Class II malocclusion with accentuated occlusal plane inclination corrected with miniplate: a case report

ABSTRACT Introduction: A canted occlusal plane presents an unesthetic element of the smile. The correction of this asymmetry has been typically considered difficult by orthodontists, as it requires complex mechanics and may sometimes even require orthognathic surgery. Objective: This paper outlines the case of a 29-year-old woman with Class II malocclusion, pronounced midline deviation and accentuated occlusal plane inclination caused by mandibular deciduous molar ankylosis. Methods: The patient was treated with a miniplate used to provide anchorage in order to intrude maxillary teeth and extrude mandibular teeth on one side, thus eliminating asymmetry. Class II was corrected on the left side by means of distalization, anchored in the miniplate as well. On the right side, maxillary first premolar was extracted and molar relationship was kept in Class II, while canines were moved to Class I relationship. The patient received implant-prosthetic rehabilitation for maxillary left lateral incisor and mandibular left second premolar. Results: At the end of treatment, Class II was corrected, midlines were matched and the canted occlusal plane was totally corrected, thereby improving smile function and esthetics.

RESUMO Introdução: o plano oclusal inclinado representa um elemento antiestético para o sorriso. A correção dessa assimetria é normalmente considerada difícil pelos ortodontistas, requerendo mecânica complexa e, algumas vezes, até cirurgia ortognática. Objetivo: esse artigo descreve o caso de uma paciente de 29 anos, portadora de má oclusão de Classe II, com considerável desvio das linhas médias e acentuada inclinação do plano oclusal, causada pela anquilose de molar decíduo inferior. Métodos: a paciente foi tratada com ancoragem em miniplaca, para promover a intrusão dos dentes superiores e extrusão dos dentes inferiores em um lado, eliminando a assimetria. A Classe II foi corrigida no lado esquerdo por meio de distalização, também ancorada na miniplaca. No lado direito, o primeiro pré-molar superior foi extraído e a relação de molares de Classe II foi mantida, enquanto os caninos foram movidos para relação de Classe I. A paciente recebeu reabilitação por meio de implante e prótese no incisivo lateral superior esquerdo e no segundo pré-molar inferior esquerdo. Resultados: ao término do tratamento, a Classe II foi corrigida, as linhas médias estavam coincidentes e a inclinação do plano oclusal foi totalmente corrigida, melhorando consideravelmente os aspectos funcionais e estéticos da oclusão.

Tratamento da classe II com o auxílio de aparelhos funcionais fixos / Class II treatment with the aid of fixed functional appliances

A má-oclusão de classe II foi descrita por Angle e é caracterizada por alterações dentárias e/ou esqueléticas. Seja qual for a combinação dos fatores que acometem o paciente de classe II, o sulco vestibular do molar inferior encontra-se distalmente à cúspide mesiovestibular do molar superior. Estratégias biomecânicas para estabelecer a correta relação entre os arcos envolvem elásticos intermaxilares e dispositivos removíveis que necessitam da colaboração do paciente, ou ainda de aparelhos funcionais fixos, os quais dispensam a colaboração e prometem maior eficiência clínica. O objetivo deste artigo foi revisar as características gerais destes tipos de aparelho, sua forma de funcionamento e aplicabilidades clínicas.

The class II malocclusion has been described by Angle and characterized by dental and/or skeletal abnormalities. Whatever the combination of factors that affect the class II patients, the buccal groove of the lower molar is distal to the mesiobuccal cusp of the upper molar. Biomechanical strategies to establish the correct relationship between the archs involve intermaxillary elastics and removable devices that require the patient's cooperation or fixed functional appliances, which do not require collaboration and promise greater clinical efficiency. The aim of this article was to review the general characteristics of these types of appliance, how they work, and their and clinical applications.

Evaluation of long-term stability of mesiodistal axial inclinations of maxillary molars through panoramic radiographs in subjects treated with Pendulum appliance

