What comes first: teeth or face? Recommendations for an interdisciplinary collaboration between facial esthetic surgery and dentistry.

OBJECTIVE: The aim of the present study was to provide recommendations in order to facilitate communication between dental professionals and surgeons who are collaborating in the field of dentofacial esthetics. CLINICAL CONSIDERATIONS: Smile esthetics are beyond the scope, both of the surgeons who are collaborating with facial esthetics and of the dentists, as a wide range of treatment options from both sides is available. It can be difficult for the surgeon or the dentist that first comes in contact with the patient to conduct an individualized global treatment plan, in order to find out how the various phases of the treatment can be sequenced, as a workflow for an efficient interaction between facial surgery and dentistry still does not exist in the scientific literature. CONCLUSIONS: Facial cosmetic procedures and dental treatment have to be planned as individual elements of the whole dentofacial esthetic rehabilitation. The treatment has to be initiated with the design of the smile and the intraoral mock-up, followed by the required surgical interventions, and to be finished with the delivery of the definitive dental restoration. CLINICAL SIGNIFICANCE: Dentofacial esthetics require comprehensive communication between surgeons and dentists. Following the proposed recommendations, an individualized interdisciplinary treatment plan can be conducted, defining the role of each specialty.

Predictability of orthodontic tooth movement with aligners: effect of treatment design.

BACKGROUNDS: The present study was designed to define: (1) which are the less predictable OTM with Invisalign aligners when the treatment plan is designed by expert operators, (2) if the presence and shape of attachments influence the predictability of OTM and (3) if patients' demographics influence OTM predictability. The sample comprises 79 prospectively recruited patients (mean age 30.8 years; SD 12.0; 23 M, 56 F), treated by expert operators with an average of 27 aligners (SD 15) in the maxillary arch and 25 aligners (SD 11) in the mandibular arch. Post-treatment digital models and final virtual treatment plan models were exported from ClinCheck® software as STL files and subsequently imported into Geomagic Qualify ®software, to compare final teeth positions. The differences were calculated and tested for statistical significance for each tooth in the mesial-distal, vestibular-lingual and occlusal-gingival directions, as well as for angulation, inclination and rotation. In addition, the statistical significance of categorical variables was tested. RESULTS: The lack of correction was significant for all movements and in all group of teeth (P < 0.01) except for the rotation of maxillary first molar. The prescribed OTM, the group of teeth and movement, the frequency of aligner change and the use of attachment influence the outcome. The greatest discrepancies in predicted and achieved tooth position were found for angular movements and rotation of teeth characterized by round-shaped crowns, for a ratio of approximately 0.4° per 1° prescribed. Optimized attachments for upper canines and lower premolar rotation seem not working properly. Second molar movements are mostly unexpressed. Furthermore, changing the aligner every 14 days will reduce the lack of correction of the 12% with respect to 7 days aligner change. CONCLUSIONS: Predictability of orthodontic movement with aligners still has limitations related to the biomechanics of the system: the shape of some attachments and the characteristics of aligner material need to be redefined. However, the results of this study allow to properly design the virtual treatment plan, revealing how much overcorrection is needed and which attachments are most effective.

Dental implant placement with inferior alveolar nerve repositioning in severely resorbed mandibles: a retrospective multicenter study of implant success and survival rates, and lower lip sensory disturbances.

