The First Hybrid International Educational Comprehensive Cleft Care Workshop.

OBJECTIVE: Describe the first hybrid global simulation-based comprehensive cleft care workshop, evaluate impact on participants, and compare experiences based on in-person versus virtual attendance. DESIGN: Cross-sectional survey-based evaluation. SETTING: International comprehensive cleft care workshop. PARTICIPANTS: Total of 489 participants. INTERVENTIONS: Three-day simulation-based hybrid comprehensive cleft care workshop. MAIN OUTCOME MEASURES: Participant demographic data, perceived barriers and interventions needed for global comprehensive cleft care delivery, participant workshop satisfaction, and perceived short-term impact on practice stratified by in-person versus virtual attendance. RESULTS: The workshop included 489 participants from 5 continents. The response rate was 39.9%. Participants perceived financial factors (30.3%) the most significant barrier and improvement in training (39.8%) as the most important intervention to overcome barriers facing cleft care delivery in low to middle-income countries. All participants reported a high level of satisfaction with the workshop and a strong positive perceived short-term impact on their practice. Importantly, while this was true for both in-person and virtual attendees, in-person attendees reported a significantly higher satisfaction with the workshop (28.63 ± 3.08 vs 27.63 ± 3.93; P = .04) and perceived impact on their clinical practice (22.37 ± 3.42 vs 21.02 ± 3.45 P = .01). CONCLUSION: Hybrid simulation-based educational comprehensive cleft care workshops are overall well received by participants and have a positive perceived impact on their clinical practices. In-person attendance is associated with significantly higher satisfaction and perceived impact on practice. Considering that financial and health constraints may limit live meeting attendance, future efforts will focus on making in-person and virtual attendance more comparable.

Simulation-Based Comprehensive Cleft Care Workshops: A Reproducible Model for Sustainable Education.

OBJECTIVE: Evaluate simulation-based comprehensive cleft care workshops as a reproducible model for education with sustained impact. DESIGN: Cross-sectional survey-based evaluation. SETTING: Simulation-based comprehensive cleft care workshop. PARTICIPANTS: Total of 180 participants. INTERVENTIONS: Three-day simulation-based comprehensive cleft care workshop. MAIN OUTCOME MEASURES: Number of workshop participants stratified by specialty, satisfaction with the workshop, satisfaction with simulation-based workshops as educational tools, impact on cleft surgery procedural confidence, short-term impact on clinical practice, medium-term impact on clinical practice. RESULTS: The workshop included 180 participants from 5 continents. The response rate was 54.5%, with participants reporting high satisfaction with all aspects of the workshop and with simulation-based workshops as educational tools. Participants reported a significant improvement in cleft lip (33.3 ± 5.7 vs 25.7 ± 7.6; P < .001) and palate (32.4 ± 7.1 vs 23.7 ± 6.6; P < .001) surgery procedural confidence following the simulation sessions. Participants also reported a positive short-term and medium-term impact on their clinical practices. CONCLUSION: Simulation-based comprehensive cleft care workshops are well received by participants, lead to improved cleft surgery procedural confidence, and have a sustained positive impact on participants' clinical practices. Future efforts should focus on evaluating and quantifying this perceived positive impact, as well reproducing these efforts in other areas of need.

Columella Elongation Surgery Outcome in Complete Bilateral Cleft Lip and Palate.

BACKGROUND: The evaluation of surgical outcomes is needed to achieve excellence in nasal reconstruction of patients with complete bilateral cleft lip and palate (BCLP). The study objective is to evaluate the quality of nasal aesthetics after the columella elongation surgery. METHODS: The sample of this study consisted of 70 patients with complete BCLP, operated on columella elongation surgery and analyzed at 6 to 12 years. The system for evaluation of nasal appearance after the columella elongation surgery was performed by objective and subjective analyses. ANTHROPOMETRIC MEASUREMENTS: Four anthropometric nose measurements were performed directly on the faces, and the same was performed in control group (60 children without oral clefts), paired by age and sex with the experimental group. The measurements were repeated 3 times (triplicate). SUBJECTIVE ANALYSIS: Scores to evaluate nasal width, nasal tip projection, and length of the columella were applied before and after the columella elongation surgery by 5 raters from the rehabilitation team. Interrater and intrarater agreement was calculated by means of the kappa test. RESULTS: Nasal width in BCLP group was higher when compared to the control group (P < 0.05). Nasal tip projection (subnasal-pronasal) and columella length (subnasal-columella) were decreased in BCLP group compared to that of the controls (P < 0.05). Columella width was similar in both study groups (P > 0.05). All scores of nasal aesthetics significantly improved after the columella elongation surgery. CONCLUSIONS: Nose of the patients with BCLP is wider, is less projected, and has the shorter columella compared to that of the noncleft subjects. After secondary columella elongation surgery in BCLP, nasal width, nasal projection, and columella length significantly improved.

