Gregory S. Antonarakis

Maxillary molar distalization with noncompliance intramaxillary appliances in Class II malocclusion. A systematic review.

OBJECTIVE To use published data to evaluate quantitatively the dental effects of noncompliance intramaxillary appliances in individuals with Class II malocclusion. MATERIALS AND METHODS A literature search was carried out identifing 13 prospective or retrospective clinical studies matching inclusion criteria. Only appliances with conventional anchorage designs were considered for the review. The data provided in these publications were grouped and analyzed in terms of molar distalization, tipping and vertical movements, and incisor and premolar mesialization, tipping, and vertical movements. RESULTS Maxillary first molars showed distal crown movement and tipping greater than the mesial crown movement and tipping shown by incisors and premolars. Vertical movements of incisors and premolars were in general extrusive, but molars were intrusive or extrusive, depending on the study and the type of appliance used. Appliances that acted palatally seemed to display a smaller distal tipping movement, as well as smaller incisor and premolar mesial tipping movements, when compared with those that acted buccally. Friction-free appliances, namely the pendulum, produced a large amount of mesiodistal movement and tipping, if no therapeutic uprighting activation was applied. CONCLUSIONS Noncompliance intramaxillary molar distalization appliances all act by distalizing molars with a concomitant and unavoidable loss of anchorage, as revealed by incisor and premolar mesial movement. Buccal acting and palatal acting appliances demonstrate almost similar results, with palatal acting appliances showing less tipping. Friction-free palatal acting appliances appear to produce better molar distalizing effects, but with a concomitant notable loss of anchorage.

Genomewide Scan for Nonsyndromic Cleft Lip and Palate in Multigenerational Indian Families Reveals Significant Evidence of Linkage at 13q33.1-34

Nonsyndromic cleft lip with or without cleft palate (CL-P) is a common congenital anomaly with incidence ranging from 1 in 300 to 1 in 2,500 live births. We analyzed two Indian pedigrees (UR017 and UR019) with isolated, nonsyndromic CL-P, in which the anomaly segregates as an autosomal dominant trait. The phenotype was variable, ranging from unilateral to bilateral CL-P. A genomewide linkage scan that used approximately 10,000 SNPs was performed. Nonparametric linkage (NPL) analysis identified 11 genomic regions (NPL>3.5; P<.005) that could potentially harbor CL-P susceptibility variations. Among those, the most significant evidence was for chromosome 13q33.1-34 at marker rs1830756 (NPL=5.57; P=.00024). This was also supported by parametric linkage; MOD score (LOD scores maximized over genetic model parameters) analysis favored an autosomal dominant model. The maximum LOD score was 4.45, and heterogeneity LOD was 4.45 (alpha =100%). Haplotype analysis with informative crossovers enabled the mapping of the CL-P locus to a region of approximately 20.17 cM (7.42 Mb) between SNPs rs951095 and rs726455. Thus, we have identified a novel genomic region on 13q33.1-34 that harbors a high-risk variant for CL-P in these Indian families.

Internet-Derived Information on Cleft Lip and Palate for Families With Affected Children

Objective: To investigate the nature and readability of cleft lip and palate–related family information on the Internet. Materials and Methods: An Internet search for “cleft lip,” “cleft palate,” and “family information” was carried out using three search engines. Within each search, the first 25 relevant websites identified were downloaded and assessed for country of origin, authorship, domain, referencing, links, advertising, mention of orthodontics, illustrations, cleft-specificity, and content. Readability was determined using the Flesch Reading Ease Score, the Flesch-Kincaid Grade Level, and the Fog Scale Level. Data were analyzed by simple descriptive statistics. Results: The initial search returned in excess of 1,800,000 hits. A total of 49 websites were evaluated, excluding repetitions, with a wide range of information available. The websites assessed were mostly of U.S. origin, with a .org domain, authored by universities/hospitals, not cleft-specific, without advertisements, contained links but not references, mentioned orthodontics even if to a small extent, contained some form of illustrations, and varied greatly in quantity and quality of information presented. A wide range of readability scores was obtained, equating to reading ages from fourth grade to university graduate level, with a mean reading age at the eighth to ninth grade level. Conclusions: Cleft lip and palate–related information for families on the Internet is variable in content, quality, and readability. Clinicians should have the responsibility to guide and help parents with website retrieval, while authors of websites should aim to keep information readable and relevant to family demands.

