Calogero Dolce

Comparison of peer assessment ratings (PAR) from 1-phase and 2-phase treatment protocols for class II malocclusions

The purpose of this study was to compare the dentoalveolar outcomes after 1-phase and 2-phase orthodontic treatment of Class II malocclusions. Class II subjects (n = 208) were randomized to 1-phase or 2-phase treatment with either bionator or headgear/biteplate. The peer assessment rating (PAR) was calculated from pretreatment, prephase 2, and final study models. Chi-square, Kruskal-Wallis, and Wilcoxon rank sum tests were used to evaluate the differences among treatment groups, sexes, races, pretreatment, mandibular plane angle, severity, and compliance. Spearman rank correlation coefficients were used to examine relationships between PAR at different times. The dropout rate of 24.6% did not adversely affect the ability to detect differences of clinical importance or impact treatment groups disproportionately. There were no significant differences with respect to initial PAR or final PAR among the 3 treatment protocols. The 2 early treatment groups had lower PAR scores than the 1-phase group before phase 2 (P =.0001). Lower PAR scores were achieved at both the beginning and end of phase 2 in girls (P =.03; P =.02, respectively). There were differences in the pre-phase-2 and post-phase-2 PAR scores based on initial severity (P =.0006; P =.02, respectively), with greater improvement in the patients whose malocclusions were less severe initially. Mandibular plane angle had no effect on pre-phase-2 or post-phase-2 PAR scores. These results do not support the hypothesis that different dentoalveolar outcomes are obtained between 2-phase and 1-phase treatment of Class II malocclusions.

Effects of Matrix Metalloproteinase Inhibitors on Bone Resorption and Orthodontic Tooth Movement

Matrix metalloproteinases are involved in the regulation of bone remodeling. The hypothesis that matrix metalloproteinase inhibitors may be useful for experimentally limiting orthodontic tooth movement, a process involving perturbations of normal bone remodeling, was tested. General matrix metalloproteinase inhibitors limited the resorption of bone slices by mouse marrow cultures stimulated by calcitriol, parathyroid hormone, and basic-fibroblast growth factor. Pre-coating dentin slices with short arginine-glycine aspartic acid (RGD) peptides, but not arginine-glycine-glutamic acid (RGE) controls, restored bone resorption in the presence of matrix metalloproteinase inhibitors. Orthodontic tooth movement was inhibited by local delivery of Ilomastat, a general matrix metalloproteinase inhibitor, with the use of ethylene-vinyl-acetate (ELVAX) 40, a non-biodegradable, non-inflammatory sustained-release polymer. This study shows that orthodontic tooth movement can be inhibited with the use of matrix metalloproteinase inhibitors, and suggests a mechanistic link between matrix metalloproteinase activity and the production of RGD peptides.

Technical factors accounting for stability of a bilateral sagittal split osteotomy advancementWire osteosynthesis versus rigid fixation

OBJECTIVE Relapse after bilateral sagittal split osteotomy has been attributed to various technical factors that are inherent in the surgical procedure. The purpose of this article was to analyze technical factors that predispose to relapse when wire or rigid fixation is used. STUDY DESIGN Patients were randomized to either rigid or wire osteosynthesis. Cephalometric radiographs were obtained and digitized at multiple time periods before and after surgery. Data were analyzed through use of 2-sample t tests and stepwise regression analyses. RESULTS Multivariate analysis indicated that the following factors correlated with relapse: initial advancement, change in ramus in inclination, change in the mandibular plane, and fixation type. CONCLUSIONS Relapse increased with the amount of initial advancement and, to a lesser extent, with control of the proximal segment and change in the mandibular plane. These factors are similar for wire osteosynthesis and rigid fixation.

Five-year outcome and predictability of soft tissue profiles when wire or rigid fixation is used in mandibular advancement surgery

The purpose of this study was to follow the covariation of hard and soft tissue changes in Class II malocclusion subjects who received a bilateral sagittal split osteotomy. The subjects were randomized to receive wire or rigid fixation after the surgery. Subjects in the rigid group (n = 78) received 2-mm bicortical position screws, and those in the wire group (n = 49) received inferior border wires and 6 weeks of skeletal intermaxillary fixation with 24-gauge wires. Additionally, some subjects received genioplasty in both the rigid (n = 35) and the wire groups (n = 24). Soft and hard tissue profile changes were obtained from cephalometric films immediately before surgery and at various times up to 5 years postsurgery. Soft and hard tissue profile changes were referenced to a cranial-base X-Y coordinate system. Horizontal changes in mandibular incisor, lower lip, B-point, soft tissue B-point, pogonion, and soft tissue pogonion were calculated at each time. There was considerable skeletal relapse in the wire fixation group. Bivariate correlations and ratios between the hard and soft tissue changes were calculated for each time period. Hard to soft tissue correlations were the highest at the earlier times, although the ratios varied among the 4 groups. These results provide a solid basis for both short-term and long-term prediction.

