reverse-torque removal kit seemed to be critical in limiting the dimensional changes of the ridge. Minimal hard tissue changes can be expected following implant removal due to peri-implantitis. Simultaneous bone regeneration procedures and the use of a removal kit may considerably reduce the impact upon the dimensional changes (NCT04534361).

A comparison of postoperative, three-dimensional soft tissue changes in patients with skeletal class III malocclusions treated via orthodontics-first and surgery-first approaches

The aim of this retrospective study was to compare three-dimensional (3D) soft tissue and hard tissue changes between orthodontics-first approach (OFA) and surgery-first approach (SFA) after mandibular setback surgery. All patients underwent bilateral sagittal split osteotomy, and were examined by lateral cephalograms and 3D optical scanner before surgery (T0) and 1 (T1), 3 (T2), and 12 (T3) months after surgery. Three standard angles (FMA, U1 to FH, IMPA) were measured as hard tissue change and the 2 sets of 3D data were superimposed, and volumetric differences were calculated as soft tissue change. Statistical analyses were performed by using unpaired t-tests. Differences with P < 0.05 were considered significant. A total of 39 patients with mandibular prognathism were included in this study. The OFA group consisted of 24 patients and the SFA group of 15 patients. The SFA group exhibited more labial inclination from T1 to T2 (p = 0.008) and T2 to T3 (p = 0.003) than did the OFA group. There were no significant changes at maxilla and mandible at each term of T0, T1, T2 and T3 (p > 0.05), but compared to before surgery, mandibular volume in SFA group significant increased at 1year (p = 0.049) after surgery. We found that the soft tissue changes after the SFA differed significantly from those after the OFA; thus, soft tissue predictions require more care. An analysis of our data compared with OFA and SFA for the patient with mandibular prognathism confirm that the mandibular soft tissue changes by postoperative orthodontic treatment and occlusal relationship in SFA.

Changes in the facial soft tissue profile after maxillary orthognathic surgery.

ObjectivesTo compare the changes of the soft tissue profile in relation to the displacement of the underlying hard structures in maxillary orthognathic surgery and to contribute to the esthetic prediction of the facial profile after surgical procedures.Materials and methodsWe analyzed the sagittal changes in the facial soft tissue profile related to surgical changes in skeletal structures after maxillary osteotomy in a retrospective study. The study sample comprised 115 adult patients between the ages of 18–50 years who had undergone maxillary orthognathic surgery and interdisciplinary orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. LeFort I osteotomy cases in both maxillary monognathic and bignathic osteotomy procedures were included. All subjects had received rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed and the correlations between hard tissue and soft tissue change ratios were evaluated using a bivariate linear regression analysis. A vertical line through the landmark sella (S) perpendicular to the nasion-sella line (NSL) served as the reference plane.ResultsThe subnasale (Sn) followed the A point (A) by 57%, the soft tissue A point (A′) followed the A point (A) by 73% and the upper lip, represented by the landmark labrale superius (Ls) followed the upper incisor (Is) by 73%; all three in a linear correlation with a mean prediction error of nearly 2 mm.ConclusionThe scatterplots show a linear correlation with a wide spread for all three pairs of reference points. The wide spread and the high prediction error of almost 2 mm indicate low predictability of the expected lip position and Sn.

Arthrocentesis Followed by Autologous Blood Injection in the Treatment of Chronic Symptomatic Subluxation of Temporomandibular Joint.