Novel software for quantitative evaluation and graphical representation of masticatory efficiency

Blending of chewing gums of different colours is used in the clinical setting, as a simple and reliable means for the assessment of chewing efficiency. However, the available software is difficult to use in an everyday clinical setting, and there is no possibility of automated classification of the patients chewing ability in a graph, to facilitate visualisation of the results and to evaluate potential chewing difficulties. The aims of this study were to test the validity of ViewGum - a novel image analysis software for the evaluation of boli derived from a two-colour mixing ability test - and to establish a baseline graph for the representation of the masticatory efficiency in a healthy population. Image analysis demonstrated significant hue variation decrease as the number of chewing cycles increased, indicating a higher degree of colour mixture. Standard deviation of hue (SDHue) was significantly different between all chewing cycles. Regression of the log-transformed values of the medians of SDHue on the number of chewing cycles showed a high statistically significant correlation (r² = 0.94, P < 0.01). ViewGum eliminates drawbacks of previous two-colour chewing gum test methods by the simplicity of its application. The newly developed ViewGum software provides speed, ease of use and immediate extraction of clinically useful conclusions to the already established method of chewing efficiency evaluation and is a valid adjunct for the evaluation of masticatory efficiency with two-colour chewing gum.

Combined Orthodontic and Orthognathic Surgical Treatment for the Correction of Skeletal Anterior Open-Bite Malocclusion: A Systematic Review on Vertical Stability

PURPOSE To evaluate vertical stability after combined orthodontic surgical treatment of skeletal anterior open-bite malocclusion. MATERIALS AND METHODS A literature search was performed to locate studies pertaining to vertical stability after combined orthodontic surgical treatment of skeletal anterior open-bite malocclusion. Data from the identified studies were extracted and assessed for quality. Short-term and long-term changes in the following variables were evaluated: overbite; mandibular plane, palatal plane, and intermaxillary angles; and anterior facial height. RESULTS Nine studies, all retrospective, were appropriate for inclusion after review. The postoperative follow-up period ranged from 1 to 18 years. A wide variation was present for post-treatment changes and relapse. Dentally, overbite changes showed a wide variation, with more long-term relapse observed in patients after Le Fort I osteotomy. Skeletally, the mandibular plane and intermaxillary angles showed greater long-term relapse after bimaxillary surgery than after Le Fort I osteotomy. The same trend was seen for the post-treatment increase in anterior facial height. In contrast, the palatal plane seemed to remain rather stable. CONCLUSIONS Vertical relapse is a characteristic in a certain number of patients after combined orthodontic surgical treatments regardless of surgery type. This can be observed dentally by an opening of the bite and skeletally by an increase in the mandibular plane and intermaxillary angles during long-term follow-up. Long-term skeletal relapse seems to be more common after bimaxillary surgery.

Prevalence and patterns of permanent tooth agenesis in patients with nonsyndromic Pierre Robin sequence

INTRODUCTION Individuals with Pierre Robin sequence (PRS) frequently have tooth agenesis, especially in the mandible. The aims of this study were to characterize permanent tooth agenesis patterns and to determine their prevalence in patients with nonsyndromic PRS. METHODS Radiographs and clinic charts of 146 children with nonsyndromic PRS were examined for permanent tooth agenesis, excluding third molars, and the tooth agenesis patterns were identified with the tooth agenesis code. RESULTS The overall prevalence of permanent tooth agenesis was 32.9% (48 of 146 patients), with about two thirds having bilateral tooth agenesis. No sex or racial predilection was found for tooth agenesis. The most common tooth agenesis pattern was the absence of both mandibular second premolars. Among the children with tooth agenesis, almost half had agenesis patterns involving both mandibular second premolars. Other common patterns of permanent tooth agenesis involved the maxillary lateral incisors and the maxillary premolars. CONCLUSIONS Symmetric agenesis of individual tooth types occurs much more frequently in the mandible than in the maxilla in patients with nonsyndromic PRS. Bilateral absence of the mandibular second premolars is the predominant pattern of dental agenesis.

Agenesis of maxillary lateral incisor and tooth replacement: cost-effectiveness of different treatment alternatives.

PURPOSE To evaluate the long-term cost-effectiveness of five treatment alternatives for maxillary lateral incisor agenesis where space maintenance and tooth replacement are indicated. MATERIALS AND METHODS The following treatment modalities were considered: single-tooth implant-supported crown, resin-bonded fixed partial denture (FPD), cantilever FPD, full-coverage FPD, and autotransplantation. The cost-effectiveness for each treatment modality was determined as the ratio of the outcome of each modality divided by the cost. Direct costs, clinical and laboratory, were calculated based on national fee schedules and converted to international dollars using purchasing power parity exchange rates. Outcomes were based on the most recently published long-term (10-year) survival rates. Sensitivity analyses were carried out, testing the robustness of the cost-effectiveness analysis. RESULTS The five treatment modalities ranked in the following order from most to least cost-effective: autotransplantation, cantilever FPDs, resin-bonded FPDs, single-tooth implants and implant-supported crowns, and full-coverage FPDs. Sensitivity analysis illustrated that the cost-effectiveness analysis was reliable in identifying autotransplantation as the most and full-coverage FPDs as the least cost-effective treatment modalities. CONCLUSIONS When replacing a missing maxillary lateral incisor, the most costeffective, long-term treatment modality is autotransplantation, whereas the least cost-effective is full-coverage FPDs. However, factors such as patient age, the state of the dentition, occlusion, and tooth conservation should also influence the choice of restoration.

