Isabella Tollaro

Skeletal effects of early treatment of Class III malocclusion with maxillary expansion and face-mask therapy

The effectiveness of maxillary expansion and face-mask therapy in children with Class III malocclusion was studied in a sample of 46 subjects in mixed dentition and compared with a control sample of 32 subjects with untreated Class III malocclusion. Treated and untreated samples were divided into early and late mixed-dentition groups to aid identification of the optimum timing of the orthopedic treatment of the underlying skeletal disharmony. Cephalometric analysis was based on a stable basicranial reference system, appropriate for longitudinal studies started in the early developmental ages. The level of significance for intergroup comparisons was set at a p value of 0.01. Significant forward displacement of the maxillary complex was found in the early-treatment group. The region of the pterygomaxillary suture, in particular, showed significant changes in the subjects treated during early mixed dentition. No significant maxillary modifications were recorded in the late-treatment group. Both early and late groups exhibited smaller increments in mandibular protrusion and larger increments in the intermaxillary vertical relationship compared with their respective Class III control groups. Only children treated at an early age, however, showed a significant upward and forward direction of condylar growth, leading to smaller increments in total mandibular length. These results indicate that the combination of a bonded maxillary expander and face-mask therapy is more effective in early mixed dentition than in late mixed dentition, especially with regard to the magnitude of the protraction effects on maxillary structures.

Early dentofacial features of Class II malocclusion: A longitudinal study from the deciduous through the mixed dentition☆☆☆★★★♢♢♢

A group of 25 untreated subjects with Class II malocclusion in the deciduous dentition (featuring the concomitant presence of distal step, Class II deciduous canine relationship, and excessive overjet) was compared with a control group of 22 untreated subjects with ideal occlusion (flush terminal plane, Class I deciduous canine relationship, minimal overbite, and overjet) at the same dentitional stage. The subjects were monitored during a 2 1/2-year period in the transition from the deciduous to the mixed dentition, during which time no orthodontic treatment was provided. Occlusal analysis of the Class II group in the deciduous dentition revealed an average interarch transverse discrepancy due to a narrow maxillary arch relative to the mandible. All occlusal Class II features were maintained or became exaggerated during the transition to the mixed dentition. The skeletal pattern of Class II malocclusion in the deciduous dentition typically was characterized by significant mandibular skeletal retrusion and mandibular size deficiency. During the period examined, cephalometric changes consisted of significantly greater maxillary growth increments and smaller increments in mandibular dimensions in the Class II sample. Moreover, a greater downward and backward inclination of the condylar axis relative to the mandibular line, with consequent smaller decrements in the gonial angle, were found in the Class II group, an indication of posterior morphogenetic rotation of the mandible in patients with Class II malocclusion occurring during the period examined. The results of this study indicate that the clinical signs of Class II malocclusion are evident in the deciduous dentition and persist into the mixed dentition. Whereas treatment to correct the Class II problem can be initiated in all three planes of space (e.g., RME, extraoral traction, functional jaw orthopedics), other factors such as patient cooperation and management must also be taken into consideration before early treatment is started.

Role of posterior transverse interarch discrepancy in Class II, Division 1 malocclusion during the mixed dentition phase

Posterior transverse interarch discrepancy (PTID), measured as the difference between the maxillary and mandibular intermolar widths, was investigated in a sample of 60 Class II, Division 1 subjects during the mixed dentition phase. Two main groups were detected: Class II group 1 (30 subjects) with PTID and Class II group 2 (30 subjects) without PTID. A sample of 30 Class I subjects in the mixed dentition phase was used as a control group. In Class II group 1, PTID was found to be due to a significantly narrower maxillary arch. The craniofacial skeletal features of both Class II groups and of the Class I group were assessed. The Class II group with PTID showed mandibular retrusion associated with a posteriorly displaced mandible of normal size (functional mandibular retrusion). The Class II group without PTID had mandibular retrusion due to a micrognathic mandible (anatomic mandibular retrusion). The relevance of these findings for treatment planning in Class II, Division 1 malocclusion in the mixed dentition was stressed.