BACKGROUND: The purpose of this study was to analyze medium-to-long-term implant success and survival rates, and lower lip sensory disturbance after placement of dental implants with simultaneous inferior alveolar nerve (IAN) repositioning. METHODS: Fifteen patients (3 men, 12 women) treated in two centers were included in this retrospective study. The ages of the participants ranged from 19 to 68. A total of 48 dental implants were placed in 23 posterior mandibular segments simultaneously with IAN transposition or lateralization. The residual bone above the IAN ranged from 0.5 to 7.0 mm. Crestal bone changes were measured using cone beam computed tomography (CBCT) images. Disturbance of the IAN was evaluated subjectively using a modified questionnaire. RESULTS: The healing process was uneventful in fourteen patients. In one patient, spontaneous fracture of the operated mandible occurred on tenth day after the surgery. The implant in the fracture line was removed at the time of open reduction and fixation. One more implant was lost after 5 years of loading. Therefore, the overall dental implant survival rate was 95.8%, whereas all implants in function were judged as successful after a follow-up period of 1 to 10 years. Transient neurosensory disturbances (ND) were observed in all patients who underwent IAN lateralization and IAN transposition. At follow-up times of 3 years, 5 years, and 10 years, weak hypoesthesia remained in two subjects treated with IAN transposition. None of the patients developed neuropathic pain after the procedure. CONCLUSIONS: Within the limitations of this study, we conclude that reconstruction of severely resorbed mandibles with dental implants in conjunction with IAN repositioning is an effective and reliable technique. Although neurosensory disturbances are the most common complication after surgery, they tend to resolve over time. Advanced surgical skills are required to perform this technique.

Digital platform for planning facial asymmetry orthodontic-surgical treatment preparation.

Dentofacial deformities usually are surgically treated, and 3D virtual planning has been used to favor accurate outcomes. Cases reported in the present article show that orthognathic surgery carried out to correct facial asymmetries does not comprise only one treatment protocol. 3D virtual planning might be used for surgical planning, but it should also be used to diagnose the deformity, thus allowing for an analysis of the best-recommended possibilities for the orthodontic preparation that suits each individual case.

Digital platform for planning facial asymmetry orthodontic-surgical treatment preparation

ABSTRACT Dentofacial deformities usually are surgically treated, and 3D virtual planning has been used to favor accurate outcomes. Cases reported in the present article show that orthognathic surgery carried out to correct facial asymmetries does not comprise only one treatment protocol. 3D virtual planning might be used for surgical planning, but it should also be used to diagnose the deformity, thus allowing for an analysis of the best-recommended possibilities for the orthodontic preparation that suits each individual case.

RESUMO As deformidades dentofaciais são, geralmente, tratadas de forma cirúrgica, e o planejamento virtual 3D tem sido utilizado para aumentar a precisão dos resultados. Os casos exemplificados no presente artigo mostram que a cirurgia ortognática para correção das assimetrias faciais não apresenta um único protocolo de tratamento. O planejamento virtual 3D pode ser adotado para planejar a cirurgia, mas também deve ser utilizado na fase de diagnóstico da deformidade, assim permitindo uma análise das possibilidades mais indicadas para o preparo ortodôntico mais adequado em cada caso.

Volumetric analysis of implanted biphasic calcium phosphate/collagen composite by three-dimensional cone beam computed tomography head model superimposition.

Facial onlay augmentation is often performed as an ancillary procedure simultaneously with orthognathic surgery to improve facial appearance, with hydroxyapatite (HAp) and HAp-based composites often used as the materials of choice. The ability to apply HAp in a granular rather than solid shape form may be responsible for its comparatively reduced rate of complications. However, a known complication of HAp and HAp composites is reduction of implant volume over time associated with resorption of the material. Evaluation of the volumetric changes of implanted biphasic calcium phosphate (HAp/ß-TCP)/collagen composite in the malar areas from baseline to 4 months, 9-12 months, and 18-24 months after surgery using cone beam computed tomography (CBCT) surface superimposition and volumetric subtraction was done. The average decrease of volume of implanted HAp/ß-TCP 4 months after surgery was 18.6%. Further volumetric decreases were negligible and a mean total volume loss of 21.65% was found at 18-24 months postoperatively.

Influence of thin mucosal tissues on crestal bone stability around implants with platform switching: a 1-year pilot study.