A comparative study of skeletal and dental stability between rigid and wire fixation for mandibular advancement.

This study examined the skeletal and dental stability after mandibular advancement surgery with rigid or wire fixation for up to 2 years after the surgery. Subjects for this multisite, prospective, randomized, clinical trial were assigned to receive rigid (n = 64) or wire (n = 63) fixation. The rigid cases received three 2-mm bicortical position screws bilaterally and elastics; the wire fixation subjects received inferior border wires and 6 weeks of skeletal maxillomandibular fixation with 24-gauge wires. Cephalometric films were obtained before surgery, and at 1 week, 8 weeks, 6 months, 1 year, and 2 years after surgery. Skeletal and dental changes were analyzed using the Johnstons analysis. Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean anterior advancement of the mandibular symphasis was 5.5 mm (SD, 3.2) in the rigid group and 5.6 mm (SD, 3.0) in the wire group. Two years after surgery, mandibular symphasis was unchanged in the rigid group, whereas the wire group had 26% of sagittal relapse. Dental compensation occurred to maintain the corrected occlusion, with the mandibular incisor moving forward in the wire group and posteriorly in the rigid group. However, at 2 years after surgery, when most subjects were without braces, the overjet and molar discrepancy had relapsed similarly in both groups.

Effects of surgical mandibular advancement and rotation on signs and symptoms of temporomandibular disorder: A 2-year follow-up study

INTRODUCTION The possible effects of orthognathic surgery on signs and symptoms of temporomandibular disorder (TMD) are still controversial. We prospectively investigated the association between the amount of advancement and rotation of the mandible during bilateral sagittal split osteotomy (BSSO) and the development of TMD signs and symptoms. METHODS Class II patients (n = 127) received mandibular advancement with BSSO. We used factorial analysis of covariance to assess whether the magnitude (< or > or = 7 mm) and the direction (clockwise or counterclockwise) of the movement were associated with the onset or worsening of TMD signs and symptoms during 2 years of follow-up. RESULTS Counterclockwise rotation of the mandible was associated with more muscle tenderness, especially in patients receiving long advancements. The combination of long advancement with counterclockwise rotation was also associated with increased joint symptoms. All symptoms declined over the 2-year follow-up period. CONCLUSIONS Counterclockwise rotation of the mandible is related to a slight increase in muscle symptoms after BSSO. The combination of counterclockwise rotation with long advancement also might increase joint signs and symptoms. All symptomatology tended to decline over time, suggesting that the amount of advancement and mandibular rotation should not be considered as risk factors for the development of TMD in patients without preexisting conditions.

Effect of early treatment on stability of occlusion in patients with Class II malocclusion

INTRODUCTION The purpose of this study was to evaluate the effect of early treatment on the stability of occlusion in patients with Class II malocclusions. The peer assessment rating (PAR) index was used to evaluate changes in occlusion after treatment of subjects treated in 1 phase or 2 phases. This study was a prospective, randomized, controlled clinical trial. METHODS Dental casts were obtained from the participants, who were randomized into 3 phase-1 early treatment groups: bionator, headgear/bite plane, or observation. Phase 2 consisted of continued treatment of the bionator and the headgear/biteplane subjects and comprehensive treatment of the observation subjects. PAR scores were obtained for 208 subjects at end of treatment; 173 (83%) had at least 1 follow-up visit, with a median follow-up time of 5.0 years. PAR scores were calculated for each subject at key treatment and posttreatment time points. Linear mixed-effect models were used to evaluate the impact of phase-1 treatment group, years posttreatment, end of treatment PAR score, and other covariates that could affect stability on the posttreatment PAR score. RESULTS Factors significantly affecting posttreatment PAR scores were PAR score at end of treatment (P <.0001), years posttreatment (P =.0064), and PAR score at the start of phase 2. Although phase-1 treatment was not statistically significant, those with early treatment had lower PAR scores at the start of phase 2 than the observation subjects (means [SD]: bionator 17.5 [7.4], headgear/biteplane 15.3 [7.0], observation 22.2 [8.6], P <.0001). Thus, early treatment had an indirect effect. CONCLUSIONS Factors that affect posttreatment PAR score stability include PAR score at the end of treatment, years posttreatment, and PAR score at the start of phase-2 treatment. The early treatment modalities have limited positive impact on posttreatment stability PAR scores in Class II malocclusion patients due to their effect on PAR scores at the start of phase-2 treatment.