Assessment of Orthodontic Burden of Care in Patients With Unilateral Complete Cleft Lip and Palate.

OBJECTIVE: To assess the orthodontic burden of care of patients from a Brazilian rehabilitation center (Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo [HRAC-USP]). DESIGN: Retrospective. SETTING: Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo. INTERVENTIONS: One hundred files of unilateral complete cleft lip and palate patients who had consecutively finished orthodontic rehabilitation at HRAC-USP were evaluated from January 2011 to January 2013. The duration of orthodontic treatment, number of visits, kilometers traveled, number of appliances and surgical procedures performed were recorded. The sample was divided into 2 subgroups according to severity the interarch relation (Goslon Yardstick score) at the beginning of orthodontic treatment. Mann-Whitney test was applied for intergroup comparison ( P < .05). RESULTS: For the total sample (n = 100), the mean time of orthodontic treatment was 140.2 months, the mean number of orthodontic appointments was 61.8, the mean number of appliances was 10, the mean number of surgical procedures was 6.2, and the mean distance traveled to attend the center for orthodontic appointments was 38,978.5 km. The subgroup with the most severe malocclusion (Goslon yardsticks scores 4 and 5) showed a longer orthodontic treatment length, greater number of surgical procedures, and longer distance traveled than those presenting Goslon yardstick scores 1, 2, and 3. CONCLUSION: Patients with greater severity of the initial malocclusion experienced a higher burden of care than patients with less severity of the initial malocclusion. To reduce the burden of care, research and efforts should focus on minimizing maxillary growth deficiency related to primary surgery.

Extreme maxillomandibular discrepancy in unilateral cleft lip and palate: Longitudinal follow-up in a patient with mandibular prognathism.

Growth deficiency of the maxilla is a frequent finding in patients with complete unilateral cleft lip and palate. When the sagittal discrepancy is severe, orthodontic treatment combined with orthognathic surgery is required. This article reports the treatment of a girl born with unilateral cleft lip and palate who had lip and palate repair at 3 and 12 months of age, respectively. At 3 years of age, she already showed a severe anteroposterior maxillary deficiency with an anterior crossbite in the deciduous dentition. A Class III skeletal pattern progressively increased during the mixed dentition period. Mandibular prognathism coupled with an extremely hyperdivergent growth pattern was observed. An alveolar bone graft was performed at 10 years of age. At 16 years of age, the ANB angle was -13.7° with a negative overjet of -9.8 mm. Comprehensive orthodontic treatment was conducted with extraction of the mandibular first premolars and maxillary lateral incisors due to dental crowding. Orthognathic surgery was performed at 18.9 years of age involving maxillary advancement of 7.4 mm and mandibular setback of 6.6 mm. Facial and occlusal changes were dramatic. Final nose repair was conducted at 19.7 years of age. At 22 years of age and 3 years after debonding, stability of the occlusal and skeletal results was observed, clearly demonstrating that the objectives established for the rehabilitation have been achieved.

Evaluation of maxillary buccal alveolar bone before and after orthodontic alignment without extractions: A cone beam computed tomographic study.