Temporomandibular joint subluxation is defined as self-reducing partial dislocation of the TMJ during which the condyle passes anterior to the articular eminence. The study consisted of 30 patients, 19 females and 11 males with 14 unilateral and 16 bilateral cases of chronic symptomatic subluxation. Treatment consisted of arthrocentesis followed by 2ml of autologous blood injection into upper joint space and 1ml into pericapsular tissues using an autoclaved soldered double needle with single puncture technique. Parameters evaluated were pain, maximum mouth opening, excursive jaw movements, deviation on mouth opening and quality of life, hard and soft tissue changes on X-ray TMJ view and MRI. At 12month follow-up, average reduction in maximum interincisal opening, deviation on mouth opening, range of excursive movements on right and left sides and VAS scores were 20.54%, 32.84%, 29.59%, 27.37% and 74.53%, respectively. Out of 93.3% who responded to therapy, 66.7%, 20% and 6.7% responded after 1st, 2nd and 3rd AC + ABI, respectively. Remaining 6.7% patients had persistent painful subluxation and underwent open joint surgery. 93.3% patients responded to therapy, 80% were relieved of painful subluxation, 13.3% had painless subluxation and kept on follow-up. X-ray TMJ and MRI did not show any hard and soft tissue changes. A soldered double needle, single puncture, AC + ABI are a simple, safe, cost-effective, repeatable and minimally invasive nonsurgical therapy for treatment of CSS without any permanent radiographically evident soft or hard tissue changes.

Sealing Socket Abutments (SSAs) in Molar Immediate Implants with a Digitalized CAD/CAM Protocol: Soft Tissue Contour Changes and Radiographic Outcomes After 2 Years

Immediate implant placement in molar sites has the potential to improve the patient experience by reducing the number of appointments and the overall treatment time. However, primary closure remains a technical challenge. The present prospective case series evaluated the soft tissue contours and the radiographic bone levels of 17 patients who received immediate implants in molar sites and a digitally customized CAD/CAM sealing socket abutment. At the 2-year follow-up, the mean buccal tissue contours at the most coronal portion were reduced horizontally by an average of 1 mm at 1, 2, 3, and 4 mm below the gingival margin. A mean 0.53-mm apical migration of the gingival margin was seen, and the mean interproximal bone level at the 2-year follow-up was 0.89 mm. The use of CAD/CAM-generated customized healing abutments in immediate molar sites yielded minimal hard and soft tissue changes at the 2-year follow-up.

Three-dimensional digital planning of class III decompensation with clear aligners: Hard and soft tissue augmentation with concomitant corticotomy to stretch the limits of safe orthodontic treatment

PurposeThree-dimensional diagnosis has shown that orthodontic therapy could potentially move the roots of the teeth outside the original bone structure. The purpose of these case studies was to test the possibility of obtaining correct three-dimensional tooth positioning with clear aligners, thereby modifying the periodontal structure accordingly, at the same time. MethodsRegenerative Corticotomy (RC) was performed with clear aligners on ten adult patients (40 anterior teeth) with skeletal Class III malocclusion, for dental decompensation, prior to the orthognathic surgery. The CBCT examinations were performed before treatment (T0) and 1 year after orthognathic surgery (T1). The vertical and the horizontal hard tissue changes, the width of keratinized gingiva, the incisors proclination (IMPA) and the percentage of inclination compared to the planning were analyzed. ResultsThe distance between the Cemento-Enamel Junction (CEJ) and the Bone Marginal Level (BML) decreased in average from 5.5 ​± ​3.2 ​mm to 1.39 ​± ​0.53 ​mm. The horizontal changes were at the 3 ​mm level 1.42 ​± ​0.5 ​mm, at the 5 ​mm level 1.98 ​± ​0.66 ​mm and at the 7 ​mm level 2.70 ​± ​0.87 ​mm. The width of Keratinized gingiva changes were on average 1.42 ​± ​0.36 ​at T0 and 4.16 ​± ​2.25 ​at T1. All the changes were statistically significant with p ​< ​0,05. The mean proclination based on IMPA values was +9.16 +-1.19°. The mean difference of the incisor’s proclination compared to the digitally planned was −1 +-0.6° (89.87 +- 6.46%). ConclusionClear Aligners with three-dimensional digital planning seems to be reliable in controlling teeth movements in the pre-orthognathic decompensation phase. Regenerative Corticotomy seems to have the ability to improve the periodontal tissues despite proclination.