PURPOSE: The aim of this pilot study was to determine what effect thin mucosal tissues can have on crestal bone stability around implants with platform switching. MATERIALS AND METHODS: Twelve 2-piece implants, consisting of 6 implants with horizontally matching implant-abutment connection (control) and 6 implants with platform switching (test) were placed in 4 patients. The mean age of the patients was 43 years (range, 37 to 56 yrs). Mucosal tissue thickness at implant sites was measured to be 2 mm or less. Implants were restored with 5 splinted crowns and single 3-unit fixed partial denture. Intraoral radiographs were obtained and crestal bone changes were measured at implant placement and after a 1-year follow-up post-treatment. The statistical significance level was set to P less than .05. RESULTS: Bone loss around the test implants was 1.81 +/- 0.39 mm on the mesial site and 1.70 +/- 0.35 mm on the distal aspect. Control implants overcame marginal bone resorption equaling 1.60 +/- 0.46 mm on the mesial site and 1.76 +/- 0.45 mm on distal measurement. No statistically significant difference was found between control and test implants either mesially (F([1,10]) = 0.746; P = .408) or distally (F([1,10]) = 0.080; P = .783). CONCLUSION: Within the limitations of this pilot study it can be concluded that implants with platform switching did not preserve crestal bone better in comparison with implants with traditional implant-abutment connection if, at the time of implant placement, thin mucosal tissues were present.

Reaction of crestal bone around implants depending on mucosal tissue thickness. A 1-year prospective clinical study.

PURPOSE: The aim of this paper was to distinguish what kind of mucosal tissue, measured at the top of the crest can be referred to as thin, medium or thick and its influence on crestal bone loss around dental implants after a 1-year follow-up. MATERIALS AND METHODS: Totally 64 implants were evaluated in 26 patients. 32 implants (test group) were placed about 2 mm supracrestally and 32 implants (control group) were positioned equal to the bone level. Mucosal tissues at a time of implant placement were divided into 3 groups--thin, medium and thick. Crestal bone changes were measured at implant placement and after a 1-year follow-up. RESULTS: Mean bone loss around test implants in thin tissue group (up to 2 mm) was 1.35 mm+/-0.33 SD, in medium thickness group mean bone loss was 0.32 mm+/-0.44 SD and 0.12 mm+/-0.16 SD of bone loss was registered in thick tissue group (3.1 mm and more). Mean bone loss around control implants in all 3 groups was as follows: 1.8 mm+/-0.52 SD in thin, 1.62 mm+/-0.63 SD in medium and 1.55 mm+/-0.47 SD in thick tissue group. ANOVA analysis showed statistically significant differences between 3 groups of thickness, as crestal bone loss around test implants is concerned. (F[2,29]=37.3; P=.000). In control implants bone loss did not vary between 3 groups of tissue thickness (F[2,29]=0.73; P=.503). CONCLUSIONS: It can be concluded that initial tissue thickness can influence crestal bone changes around implants.

The influence of soft tissue thickness on crestal bone changes around implants: a 1-year prospective controlled clinical trial.

PURPOSE: The aim of this clinical trial was to evaluate the influence of gingival tissue thickness on crestal bone loss around dental implants after a 1-year follow-up. MATERIALS AND METHODS: Forty-six implants (23 test and 23 control) were placed in 19 patients. The test implants were placed about 2 mm supracrestally, whereas the control implants were positioned at the bone level. Before implant placement, the tissue thickness at implant sites was measured with a periodontal probe. After healing, metal-ceramic cement-retained prostheses were constructed. According to tissue thickness, the test implants were divided into A (thin) and B (thick) groups. Intraoral radiographs were performed and crestal bone changes were measured at implant placement and after 1 year. RESULTS: Mean bone loss around the test implants in group A (thin mucosa) was 1.61 +/- 0.24 mm (SE; range, 0.9 to 3.3 mm) on the mesial and 1.28 +/- 0.167 mm (range, 0.8 to 2.1 mm) on the distal. Mean bone loss in test group B (thick mucosa) implants was 0.26 +/- 0.08 mm (range, 0.2 to 0.9 mm) on the mesial aspect and 0.09 +/- 0.05 mm (range, 0.2 to 0.6 mm) on the distal aspect. Mean bone loss around control implants was 1.8 +/- 0.164 mm (range, 0.6 to 4.0 mm) and 1.87 +/- 0.166 mm (range, 0.0 to 4.1 mm) on the mesial and distal aspects, respectively. Analysis of variance revealed a significant difference in terms of bone loss between test A (thin) and B (thick) groups on both the mesial and the distal. CONCLUSION: Initial gingival tissue thickness at the crest may be considered as a significant influence on marginal bone stability around implants. If the tissue thickness is 2.0 mm or less, crestal bone loss up to 1.45 mm may occur, despite a supracrestal position of the implant-abutment interface.