OBJECTIVES:: To assess the changes in the maxillary buccal alveolar bone during alignment without extractions. Secondarily, to evaluate the changes in arch dimensions and buccolingual inclinations of teeth and to identify risk factors for bone loss. MATERIALS AND METHODS:: Twenty-two adolescents with crowded permanent dentitions were treated without extractions with Damon 3MX brackets. Cone beam computed tomographic scans were taken before treatment (T0) and after alignment (T1). Bone thickness (BT) and height from the cementoenamel junction to the alveolar crest (BH) were evaluated at the maxillary central incisors, second premolars, and buccal roots of first molars. Changes in all variables from T0 to T1 were assessed. Correlations between bone changes and initial bone thickness, initial arch widths, initial crowding, amount of expansion, amount of tipping, and amount of molar rotation were calculated. RESULTS:: BT decreased and BH increased significantly for the incisors and mesiobuccal root of the first molars. Arch dimensions generally increased together with tipping. Bone loss was correlated with crowding and amount of expansion in the premolar region. Initially thinner BT was correlated with greater apical migration of bone for the incisors. CONCLUSIONS:: Nonextraction alignment with self-ligating brackets led to arch expansion associated with tipping of teeth. Expansion related to alignment resulted in horizontal and vertical bone loss at the incisors and mesiobuccal root of the first molars. Thinner BTs and more severe crowding before treatment increased the risk for buccal bone loss.

Mandibulofacial dysostosis Bauru type: Refining the phenotype.

Mandibulofacial dysostosis (MFD) Bauru type (OMIM 604830) is a rare genetic condition characterized mainly by malar hypoplasia, orofacial cleft, and micrognathia. Here, we describe the clinical and radiographic sings of 13 individuals (12 female and 1 male) from eight unrelated kindreds with MFD Bauru type, including four previously reported cases, treated at the Hospital for Rehabilitation of Craniofacial Anomalies. The clinical phenotype was characterized by severe underdevelopment of mandible, midface hypoplasia, orofacial cleft, bitemporal narrowing, mild upper eyelid down slanting, high nasal bridge, thick and everted lower lip, minor ears abnormalities, and hearing loss. Radiographic aspects included downslanting of zygomatic arch, maxillary hypoplasia, microretrognathia, hypoplastic mandibular condyles, and ectopic external auditory canal. Recurrence was observed in two of eight families and the affected distribution pattern was compatible with autosomal dominant inheritance in one and autosomal recessive in another, indicating possible genetic heterogeneity for this condition. Clinical and radiographic findings in this report contribute to the delineation of this rare MFD.

Tratamento de correção de biprotrusão com extrações de quatro primeiros molares permanentes / Treatment for the correction of biprotrusion with fourfirst permanent molars extractions

Apresentação de caso clínico de uma paciente feoderma portadora de biprotrusão, tratada com extrações dos quatro primeiros molares permanentes.

Clinical case report of patient Brazilian African-Caucasian descendent with biprotrusion treated with four first molars extractions.

Is there a consensus for CBCT use in Orthodontics?

This article aims to discuss current evidence and recommendations for cone-beam computed tomography (CBCT) in Orthodontics. In comparison to conventional radiograph, CBCT has higher radiation doses and, for this reason, is not a standard method of diagnosis in Orthodontics. Routine use of CBCT in substitution to conventional radiograph is considered an unaccepted practice. CBCT should be indicated with criteria only after clinical examination has been performed and when the benefits for diagnosis and treatment planning exceed the risks of a greater radiation dose. It should be requested only when there is a potential to provide new information not demonstrated by conventional scans, when it modifies treatment plan or favors treatment execution. The most frequent indication of CBCT in Orthodontics, with some evidence on its clinical efficacy, includes retained/impacted permanent teeth; severe craniofacial anomalies; severe facial discrepancies with indication of orthodontic-surgical treatment; and bone irregularities or malformation of TMJ accompanied by signs and symptoms. In exceptional cases of adult patients when critical tooth movement are planned in regions with deficient buccolingual thickness of the alveolar ridge, CBCT can be indicated provided that there is a perspective of changes in orthodontic treatment planning.

