Treatment of absent maxillary lateral incisors: orthodontic space closure and associated procedures.

Missing maxillary lateral incisors can be treated either with orthodontic space closure or preservation of the edentulous space for tooth replacement. Orthodontic space closure coupled with non-invasive post-orthodontic cosmetic dentistry is a compelling option compatible with optimal function, favourable aesthetics, and periodontal health in the long-term. We present the rationale for space closure and detail contemporary clinical strategies underpinning interdisciplinary treatment planning and excellence in finishing.

Detailed three-dimensional orthodontic tooth repositioning to improve restorative outcome.

The case describes the interdisciplinary treatment of a 23-year-old woman with a Class III malocclusion, missing an upper right lateral incisor, abrasion of the maxillary incisal edges, anterior gingival margin discrepancies, and gingival recession. Initially, the patient was treated with fixed appliances combined with orthognathic surgery. The extraction of the upper left lateral incisor and bilateral canine substitution plan was chosen. At the end of the surgical and orthodontic treatment, the restorative treatment with six veneers was accomplished to improve smile esthetics. Despite the missing lateral incisors, the patient showed a natural, good-looking final result. A symmetric incisal plane was established, a functional occlusion with average vertical and horizontal overlap was set, and the bone scallop and consequently the gingival margins were leveled. The interdisciplinary approach hid all of the initial esthetic defects of the case. The result highlights how to obtain a remarkable improvement of the smile outcome with a well-functioning masticatory system.

Immediate Loading of Implants Inserted Through Impacted Teeth in the Esthetic Area: A Series of 10 Cases with up to 7 Years of Follow-up.

The purpose of this case series was to evaluate the survival rate and the incidence of complications of implants inserted and immediately loaded in sites where an impacted tooth was present in the anterior maxillary or mandibular arches (incisor to premolar). The implants were immediately inserted, drilling through the impacted teeth. Site preparation started in the crestal bone and continued into the impacted tooth's enamel and dentin. Seven patients were treated and 11 implants were inserted, 3 in the mandibular arch and 8 in the maxillary arch. All implants healed uneventfully without any adverse clinical or radiographic signs or symptoms, resulting in a success rate of 100%. Once loaded, the implants were in function and monitored for 5 to 7 years. Although more studies and a larger sample size are needed to validate this unconventional procedure, it may be considered as a possible clinical option to overcome invasive procedures and surgical complications related to the extraction of impacted teeth.

Cone-beam computed tomography evaluation of periodontal and bone support loss in extraction cases.

BACKGROUND: The aim of this study was to evaluate, in particular, whether bone resorption occurred at the extraction sites of a group of patients under orthodontic treatment, and, in general, whether extraction treatment predisposes patients to a greater degree of root resorption. METHODS: The study group comprised 12 class II division 1 malocclusion patients who underwent orthodontic treatment and extraction, and the control group comprised 10 class II division 1 patients who underwent orthodontic treatment without extraction. In both groups, treatments were carried out by the same operator using the same techniques. Cone-beam computed tomography performed before (T1) and after (T2) treatment was used to determine and compare the root length, the distance from the cementoenamel junction to the base of the defect and to the bone peak, the width of the defect and the buccolingual bone thickness. RESULTS: Root length was reduced following treatment in both groups, although to a statistically significantly greater extent in the study group. The buccolingual bone thickness was reduced after treatment in both groups, with no differences found between the study and control groups. The bone loss at the sites assessed was greater in the patients after extraction treatment, with a statistically significant difference revealed between the two groups. The site that showed the greatest variation in both groups was distal to the upper canines. CONCLUSIONS: In the present study, extractive orthodontic treatment appeared to predispose patients to a greater degree of root resorption. Indeed, the bone at the extraction site showed greater resorption in the study group with respect to the control group, and the appearance of intraosseous defects was noted in the former.

Dental and alveolar arch forms in a Caucasian population compared with commercially available archwires.