Bis-enoxacin Inhibits Bone Resorption and Orthodontic Tooth Movement

Enoxacin inhibits binding between the B-subunit of vacuolar H+-ATPase (V-ATPase) and microfilaments, and also between osteoclast formation and bone resorption in vitro. We hypothesized that a bisphosphonate derivative of enoxacin, bis-enoxacin (BE), which was previously studied as a bone-directed antibiotic, might have similar activities. BE shared a number of characteristics with enoxacin: It blocked binding between the recombinant B-subunit and microfilaments and inhibited osteoclastogenesis in cell culture with IC50s of about 10 µM in each case. BE did not alter the relative expression levels of various osteoclast-specific proteins. Even though tartrate-resistant acid phosphatase 5b was expressed, proteolytic activation of the latent pro-enzyme was inhibited. However, unlike enoxacin, BE stimulated caspase-3 activity. BE bound to bone slices and inhibited bone resorption by osteoclasts on BE-coated bone slices in cell culture. BE reduced the amount of orthodontic tooth movement achieved in rats after 28 days. Analysis of these data suggests that BE is a novel anti-resorptive molecule that is active both in vitro and in vivo and may have clinical uses. Abbreviations: BE, bis-enoxacin; V-ATPase, vacuolar H+-ATPase; TRAP, tartrate-resistant acid phosphatase; αMEM D10, minimal essential media, alpha modification with 10% fetal bovine serum; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; RANKL, receptor activator of nuclear factor kappa B-ligand; NFATc1, nuclear factor of activated T-cells; ADAM, a disintegrin and metalloprotease domain; OTM, orthodontic tooth movement.

Effect of early Class II treatment on the incidence of incisor trauma

INTRODUCTION Many researchers have examined the prevalence of dental injuries in children and adolescents. The purpose of this study was to examine the prevalence and incidence of incisor trauma in subjects who participated in a randomized clinical trial designed to investigate early growth modifications in the treatment of Class II malocclusion. METHODS The subjects were randomized to 3 treatment groups during the initial phase of the study: (1) headgear or biteplane, (2) bionator, and (3) observation (no treatment). All 3 groups underwent phase 2 treatment with fixed appliances. Incisor injury was scored at every data collection point with the Ellis index by a blinded examiner using dental casts, intraoral photos, and panoramic and periapical x-rays. RESULTS Twenty-five percent of the subjects had incisor trauma at the baseline examination, and 28% experienced new or worsening maxillary incisor injury during the study. No significant differences were found with regard to sex and prevalence of injury at baseline. No differences in incidence of trauma were found between the 3 treatment groups throughout the study (P = 0.19); however, boys were more likely to experience maxillary incisor injury (odds ratio estimate, 2.37; 95% CI, 1.33, 4.21), and those with an injury at baseline were more likely to experience an additional injury (odds ratio estimate, 1.81; 95% CI, 1.03, 3.17). CONCLUSIONS Early orthodontic treatment did not affect the incidence of incisor injury. The majority of the injuries before and during treatment were minor; therefore, the cost-benefit ratio of orthodontic treatment primarily to prevent incisor trauma is unfavorable.

Perceptions of orthognathic surgery patient's change in profile. A five-year follow-up.

OBJECTIVES To compare pairs of silhouettes generated from presurgical and 5-year postsurgical cephalometric radiographs to evaluate whether orthodontists, oral surgeons, and lay persons perceive changes in profile resulting from orthodontics and mandibular advancement surgical treatment. MATERIALS AND METHODS A survey-based method of data collection was used to evaluate 15 pairs of silhouettes. These silhouettes included 1 control pair and 14 surgically treated pairs representing mandibular advancements ranging from 0.11 mm to 10.13 mm. Collected data were analyzed to determine whether changes can be perceived and whether these changes were esthetically pleasing. RESULTS The control silhouette pair was identified by 104 of 127 evaluators. For the 14 surgical treated silhouette pairs, the vast majority of evaluators (N = 127; 53 orthodontists, 32 oral surgeons, and 42 lay persons) were able to identify changes in profile and individual features. At least one group of evaluators was able to perceive significant (P < .05) improvement in the visual analog scale (VAS) score for all these silhouette pairs, except for the pair with 10.13 mm of mandibular advancement. This silhouette pair, which represented the largest mandibular advancement, was perceived to have a significant (P < .05) worsening in the VAS score by the lay person group. There were significant differences among the groups of evaluators. Esthetic improvement in profile was perceived for 13 of 14 surgically treated silhouette pairs. CONCLUSION In some cases, orthodontists, oral surgeons, and lay persons perceived changes in profile differently.