Objective: To evaluate the stability of mesiodistal inclination of maxillary molars produced by a pendulum appliance, five years after completion of orthodontic treatment. Angulation changes were compared to an untreated sample. Methods: The sample consisted of 20 patients (14 females and 6 males) with Class II, Division 1 malocclusion that was treated through molar distalization with a pendulum appliance followed by cervical headgear and full fixed appliances. Maxillary molar inclination was evaluated through panoramic radiograph. The mean age at pretreatment was 14.3 ± 1.6 years, whereas at immediate post-treatment it was 18.6 ± 1.8 years, and at long-term post-treatment it was 23.8 ± 2.0 years. A control group of 16 untreated individuals with untreated normocclusion ranging in age from 12 to 17 years old were used as comparison group. Data were statistically analyzed with independent t-tests and ANOVA test followed by Tukey post-hoc tests. Results: Statistically significant differences were found between T1(94.50) and T2 (98.80) as well as between T2 and T3 (94.70) for maxillary first molars. Maxillary second molars did not show any statistically significant positional changes during the evaluated time periods T1 (107.50), T2 (109.30) and T3 (106.90). Conclusion: Although maxillary first molars underwent distal crown inclination immediately after treatment, approximately five years thereafter their roots tended to upright close to the pretreatment positions.

Objetivo: avaliar a estabilidade da inclinação mesiodistal dos molares superiores cinco anos após o tratamento realizado com o aparelho Pendulum seguido de aparelho ortodôntico fixo. As mudanças na angulação foram comparadas com uma amostra não tratada. Métodos: a amostra consistiu de 20 pacientes (14 do sexo feminino e 6 do masculino) com má oclusão de Classe II, divisão 1 tratados por meio da distalização dos molares com o aparelho Pendulum seguido de ancoragem extrabucal cervical e aparelho fixo. A inclinação dos molares superiores foi avaliada por meio de radiografias panorâmicas. A média da idade ao início do tratamento foi de 14,3 ± 1,6 anos; ao final do tratamento, de 18,6 ± 1,8 anos e, no longo tempo pós-tratamento, de 23,8 ± 2,0 anos. Para comparação, foi usado um grupo controle com 16 indivíduos não tratados e com oclusão normal, apresentando idades entre 12 e 17 anos. Os dados foram analisados estatisticamente pelo teste t independente e ANOVA, seguido do teste de Tukey. Resultados: os primeiros molares superiores apresentaram diferenças estatisticamente significativas entre T1 (94,5o) e T2(98,8o), bem como entre T2 e T3(94,7o). Os segundos molares superiores não apresentaram alterações estatisticamente significativas no seu posicionamento durante os períodos avaliados, T1 (107,5o), T2(109,3o) e T3 (106,9o). Conclusões: apesar de os primeiros molares superiores apresentarem inclinação distal da coroa imediatamente após o tratamento, aproximadamente cinco anos depois suas raízes tendem a ocupar posições próximas às do início do tratamento.

Cervical vertebral anomalies in skeletal malocclusions: A cross-sectional study on orthodontic patients at the Aga Khan University Hospital, Pakistan.

Introduction: Morphological deviations of the cervical vertebral column have been described in relation to craniofacial aberrations and syndromes. Furthermore, it has recently been shown that abnormal morphology of upper cervical vertebrae is associated with malformation of the jaws and occlusion. Accordingly, it is relevant to focus on similar associations in patients with skeletal malocclusions. Therefore, the objectives of this study are to: • Identify the anomalies of the cervical column in patients with skeletal malocclusions • Determine the association between cervical vertebral anomalies and skeletal malocclusions. Materials and Methods: This cross‑sectional study was conducted on a total of 90 subjects at the Aga Khan University Hospital, Pakistan. The inclusion criteria were: (1) Pakistani origin; (2) standardized pretreatment profile radiograph with first six cervical vertebrae visible; and (3) accessibility of the second‑profile radiograph (mid‑ or posttreatment). The exclusion criteria were: (1) A prior history of orthodontic treatment; (2) any craniofacial anomaly; and (3) systemic muscle or joint disorder. Lateral cephalograms of all subjects (n = 90) were traced by the principal investigator and sagittal jaw relationship was assessed. A total of 30 subjects each with skeletal Class I, Class II, and Class III malocclusions were selected and the cervical vertebral anomalies were observed on their cephalometric radiographs. The frequencies of cervical vertebral anomalies according to skeletal malocclusion categories and gender were analyzed with the Chi‑square test, whereas association of cervical vertebral anomalies with skeletal malocclusions was assessed with logistic regression analysis. The level of significance (P ≤ 0.05) was used for the statistical tests. Results: Most common anomaly observed in the three groups was fusion between C2 and C3 (P = 0.006). This anomaly was found in 20% of subjects with skeletal Class I, 50% of subjects with skeletal Class II and 53.3% with skeletal Class III malocclusions. The highest frequencies of partial cleft at the level of C1 and occipitalization were observed in subjects with skeletal Class II and III malocclusions, respectively. However, none of the subjects showed fusion between C1 and C2 or dehiscence. No statistically significant gender difference was found in the occurrence of morphological deviations of the cervical column. The association of cervical vertebral anomaly was found to be the highest with skeletal Class III and lowest with skeletal Class I malocclusions. Conclusion: Fusion between C2 and C3 seems to be the most commonly occurring anomaly. This anomaly seems to be more often associated with skeletal Class III than skeletal Class I or Class II malocclusions.