O presente artigo visa discutir as evidências e recomendações atuais concernentes à indicação da tomografia computadorizada de feixe cônico (TCFC) em Ortodontia. Devido à dose de radiação mais elevada em relação às radiografias, a TCFC não é o método padrão de diagnóstico em Ortodontia. O seu uso rotineiro, em substituição à documentação convencional, é considerado uma prática inaceitável. A TCFC deve ser indicada com muito critério, e somente após uma análise clínica, quando os benefícios para o diagnóstico e tratamento superarem os riscos de uma dose mais elevada de radiação. Deve ser requisitada estritamente quando houver um potencial de prover novas informações não demonstradas em exames radiográficos convencionais, modificando o plano de tratamento ou facilitando a sua execução. As indicações mais frequentes em Ortodontia, que demonstram algum nível de evidência sobre sua eficácia clínica, podem ser resumidas em casos de dentes permanentes retidos; anomalias craniofaciais complexas; discrepâncias faciais severas com indicação de tratamento ortodôntico-cirúrgico; e malformações ou irregularidades ósseas na ATM acompanhadas de sinais e sintomas. Em casos excepcionais, em pacientes adultos em que se planeja movimentos dentários críticos em áreas com espessura óssea vestibulolingual deficiente, a TCFC pode ser indicada, desde que se vislumbre uma perspectiva de alteração no plano de tratamento ortodôntico.

Is there a consensus for CBCT use in Orthodontics?

This article aims to discuss current evidence and recommendations for cone-beam computed tomography (CBCT) in Orthodontics. In comparison to conventional radiograph, CBCT has higher radiation doses and, for this reason, is not a standard method of diagnosis in Orthodontics. Routine use of CBCT in substitution to conventional radiograph is considered an unaccepted practice. CBCT should be indicated with criteria only after clinical examination has been performed and when the benefits for diagnosis and treatment planning exceed the risks of a greater radiation dose. It should be requested only when there is a potential to provide new information not demonstrated by conventional scans, when it modifies treatment plan or favors treatment execution. The most frequent indication of CBCT in Orthodontics, with some evidence on its clinical efficacy, includes retained/impacted permanent teeth; severe craniofacial anomalies; severe facial discrepancies with indication of orthodontic-surgical treatment; and bone irregularities or malformation of TMJ accompanied by signs and symptoms. In exceptional cases of adult patients when critical tooth movement are planned in regions with deficient buccolingual thickness of the alveolar ridge, CBCT can be indicated provided that there is a perspective of changes in orthodontic treatment planning.

Is missing maxillary lateral incisor in complete cleft lip and palate a product of genetics or local environment?

OBJECTIVE: To test the null hypothesis: Subjects with isolated complete unilateral cleft lip and palate (UCLP) show no differences in overall frequency of tooth agenesis (hypodontia), comparing a subsample with cleft-side maxillary lateral incisor (MxI2) agenesis to a subsample without cleft-side MxI2 agenesis. Findings could clarify the origins of cleft-side MxI2 agenesis. MATERIALS AND METHODS: Tooth agenesis was identified from dental radiographs of 141 subjects with UCLP. The UCLP cohort was segregated into four categories according to the status and location of MxI2 in the region of the unilateral cleft: group M: subjects with one tooth, located on the mesial side of the alveolar cleft; group D: subjects with one tooth, located on the distal side of the alveolar cleft; group MD: subjects with two teeth present, one mesial and one distal to the cleft; and group ABS: subjects with lateral incisor absent (agenesis) in the cleft area. RESULTS: The null hypothesis was rejected. Among UCLP subjects, there was a twofold increase (P < .0008) in overall frequency of tooth agenesis outside the cleft region in a subsample with cleft-side MxI2 agenesis (ABS), compared to a subsample presenting with no agenesis of the cleft-side MxI2 (M+D+MD). CONCLUSIONS: Cleft-side MxI2 agenesis in CLP subjects appears to be largely a genetically controlled anomaly associated with cleft development, rather than a collateral environmental consequence of the adjacent cleft defect, since increased hypodontia involving multiple missing teeth observed remote from a cleft clearly has a significant genetic basis.

Relationship between maxillary and mandibular base lengths and dental crowding in patients with complete Class II malocclusions.