Study on the changes of soft and hard tissue before and after early treatment of ClassIIskeletal malocclusion with Twin-block appliance

PURPOSE To investigate the effect of early correction with Twin-block appliance on soft and hard tissues of patients with Class Ⅱ skeletal malocclusion. METHODS Sixty patients with Angle Class Ⅱ skeletal malocclusion were prospectively selected. The patients were divided into 2 groups, 30 cases in each group, by random number table method. Patients in the experimental group were treated with a Twin-block appliance combined with straight wire appliance, while patients in the control group were treated with a straight wire appliance. The soft and hard tissue indexes(SNA, SNB, ANB, U1-NA angle, U1-NA distance, L1-NB distance, L1-NB angle, U1-L1) before, and 12 months after treatment were measured. Soft tissue measurement indicators included UL-U1, LL-L1, over jet, overbite, E-upper-lip from the upper lip to the E-line, and the lower lip to the E-line, changes in the vertical distance (E-lower-lip), the dip angle of the sulcus, and the thickness of the soft tissue. SPSS 25.0 software package was used for statistical analysis of the data. RESULTS U1-NA, U1-NA, L1-NB, L1-NB, overjet, overbite, E-upper-lip, and E-lower-lip were significantly less than the control group at 12 months and 36 months after treatment in the experimental group(P<0.05). U1-L1, nasolabial angle, sulcus angle, and soft tissue thickness of the experimental group were significantly greater than those of the control group(P<0.05). CONCLUSIONS Twin-block appliance combined with straight wire appliance can significantly improve the relationship between the jaw and the soft and hard tissues of patients with Class Ⅱ skeletal malocclusion, and the long-term effect is good.

An isthmus of isolation: The likely elevated prevalence of genetic disease in ancient Panama and implications for considering rare diseases in paleopathology

ObjectiveThis study considers the evidence for elevated frequencies of “rare” diseases in ancient Panama. Indications of population isolation by multidisciplinary sources allow for the possibility that rare inherited conditions may have been maintained at relatively high prevalences in the region due to gene flow restriction. MaterialsA sample of 267 skeletal human remains with diverse demographical characteristics from Pre-Columbian archaeological sites throughout Panama. MethodsRemains were analyzed macroscopically and hard tissue developmental anomalies were documented. ResultsFrequencies of developmental anomalies and hard tissue changes consistent with specific rare genetic diseases, such as osteogenesis imperfecta, on the comparatively few human remains recovered from pre-Columbian archaeological sites are elevated as compared with global averages. ConclusionsThe paleopathological evidence is concordant with a scenario of isolation in Pre-Columbian times and with an increased presence of genetic disorders in the population. SignificanceThis study advocates for the special consideration of rare diseases by paleopathologists in regions where populations may have experienced prolonged geographical or social isolation in the past. LimitationsA dearth of local modern epidemiological data and low sample sizes of preserved human remains in certain regions of the country limited the possibilities of spatiotemporal comparisons of rare disease prevalence. Suggestions for further researchFurther scrutiny of developmental anomalies of genetic origin on ancient Panamanian remains and biomolecular testing of remains for specific disorders should be pursued to confirm the findings of this study.

Dental implant survival rate in irradiated and non-radiated patients: a systematic review and meta-analysis.

