Changes in third molar position after Class II subdivision malocclusion treatment with asymmetric extractions.

INTRODUCTION: This study aimed to assess the changes in third molars angulation and their available space after Class II subdivision malocclusion treatment with asymmetric premolar extractions. METHODS: The sample consisted of 37 patients (17 male, 20 female and mean age 13.18 ± 1.99 years) in group 1 (Type 1 Class II subdivision) and 25 (10 male, 15 female, mean age 13.56 ± 2.46 years) in group 2 (Type 2 Class II subdivision). In group 1, extractions were performed in the two maxillary quadrants and in the Class I mandibular quadrant. In group 2, extraction was performed in the Class II maxillary quadrant. Panoramic radiographs were used to evaluate third molar angulations and their available space pre- and post-treatment. Radiographic measurements were performed with Dolphin® Imaging 11.9. Paired t tests were used for intragroup comparison between stages and sides. RESULTS: In Type 1, there were similar improvements in third molar angulations and increases in the space available on the extraction quadrants in the maxillary arch. In the mandibular arch, there was significantly greater improvement in angulation and greater space availability in the extraction quadrant after treatment. In Type 2, there was significantly greater improvement in angulation and available space for the maxillary third molar on the extraction quadrant. In the mandibular arch, there was a similar improvement in the available space for the third molars. CONCLUSIONS: After treatment, both groups presented better angulation and significantly greater space for third molar eruptions on the extraction quadrants, when compared to the homologous non-extraction quadrants.

Permanent canine eruption into the alveolar cleft region after secondary alveolar bone grafting: Are there prediction factors for impaction?

INTRODUCTION: The aims of this study were to investigate the eruption pattern of maxillary permanent canines in the alveolar cleft area after secondary alveolar bone grafting and to assess the risk indicators for canine impaction. METHODS: The sample consisted of 75 patients with unilateral cleft lip and palate who underwent secondary alveolar bone grafting with rhBMP-2 with a mean age of 9.8 years of age at 1 center. A split-mouth study design was used, with the noncleft hemiarch comprising the control group. Panoramic radiographs taken before, immediately after, and 1 year after secondary alveolar bone grafting were used to assess the following parameters in both cleft side (CS) and noncleft side: canine mesiodistal angulation, canine height relative to the occlusal plane, canine mesial displacement, and superimposition with the neighboring maxillary incisors. The frequency of associated dental anomalies was compared between patients with and without CS canine impaction. Data were evaluated using analysis of variance, t tests, Fisher tests, and multiple logistic regression analysis (P <0.05). RESULTS: On the CS, maxillary canines were usually more mesially angulated and more distant from the occlusal plane compared with the noncleft side. The prevalences of canine impaction on the CS and noncleft side were 24% and 1.3%, respectively. Maxillary impacted canines on the CS demonstrated increased mesiodistal angulation and height at all time points. No association between CS canine impaction and mesial displacement (sectors) was found. An increased prevalence of lateral incisor agenesis on the CS was observed in the subgroup with canine impaction. CONCLUSIONS: Increased mesial angulation and lateral incisor agenesis on the CS are early risk indicators for maxillary canine impaction in patients with unilateral cleft lip and palate.

Comparison of two treatment protocols in children with unilateral complete cleft lip and palate: Tridimensional evaluation of the maxillary dental arch.

OBJECTIVE: The aim of this study was to evaluate the dimensional alterations of the maxillary dental arches after lip repair in children with unilateral complete cleft lip and palate of two different protocols. MATERIAL AND METHODS: The sample was composed of 94 digital models and divided in two groups: Group I - 23 children, (protocol 1) - with presurgical orthopedic intervention: Hotz plate; Group II - 24 children, (protocol 2) - without presurgical orthopedic intervention. The three dimensional images of the maxillary arch were obtained before lip repair (stage 1) and at approximately 1 year of age (stage 2). Interstages changes for each group were evaluated using dependent t test and Wilcoxon test, and in the intergroup were used independent t test, and Mann-Whitney test. RESULTS: The comparison of the dimensional alterations of dental arches between the two protocols exhibited differences: in the stage 1, the intercanine was smaller in Group II; in the stage 2, the anterior cleft width, the intercanine and the anteroposterior cleft were smaller in Group II. CONCLUSION: The results reported here suggest that the use of infant orthopedic plate as applied in protocol 1 may favor correct arch form establishment in infants with unilateral complete cleft lip and palate.