RESUMEN

Hereditary vitamin D-resistant rickets (HVDRR) is a rare genetic disorder caused by mutations at the level of the vitamin D receptor ( VDR) gene. The disease is characterized by refractory hypocalcemia, elevated serum levels of 1,25-dihydroxy-vitamin D, retarded growth, sparse body hair (sometimes alopecia), premature tooth loss, enlarged pulp chambers, thin dentine, and hypoplastic enamel. The aims of this study were 1) to document the dental development of children with HVDRR in association with the mutation type within the VDR and 2) to evaluate the association between dental development and the timing of and response to HVDRR treatment. Genome analysis was performed for 4 affected children (2 y 2 mo to 6 y 8 mo) under treatment with high doses of vitamin D and calcium. Longitudinal records of clinical and radiographic data on their dental development were assessed in relation to genetic profile and response to treatment. Treatment success depended on the position of the mutation within the VDR protein: children with the p.R391S mutation had a favorable outcome but maintained alopecia totalis, while 1 child with the p.H397P mutation and normal hair had no response to very high doses of vitamin D. The primary incisors, formed prenatally and first to emerge, were missing in 3 children and mobile in 1 child; parents reported loss within months posteruption. Posterior teeth were present, having erupted after treatment initiation. Hypoplastic enamel in emerging teeth was associated with late treatment onset. Mutation type in the VDR gene appears to be related to differences in the disease phenotype and response to treatment. Dental development represents an indicator of the disease process, initially protected by maternal blood levels of calcium and later restored by therapeutic supplies that normalize these levels. Knowledge Transfer Statement: Two novel mutations were associated with different HVDRR phenotypes, one of which responded positively to treatment. Early detection of the mutation should help pediatricians forecast treatment protocol and response. The results also highlight the direct relationship between dental development and blood calcium levels, underscoring the importance of early diagnosis and treatment of HVDRR to minimize the loss of primary teeth and reduce structural abnormalities of permanent teeth.

Asunto(s)

Raquitismo Hipofosfatémico Familiar/genética , Mutación , Odontogénesis/genética , Receptores de Calcitriol/genética , Alopecia/etiología , Calcio/uso terapéutico , Niño , Preescolar , Análisis Mutacional de ADN , Raquitismo Hipofosfatémico Familiar/complicaciones , Raquitismo Hipofosfatémico Familiar/tratamiento farmacológico , Raquitismo Hipofosfatémico Familiar/fisiopatología , Femenino , Humanos , Hipocalcemia/tratamiento farmacológico , Masculino , Odontogénesis/fisiología , Linaje , Fenotipo , Vitamina D/uso terapéutico , Vitaminas/uso terapéutico

RESUMEN

While abundant research has been conducted on palatal rugae (PR), the literature pertaining to the sex dimorphism of the palatal rugae and their use for sex prediction is inconclusive. Moreover, palatal rugae have been classified into categories based on length, shape, direction and unification but accurate rugal morphometric linear and angular measurements have not yet been reported. OBJECTIVE: The aims of this study were to -1- assess the dimensions and bilateral symmetry of the first three palatal rugae in an adult population and -2- explore sex dimorphism and the ability to predict sex from palatal rugae measurements. MATERIALS AND METHODS: The maxillary dental casts of 252 non-growing subjects (119 males, 130 females, mean age 25.6 ± 7.7 years) were scanned using a laser system (Perceptron ScanWorks® V5). Angular and linear transverse and anteroposteior measures of the first three palatal rugae were recorded. Independent samples t-tests and paired samples t-tests were used to test for side related differences and sex dimorphism. Multiple logistic regression was employed to model sex using associated palatal rugae measures. RESULTS: Palatal rugae exhibited lateral asymmetry in the majority of bilateral measures. Males presented with larger values for 9 out of 28 parameters. Four linear rugae measurements and one angular measurement together correctly classified 71.4% of the subjects in their true gender. CONCLUSIONS: Morphometric palatal rugae measurements demonstrated promising usefulness in sex prediction. Recording morphometric linear and angular measures is recommended as an adjunct to the commonly used classification based on the shapes of rugae.