Facial and dental alterations according to the breathing pattern

There is controversy in the literature about possible interaction of the respiratory mode with the facial and dental structures. OBJECTIVES: The aim of this study was to perform a longitudinal assessment of the changes in facial and dental structures in Angle's Class II, division 1 malocclusion individuals, divided according to the respiratory pattern (predominantly nasal or mouth), at two distinct moments of craniofacial development. MATERIAL AND METHODS: Pogonium and nose measurements were made on the lateral cephalometric tracings (LS'-Pog', LS'-B', B'-Pog', Pog'-PogTeg', Line NB, Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn, Prn-Sn-LS). Dental measurements were made on the plaster models (distances between the tips of the canine cusps and the tips of mesial cusps of the first molars) of 40 individuals aged 10 to 14 years (moment 1) and 13 to 16 years (moment 2), 23 being nose breathers (NB) and 17 being predominantly mouth breathers (MB). RESULTS: The Student's-t test and two-way ANOVA with repeated measures were applied to indicate differences between the mean values of these variables according to the moments and/or respiratory mode. CONCLUSIONS: There were alterations in the facial measurements, without interference of the breathing pattern. However, the breathing pattern infuenced dental alterations.

Mordida profunda / Deep bite

Los trastornos oclusales van ligados a factores hereditarios, generales y locales. Las maloclusiones verticales más comunes son: la mordida abierta, intensificada por los hábitos insanos como la interposición labial, la deglución atípica y la succión del pulgar, característicos en la edad infantil; y la sobremordida vertical o mordida profunda, que si no se corrige a tiempo ocasiona en la edad adulta trastornos de disfunción temporomandibular, desgastes dentarios, retracciones gingivales y problemas periodontales. El objetivo de este trabajo es describir la etiología y sus variantes, y el diagnóstico y el tratamiento de las disgnacias entre la base craneal y ambos maxilares, con el propósito de brindar al especialista una guía para la identificación de la anomalías esqueletal o dentaria y la elección del plan de tratamiento adecuado para cada caso en particular.

Transverse craniofacial dimensions in Angle Class II, Division 1 malocclusion according to breathing mode

The aim of this longitudinal study was to assess the relation between the transverse craniofacial dimensions of subjects with Class II, Division 1 malocclusion and the breathing mode presented by them. Forty Angle Class II, Division 1 malocclusion subjects of both genders participated in the study, 23 of which were predominantly nose breathers and 17 were predominantly mouth breathers. The mean age ranged from 10 years and 9 months to 14 years - Age range 1; and from 13 years and 4 months to 16 years and 6 months - Age range 2. Measurements of six transverse craniofacial dimensions were performed in P-A teleradiographs: Total Sphenoid, Total Zygomatic, Total Nasal Cavity, Total Maxilla, Total Mastoid and Total Antegonion. The transversal craniofacial dimensions were measured and compared in both groups at age ranges 1 and 2. The longitudinal assessment of age ranges 1 and 2 showed that there was no statistically significant influence of the breathing mode on the craniofacial dimensions evaluated, or on the alteration of these dimensions. Breathing mode had no influence on craniofacial development in the sample studied.

Considerações sobre a etiologia da classe II subdivisão / Considerations about the etiology of the class II subdivision malocclusion

É um desafio o tratamento ortodôntico da Classe Il subdivisão devido à relação oclusal assimétrica (Classe II de um lado da arcada dentária e Classe I do outro) e a dificuldade em diagnosticar seus fatores etiológicos. Com o objetivo de facilitar ao ortodontista o tratamento da Classe II subdivisão foi realizada uma pesquisa sobre a etiologia desta má-oclusão. Foram pesquisados vários bancos de dados eletrônicos (Pubmed, Medline, Biblioteca Cochrane, Scopus) e realizadas pesquisas secundárias. Osdados coletados demonstraram que nesta má-oclusão existe uma predominância de alterações dentoalveolares que envolvemprincipalmente o arco inferior, com o molar inferior posicionado mais posterior no lado da Classe II e um desvio de linha média dentária inferior para o lado da Classe II.Secundariamente existe uma assimetria no arco superior, com molar mais mesializado no lado da Classe II e um desvio de linha média dentária para o lado da Classe I. Portanto, a Classe II subdivisão tem uma etiologia primordialmente dentoalveolar inferior, secundariamente dentoalveolar superior e casualmente esquelética. Quandopresente, a alteração esquelética é suave e compromete principalmente a mandíbula.