Radiotherapy to head and neck has always been considered as a risk factor for rehabilitation with dental implants. Nevertheless, recent data suggest that overall, 5-year implant survival in irradiated patients can be greater than 90%. The purpose of this review was to compare the implant survival rates of irradiated and non-radiated head and neck cancer sites, and discuss the outcomes, through a systematic review approach of prospective and retrospective studies. Electronic searches were performed in the EMBASE, Cochrane, and PubMed/Medline databases up to 2019 Dec, to identify retrospective and prospective clinical studies addressing the subject. This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary variables collected from the studies were the site of tumor, age and sex of the patient, site of implant placement, radiation dosage, frequency and duration of radiotherapy, follow-up duration, implant survival and stability, hard and soft tissue changes after implant placement, any type of biological and mechanical complication, and oral health quality of life (QOL). Fifteen studies including 1097 patients and a total of 4637 implants placed in irradiated and non-irradiated sites, with a follow up duration varying from 6 to 120 months, were selected for the systematic review. The results of the quantitative synthesis suggested statistically significantly better survival rate of implants placed in nonradiated sites, as compared to irradiated sites (p<0.00001). However, the cumulative survival rates over a period of 7-10 years were reported to be comparable. Quality of life (QOL) after implant rehabilitation was not found to be significantly different between the compared groups. Due to the limited number of information, insufficient data was available to draw conclusion on peri-implant complication rate. No relationship was found between age, gender, and implant survival rates. Implant placement in irradiated sites is challenging and often warrants protocol modifications. Although statistically the survival rates at irradiated sites were lower in comparison to non-radiated sites, a strict inclusion criterion in patient selection, timing of implant placement after radiotherapy, radiation dosage and regular oral hygiene maintenance could minimize the chances of implant failure in irradiated patients.

Efficacy of different surgical techniques for peri-implant tissue preservation in immediate implant placement: a systematic review and meta-analysis.

Preserving peri-implant tissues after immediate implant placement (IIP), especially in aesthetic zones, is a topic of interest. This systematic review investigated the effects of currently available surgical procedures for preserving peri-implant tissue or ensuring dimensional stability following immediate implant placement. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement's guidelines were followed, and articles were sought on the PubMed and Cochrane databases with no date restrictions. Only randomised clinical trials that evaluated changes in soft and hard tissues around immediately placed implants were included. Statistical analyses were performed, and the studies´ quality was assessed using the Cochrane Collaboration tool. The agreement between reviewers was assessed based on Cohen's kappa statistics. Of the 14 studies that met the inclusion criteria, 11 were analysed in the meta-analysis (kappa = 0.814; almost perfect agreement). The use of connective tissue grafts resulted in a significantly greater improvement of the facial gingival level (MD = -0.51; 95% CI: -0.76 to -0.31; p = < .001), and the placement of bone grafts significantly reduced the horizontal resorption of the buccal bone (MD = -0.59; 95% CI: -0.78 to -0.39; p < .001). Connective tissue grafts and bone grafts positively influence tissue preservation around immediately placed implants. Neither the flapless technique nor palatal implant positioning resulted in significant improvements to any of the investigated parameters. Additional longitudinal studies are required. This meta-analysis is useful for discerning the effects of soft tissue augmentation, bone grafting, the flapless technique, and palatal implant positioning on preserving peri-implant tissues after immediate implant placement.

Immediate implant in the posterior region combined with alveolar ridge preservation and sealing socket abutment: A retrospective 3D radiographic analysis.

Customized sealing socket abutment (SSA) has been claimed to optimize the peri-implant hard and soft tissues in type 1 implant placement. However, the evidence to claim the benefits of this technique over the use a conventional healing abutment remains weak. The aim of this retrospective study was to provide a 3D-radiographic evaluation of hard tissues changes following immediate implant placement in molar sites combined to ARP technique and installation of SSA. Baseline and follow-up (FU) CBCTs (from 1 to 5 years) of 26 patients were collected and included in the study. Baseline and FU CBCTs were superimposed and horizontal and vertical bone changes were assessed. A total of 26 patients and 27 implants were included. Horizontal bone remodeling was not significant in any of the measured areas except in the most cervical level, where a mean bone remodeling of 0.73 mm was found. Proximal and buccal vertical bone changes were not significant. Within the limits of a retrospective study, dimensional alveolar ridge changes 1 to 5 years after immediate implant placement in molar sites with simultaneous ARP technique and installation of SSA seem to be very limited.

