Cristina Grippaudo

Relationship between vertical facial patterns and dental arch form in class II malocclusion

BackgroundThe purpose of this study is to evaluate the relationship between dental arch form and the vertical facial pattern determined by the angle between the mandibular plane and the anterior cranial base (Sella-nasion/mandibular plane angle (SN-MP)) in skeletal class II untreated patients.MethodsA sample of 73 Caucasians patients with untreated skeletal class II in permanent dentition was divided into three groups according to the values of the angle SN-MP. An evaluation of the arch form was performed by angular and linear relation values on each patient. Regression analysis was used to determine the statistical significance of the relationships between SN-MP angle and dental arch form. The differences among the three groups were analyzed for significance using a variance analysis.ResultsA decrease of the upper arch transversal diameters in high SN-MP angle patients and an increase in low angle SN-MP ones (P < 0.05) were shown. Result analysis showed a change in upper arch shape, with a smaller intercanine width in patients with high SN-MP angle and a greater one in low angle patients. As SN-MP angle increased, the upper arch form tended to be narrower. No statistically significant difference in mandibular arch form among the three groups was found, except the angle value related to incisors position.ConclusionsThe results showed the association between the upper dental arch form and the vertical facial pattern. On the contrary, the lower arch form was not related to the mandibular divergence.

Comparison between different interdental stripping methods and evaluation of abrasive strips: SEM analysis

OBJECTIVES The aim of this study was to evaluate the morphological effects and the surface irregularities produced by different methods of mechanical stripping (abrasive strips and burs) and chemical stripping (37% orthophosphoric acid) and the surface changes following the finishing procedures (polishing strips) or the subsequent application of sealants, in order to establish the right stripping method that can guarantee the smoothest surface. We have also analysed the level of wear on the different abrasive strips employed, according to their structure. MATERIALS AND METHODS 160 proximal surfaces of 80 sound molar teeth extracted for orthodontic and periodontal reasons, were divided into: 1 control group with non-treated enamel proximal surfaces and 5 different groups according to the stripping method used, were observed with scanning electron microscopy (SEM). Each one of the 5 treated groups was also divided into 3 different subgroups according to the finishing procedures or the subsequent application of sealants. RESULTS The finishing stage following the manual reduction proves to be fundamental in reducing the number and depth of grooves created by the stripping. After the air rotor stripping method, the use of sealants is advised in order to obtain a smoother surface. The analysis of the combinations of mechanical and chemical stripping showed unsatisfactory results. Concerning the wear of the strips, we have highlighted a different abrasion degree for the different types of strips analysed with SEM. CONCLUSIONS The enamel damages are limited only if the finishing procedure is applied, independently of the type of abrasive strip employed. It would be advisable, though clinically seldom possible, the use of sealants after the air rotor stripping technique.

Association between oral habits, mouth breathing and malocclusion

SUMMARY The ratio of bad habits, mouth breathing and malocclusion is an important issue in view of prevention and early treatment of disorders of the craniofacial growth. While bad habits can interfere with the position of the teeth and normal pattern of skeletal growth, on the other hand obstruction of the upper airway, resulting in mouth breathing, changes the pattern of craniofacial growth causing malocclusion. Our crosssectional study, carried out on 3017 children using the ROMA index, was developed to verify if there was a significant correlation between bad habits/mouth breathing and malocclusion. The results showed that an increase in the degree of the index increases the prevalence of bad habits and mouth breathing, meaning that these factors are associated with more severe malocclusions. Moreover, we found a significant association of bad habits with increased overjet and openbite, while no association was found with crossbite. Additionally, we found that mouth breathing is closely related to increased overjet, reduced overjet, anterior or posterior crossbite, openbite and displacement of contact points. Therefore, it is necessary to intervene early on these aetiological factors of malocclusion to prevent its development or worsening and, if already developed, correct it by early orthodontic treatment to promote eugnatic skeletal growth.