The orthodontic treatment of the Class II subdivision malocclusion is challenging due to the asymmetrical occlusal relationship (Class II on one side of the dental arch and Class I on the other side) and to the complexity in the diagnosis of its etiological factors. The objective of the actual study was to bring information that facilitates the orthodontist to accomplish the Class II subdivisionmalocclusion treatment. Electronic data sources available were examined (Pubmed, Medline, Cochrane Library, Scopus) as well as secondary sources searched. The data collected indicate that in this malocclusion there is a predominance of dentoalveolaralterations which involve mainly the mandibular arch with the mandibular molar positioned more posterior on the side of the Class II and a shift of the mandibular dental medline towards the side of the Class II. Secondary there was an. asymmetry in the maxillaryarch, with greater mesial migration of the maxillary molar on the side of the Class II and a dental midline shift towards the side of the Class I. Therefore, the etiology of the Class II subdivision malocclusion is primarily dentoaveolar mandibular; secondarilydentoalveolar maxillary and occasionally skeletal. When the skeletal asymmetry is present, it is slight and it mainly compromises the mandible.

Distribution of malocclusion types among thumb suckers seeking orthodontic treatment.

The present study was conducted to evaluate the influence of thumb sucking and its duration on the type of malocclusion. A total of 410 North Indian individuals between ages 12-30 years, 161 males and 249 females were examined. A specially designed proforma was used to record the detailed history of the individual. Among the etiological factors it was found that history of thumb sucking was present in 13.9% and significantly related to Class II div 1 malocclusion. When thumb sucking exceeded 18 months, it was found statistically significant (P < 0.1) in Class II skeletal malocclusion, in open bite (P < 0.1) and in extreme overjet (P < 0.5). CONCLUSION: If thumb sucking is not treated early, it can cause skeletal Class II malocclusion, anterior open bite and excessive overjet.

Avaliação da postural corporal associada às maloclusões de Classe II e Classe III / Evaluation of body posture associated with Class II and Class III malocclusion

Objetivo: Avaliar a postura corporal de indivíduos com maloclusões esqueléticas de Classe II e III. Metodologia: Foram avaliados 59 pacientes do sexo masculino e feminino, com idade cronológica entre 7 e 12 anos. As variáveis posturais frontais (linha biocular, bicomissural e biacromial) e sagitais (lordose lombar e cervical e cabeça anteriorizada) foram analisadas em fotografias digitais de corpo inteiro em norma frontal e sagital. O tipo de maloclusão de Classe II ou III foi verificado por meio de análise cefalométrica. Resultados: Quanto à maloclusão de Classe II, 75% dos pacientes estavam fora da normalidade quanto à lordose lombar. Para lordose cervical, 25% dos pacientes com maloclusão de Classe II e Classe III apresentaram valores fora da normalidade. Noventa e dois por cento dos pacientes com maloclusão de Classe III possuíam a cabeça anteriorizada. Conclusão: Na análise frontal todos os indivíduos da amostra estavam fora do padrão de normalidade para as linhas biocular, bicomissural e biacromial. A postura anteriorizada da cabeça foi a alteração mais visualizada tanto na maloclusão de Classe II quanto na de Classe III.

Purpose: To evaluate body posture of subjects with skeletal Class II and Class III malocclusions. Methods: The sample was composed by 59 patients, aged between 7 and 12 years-old, male or female gender. Body posture variables comprised frontal (biocular, bicomissural, and biacromial lines) and saggital (lumbar and cervical lordosis, forward head position) variables, which were analyzed by means of digital photographs of the entire body. Class II or Class III malocclusions were defined by cephalometric analysis. Results: For Class II malocclusion 75% of the patients had abnormal lumbar lordosis. Regarding cervical lordosis, 25% of the patients with Class II and Class III malocclusion presented values out of the normality range. Ninety-two percent of the patients with Class III malocclusion showed forward head position. Conclusion: In the frontal analysis all subjects of this sample were out of the normal pattern for the biocular, bicomissural, and biacromial lines. The forward head posture was the most frequent alteration in subjects with Class II and Class III malocclusion.