Linear correlation between tooth movement and facial profile change in patients with class Ⅱ division 1 malocclusion

Objective: To investigate the correlation between tooth movement and profile change in patients with class Ⅱ division 1 malocclusion. Methods: Pre- and post-treatment lateral cephalograms of 42 patients [10 males and 32 females, (23.8±6.3) years old, mean treatment time: 1.9 years] with class Ⅱ division 1 malocclusion were collected in Department of Oral & Cranio-Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from June 2012 to November 2017. The patients were treated with extraction of four first premolars or two maxillary first premolars. Cephalometric analysis was carried out before and after treatment. Thirty parameters were measured. The changes of soft and hard tissue after orthodontic treatment and their correlations were analyzed using bivariate linear regression. Related factors affecting the upper and lower lip, nasolabial angle (NLA) and mentolabial angle (MLA) were analyzed according to the standardized regression coefficient (Beta). Results: Among all the 30 parameters, 18 parameters were statistically different before and after treatment. After treatment, upper central incisor sagittal distance [(63.87±7.14) mm] and upper lip sagittal distance [(77.73±7.60) mm] were significantly decreased (P<0.05). The changes in 14 parameters after treatment showed linear relationship including strong positive correlation between upper lip sagittal retraction and upper central incisor sagittal retraction (r=0.649, P<0.01). There were moderate positive correlations between upper lip and upper central incisor vertical movement (r=0.544, P<0.01). While the sagittal change of gnathion and the Y-axis angle showed moderate negative correlations (r=0.537, P<0.01). The stepwise multiple linear regression showed that the retraction of upper lip process was correlated with the retraction of upper central incisor, the increase of occlusal plane angle and the increase of upper central incisor angle, which was most correlated with the retraction of upper central incisor (Beta=0.79). The downward displacement of upper lip process was correlated with the downward displacement of upper incisor, the decrease of upper central incisor angle, the decrease of the distance between maxillary first molar and palatal plane, and the increase of occlusal plane angle, which was more correlated with the downward displacement of upper incisor and the increase of occlusal plane angle (Beta=0.59). The downward displacement of lower lip process was correlated with the downward displacement of upper incisor and lower incisor, which was more correlated with the upper incisor (Beta=0.36). Conclusions: The relationship among nose, lips and chin was more coordinated. Incisor retraction had significant influence on lip prominence, and the lower lip position was highly related to the movement of upper incisor in sagittal and vertical dimension after orthodontic treatment in patients with class Ⅱ division 1 malocclusion. However, tooth movement had limited impact on the chin position.

Raman spectroscopy and its application in different areas of medicine

The aim of the review is to learn about the areas of application of the Raman spectroscopy in medicine, particularly in dentistry. The method is widely used in biology, medicine, pharmacy, forensic science, gemology, food industry and other industries. The main advantages of Raman spectroscopy are no need for sample preparation and small amounts of the object of study, as well as the ability to contactlessly obtain unique information about the conformation and microenvironment of living cell molecules. The disadvantages are high costs of the equipment that are compensated with the long-term use by having no costs for additional reagents. The combinatorial scattering is used in dermatology, as it is a high-accuracy automated method of visualization and diagnostics of both benign growths as pigmented nevus, seborrheic keratosis, and malignant neoplasms as melanoma and basal cell carcinoma. This method is an analytical tool for diagnosing various diseases, making the direct measurements in hard and liquid media easier, does not require special treatment of samples and is not sensitive to absorption bands. The Raman spectroscopy use in dentistry allows diagnosing and comparative analysis of the changes of hard tissues of teeth and mucous membrane of the mouth, which improves security and rationalization of treatment and further prevention of complications before and after making different operations.

Head and neck radiotherapy-induced changes in dentomaxillofacial structures detected on panoramic radiographs: A systematic review.