BaS analysis: a new cephalometric study for craniofacial malformations

ObjectPatients submitted to surgical advancement of the upper and middle facial third might have a relapse of the skeletal retraction after the removal of the distractor devices. Clinical signs related to this process are usually represented by exophthalmos, Obstructive sleep apnea syndrome (OSAS) or prognathism; however, the analytic definition of the relapse is very difficult , conventional cephalometric methods being influenced by the spatial movement of “N” (nasion) or “Or” (orbital) points. The authors present a new cephalometric technique that could be used as a more objective mean of follow-up evaluation of patients undergoing craniofacial advancement.Materials and methodsThe cephalometric analysis proposed is based on angles, lines, areas and distances between BaS (Basion-Sella) axis and other craniofacial landmark points. We have defined this cephalometric technique as “BaS Analysis”.ConclusionThe “BaS analysis” is not influenced by splanchnocranium movements in the space; for this reason, it can be considered a useful method for cephalometric analysis in the follow-up of patients with craniofacial malformations.

Three-Dimensional Analysis and Treatment Planning of Hemimandibular Hyperplasia

IntroductionThe advent of computed tomography (CT) provided a useful instrument for diagnosis and surgical treatment of patients with craniofacial malformations. The development of software for three-dimensional graphic simulation applied to CT scan has made possible the three-dimensional computerized analysis, surgical planning, and simulation. This kind of analysis is particularly useful in case of complex facial malformations, making reliable a surgical treatment in 1 step. The purpose of this report was to present the diagnosis and treatment planning on a patient with hemimandibular hyperplasia by three-dimensional cephalometric analysis. MethodsA 20-year-old young woman who presented with hemimandibular hyperplasia was investigated with CT scan and plaster cast mounted on an articulator; a two-dimensional manual and computerized cephalometric analysis was also developed on frontal and lateral cephalograms. Images in DICOM format were processed on a PC by means of commercial software, thus obtaining the three-dimensional reconstruction of the skeletal structures. ResultsThree-dimensional CT permits to program skeletal corrections and to foresee surgical outcomes with adequate realism. Surgical planning based on three-dimensional CT makes it easy and reliable to achieve the correction of the malformation in a single surgical intervention. ConclusionsThe virtual three-dimensional CT model, a versatile diagnostic aid, has proven to be effective in the exact reproduction of bone and soft tissue anatomy, thus helping in the diagnosis, surgical planning, and simulations. Three-dimensional analysis is particularly indicated in case of complex asymmetric malformations, in which the more accurate reproduction of the individual anatomy can be very useful in implementing surgical results.

Comparing orthodontic treatment need indexes

Background : Orthodontic Treatment Need Indexes are investigated to evaluate their validity criteria and their formulation on a scientific basis. Methods : A bibliographic research was performed on Medline Database to find articles about orthodontic treatment need indexes published from 1960 to 2007. English language papers about criteria to establish indexes, their validity and reproducibility, and comparing two or more indexes were chosen. Results : The study shows that orthodontic treatment need indexes are not based on evidence but are all based on the opinion of experts, although widely shared by the orthodontic community since the use of these indexes in clinical practice. The validity is assessed in terms of objectivity of the measurements needed to evaluate the clinical severity of the case under consideration. In this case, the quantitative methods seem to be more reliable and objective than the qualitative. Conclusions : Currently in the orthodontic field the theory that orthodontic therapy is useful to prevent any disease in the patients is not supported by evidence based medicine. The recommendations about orthodontic treatment need should come from scientific debates, in order to support consensus based decisions.

The role of masseter muscle EMG during DISE to predict the effectiveness of MAD: preliminary results

SUMMARY The use of a mandibular advancement device (MAD) increases the activity of the temporo-mandibular (TM) complex and masseter (MM) muscles with the risk of reducing treatment compliance. Predictors of treatment outcome are of importance in selecting patients who might benefit from MAD without side effects. The role of mandibular advancement (MA) during drug-induced sleep endoscopy (DISE) is controversial. In three cases (BMI < 30) affected by non-severe OSAS (AHI < 30 e/h), we recorded the surface EMG signal of MM activity during DISE. At follow-up all cases improved the AHI, two cases that showed transient increase of MM activity did not suffer from changes of overjet and did not complain of discomfort with the use of MAD. The case that showed a continuing increase of MM activity reported TM discomfort without changes of dental occlusion. EMG of MM during DISE may contribute to ameliorate the selection of cases amenable to treatment with MAD.

