The combined use of computer-guided, minimally invasive, flapless corticotomy and clear aligners as a novel approach to moderate crowding: A case report.

The aim of this case report was to describe an innovative orthodontic treatment method that combined surgical and orthodontic techniques. The novel method was used to achieve a positive result in a case of moderate crowding by employing a computer-guided piezocision procedure followed by the use of clear aligners. A 23-year-old woman had a malocclusion with moderate crowding. Her periodontal indices, oral health-related quality of life (OHRQoL), and treatment time were evaluated. The treatment included interproximal corticotomy cuts extending through the entire thickness of the cortical layer, without a full-thickness flap reflection. This was achieved with a three-dimensionally printed surgical guide using computer-aided design and computer-aided manufacturing. Orthodontic force was applied to the teeth immediately after surgery by using clear appliances for better control of tooth movement. The total treatment time was 8 months. The periodontal indices improved after crowding correction, but the oral health impact profile showed a slight deterioration of OHRQoL during the 3 days following surgery. At the 2-year retention follow-up, the stability of treatment was excellent. The reduction in surgical time and patient discomfort, increased periodontal safety and patient acceptability, and accurate control of orthodontic movement without the risk of losing anchorage may encourage the use of this combined technique in appropriate cases.

The Survival of Morse Cone-Connection Implants with Platform Switch.

PURPOSE: The aim of this prospective clinical study was to evaluate the survival up to 5 years of Morse cone-connection implants with platform switch considering the influence of biologically relevant, anatomical, and stress-related variables. STROBE guidelines were followed. MATERIALS AND METHODS: Seven hundred forty-eight implants were inserted in 350 patients. Follow-up visits were scheduled at the time of stagetwo surgery (2 months later) and at 6, 12, 24, 36, and 60 months. All implants were initially loaded with a cemented provisional acrylic restoration. The definitive metal-ceramic restorations were cemented at the 6-month follow-up. Implant cumulative survival rates (CSRs) were calculated using life table actuarial method. Survival data were also analyzed by the log-rank test and Cox regression. The statistical analysis was conducted at the patient level. P ≤ .05 was considered as an indicator of statistical significance. RESULTS: During the follow-up (mean: 40 months; SD: 20.27), 28 patients were considered failed (8%). The CSR and its standard error (SE) was 92% ± 2.17%. Patients with implant-supported single crowns had a CSR of 90%, whereas those with implant-supported fixed dental prostheses had a CSR of 93%. The implant diameter (P = .0399) and implant length (P = .0441) were statistically significant. The probability of failure was almost 75% lower for patients with wide rather than standard implants, 91% lower for patients with long implants, and 69% lower for patients with standard implants compared with short implants. CONCLUSION: The use of Morse cone-connection implants with platform switch is a safe and reliable treatment method. Stress-related variables influence the risk of failure confirming the importance of biomechanical factors in the longevity of osseointegrated implants; thus, the clinician may obtain better results if attention is paid to these factors.

A 36-month follow-up prospective cohort study on peri-implant bone loss of Morse Taper connection implants with platform switching.

A prospective cohort study was designed to measure marginal bone level changes at 36-month follow-up and to evaluate the influence of biologically relevant, anatomic and stress-related variables. STROBE guidelines were followed. Totally, 748 implants were inserted into 350 patients. Standardized periapical radiographs were taken at 2- (stage-two surgery), 12-, 24-, and 36-month follow-ups. Descriptive statistics were used and inter- and intra-examiner reliability were determined. A mixed-model was used to evaluate predictor variables. Statistical analysis was performed at implant level (statistical significance: P < 0.05). A total of 34 (4.5%) implants failed; of the 34 implants, 6 were early failures (0.8%) and 28 were late failures (3.7%). A total of 576 implants reached 36-month follow-up (mean follow-up: 25.58 months; SD: 10.32). Mean marginal bone remodeling was -0.56 mm. (SD: 1.30; range: -6.80 ± 3.65). A statistically significant, higher marginal bone loss was found for subcrestal implants and subcrestal implants inserted into the maxilla, for implants inserted into patients aged over 50 years, and for early-delayed implants inserted into patients aged over 50 years. In conclusion, a low, mean crestal bone loss at 36-month follow-up was recorded but implant positioning in the apico-occlusal dimension was found to be the most significant variable that influenced bone loss. (J Oral Sci 58, 49-57, 2016).

Accuracy of positioning of implants inserted using a mucosa-supported stereolithographic surgical guide in the edentulous maxilla and mandible.

PURPOSE: The aim of this study was to evaluate the accuracy of implants inserted using a mucosa-supported stereolithographic surgical guide and to determine the influence of surgical management of the guide (fixed or unfixed), arch (maxilla or mandible), and smoking habit (normal or hyperplastic mucosa) on accuracy. MATERIALS AND METHODS: In completely edentulous subjects, preoperative computed tomography (CT) was performed, and the images were used to plan implant positions. After the implants were placed, CT was performed again, and the presurgical and postoperative images were compared. With computer software, the jaw contours from the two CT scans were matched and the deviations between the planned and actual implant positions were evaluated. Surgical technique, arch, and smoking habit were examined as independent variables, and their influence on accuracy was evaluated with a t test. RESULTS: Twenty-eight surgical guides (225 implants) were included in this study. Deviations between planned and actual positions were seen in the global coronal (mean±SD: 1.68±0.6 mm), global apical (2.19 ± 0.83 mm), and angular (4.67 ± 2.68 degrees) dimensions. Fixation of surgical guides (fixed: 4.09 degrees; not fixed: 5.62 degrees) and use of the guide in the maxilla (4.36 degrees; mandible: 5.46 degrees) resulted in statistically significantly less angular deviation (ie, better accuracy). Nonsmoking patients showed statistically significantly better accuracy in global coronal (nonsmokers: 1.54 mm; smokers: 1.83 mm) and global apical (nonsmokers: 2.08 mm; smokers: 2.27 mm) deviations. CONCLUSION: The greater supporting surface of the maxilla and fixation of the surgical guide improved the accuracy of the guides. The reduced mucosa thickness in nonsmokers decreased global coronal and global apical deviation.