PurposeThis study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs.Materials and MethodsIn this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to “radiotherapy” and synonyms combined with keywords related to “panoramic radiography” and “oral diagnosis” and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies.ResultsThirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176.ConclusionThe interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

Comparison of conventional Le-fort I advancement, anterior maxillary segmental distraction, and distraction osteogenesis of maxilla for surgical management of cleft maxillary hypoplasia

This systematic review compares conventional Le-fort I advancement (CLO), anterior maxillary segmental distraction (AMD) and distraction osteogenesis of maxilla (DOM) for the treatment of cleft maxillary hypoplasia in terms of the amount of maxillary advancement achievable, relapse, residual velopharyngeal incompetence and soft tissue changes. All patients with maxillary hypoplasia secondary to cleft palate repair were taken into consideration irrespective of their gender, age and ethnic background. Literature research was done in databases PubMed, Ovid and Google scholar beta. From the original 429 articles identified, 17 articles were finally included, which passed the critical appraisal checklist and met the inclusion criteria. The mean advancement ranged from 6.59 mm to 16.5 mm for DOM, 6–14.28 mm for AMD and 5.17–7.2 mm for CLO. Relapse was 8.24%–45% for DOM, 4.6%–7% for AMD and 21.63%–63% for CLO. Velopharyngeal insufficiency increased significantly following Le-fort I advancement, while there was no significant change after anterior maxillary distraction and DOM. The ratio of soft tissue to hard tissue changes was greatest with AMD, followed by DOM and then CLO. Distraction osteogenesis of the maxilla and AMD are plausible treatment options for cleft maxillary advancement. Due to less stability and restricted amount of possible advancement, Le-fort I osteotomy should be reserved for minor skeletal discrepancies in cleft patients.

Three-Dimensional Analysis of Soft and Hard Tissue Changes following Orthognathic Surgery

Change in soft tissue in relation to that in hard tissue following orthognathic surgery was evaluated. Twenty-five patients were enrolled in the study. The diagnosis in all was jaw deformity (maxillary retrusion and mandibular protrusion) and all underwent a Le Fort I osteotomy and bilateral sagittal splitting ramus osteotomy. Three-dimensional (3D) computer-aided design (CAD) models (polygon models) of the hard and soft tissue of the maxilla and mandible were constructed and superimposed. Reference points were established on the pre- and postoperative hard and soft tissues. Specific elements of each reference point were divided into X, Y, and Z components, respectively, and the distances in each direction and 3D distance (normal distance) measured. The Wilcoxon signed-rank test was used to determine differences in the mean values for the distance moved of each element as the error between pre- and postoperatively. The results revealed statistically significant differences in the Y-direction in the maxilla and the X- and Z-directions in the mandible. A significant difference was also observed in the 3D distances of the maxilla and mandible. Little evidence was found of linearity between the amount of hard and soft tissue movement in the X- and Z-directions in the maxilla. This means that 3D movement in the maxilla was masked more by changes in the morphology of the soft tissue than in the mandible, making it less evident. The results of this study suggest that the 3D analysis method used enables changes in hard and soft tissues to be understood qualitatively, and that it can be used in diagnosis and treatment in orthognathic surgery. It may also be useful in simulation of morphological change in soft tissue.

Evaluation of lateral hard and soft tissue changes following orthodontic treatment of bimaxillary protrusion in adults

Evaluation of lateral hard and soft tissue changes following orthodontic treatment of bimaxillary protrusion in adults

Lip morphology changes after first premolar extractions in patients with bimaxillary protrusion in North Indian population – A pilot study