Veneer fracture in implant-supported metal-ceramic restorations. Part I: Overall success rate and impact of occlusal guidance.

PURPOSE: The aims of the presented study were to define the fracture rate of implant-supported metal-ceramic restorations delivered in private practice, and to identify if a restoration's contact during eccentric mandible movements has any influence on ceramic fracture rates. MATERIAL AND METHODS: Within the period from 2005 to 2008, 251 patients, namely 105 men (42%) and 146 women (58%), received 775 dental implants which later were restored with metal-ceramic restorations. Data was gathered and analyzed in the form of a specially-designed electronic questionnaire. In total, 251 patients were rehabilitated with 350 prostheses consisting of 151 single crowns, 208 fixed partial dentures of various extents and 21 full-arch restorations. The method for retention of prostheses included cement-, screw-, or hybrid cement-screw retained prosthetic devices. The patients were recalled and examined for the presence of mechanical complications, namely ceramic fractures. Fractures were distinguished as adhesive or co-adhesive. The follow-up time was registered. RESULTS: The mean ceramic fracture rate was 6.7%, as fracture occurred in 24 restorations. In the single crown group, the fracture rate was 1.3%, in the fixed partial denture division it was 6.7%, and the full-arch metal-ceramic restorations experienced 38.1% chipping. The mean follow-up period of prostheses was 9.5 months, ranging from 1 to 42 months. The analysis revealed that 66 prostheses had contact in protrusive and/or lateral mandibular movements, constituting 17.4% of all restorations; while 13 restorations had ceramic fractures, composing 19.7% of all guiding prostheses. CONCLUSIONS: Within the limitations of this trial, it can be noted that ceramic veneer fracture rate was 6.7% in 380 restorations, and a conclusion that a restoration's contact during eccentric excursions may significantly enlarge fracture rates can be made.

Validity and reproducibility of cephalometric measurements obtained from digital photographs of analogue headfilms.

UNLABELLED: The emerging market of digital cephalographs and computerized cephalometry is overwhelming the need to examine the advantages and drawbacks of manual cephalometry, meanwhile, small offices continue to benefit from the economic efficacy and ease of use of analogue cephalograms. The use of modern cephalometric software requires import of digital cephalograms or digital capture of analogue data: scanning and digital photography. The validity of digital photographs of analogue headfilms rather than original headfilms in clinical practice has not been well established. Digital photography could be a fast and inexpensive method of digital capture of analogue cephalograms for use in digital cephalometry. AIM: The objective of this study was to determine the validity and reproducibility of measurements obtained from digital photographs of analogue headfilms in lateral cephalometry. MATERIAL AND METHODS: Analogue cephalometric radiographs were performed on 15 human dry skulls. Each of them was traced on acetate paper and photographed three times independently. Acetate tracings and digital photographs were digitized and analyzed in cephalometric software. Linear regression model, paired t-test intergroup analysis and coefficient of repeatability were used to assess validity and reproducibility for 63 angular, linear and derivative measurements. RESULTS AND CONCLUSIONS: 54 out of 63 measurements were determined to have clinically acceptable reproducibility in the acetate tracing group as well as 46 out of 63 in the digital photography group. The worst reproducibility was determined for measurements dependent on landmarks of incisors and poorly defined outlines, majority of them being angular measurements. Validity was acceptable for all measurements, and although statistically significant differences between methods existed for as many as 15 parameters, they appeared to be clinically insignificant being smaller than 1 unit of measurement. Validity was acceptable for 59 of 63 measurements obtained from digital photographs, substantiating the use of digital photography for headfilm capture and computer-aided cephalometric analysis.