Graziano Montaruli

Post-orthodontic position of lower incisors and gingival recession: A retrospective study

Background To evaluate if changes in lower incisor position following orthodontic treatment are correlated with development of gingival recessions. Material and Methods Pre- and post-treatment digital models and lateral cephalograms of 22 subjects were collected retrospectively. The clinical crown length, gingival scallop, and papilla height of the central lower incisor were measured along with the cephalometric incisor’s inclination, the distance from the mandibular plane, and the distance between the Infradentale and Menton points. Statistical correlations between gingival and cephalometric variables were studied. In addition, two groups were defined based on the post-treatment incisor inclination value (‘normal’ or ‘proclined’) and compared. Results The incisor inclination was correlated with the change in gingival scallop and papilla height. Moreover, there was a statistically significant difference in clinical crown height and gingival scallop between the ‘normal’ group and the ‘proclined’ group. Conclusions Changes in lower incisor position, especially an excessive proclination, after orthodontic treatment may play a role in the development of gingival recession. Key words:Orthodontic treatment, Incisor inclination, IMPA, Gingival recession, Alveolar bone.

Effects of crown movement on periodontal biotype: a digital analysis

Orthodontic treatment has important correlations with periodontal changes. Various mechanical and biological factors are involved in determining such changes, but anatomical and morphological variables, generally addressed as periodontal biotype, play a key role. In measurement of such modifications, digital and non-contact reverse engineering technologies may be of tremendous advantage. The aim of this study is to retrospectively evaluate, in a series of digitized dental casts, some of the parameters addressing periodontal biotype and correlate them to extent and direction of tooth movement. Pre- (T0) and post-treatment (T1) dental casts of 22 patients were scanned by 3Shape TRIOS 3® scanner. A number of variables (crown ratio, gingival margin position, gingival contour, papillae position, gingival scallop) were investigated and their variations calculated after digital measurements on single casts at T0 and T1, or after direct measurement (T1 vs T0) on the superimposition and alignment of digital models. Univariate and multivariate statistics were then performed. No significant correlation was detected between the sagittal or vertical movement of dental crown and displacement of the gingival margin. On the other hand, vestibular gingival contour resulted significantly altered by vestibular and extrusion movements. Further studies are needed to ascertain the differential effect of bone and soft tissue on such modifications. The relationship between orthodontic treatment and the periodontium overcomes the consideration of gingival recession and includes all the concepts of periodontal biotype with its characteristics. Digital technologies and non-contact reverse engineering techniques now available have the potential to allow a more precise definition of such a relationship.

Non-surgical Treatment of Condylar Fracture in an 11-Year-Old Patient: a Case Report

ABSTRACT Background Mandibular condylar fractures commonly occur after trauma and account for 25 to 35% of all mandibular fractures; its appropriate therapy still remains a point of controversy in children. The purpose of this paper is to describe the treatment of an 11-years-old male patient affected by neck-condylar fracture as result of trauma in evolutive age. Methods No surgical treatment was performed. A functional therapy was applied with a jaw splint. A closed treatment for mandibular condyle fractures was preferred because the amount of condylar displacement wasn’t considerable. Results The early treatment with functional therapy generated a functional adaptation of the condyle in the glenoid fossa and a normal mandibular function. After a 12-month follow-up the fracture resolution and an optimal condylar position were recorded. Conclusions The current case report and literature review showed that non-surgical therapy of neck-condylar fracture in a child with lower resin splint can restore mandibular movements and aesthetics. Facial growth after one year treatment resulted normal. A conservative treatment may be appropriate for children in selected cases with minimally displaced condyle.

Determinants of maxillary canine impaction: Retrospective clinical and radiographic study

Background The aim of this study is to evaluate determinants of maxillary canine impaction taking into account both canine position related variables and the pattern of facial growth. Material and Methods A retrospective clinical and radiographic analysis was carried out on 109 patients aged between 9 and 10 years at the time of first evaluation. At baseline, SN-GoMe angle, the interincisal angle, the canine angle α and the canine distance d were used to characterize canine location and vertical facial growth. At the end of a two years follow up period the eruption state of each canine of each patient was recorded and accordingly classified as erupted or impacted on a clinical and radiographic basis. Univariate and multivariate statistical analyses were performed, including correlation among the studied variables and principal components analysis; several machine learning methods were also used in order to built a predictive model. Results At the end of the two years follow up period after the first examination, 54 (24.77%) canines were classified as impacted. Except for Angle α values, there were no statistically significant differences between impacted and erupted canines. The studied variables were not significantly correlated, except for the SN-GoMe Angle and the distance d in the impacted canine group and the angle α and the distance d in erupted canines group. All variables, except for SN-GoMe Angle in erupted canines, have a partial communality with the first two principal components greater than 50%. Among the learning machine methods tested to classify data, the best performance was obtained by the random forest method, with an overall accuracy in predicting canine eruption of 88.3%. Conclusions The studied determinants are easy to perform measurements on 2D routinely executed radiographic images; they seems independently related to canine impaction and have reliable accuracy in predicting maxillary canine eruption. Key words:Canine impaction, Determinants, Facial growth.

Peri-Implant Bone Level Stability With and Without Platform Switching: A Six-Years Follow-Up Case

Purpose : The aim of this case is the long-term, clinical and radiographical, evaluation of bone resorption around implants rehabilitated with and without the platform switching. Materials and Methods : Two implants with external connection were placed in a 41 years old healthy woman in order to replace the upper right first molar and the upper right first premolar. The implant replacing the upper right first molar was managed, for both the healing screw and the final prosthesis, according to the platform switching paradigm (i.e. the healing screw and the final abutment were 1 mm narrower than the implant platform diameter), whereas for the other implant no platform switching was performed. The measurements of bone levels were carried out on intraoral radiographs, taken at 12 and 72 months after implant loading, using AutoCAD software on both the mesial and the distal aspect of each implant. Results : The bone loss around the implant with platform switching was, on average, 0.1 and 0.18 at 1 year and 6 years after loading, respectively; whereas, bone resorption around the implant without platform switching was, on average, 1.15 and 1.98 at 1 year and 6 years, respectively. Conclusions : Within the limits of the present study, the results obtained demonstrate that the platform switching can reduce peri-implant bone resorption by increasing long-term predictability of dental implants.