Asunto(s)

Paladar Duro/anatomía & histología , Determinación del Sexo por el Esqueleto/métodos , Adulto , Femenino , Humanos , Masculino

RESUMEN

BACKGROUND: The use of the palatal rugae in forensic odontology is based on their unique and individual characteristics. Few studies have assessed the palatal rugae in Mediterranean populations and none in the Lebanese population. OBJECTIVE: Assess the shape and other morphological features of the palatal rugae in a Lebanese adult population, and compare them with reported similar features in other populations. MATERIALS AND METHODS: Rugae characteristics were assessed on the maxillary dental casts of 217 non-growing subjects (95 males, 122 females, age 25.5 ± 7.6 years) according to guidelines established by Thomas and Kotze (1983) and Lysell (1955). The overall number of rugae and numbers of primary rugae (> 5mm in length), secondary rugae (3-5mm) and fragmentary rugae (2-3mm) on either side were recorded. Rugae were classified according to shape, direction and presence of unification. Z-tests were used to compare the proportions between right and left sides and between genders. The mean numbers of rugae in each category were compared with independent samples t-tests between males and females; paired samples t-tests were employed to compare mean numbers of rugae in each category between right and left sides. The data were compared with published reports on other Mediterranean cohorts. RESULTS: The average number of rugae was 7.7 per individual, 3.81 on the right and 3.89 on the left. Curved, wavy and straight rugae patterns were equally common (one third each). The spatial direction of most rugae (49.3%) was backward. Circular, non-specific and convergent rugae were rare (< 2% each). Rugae numbers (total, primary, secondary, fragmentary) were symmetrical but shape, direction and the occurrence of convergence were asymmetrical (p < 0.05). None of the examined characteristics showed gender dimorphism. Tabulated comparisons disclosed the equality of rugae patterns as major differences with findings from other Mediterranean studies. CONCLUSIONS: The palatal rugae in the Lebanese population display shape distinct from other reported Mediterranean and non-Caucasian populations. Studies in large samples and primary comparisons with other Mediterranean populations are warranted.

Asunto(s)

Paladar Duro/anatomía & histología , Adulto , Femenino , Humanos , Líbano , Masculino , Modelos Dentales

RESUMEN

BACKGROUND: The associations between the length and morphological shape-related characteristics of palatal rugae have not been fully explored. OBJECTIVE: We aimed to assess the possible association among various geometric configurations of the palatal rugae in an adult population. MATERIALS AND METHODS: The maxillary dental casts of 217 non-growing subjects (95 males, 122 females, mean age 25.5±7.6 years) were scanned (laser scanning system Perceptron ScanWorks® V5) and digitized for linear measurements. The casts were also surveyed for visual categorization into curved, wavy, straight and other topographical forms, along with spatial direction of the rugae and the presence of unification. The rugae were categorized as primary, secondary, and fragmentary based on their lengths (> 5mm, 2-3mm, < 2mm, respectively). Chi square and one-way ANOVA and post-hoc tests were used to compare the palatal rugae groupings. RESULTS: Primary and backward-directed rugae prevailed in the total sample (84.7% and 49.3%, respectively). Wavy form was dominant among primary lengths, while straight form was associated with the shorter secondary and fragmentary groups (p=0.0042). Absence of unification was the norm (88.8%). CONCLUSIONS: Associations of length and shape characteristics among palatal rugae combine wavy patterns with increased length, and straight forms with shorter folds. These features contribute to the definition of ruga individuality in combination rather than separately.

Asunto(s)

Paladar Duro/anatomía & histología , Adulto , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Modelos Dentales , Programas Informáticos

RESUMEN

OBJECTIVES: To evaluate the relation between adenoid hypertrophy and facial morphology across age in a pediatric population. SETTING AND SAMPLE POPULATION: The American University of Beirut Department of Otolaryngology. Two-hundred consecutive children (age 6.00 ± 2.62 years) referred from the Pediatric Otolaryngology unit to the Orthodontic division and requiring a lateral cephalogram for adenoid hypertrophy assessment. METHODS: Cephalometric measurements included relations among cranial base, maxilla and mandible, and airway clearance measured from adenoid to soft palate (AD). The children were classified into two age groups, Group 1: ≤ 6 years (n = 124) and Group 2: ≥ 6.01 years (n = 76), and also stratified in four subgroups (A, B, C, D) based on maxillo-mandibular divergence (palatal to mandibular plane angle, PP-MP): A- PP-MP ≤ 27.5°, n = 34; B- 27.5° < PP-MP ≤ 32°, n = 68; C- 32°

Asunto(s)