OBJECTIVE: To verify the relationship between maxillary and mandibular effective lengths and dental crowding in patients with Class II malocclusions. MATERIALS AND METHODS: The sample comprised 80 orthodontic patients with complete Class II malocclusions in the permanent dentition (47 male, 33 female) who were divided into two groups according to the amount of mandibular tooth-arch size discrepancy. The maxillary and mandibular effective lengths (Co-A and Co-Gn) and tooth-arch size discrepancies were measured on the initial cephalograms and dental casts, respectively. Intergroup comparisons of apical base lengths were performed with independent t-tests. Correlation between base length and dental crowding was examined by means of Pearson's correlation coefficient (P < .05). RESULTS: Patients with Class II malocclusion and moderate to severe crowding had significantly smaller maxillary and mandibular effective lengths than subjects with the same malocclusion and slight mandibular crowding. A weak inverse correlation was also found between maxillary and mandibular effective lengths and the severity of dental crowding. CONCLUSION: Decreased maxillary and mandibular effective lengths constitute an important factor associated with dental crowding in patients with complete Class II malocclusion.

Reprodutibilidade das mensurações da espessura das tábuas ósseas na tomografia computadorizada Cone-Beam utilizando diferentes protocolos de aquisição de imagem / Reproducibility of bone plate thickness measurements with Cone-Beam Computed Tomography using different image acquisition protocols

INTRODUÇÃO: quanto menor a dimensão do voxel, maior a nitidez da imagem de tomografia computadorizada Cone-Beam (TCCB), porém, maior a dose de radiação emitida. OBJETIVOS: avaliar e comparar a reprodutibilidade da mensuração da espessura das tábuas ósseas vestibular e lingual em imagens de TCCB, utilizando diferentes protocolos de aquisição de imagem com variação da dimensão do voxel. MÉTODOS: exames de TCCB foram tomados de 12 mandíbulas humanas secas, com dimensão do voxel de 0,2; 0,3 e 0,4mm, no aparelho i-CAT Cone-Beam 3-D Dental Imaging System. No software i-CAT Viewer, foi mensurada a espessura das tábuas ósseas vestibular e lingual, em um corte axial passando 12mm acima do forame mentoniano do lado direito. A reprodutibilidade intraexaminador foi avaliada por meio da aplicação do teste t pareado. Para a comparação interexaminadores, foi utilizado o teste t independente. Os resultados foram considerados com o nível de significância de 5 por cento. RESULTADOS: observou-se uma excelente reprodutibilidade interexaminadores para os três protocolos avaliados. A reprodutibilidade intraexaminadores foi muito boa, com exceção de algumas regiões dos dentes anteriores, que mostraram diferenças estatisticamente significativas, independentemente da dimensão do voxel. CONCLUSÃO: a mensuração da espessura das tábuas ósseas vestibular e lingual em imagens de TCCB mostrou boa precisão para exames obtidos com voxel de 0,2; 0,3 ou 0,4mm. A reprodutibilidade das mensurações na região anterior da mandíbula foi mais crítica do que na região posterior.

INTRODUCTION: A smaller voxel dimension leads to greater resolution of Cone-Beam Computed Tomography (CBCT), but a greater dosage of radiation is emitted. OBJECTIVE: Assess and compare the reproducibility of buccal and lingual bone plate thickness measurements in CBCT images using different image acquisition protocols, with variations in the voxel dimension. METHODS: CBCT exams were taken of 12 dried human mandibles with voxel dimensions of 0.2, 0.3 and 0.4 mm using the i-CAT Cone-Beam 3-D Dental Imaging System. The thickness of the buccal and lingual bone plates was measured, with the i-CAT Vision software, on an axial section passing 12 mm above the right mental foramen. Intra-examiner and inter-examiner reproducibility was assessed using the paired t-test and independent t-test, respectively, with the level of significance set at 5 percent. RESULTS: Excellent inter-examiner reproducibility was observed for the three protocols analyzed. Intra-examiner reproducibility was very good, with the exception of some regions of the anterior teeth, which exhibited statistically significant differences regardless of the voxel dimensions. CONCLUSION: The measurement of buccal and lingual bone plate thickness on CBCT images demonstrated good precision for voxel dimensions of 0.2, 0.3 and 0.4 mm. The reproducibility of the measurements of the anterior region of the mandible was more critical than that of the posterior region.