[ dentoskeletal effect of mandibular tongue guard in Cl II/I malocclusion]

The prevalence of Cl II malocclusion with tongue thrust and open bite is high. The pressure of the tongue during swallowing and its physiological activity could be transferred to the maxillary complex by the tongue crib and might advance the maxilla to an unfavorable position. This study aimed to evaluate the dentoskeletal change in the Cl II division 1 patients with anterior tongue thrust and mandibular deficiency treated by mandibular tongue guard, from a private office and orthodontic department of Azad University in Tehran. The sample consisted of 23 patients, [14 females aged 8 years and 9 months and 9 males aged 10 years and 6 months], with Cl II div 1 malocclusion in late mixed dentition with anterior tongue thrust. The patients were treated by mandibular tongue guard. Lateral Cephalograms were obtained and traced before and after treatment and certain angular and linear variables were measured. The pretreatment and post treatment measurements were compared using Paired t test to evaluate the significance of the results. The findings indicated that SNB, facial angle, the distance between B and Pogonion to the reference line and Interincisal angle were significantly increased [P<0.05]. The changes were mainly caused by mandibular growth, were observed after treatment by mandibular tongue guard. Decrease of IMPA, 1-SN, ANB, Wits were significant [P<0.05]. The changes of Jarabak index, SN-MP, SNA, Y-axis were not significant. In Cl II div 1 patients with mandibular deficiency combined with tongue thrust, mandibular tongue guard caused slight increase in mandibular growth

Importancia de la evaluación y clasificación del frenillo lingual / The importance of evaluation and classification of lingual frenum

El propósito de esta investigación surge a partir de la observación, cada vez más frecuente, de pacientes con maloclusiones, cuya causa principal es la anquiloglosia parcial o total. El objetivo fue determinar la cantidad de pacientes con maloclusión que presentaban anquiloglosia sobre una muestra de 282 pacientes de ambos sexos, correspondientes a las tres denticiones, quienes durante el período de un año (noviembre 2003-2004) concurrieron espontáneamente a la Facultad de Odontología de la UNC. En primer término, se evaluó la presencia de anquiloglosia, su frecuencia, y la maloclusión más frecuente en los pacientes con y sin anquiloglosia. Para categorizar los distintos tipos y grados de anquiloglosia, se aplicaron dos métodos de evaluación, considerándose 0 la norma en ambos grupos: (1) grado de movilidad lingual grados 0, 1, 2, 3, 4 (G), referido a la ubicación de la punta de la lengua y su relación con el paladar duro, por detrás de los incisivos superiores, estando el paciente en apertura bucal máxima (ABM); (2) longitud del frenillo lingual tipo 0, I, II, III, IV, medido con calibre de Boley, desde la inserción del frenillo hasta la punta de la lengua, considerándose clínicamente aceptable la lengua libre mayor de 16 mm. Los resultados obtenidos fueron: sobre 282 pacientes con maloclusión, 153 presentaron anquiloglosia, en los cuales la maloclusión más frecuente fue la Clase II, con 43,14 por ciento (n=66), siendo el grado de movilidad lingual G2 (n=92) con 60.13 por ciento y la longitud del frenillo lingual, Tipo II (n=65) con 42,50 por ciento, las más frecuentes.

Avaliação do índice de Peck Peck em pacientes portadores de maloclusão Classe I e Classe II, primeira divisão de Angle / Evaluation of Peck and Peck index in patients with Angle Class I and Class II division 1 malocclusions

Alterações no tamanho mésio-distal e vestibulo-lingual dos dentes podem significar dificuldade no correto posicionamento dos incisivos na arcada. Este estudo propôs avaliar o equilíbrio dentário através do índice de PECK PECK (1975) em pacientes leucodermas portadores de maloclusão Classe I e Classe II, 1ª divisão de Angle. Foram selecionados 100 modelos de gesso da arcada inferior com apinhamento anterior em graus variados de pacientes não tratados ortodonticamente. As dimensões mésio-distal e véstibulo-lingual dos incisivos inferiores foram mensuradas com auxílio de paquímetro digital com graduação 0,01mm. Os resultados mostraram que o Grupo I apresentou discrepância nos incisivos centrais e laterais esquerdos em 86,67 por cento dos casos, os incisivos centrais direitos apresentaram discrepância em 82,23 por cento e os incisivos laterais direitos em 84,45 por cento dos casos. O Grupo II, 1 apresentou discrepância nos incisivos centrais esquerdos em 89,10 por cento e os incisivos centrais direitos em 87,28 por cento dos casos, os incisivos laterais esquerdos apresentaram discrepância em 83,64 por cento dos casos, uma incidência menor que os incisivos laterais direitos, com 85,46 por cento. Pode-se concluir que os incisivos laterais e centrais esquerdos apresentaram maior incidência de discrepância dentária para a maioria dos casos, quando comparados aos homólogos em ambos os grupos, e houve ausência de correlação total entre homólogos em ambos os grupos.