Tonsila Faríngea/patología , Cara , Respiración por la Boca/etiología , Nasofaringe/patología , Ventilación Pulmonar/fisiología , Factores de Edad , Obstrucción de las Vías Aéreas/etiología , Cefalometría/métodos , Niño , Preescolar , Femenino , Humanos , Hipertrofia , Procesamiento de Imagen Asistido por Computador/métodos , Lactante , Masculino , Maloclusión/patología , Mandíbula/patología , Maxilar/patología , Hueso Nasal/patología , Sobremordida/patología , Paladar Blando/patología , Base del Cráneo/patología

RESUMEN

OBJECTIVE: To compare measurements from human skulls and their images from cephalometric radiographs (CR) and computed tomography (CT) scanograms, in order to gauge the potential clinical use of the latter. DESIGN: Based on specific inclusion criteria, including stable centric occlusion, 13 adult skulls were selected from a larger collection. The mandible was taped to the maxilla after securing the occlusion of teeth and condylar seating in the glenoid fossa. Lateral and posteroanterior cephalographs and CT 'scout views' were taken of each skull by standardized methods. Landmarks were identified on skulls and images. OUTCOME MEASURES: Linear measurements were made on all three records; angular measurements only on CR and CT images. Intraclass correlation coefficients (r) were calculated to assess similarity among records. Paired t-tests were used to compare differences between mean measurements. RESULTS: No statistically significant differences were noted between mean angular values on CR and CT views (P > 0.05). The highest correlations were observed for several vertical midline distances between CT and direct skull measures: 0.82 < r < 0.995-greatest for nasion-menton. For sagittal distances, the highest correlation was between the direct measure of condylion-pogonion and its CR image (r= 0.73). Correlations between CR and skull transverse measures were higher (0.46 < r < 0.80) than the corresponding skull vs. CT measures (0.06 < r < 0.38). CT and CR images are 2D slices and projections, respectively, of 3D structures. Vertical CT and skull measures correspond because the CT projection reflects a 1:1 ratio in the midsagittal plane; CT projected lateral images are smaller than the skull measures. The CR image reflects a distortion (approximately 8%) that brings Co-Pg closer to its anatomic distance, inadvertently contributing to better clinical planning, particularly in orthognathic surgery. The pattern of distortion of PA images was in opposite directions for CR and CT views. CONCLUSIONS: Cephalograms and CT scanograms are close in depicting angular relations of structures, but they differ in the accuracy of imaging linear measurements, because the location and size of an object within the imaged 3D structure varies with both records. Logistic and economic considerations favor the use of cephalographs.

Asunto(s)

Cefalometría/métodos , Cráneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Humanos , Variaciones Dependientes del Observador , Magnificación Radiográfica , Reproducibilidad de los Resultados , Estadísticas no Paramétricas

RESUMEN

The aims of this study were (1) to develop a reliable noninvasive method to evaluate the masseter muscle metabolism, by using (31)P-magnetic resonance spectroscopy, and (2) to evaluate the metabolic profile of the masseter muscle in subjects with various facial patterns. The maxillary-mandibular relationship, which varied from hypodivergent to hyperdivergent, was measured on lateral cephalograms of 20 adults, 22 to 35 years of age. (31)P-spectra were acquired from the masseter muscle at rest with a custom-made, single-turn, double-tuned, 3 x 5-cm oblong surface coil. The inorganic phosphate to phosphocreatine (Pi/PCr) ratios were measured and compared in relation to vertical and sagittal cephalometric measurements. A statistically significant (R(2) = 0.65, r = 0.81, P = .001) relationship was found between Pi/PCr ratio and the palatal-to-mandibular plane angle. As the maxillary-to-mandibular divergence increased, the Pi/PCr ratio decreased. This correlation suggests that muscles with a higher Pi/PCr ratio have a higher resting metabolic activity than those with a lower Pi/PCr ratio. Consequently, these muscles may keep bone under more tension and influence its growth in a more horizontal direction. Another possible explanation of the results is that the fiber type composition of the masseter muscle varies with facial morphology.

Asunto(s)

Cara/anatomía & histología , Espectroscopía de Resonancia Magnética/métodos , Músculo Masetero/metabolismo , Desarrollo Maxilofacial/fisiología , Adulto , Cefalometría , Humanos , Fosfatos/metabolismo , Fosfocreatina/metabolismo , Isótopos de Fósforo/metabolismo , Análisis de Regresión

RESUMEN

We report a rare case of an ectopic third molar at the level of the osteomeatal complex. A 21-year-old man came to us with a left-sided nasal obstruction of 2 years' duration. Computed tomography of the paranasal sinuses revealed that an aberrant tooth was obstructing the osteomeatal complex and bulging into the ethmoid infundibulum. Opacity of the entire left maxillary sinus indicated the presence of an associated cystic formation. A transnasal endoscopic sinus technique was employed to create a large middle meatal antrostomy and to remove the tooth as well as the cystic contents and cyst wall. Pathologic analysis revealed that the cyst was dentigerous. After recovery from surgery, the patient resumed nasal breathing. The endoscopic surgical approach used in this case caused less morbidity than do the more common methods (e.g., the Caldwell-Luc procedure) of removing ectopic teeth from the sinus.