Etiologia das más oclusões: perspectiva clínica (parte III): fissuras labiopalatinas / Etiology of malocclusions: clinical perspective (part III): cleft lip and palate

A fissura labiopalatina, como o nome sugere, aloja-se na face média, rompendo lábio, palato ou as duas estruturas. Portanto, está na área de alcance do dentista e causa problemas estruturais no osso alveolar e na maxila como um todo, na dependência da extensão da fissura. A relação óbvia e urgente com a má oclusão é compreendida de três maneiras: 1) pela ruptura anatômica que compromete a integridade do rebordo alveolar, 2) pelos problemas dentários, agenesias e más posições envolvendo os dentes adjacentes à fissura, e 3) pela deficiência maxilar, sagital e transversal induzida pelas cirurgias plásticas reconstrutivas. O presente artigo se dedica a um repasse panorâmico sobre a etiologia dessa anomalia que acomete 1 em cada 650 brasileiros.

Etiologia das más oclusões: perspectiva clínica (parte II): fatores ambientais / Etiology of malocclusions: clinical perspective (part II): environmental factors

Os fatores etiológicos ambientais, via de regra, são mais facilmente identificados pelo ortodontista, e até pelos leigos, por terem uma relação causa-efeito clara e indiscutível com as más oclusões. Simplificando, enquadram-se aqui todos os fatores etiológicos que não são genéticos. Eles foram agrupados na seguinte ordem: traumatismo, perda precoce de dentes decíduos, perda de dentes permanentes, hábitos locais deletérios de sucção, posicionamento lingual atípico, e respiração bucal.

Etiologia das más oclusões: perspectiva clínica (parte I): fatores genéticos / Etiology of malocclusions: clinical perspective (part I): genetic factors

A etiologia das más oclusões representam um tema de importância relevante na especialidade Ortodontia. Primeiro, por cumprir um compromisso acadêmico, a erudição fundamental do especialista. Segundo, por possibilitar ao ortodontista uma visão mais aprofundada, e por isso mais refinada, da origem do problema. O arsenal de informações permite ao profissional ponderar sobre a possibilidade de prevenção de uma determinada irregularidade, delinear seu prognóstico de tratamento e a estabilidade da correção, bem como valorizar a sua manifestação provável na árvore genealógica. O presente trabalho investe numa classificação simples e em consonância com a prática clínica, dividindo os fatores etiológicos em dois grandes grupos: fatores genéticos e fatores ambientais. É oportuno comentar de antemão que, pela diversidade morfológica, esses dois fatores podem estar presentes na mesma má oclusão, somando seus efeitos. Por motivos unicamente didáticos, o texto abrangendo os dois fatores etiológicos será dividido em 3 partes. A parte I discute as características dentofaciais com marcante determinação genética. A parte II destaca os fatores ambientais que provocam más oclusões. A parte III retrata as fissuras labiopalatinas, cuja etiologia congrega fatores genéticos e ambientais.

Increased occurrence of dental anomalies associated with second-premolar agenesis.

OBJECTIVE: To evaluate the prevalence of dental anomalies in patients with agenesis of second premolars and compare the findings with the prevalence of these anomalies in the general population. MATERIALS AND METHODS: A Brazilian sample of 203 patients aged 8 to 22 years was selected. All patients presented agenesis of at least one second premolar. Panoramic and periapical radiographs and dental casts were used to analyze the presence of other associated dental anomalies, including agenesis of other permanent teeth, ectopia of unerupted permanent teeth, infraocclusion of deciduous molars, microdontia of maxillary lateral incisors, and supernumerary teeth. The occurrence of these anomalies was compared with occurrence data previously reported for the general population. Statistical testing was performed using the chi-square test (P < .05) and the odds ratio. RESULTS: The sample with agenesis of at least one second premolar presented a significantly increased prevalence rate of permanent tooth agenesis (21%), excluding third molars. Among the sample segment aged 14 years or greater (N = 77), occurrence of third-molar agenesis (48%) exceeded twice its normal frequency. Significant increases in occurrence of microdontia of maxillary lateral incisors (20.6%), infraocclusion of deciduous molars (24.6%), and distoangulation of mandibular second premolars (7.8%) were observed. Palatally displaced canine anomaly was also significantly elevated (8.1%). CONCLUSION: The results provide evidence that agenesis of other permanent teeth, microdontia, deciduous molar infraocclusion, and certain dental ectopias are the products of the same genetic mechanisms that cause second-premolar agenesis.