INTRODUCTION: The aim of this study was to identify an arch form, comprising dentition and alveolus, representative of the Caucasian population, and to compare it with the shape of the main archwires on the market. MATERIALS AND METHODS: The study sample comprised 35 pairs of dental casts, taken from the arches of 35 Southern Europeans with ideal natural occlusion. After the dental casts were scanned, the reference points of the dental arches (FA points) and alveolar bone (WALA ridges) were identified with 3D software. Cartesian coordinates and intercanine and intermolar diameters were calculated for each patient, and curves representing the upper and lower dentition, as well as those showing the shape of the lower supporting bone, were traced and compared with those pertaining to different types of commonly used orthodontic archwires. RESULTS: Ideal shapes of the mandibular alveolus and of the upper and lower archwires were calculated and compared with those actually on the market. Statistical analysis showed significant differences between the two, particularly at the upper and lower molars and canines. Likewise, there were significant differences between the shapes of the available archwires and the WALA ridge, except for the intercanine width. CONCLUSIONS: None of the commercial archwires examined faithfully represented the shape of the 'ideal' dentition we calculated, particularly at the molars and canines. The bone structure of the mandibular support cannot be used as a guide to the shape of the arch form during orthodontic treatment.

Comparison of adhesion forces developed by foil mesh of various dimensions applied in combination with composites of different viscosity.

OBJECTIVES: The aim of this study was to determine what effect various combinations of particular bracket bases and composites of different viscosity have on adhesion force. MATERIALS AND METHODS: Eighty extracted premolars, upper and lower, were randomly assigned to four groups of 20 teeth and the combinations of either flowable or paste composite and brackets with either 80-gauge or 100-gauge foil mesh were applied to their labial surfaces accordingly: group A: flowable composite+80-mesh base; group B: flowable composite+100-mesh base; group C: paste composite+80-gauge base; group D: paste composite+100-gauge base. Each sample was subjected to shear bond stress to failure using a Zwick Roell Z050 testing machine at 50N/min load. The load required to detach each bracket was recorded in N and subsequently converted to MPa. After debonding, each tooth was analysed under optical microscope at 12× magnification and photographed prior to calculation of the Adhesive Remnant Index (ARI). RESULTS: The paste composite showed greater adhesion strength than the flowable in all cases, but this was further increased when the 80-gauge, rather than the 100-gauge, mesh was used. No statistically significant difference in ARI values was found between the flowable groups (groups A and B), on the other hand, in the paste composite groups, a statistically significant difference was highlighted between the 80-gauge (group D) and 100-gauge (group C) mesh bracket bases. CONCLUSIONS: Both the density of the composite and the gauge of a mesh bracket base are able to influence bond strength and the bond failure interface.

Substitution of impacted canines by maxillary first premolars: a valid alternative to traditional orthodontic treatment.

A 13-year-old girl came with the chief complaint of an unesthetic dental appearance. Her maxillary canines were bilaterally impacted. Treatment included extraction of the maxillary canines and the mandibular second premolars. The maxillary first premolars were substituted for the canines. After 26 months of active treatment, the patient had a Class I molar relationship and ideal overbite and overjet. Her profile was improved, lips were competent, and gingival levels were acceptable. Cephalometric evaluation showed acceptable maxillary and mandibular incisor inclinations. Intraoral pictures taken 3 years 7 months after the end of treatment demonstrated that the extraction of impacted canines and their substitution by first premolars can be a valid alternative to traditional orthodontic treatment when maxillary premolar extraction is a treatment option.

Assessment of lower lip changes following incisor displacement in 92 orthodontically-treated adults.