Predictive value of masseter muscle thickness and bite force on Class II functional appliance treatment: a prospective controlled study

AIM To prospectively evaluate the functional capacity of the masticatory musculature as a predictive variable in determining functional appliance treatment outcomes in Class II/1 malocclusion children. METHODS Twenty Class II/1 malocclusion children (11.4 ± 1.7 years) were treated with functional appliances during 1 year. Masseter muscle thickness and maximal molar bite force measurements, lateral cephalograms, and study casts were taken before and after treatment. Twenty age- and gender-matched untreated children were included as a control group. Regression analyses were used to identify correlations between pre-treatment muscle characteristics and treatment outcomes. RESULTS All treated patients showed dentoalveolar sagittal improvement. Maximal molar bite force and masseter muscle thickness decreased during the treatment period in the experimental group but increased in the control group. Children with lower pre-treatment maximal molar bite force showed more mesial movement of mandibular first molars, distal movement of maxillary first molars, and larger change in molar class during treatment. Children with thinner pre-treatment masseter muscles demonstrated more mandibular first molar mesialisation, mandibular incisor proclination, and opening of the gonial angle during treatment. CONCLUSIONS The initial condition of the masticatory muscles may partly determine treatment outcomes. Children with thinner pre-treatment masseter muscles or weaker bite force show greater dentoalveolar changes.

Presurgical cleft lip anthropometrics and dental arch relationships in patients with complete unilateral cleft lip and palate

Objective To investigate associations between anthropometric lip measurements and dental arch relationships in patients with complete unilateral cleft lip and palate (CUCLP). Design Retrospective cross-sectional study. Patients Children with CUCLP. Methods Anthropometric lip measurements, made immediately prior to lip repair, were available for each patient. The dental arch relationships were evaluated on dental study casts (8.6 ± 0.9 years) taken prior to any orthodontic treatment and prior to alveolar bone graft, using the modified Huddart and Bodenham (MHB) scoring system. The presence of associations between anthropometric lip measurements and dental arch relationships was determined using linear regression analysis. Results In the 63 patients included in the study, the cleft lateral lip element was deficient in height in 87% and in transverse width in 86% of patients. Patients with more deficient cleft-side lateral lip height were more likely to present with more negative MHB scores (r = .443; P < .001). Conversely, patients with more deficient cleft-side lateral lip transverse width more often presented with more positive MHB scores (r = .281; P = .025). Conclusions In patients with CUCLP, there is a wide variability in the degree of deficiency of the cleft-side lateral lip element, both in the vertical and in the transverse dimension. The extent of this deficiency may, in part, predict the resulting dental arch relationships.

The 100 Most-Cited Human Cleft Lip and Palate–Related Articles Published in Dentistry, Oral Surgery, and Medicine Journals

Objective To identify the 100 most-cited articles pertaining to human cleft lip and palate research published in dentistry, oral surgery, and medicine journals and to identify their principal bibliometric characteristics. Design Web-based bibliometric analysis. Main Outcome Measure The Web of Science was searched to identify the 100 most-cited clinical articles related to cleft lip and/or palate. Information was extracted with regard to total number of citations, number of authors, affiliations, year, and journal of publication, Medical Subject Headings, type of study, specific area of study. Trends in citations were assessed. Results The 100 most-cited articles identified received between 437 and 58 citations. The oldest was published in 1954 and the most recent in 2008. The number of authors ranged from 1 to 12, with an average of three authors per article. Most of the first authors were affiliated with institutions in the United States, with the most prolific institution being the University of Iowa. More than 70% of the studies appeared in The Cleft Palate–Craniofacial Journal. There was a significant negative correlation between average citations per year and time since publication (P < .001); whereas, a significant positive correlation was observed between average citations per year and number of total citations (P < .001). Conclusions The 100 most-cited articles in human cleft lip and palate research published in dentistry, oral surgery, and medicine journals are listed and characterized. This can be used as a potential knowledge base for specialists in training or to produce relevant knowledge defining the direction of future research.