Association between breastfeeding duration and mandibular retrusion: a cross-sectional study of children in the mixed dentition.

INTRODUCTION: In this study, we examined the relationships among breastfeeding duration, nonnutritive infantile sucking habits, Class II facial patterns with mandibular retrusion, and Class II dental relationships. METHODS: A sample of 249 children in the mixed dentition was examined by 2 orthodontists. Data about the duration of breastfeeding and nonnutritive sucking habits were obtained by written questionnaires answered by the parents. RESULTS: The chi-square test did not indicate a statistically significant association between breastfeeding duration and mandibular deficiency or Class II malocclusion. However, statistically significant associations were found between short breastfeeding duration (<6 months) and nonnutritive sucking habits, and between nonnutritive sucking habits and Class II malocclusions. CONCLUSIONS: These findings point to the hypothesis that nonnutritive sucking habits may work as a dominant variable in the relationship between breastfeeding duration and the occurrence of Class II malocclusion. However, the prevention of mandibular deficiency should not be listed as one of the advantages of breastfeeding.

Extreme variations in the shape of mandibular premolars.

INTRODUCTION: Human mandibular premolars (MnP) are highly variable in shape. An extreme variation, called here MnP tooth-shape deviation (MnP-TSD), is characterized by a squeezed faciolingual (FL) dimension and an enlarged mesiodistal (MD) dimension, reversing the typical premolar proportions. This is the first in-depth study of the MnP-TSD anomaly. METHODS: Eighteen subjects with 29 MnP-TSD teeth were selected for odontometric analysis by using dental casts. For each affected MnP, an MD/FL proportional index and a representation of crown area (MD x FL) were calculated from maximum MD and FL crown diameters. Data were compared with reference values for MnP. RESULTS: MnP-TSD was observed over 8 times more frequently in second premolars than in first premolars. Male expression was slightly greater (ratio, 1.4:1), and bilateral occurrence was observed in 59% of the subjects. Occurrence was noted among all ethno-racial groupings in the sample (16 whites, 1 black, 1 Asian). The MD/FL index of premolars with the MnP-TSD anomaly always exceeded 100 (103 to 148); this is significantly higher than normal values. In contrast, the crown areas of the affected teeth were remarkably similar to normal reference values. In addition to the squeezed tooth shape, subjects with pronounced MnP-TSD also had mesiolingual/distofacial twisting in MnP occlusal features. CONCLUSIONS: Extremely abnormal MD/FL proportions coupled with normal crown-area values provide reliable factors for differential diagnosis of the MnP-TSD anomaly. This uncommon MnP dysmorphology can be a challenge to orthodontic movement and achievement of ideal occlusal intercuspation.

Facial profile evaluation in Japanese-Brazilian adults with normal occlusions and well-balanced faces.

INTRODUCTION: The purpose of this study was to establish the norms of soft-tissue profile analysis for a sample of Japanese-Brazilian adults. METHODS: Facial-profile photographs were taken of 60 Japanese-Brazilians (30 men, 30 women) with normal occlusions and balanced faces, ranging in age from 18 to 30 years. The facial-profile variables were measured by computerized means and compared with white norms by using the independent t test. RESULTS: Statistically significant differences were found in the Japanese-Brazilian sample compared with the white norms. Japanese-Brazilian women had more anteriorly positioned glabellae, smaller nasal projections, and more opened nasolabial angles than white American women. Japanese-Brazilian men had more anteriorly positioned glabellae, smaller noses, larger protrusions of the upper and lower lips, less projected B'-points, and more obtuse nasolabial angles than white American men. CONCLUSIONS: A single norm for facial-profile esthetics does not apply to all ethnic groups. The normative data for the Japanese population should be used as a guide for comparison during diagnosis, and the orthodontist and the maxillofacial surgeon should also consider each patient's perception of beauty, to establish an individualized treatment plan.