Three-dimensional analysis of dental arch forms in Italian population

BackgroundThe aim of this study was the comparison of male and female upper and lower dental arch form in untreated Italian patients by 3D analysis, to find differences in shape, in transversal and longitudinal diameters between sexes, and to give a representative set of population’s dental arch to clinicians in order to provide suitable orthodontic treatment.MethodsThe sample consisted of 3D scans of dental casts deriving from 104 Italian untreated patients (Male = 35, Female = 69) in permanent dentition. An evaluation of the arch form was performed by angular and linear values on every patient using a 3D software (SolidWorks®). A Student’s two-tailed t test was used to determine if the differences in measurements between the male and female groups were significant and the level of significance was set at P < 0.05.ResultsStatistically significant differences in upper and lower transversal and longitudinal diameters were found. Male arch widths were significantly larger than those of females. Male intercanine, intermolar, and interpremolar diameters were significantly greater than females. Dental arch depth was significantly smaller in the female group. Anterior upper dental arch form was flatter, wider, and less sharp in the female group.ConclusionsBasing on the anatomical arches differences found between sexes concerning Italian patients, it is suggested to have regard to each patient pre-treatment arch form, width, and depth during orthodontic treatment according to gender.

Comparison between Two Radiological Methods for Assessment of Tooth Root Resorption: An In Vitro Study

Purpose This study aims to verify the validity of the radiographic image and the most effective radiological techniques for the diagnosis of root resorption to prevent, cure, and reduce it and to verify if radiological images can be helpful in medical and legal situations. Methods 19 dental elements without root resorption extracted from several patients were examined: endooral and panoramic radiographs were performed, with traditional and digital methods. Then the root of each tooth was dipped into 3-4 mm of 10% nitric acid for 24 hours to simulate the resorption of the root and later submitted again to radiological examinations and measurements using the same criteria and methods. Results For teeth with root resorption the real measurements and the values obtained with endooral techniques and digital sensors are almost the same, while image values obtained by panoramic radiographs are more distorted than the real ones. Conclusions Panoramic radiographs are not useful for the diagnosis of root resorption. The endooral examination is, in medical and legal fields, the most valid and objective instrument to detect root resorption. Although the literature suggests that CBCT is a reliable tool in detecting root resorption defects, the increased radiation dosage and expense and the limited availability of CBCT in most clinical settings accentuate the outcome of this study.

Surgical Orthodontic Treatment of a Patient Affected by Type 1 Myotonic Dystrophy (Steinert Syndrome)

Myotonic dystrophy, or Steinerts disease, is the most common form of muscular dystrophy that occurs in adults. This multisystemic form involves the skeletal muscles but affects also the eye, the endocrine system, the central nervous system, and the cardiac system. The weakness of the facial muscles causes a characteristic facial appearance frequently associated with malocclusions. Young people with myotonic dystrophy, who also have severe malocclusions, have bad oral functions such as chewing, breathing, and phonation. We present a case report of a 15-year-old boy with anterior open bite, upper and lower dental crowding, bilateral crossbite, and constriction of the upper jaw with a high and narrow palate. The patients need was to improve his quality of life. Because of the severity of skeletal malocclusion, it was necessary to schedule a combined orthodontic and surgical therapy in order to achieve the highest aesthetic and functional result. Although therapy caused an improvement in patients quality of life, the clinical management of the case was hard. The article shows a balance between costs and benefits of a therapy that challenges the nature of the main problem of the patient, and it is useful to identify the most appropriate course of treatment for similar cases.