Asunto(s)

Endoscopía/métodos , Asimetría Facial , Seno Maxilar/cirugía , Tercer Molar/diagnóstico por imagen , Tercer Molar/cirugía , Erupción Ectópica de Dientes/cirugía , Diente Impactado/diagnóstico por imagen , Adulto , Humanos , Masculino , Tomografía Computarizada por Rayos X

RESUMEN

The aim of this study was to evaluate the effect of maxillary first molar rotation on arch length in patients whose Class II, division 1 malocclusion was treated with a straight-pull headgear. The sample included 19 children who represent a subset of a population enrolled for 2 years in a prospective clinical trial of Class II treatment. The inner bow was adjusted at monthly visits and the average distalizing force was 14-16 oz per side. Measurements were made with digital calipers on casts obtained at baseline and at a time point averaging 16 months (SD 3 months) into treatment. Molar movement was related to a coordinate system referenced to the midpalatal raphae and the occlusal plane through a palatal plug that could be transferred to successive casts of the same patient. Distances from the cusp tips were measured to the reference system. The distal and lateral displacement, and the rotation of the molars over time were then computed. High correlations were observed between molar rotation and tooth displacement (that is the net differential movement between the mesiobuccal - MB - and mesiopalatal - MP - cusps): r=0.9, p=0.0001 (left side); r=0.8, p=0.0001 (right side). The average rotation of the molar was 15.4 degrees (SE+/-3.80) on the left side and 10.8 degrees (SE+/-2.20) on the right side. The average differential displacements between the MB and MP cusps were 1.04 mm (SE+/-0.29) (left) and 0.73 mm (SE+/-0.23) (right). The differences between the two sides were not statistically significant. The molar rotation did not correlate with any of the following parameters: initial tooth position; initial distance between the MB and MP cusps as a correlate of molar anatomy; transverse (mostly buccal) movement of the MB and MP cusps; distal movement of the tooth, as measured by the total displacement of the MB and MP cusps. This study qualifies the relationship between molar rotation and increase in arch length. The mean total distal movement of the molar was larger (nearly 3 mm) than the average contribution of molar rotation to space gain (about 1 mm), suggesting that the distal movement of the tooth was a combination of rotation and translation (or tipping). The contribution of the molar rotation is more significant with a smaller total displacement of the tooth.

RESUMEN

The aim of the study was to evaluate posteroanterior (PA) cephalometric characteristics in a normal longitudinal database and compare these measurements with corresponding measures in a group of patients treated with rapid maxillary expansion. Posteroanterior cephalographs of 16 girls and 14 boys from the Bolton-Brush growth study, taken at ages 10 and 18 years, were used to track growth in children with normal occlusion. Pretreatment PA cephalograms of 24 patients who had palatal distraction around age 10 were compared with the 10-year-old normal patients. Digitized landmarks included right and left jugale (J, at intersection of maxillary tuberosity and zygomatic buttress) and antegonion (AG, at notch of antegonial protuberance). Mandibular width (AG-AG) was similar in boys and girls at age 10 but not 18, when the difference between gender groups was statistically significant (P < .05). Maxillary width (J-J) was greater in boys than girls at both ages. The increase in AG-AG (5.5 mm, boys; 3.9 mm, girls) was more than twice that of J-J (2.4 mm, boys; 1.2 mm, girls). Arch width (at first molar) was nearly stable with age, indicating compensatory occlusal adaptation to differential changes between maxillary and mandibular widths. At age 18, the distance between the centers of the orbits, a surrogate measure of cranial width, was almost equal to J-J in girls and significantly correlated with AG-AG in boys (r = .71, P < .002) and girls (r = .77, P < .0001). The majority of treated children had both skeletal and dentoalveolar widths narrower than control values. Linear regressions between J-J and AG-AG revealed almost parallel slopes for control and treated groups in both genders, but the treated group was at a lower level, which is consistent with smaller maxillary widths.