Craniofacial changes induced by early functional treatment of Class III malocclusion

To evaluate the effects of a functional appliance (removable mandibular retractor) on the craniofacial skeleton in children with Class II malocclusions, a longitudinal cephalometric study was performed. A sample of 30 children with treated Class III malocclusions (18 boys, 12 girls, mean age at the first observation 5.64 +/- 1.01 years, mean age at the second observation 8.43 +/- 1.73 years) was compared to a sample of 30 children with untreated Class III malocclusions (13 boys, 17 girls, mean age at first observation 6.06 +/- 1.14 years, mean age at the second observation 8.45 +/- 1.79 years) used as controls. The treated group matched the control group as to sex, age at the first observation, age at the second observation, observation period, Class III occlusal signs, and also as to angular craniofacial dimensions at the first observation. A cephalometric analysis based on a stable basicranial reference system was applied. The main significant findings in the treated group were an anterior morphogenetic rotation of the mandible as a result of an upward-forward direction of condylar growth, a more vertical orientation of the ramus, and a reduced gonial angle; reduced mandibular protrusion and total length; increased maxillary protrusion; increased maxillary dentoalveolar protrusion and reduced mandibular dentoalveolar protrusion. No significant changes in the vertical craniofacial relationships and in cranial base angulation were observed. The role of an early correction of Class III occlusal relationship in the establishment of a more favorable craniofacial growth pattern was discussed.

Mandibular skeletal changes induced by early functional treatment of Class III maloccsion: A superimposition study

A superimposition study on mandibular stable structures was performed to evaluate changes in mandibular rotation and in the direction of condylar growth induced by early treatment of Class III malocclusion by a functional appliance (removable mandibular retractor). A sample of 18 children with treated Class III malocclusions, mean age at the first observation (immediately before the beginning of treatment) 5.47 +/- 1.14 years, mean age at the second observation 8 +/- 1.29 years, mean observation period 2.5 +/- 0.9 years, was compared with a control group of 18 children with untreated Class III malocclusions, mean age at the first observation 5.72 +/- 1.11 years, mean age at the second observation 7.86 +/- 1.44 years, mean observation period 2.27 +/- 0.92 years. No statistically significant difference between the two groups was recorded for positional (total) rotation of the mandible. A significant upward-forward direction of condylar growth was assessed in the treated group (p < 0.001). This therapeutically induced change in growth direction of the mandibular condyle was considered a skeletal sign of anterior morphogenetic rotation of the mandible, i.e., a mechanism compensating for excessive mandibular growth.

PREDICTIVE VARIABLES FOR THE OUTCOME OF EARLY FUNCTIONAL TREATMENT OF CLASS III MALOCCLUSION

The aim of this study was to select a model of cephalometric and occlusal predictive variables for the results of early treatment of Class III malocclusion, due to mandibular protrusion in the deciduous dentition. Lateral cephalograms and dental casts of 45 subjects (22 boys and 23 girls) with Class III malocclusion in the deciduous dentition were analyzed at the start of treatment (mean age 5.57 +/- 0.85 years). The patients were treated with a functional appliance (removable mandibular retractor). All subjects were reevaluated after a mean period of 9.54 +/- 2.28 years comprising active treatment plus retention. At this time, the sample was divided into two groups according to occlusal criteria: successful group (23 subjects) and unsuccessful group (22 subjects). Stepwise variable selection on the measurements at the time of first observation identified three predictive variables; the inclination of the condylar axis in relation to the stable basicranial line (CondAx-SBL), the inclination of the nasal line to the mandibular line (NL-ML), and the transverse width of the mandibular arch measured at the first deciduous molars. Discriminant analysis assigned a classificative power of 95.55% to the predictive model. On the basis of the equation generated by the multivariate statistical method, outcome of early treatment for each new case with Class III malocclusion in the deciduous dentition can be accordingly predicted. The important role of both vertical and transverse relationships in Class III prognosis was emphasized.