Manifestaciones orales de la mucopolisacaridosis IV A (síndrome de Morquio A): reporte de 5 casos / Oral manifestations of mucopolysaccharidosis IV A (Morquio syndrome A): report of 5 cases

Antecedentes: la mucopolisacaridosis IV A (MPS IVA) o Morquio A, enfermedad metabólica que es causada por desórdenes hereditarios debido a una deficiencia de enzimas lisosomales (N-acetilgalactosamina-6 sulfatasa), es una patología poco frecuente y se encuentran pocos reportes bibliográficos acerca de las manifestaciones bucales. Objetivo: identificar las manifestaciones bucales presentes en 5 pacientes con MPS IVA. Métodos: los pacientes tenían diagnóstico confirmado de la enfermedad por medio de revisión de parcial de orina, estudio de leucocitos y recuento de fibroblastos. Se realizó un examen extraoral e intraoralmente, observando la presencia de alteraciones en tejidos blandos (macroglosia e hiperplasia gingival) y tejidos duros; se examinó el tejido dental en busca de hipoplasias del esmalte, así como de caries, mediante el uso del explorador, y anomalías en la erupción, teniendo en cuenta forma, tamaño y número de dientes presentes en boca. Resultados: 5 pacientes, dos de género masculino y tres del femenino, en edades entre 18-28 años, presentaron MPS IVA, subtipo moderado(2) y subtipo severo(3). Al examen clínico extraoral se observaron pigmentaciones melánicas generales y efélides labiales en los 5 casos. Presentaron perfil clase II con tercios asimétricos (tercio superior aumentado), sellado labial incompetente y biprotrusión marcada en los 5 casos. Al examen intraoral presentaron paladar aplanado (3 casos), macroglosia (1 caso), gingivitis marginal (2 casos), microdoncia (2 casos), en los pacientes con subtipo severo. Se observó hipoplasias del esmalte, diastemas, disminución en el número de dientes debido a exodoncias realizadas, y secuencia de erupción normal en los 5 casos. Entre otros hallazgos, tenían experiencia de caries, fosas profundas y limitación de la apertura bucal

Manifestaciones maxilofaciales del raquitismo hipofosfatémico: reporte de un caso clínico / Maxillofacial manifestations of hypophosphatemic rickets: report of a clinical case

El raquitismo hipofosfatémico es una alteración metabólica transmitida genéticamente (ligada al cromosoma X) en donde disminuye la reabsorción de fosfato en el túbulo proximal. Esta enfermedad se manifiesta con defectos en la mineralización de los tejidos esquelético y dentario. El caso clínico presentado en este artículo corresponde a un niño de 8 años de edad con eta alteración en la que se observan deformidades en las extremidades inferiores (piernas arqueadas), disminución de su talla y bucalmente en los tejidos blandos, se aprecia gingivitis generalizada y sondajes periodontales no mayores de 2 mm. En el aspecto dentario existe una relación molar en clase II de Angle, con pérdida prematura de los molares temporales y por consecuencia, erupción prematura de los premolares permanentes. Debido a la asociación con la deficiente formación dentaria y la historia familiar, podríamos suponer una asociación entre raquitismo hipofosfatémico y las periodontitis de inicio precoz

Etiología de la sobremordida / Etiology of overbite

En el presente trabajo se evalúa la actividad muscular de los maseteros medios, temporales anteriores, vientres anteriores de digástricos y suprahioideos en pacientes con mordida abierta y sobremordida mediante un electromiógrafo computarizado y electrodos de superficie, en las distintas funciones, buscando relacionar la actividad muscular con la patología vertical. Se encuentra una relación de predominio de los elevadores en las sobremordidas y predominio de los depresores en las mordidas abiertas y ese equilibrio muscular sería el factor desencadenante de las patologías verticales de la oclusión.