AIM: A retrospective assessment of the lower lip changes consequent to incisor displacement in correction of malocclusion in a sample of 92 post-adolescent subjects. METHODS: The study sample comprised two groups, subdivided according to the direction of incisor movement achieved during orthodontic treatment: the retraction group (Group 1), made up of 41 patients in which the maxillary incisor had been moved in a palatal direction (palatal tipping); and the protraction group (Group 2), composed of 51 patients who had undergone labial movement of the upper incisors (labial tipping). In order to evaluate the mean changes in lower lip position, and consequent alterations in the quality of the patients' profiles, between T1 (prior to orthodontic displacement of the incisors) and T2 (following treatment), the following parameters were measured on lateral head film X rays: variation in lower lip vermilion thickness (dLVT); variation in lower lip sulcus depth (dLLSD); variation in lower vermilion height (dLVH); variation in exposure of the upper and lower incisors in relation to the lower stomion (dIs-STOi and dIi-STOi, respectively); variation in upper and lower incisor tipping with respect to the palatal plane (d1/PP and dinf1/PP); and variation in lower facial height (dLFH). RESULTS: Assessment of the changes due to incisor translocation revealed significant differences between Group 1 and Group 2 in all lower lip soft tissue parameters, except for dLVT, dLVH and dIi-STOi. Furthermore, using multiple linear regression analysis to predict the behaviour of the dependent (cutaneous) lower lip variables, a good coefficient of determination (r-square) value was only obtained for the horizontal variation of the labrale inferius point (dxLi), found to be dependent on horizontal movement of the upper and lower incisors (dxIs and dxIi) and thickness of the lower vermilion (LVT). CONCLUSIONS: The results of this study highlight great variability among the patients studied, and suggest that the behaviour of the soft tissues (lower lip changes) following displacement of the upper and lower incisors is multifactorial and very difficult to predict.

LED vs halogen light-curing of adhesive-precoated brackets.

OBJECTIVE: To test the hypothesis that bonding with a blue light-emitting diode (LED) curing unit produces no more failures in adhesive-precoated (APC) orthodontic brackets than bonding carried out by a conventional halogen lamp. MATERIALS AND METHODS: Sixty-five patients were selected for this randomized clinical trial, in which a total of 1152 stainless steel APC brackets were employed. In order to carry out a valid comparison of the bracket failure rate following use of each type of curing unit, each patient's mouth was divided into four quadrants. In 34 of the randomly selected patients, designated group A, the APC brackets of the right maxillary and left mandibular quadrants were bonded using a halogen light, while the remaining quadrants were treated with an LED curing unit. In the other 31 patients, designated group B, halogen light was used to cure the left maxillary and right mandibular quadrants, whereas the APC brackets in the remaining quadrants were bonded using an LED dental curing light. The bonding date, the type of light used for curing, and the date of any bracket failures over a mean period of 8.9 months were recorded for each bracket and, subsequently, the chi-square test, the Yates-corrected chi-square test, the Fisher exact test, Kaplan-Meier survival estimates, and the log-rank test were employed in statistical analyses of the results. RESULTS: No statistically significant difference in bond failure rate was found between APC brackets bonded with the halogen light-curing unit and those cured with LED light. However, significantly fewer bonding failures were noted in the maxillary arch (1.67%) than in the mandibular arch (4.35%) after each light-curing technique. CONCLUSIONS: The hypothesis cannot be rejected since use of an LED curing unit produces similar APC bracket failure rates to use of conventional halogen light, with the advantage of a far shorter curing time (10 seconds).

Upper lip changes correlated with maxillary incisor movement in 65 orthodontically treated adult patients.

AIM: To describe the behavior of the upper lip components following orthodontically induced movement of the maxillary incisor in a sample of 65 adults. METHODS: The study sample was divided into 2 groups: the retraction group, made up of 35 patients in whom the incisor had been moved in a palatal direction (tipping), and the protraction group, consisting of 30 patients who had undergone labial movement of the incisor (tipping). To evaluate the mean changes in lip position and quality of the patients' profiles between T1 (before movement of the incisor) and T2 (after movement of the incisor), we measured the following parameters: variation in upper lip thickness (DUVT), variation in the depth of the labial sulcus (DULSD), variation in vermillion height (DUVH), variation in upper lip length (DULL), variation in maxillary incisor exposure (DIs-STOs), and DSTOs and STOi, which indicate a variation in the gap between the lips. RESULTS: In the retraction group, all soft tissue parameters showed significant changes at T2, except for DUVT and DULL, while in the protraction group, the significance of the mean changes was decidedly lower and resulted higher for only DULSD and DUVT. Nevertheless, multiple linear regression analysis highlighted the unfeasibility of predicting the behavior of the dependent (cutaneous) variables except for DUVH and DULSD in the protraction group. CONCLUSION: The results obtained highlight a pronounced variability among the patients studied and the impossibility of accurately predicting the behavior of the soft tissues following movement of maxillary incisors.