Asunto(s)

Cefalometría/métodos , Cefalometría/normas , Desarrollo Maxilofacial , Técnica de Expansión Palatina , Adolescente , Análisis de Varianza , Estudios de Casos y Controles , Niño , Femenino , Frente/anatomía & histología , Humanos , Modelos Lineales , Masculino , Mandíbula/anatomía & histología , Maxilar/anatomía & histología , Valores de Referencia

RESUMEN

Identification of craniofacial landmarks, particularly condylar anatomy, on the lateral cephalometric radiograph is erratic. The accuracy of recognition is critical for proper diagnosis of malocclusion and for assessing growth and orthodontic treatment. The aim of this study was to evaluate the identification of condylion and other cephalometric landmarks commonly used, or thought to be easily identifiable. A lateral cephalograph was taken on each of 34 adult subjects. Five examiners, three orthodontists, a dental radiologist and a second-year orthodontic resident rated the condyle, along with sella (S), nasion (Na), point A (A), infradentale (I), pogonion (Pog) and menton (Me) as identifiable, non-identifiable and interpreted. In addition, distances between several of these landmarks were measured. The left condyle, subject to less magnification than the right condyle because it is closer to the film, was more identifiable than the right condyle, which had the highest rating as non-identifiable. Among other landmarks, nasion and point A were the least identifiable, Pog and Me the most. Correlation coefficients for measurements between identifiable landmarks (I-Me) were greater than coefficients for distances involving less identifiable landmarks (S-A). Interestingly, linear measurements were less variable than the identification of corresponding landmarks. These findings corroborate the previous conclusions that clearly identifiable (and the least amount of interpreted) landmarks should be used for proper evaluation of dentofacial relationships. They also suggest, on average, precision in landmark identification is more critical for research purposes than in routine clinical cephalomteric measurements, which serve only as a guide to diagnosis.

RESUMEN

Cephalometric superimposition on cranial base is the accepted method for evaluating mandibular displacement during orthodontic treatment and/or growth. However, assessing mandibular position relative to the maxillary base may yield different information. The aim of this study was to evaluate the effects of regional superpositions (cranial versus maxillary) on interpreting mandibular displacement. Both methods were applied to pre- and posttreatment cephalograms of 22 growing children (12 female, 10 male) treated for Class II Division 1 malocclusion. Differences in linear and angular measurements of three mandibular landmarks (pogonion, gnathion, menton) between cranial and maxillary superpositions were statistically significant (p = 0.0001). Vertical displacement of these landmarks contributed significantly to the differences (p = 0.0001). The contribution of horizontal displacement was not statistically significant. The results support the proposition that, in growing children, posttreatment displacement of mandibular skeletal and dental components should be assessed by both maxillary and cranial base superimpositions. The maxilla is subject to rotational and translational changes during growth that may affect the position of the mandible relative to the maxilla in a way inconsistent with the mandibular displacement perceived upon cranial superposition. Since occlusion is directly associated with the positions of the maxillary and mandibular basal bones, the positions of these bones relative to each other is critical in assessing occlusal changes in individual patients.

Asunto(s)

Cefalometría/métodos , Maloclusión Clase II de Angle/terapia , Desarrollo Maxilofacial/fisiología , Ortodoncia Correctiva , Evaluación de Resultado en la Atención de Salud , Adolescente , Niño , Mentón/crecimiento & desarrollo , Mentón/patología , Oclusión Dental , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Maloclusión Clase II de Angle/patología , Maloclusión Clase II de Angle/fisiopatología , Mandíbula/crecimiento & desarrollo , Mandíbula/patología , Maxilar/crecimiento & desarrollo , Maxilar/patología , Reproducibilidad de los Resultados , Rotación , Base del Cráneo/crecimiento & desarrollo , Base del Cráneo/patología , Dimensión Vertical

Asunto(s)

Maloclusión/fisiopatología , Desarrollo Maxilofacial , Ortodoncia Correctiva/métodos , Factores de Edad , Niño , Femenino , Humanos , Masculino , Planificación de Atención al Paciente , Erupción Dental

RESUMEN

In an attempt to increase retention of orthodontic bands, orthodontic companies market bands with surfaces prepared to increase roughness. A comparison of six groups of bands, including two with untreated surfaces, revealed a wide range of variation in shear forces. Three classes of retention may be differentiated on the basis of non-statistically significantly different mean shear forces in each category: high (Unitek, treated), moderate (Unitek, untreated; A Co., treated; GAC, treated), and low (A Co., untreated; Dentaurum, treated). Surface roughness, as evaluated through atomic force microscopy, correlated moderately with shear force (r = 0.61; p < 0.05). This method is examined and compared with the qualitative profiles of the orthodontic band surfaces provided by optical micrography.