Floating norms for the assessment of craniofacial pattern in the deciduous dentition

This study provides norms for the evaluation of individual skeletal patterns in subjects with full deciduous dentition. The method is based on the associations among correlated craniofacial measurements (S-N-A, S-N-B, NL-NSL, ML-NSL, N-S-Ba). The results are given in a graphical box-like form (floating norms). An easy practical procedure allows identification of either individual harmonious craniofacial features or anomalous deviations from the individual norm. The use of cephalometric floating norms in the deciduous dentition phase is strongly recommended for early diagnosis and treatment planning.

Tooth wear in the mixed dentition: a comparative study between children born in the 1950s and the 1990s.

The aim of this study was to evaluate the degree of tooth wear in posterior deciduous teeth of 100 subjects in the second phase of mixed dentition who were born in the 1950s (50sG) and 100 subjects born in the 1990s (90sG). The degree of abrasion for each posterior deciduous tooth was scored ranging from 0 to 3. The comparison of the degree of abrasion showed significant differences between the two groups for all examined teeth (upper and lower deciduous canines and first and second primary molars) all of which appeared to be more abraded in the 50sG. The findings of the present study indicate that subjects who were born in the 1950s exhibited a significantly greater degree of tooth wear on the posterior deciduous teeth when compared with contemporary subjects, along with a well-recognized lower prevalence of malocclusions. Changes in dietary habits and a diet based on processed foods may be postulated as factors involved with a decrease of dental attrition in contemporary populations. An increase in the prevalence of mouth breathing (tested in the present study) appears to be associated with a decrease in tooth wear in the contemporary population as well.

Biometric and magnetic resonance imaging assessment of dentofacial abnormalities in a case of Klippel-Trénaunay-Weber syndrome

Klippel-Trénaunay-Weber syndrome is characterized by cutaneous hemangioma, arteriovenous fistulas or varicosities (or both), and unilateral hypertrophy of hard and soft tissues with different localization. Klippel-Trénaunay-Weber syndrome represents a syndrome of interest for those in the fields of oral and maxillofacial radiology and pathology because of the high incidence of compromise of the orofacial area in affected patients. The patient reported here presents with all of the 3 characteristic signs of the syndrome. The somatic and facial hypertrophy is contralateral to angiomata. As revealed through the use of magnetic resonance imaging, the primary component of facial hypertrophy is adipic subcutaneous tissue. Statistical analysis of the dental dimensions revealed that teeth on the hypertrophic side are significantly larger than normal.

Dental anomalies in the primary dentition and their repetition in the permanent dentition: a diagnostic performance study

This study investigated the recurrence in the permanent dentition of dental anomalies of the primary dentition. A sample of 189 subjects (100 males, 89 females, mean age of 5xa0years and 7xa0months) with anomalies of primary teeth (tooth hypodontia, supernumerary teeth, geminated teeth, and fused teeth) was selected and re-analyzed at a mean age of 11xa0years and 2xa0months for the recurrence of the dental anomalies in the permanent dentition. As a control group, 271 subjects (123 males, 148 females) without dental anomalies in the primary dentition were selected. The recurrence in the permanent dentition of the dental anomalies in the primary dentition was evaluated by measures of diagnostic performance. The results showed high values for the repetition of hypodontia (positive likelihood ratioxa0=xa0102.0); low score for the repetition of hyperdontia (positive likelihood ratioxa0=xa06.5); low positive likelihood ratio (9.1) for gemination of primary teeth resulting in supernumerary permanent teeth; high positive likelihood ratio (47.0) for fusion of primary teeth followed by missing permanent teeth. Dental anomalies in the primary dentition are associated with an increased likelihood of anomalies of the succedaneous permanent.