Morphological and topographical characteristics of posterior supernumerary molar teeth: an epidemiological study on 25,186 subjects.

OBJECTIVES: To investigate the prevalence , gender difference , arch , morphology and position within the arch of supernumerary molar (SM) teeth in a referred Italian Caucasian population. STUDY DESIGN: Records of 25,186 young patients were evaluated. Only data related to supernumerary teeth in the posterior region of the jaws were analyzed. The diagnosis of hyperdontia was formulated during the clinical and radiological examinations based on panoramic radiographs. Statistical analysis was conducted at level of subjects in the assessment of prevalence of SMs and sex ratio. Statistical analysis was conducted at level of teeth according to their morphological and topographic characteristics. The analysis of association between supernumerary morphology and arch, between supernumerary position and arch and between morphology and position was performed using the χ2 test (P≤ 0.05). RESULTS: 61 posterior supernumerary teeth were found in 45 patients. The male to female ratio was 2.5:1 ;the mean age was 21.23 (IC:95%).The SMs were found more frequently in the maxilla (62.3%) than in the mandible; supernumerary teeth (60.7%) were more frequent than supplemental teeth. The SMs were mostly of tuberculate shape (56.8%) and paramolars teeth (64.9%) were more common than distomolars. 54% of teeth were erupted in the arch. No statistically significant relationship were found between the supernumerary teeth shape and the arch (P= 0.087) , between supernumerary teeth position and the arch (P=0.511) and between morphology and position (P=0.216). CONCLUSIONS: Epidemiological studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. In this retrospective study the prevalence of SMs was 0.18%. SMs were more frequent in males and in the maxilla. Supernumerary were more frequent than supplemental; the conical morphology and paramolar position were the most common shape and position.

Accuracy of a computer-aided implant surgical technique.

The purpose of this in vivo retrospective study was to evaluate the accuracy of a computer-designed stereolithographic surgical guide. One hundred eleven implants were placed in 10 patients. Pre- and postoperative computed tomography images were compared using specific software. Global, angular, depth, and lateral deviations were calculated between planned and placed implants. Mean global deviations between planned and placed implants at the coronal and apical aspects were 1.52 mm (range, 0.13 to 3.00 mm) and 1.97 mm (range, 0.34 to 4.23 mm), respectively, while the mean angular deviation was 4.68 degrees (range, 0.10 to 15.25 degrees). This study highlighted a reasonable mean accuracy with relatively high maximum deviations between the postoperative position and the preoperative plan. These results should serve as a warning for the clinician if implants are placed near vital structures.

Accuracy of two stereolithographic surgical templates: a retrospective study.

BACKGROUND: The use of computer software and stereolithography for dental implant therapy has significantly increased during the last few years. The aim of this study was to evaluate and compare the mean accuracy and maximum deviations values of dental implant placement using two stereolithographic (SLA) guide systems. MATERIALS AND METHODS: Twenty patients were selected and 227 implants were inserted using bone-, tooth- and mucosa-supported SLA surgical guides. Thirty-one guides, both single- and multiple-type, were used. Some of the single-type surgical guides were fixed with osteosynthesis screws. A postoperative computer tomography (CT) was performed and an iterative closest point algorithm was used to match the jaw of the CT preoperative with the jaw of the postoperative CT. Quantitative data of each group were described. The t-test was used to determine the influence of the utilization of the different types of SLA on accuracy values. RESULTS: t-Test demonstrated a better accuracy of the multiple-type guides in almost all deviation values when the mucosa-supported guides were considered. Regarding the bone-supported template, the single-type fixed group showed a better accuracy while the highest values of deviation were registered by the multiple-type guides. The single-type group showed a better accuracy when the tooth support was considered. CONCLUSIONS: The results of the present study indicated best accuracy of the single-type guide using a bone or tooth support. The multiple-type guide recorded the best accuracy data when the mucosa support was considered comparing either a fixed and a not-fixed single-type guide.

Accuracy of implant placement with a stereolithographic surgical template.

PURPOSE: The possible advantages of stereolithographic (SLA) surgical template use have not been adequately demonstrated, and studies of the accuracy of computer-aided implant placement are few. The purpose of this in vivo study was to evaluate the accuracy of a computer-designed (SLA) surgical guide by comparing the three-dimensional positions of planned and placed implants. MATERIALS AND METHODS: One hundred sixteen implants were inserted in partially and completely edentulous patients using multiple SLA templates. Preoperative and postoperative computed tomographic images were compared. Four deviation parameters--global, angular, depth, and lateral--were defined and calculated between the planned and actual implant positions and analyzed statistically. RESULTS: The mean global deviations between planned and actual implant positions at the coronal and apical ends were 1.47 mm and 1.83 mm, respectively; the mean angular deviation was 5.09 degrees. There were significant linear correlations at the implant level between coronal and angular deviations and between coronal and apical deviations. CONCLUSIONS: The study highlighted deviations between the postoperative position and the preoperative plan at the coronal and apical portions of the implant, as well as in the angulation of the implant. Although the reported deviation values were extremely high, they do not appear to have resulted in important clinical complications. This suggests the necessity of always keeping a safety zone of at least 2 mm to avoid critical anatomical structures.