Introduction: As we witness the soft-tissue paradigm, treating the face becomes more important than just treating the hard tissue variables. Therefore, it becomes crucial to quantify the soft-tissue response to changes in the hard tissue following orthodontic treatment.Purpose of the Study: To determine lip morphology changes after first premolar extractions in patients with bimaxillary protrusion as ratios of hard and soft-tissue changes.Materials and Methods: The sample consisted of pretreatment and posttreatment lateral cephalograms of 15 subjects with Class I bimaxillary protrusion who had undergone orthodontic treatment with four first premolars extraction and retraction of upper and lower incisors. Pre- and post-treatment lateral cephalograms were traced and superimposed by using SN-7˚ plane. Sixteen linear measurements were made. Statistical analysis was performed to analyze the co-relation between the hard and soft tissue change by Pearson's correlation. Stepwise multiple regression were made to determine factors that related with lip changes.Results: Significant changes after treatment were found both in dental and lip analysis. The equations of upper and lower lip changes in sagittal and vertical dimensions were derived.Conclusion: Stepwise multiple regression analysis revealed that a 1 mm retraction of the maxillary incisor cervical point would produce a 0.59 mm retraction of upper lip and 1 mm retraction of the mandibular incisor cervical point would produce 0.89 mm retraction of the lower lip. The predictability of this study may be helpful for the clinician in predicting the amount of change in profile of the patient post treatment, thus aiding in planning the treatment.

Evaluation of hard and soft tissue changes around implant in partially edentulous patients: a aclinico-radiographic study

Introductionimplant supported prosthesis has become a viable treatment option for missing teeth. An important tool to detect early changes around implants is the standardized assessment of peri-implant hard and soft tissue parameters. The purpose of this prospective study was to clinically and radiographically assess the soft and hard tissues around implants.Methodsten (10) patients with 13 implant supported prosthesis were included in the study. Clinical parameters plaque index (PI), gingival index (GI), modified sulcus bleeding index (mSBI), peri-implant Probing Depth (PD), gingival margin Level, width of keratinized mucosa (WKM) and implant mobility were measured at loading and at 3 and 6 months. The radiographic crestal bone loss and peri-apical implant radiolucencies were also evaluated at loading and at 3 and 6 months. Student paired t test and correlation and regression analysis was done to evaluate the effect of clinical variables over bone loss.Resultsthere was decrease in the site specific PI, GI, mSBI and peri-implant PD and an increase in the gingival recession from baseline to 6 months. The WKM remained stable throughout the study. Significant crestal bone loss was observed around implants more on the distal as compared to the mesial aspect. No mobility or peri-apical implant radiolucency was observed. Regression analysis of the confounding variables with bone loss showed no significant effect.Conclusionthe occlusal loading of implants after 6 months showed significant bone loss (<1mm), which was within acceptable limits and the soft tissues around implants were in good health.

Study of soft tissue changes in the upper lip and nose after backward movement of the maxilla in orthognathic surgery.

ObjectivesThis study evaluates soft tissue changes of the upper lip and nose after maxillary setback with orthognathic surgery such as Le Fort I or anterior segmental osteotomy.Materials and MethodsAll 50 patients with bimaxillary protrusion and skeletal Class II malocclusion underwent Le Fort I or anterior segmental osteotomy with backward movement. Soft and hard tissue changes were analyzed using cephalograms collected preoperatively and 6 months postoperatively.ResultsCluster analysis on the ratios shows that 2 lines intersected at 4 mm point. Based on this point, we divided the subjects into 2 groups Group A (less than 4 mm, 27 subjects) and Group B (more than 4 mm, 23 subjects). Also, each group was divided according to changes of upper incisor angle (≥4°=A1, B1 or <4°=A2, B2). The correlation between A and B groups for Aʼ/ANS and Ls/Is (P<0.001) was significant; Aʼ/A (P=0.002), PRN/A (P=0.043), PRN/ANS (P=0.032), and St/Is (P=0.010). Variation of nasolabial angle between the two groups was not significant. There was no significant correlation of vertical movement and angle variation.ConclusionThe ratio of soft tissue to hard tissue movement depends on the amount of posterior movement in the maxilla, showing approximately two times higher rates in most of the midface when posterior movement was greater than 4 mm. The soft tissue changes caused by posterior movement of the maxilla were little affected by angular changes of upper incisors. Interestingly, nasolabial angle showed a different tendency between A and B groups and was more affected by incisal angular changes when horizontal posterior movement was less than 4 mm.