Asunto(s)

Alambres para Ortodoncia , Análisis de Varianza , Recubrimiento Dental Adhesivo , Análisis del Estrés Dental , Fricción , Ensayo de Materiales , Microscopía de Fuerza Atómica , Diseño de Aparato Ortodóncico , Acero Inoxidable , Propiedades de Superficie

RESUMEN

A prospective randomized clinical trial was conducted to evaluate the early treatment of Class II, Division 1 malocclusion in prepubertal children. Facial and occlusal changes after treatment with either a headgear or a Fränkel function regulator are reported. Molar and canine relationships, overjet, intermolar and intercanine distances were measured from casts taken every 2 months, and mounted on a SAM II articulator. Cephalometric radiographs were taken annually. The results indicate that both the headgear and function regulator were effective in correcting the malocclusion. A common mode of action of these appliances is the possibility to generate differential growth between the jaws. The extent and nature of this effect, as well as other skeletal and occlusal responses differ. Treatment in late childhood was as effective as that in midchildhood. This finding suggests that timing of treatment in developing malocclusions may be optimal in the late mixed dentition, thus avoiding a retention phase before a later stage of orthodontic treatment with fixed appliances. However, a number of conditions may dictate an earlier intervention in the individual patient.

Asunto(s)

Aparatos de Tracción Extraoral , Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Adolescente , Factores de Edad , Cefalometría , Niño , Diente Canino/diagnóstico por imagen , Diente Canino/patología , Arco Dental/diagnóstico por imagen , Arco Dental/patología , Articuladores Dentales , Dentición Mixta , Estudios de Evaluación como Asunto , Huesos Faciales/diagnóstico por imagen , Huesos Faciales/crecimiento & desarrollo , Huesos Faciales/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Maloclusión Clase II de Angle/diagnóstico por imagen , Maloclusión Clase II de Angle/patología , Mandíbula/crecimiento & desarrollo , Mandíbula/patología , Maxilar/crecimiento & desarrollo , Maxilar/patología , Modelos Dentales , Diente Molar/diagnóstico por imagen , Diente Molar/patología , Retenedores Ortodóncicos , Ortodoncia Correctiva/métodos , Estudios Prospectivos , Pubertad , Radiografía , Resultado del Tratamiento

RESUMEN

This communication addresses the issue of interpretation of serial cephalometric records. Angular measurements provide information that combines the vertical and sagittal components of a landmark's displacement. For example, a decrease in the SNA angle following orthodontic treatment with a headgear demonstrates maxillary retraction relative to nasion, an important assessment to depict a change closely related to the facial profile. Upon superimposition on the anterior cranial base, however, the vertical movement of point A may be the prevalent displacement, which would still account for the decrease in the SNA angle. The superposition allows the evaluation of the displacement in its vertical and sagittal components separately, relative to a structure that is relatively more stable than nasion. The superimposition enhanced the precision of the information regarding the actual displacement of the jaw. A patient's cephalometric records are presented, further demonstrating that the interpretation of changes during growth and treatment should be based not only on angular measurements, but also on regional superpositions. The frames of reference of both procedures are needed to fully understand the facial changes.

Asunto(s)

Cefalometría/métodos , Errores Diagnósticos , Maloclusión/diagnóstico , Desarrollo Maxilofacial , Estudios de Evaluación como Asunto , Cara/anatomía & histología , Humanos , Maloclusión/terapia , Evaluación de Resultado en la Atención de Salud/métodos

RESUMEN

The purpose of this paper was to compare the findings from three randomized clinical trials that investigated alternative treatments of Class II, division 1 malocclusion in young children. The trials were conducted at the University of North Carolina, the University of Florida, and the University of Pennsylvania. The appliances investigated in each center were a functional appliance versus a headgear. Variations in the specific aims and the working hypotheses were noted. The types of appliances, length of treatment, and methods of evaluation were also different. A general comparison of selected clinically relevant findings reveals similarities and differences in conclusions, but underlines the importance of assessing each study on the basis of its original hypothesis. The separate and combined contribution of these studies to the state of knowledge and research is discussed.

Asunto(s)

Aparatos de Tracción Extraoral , Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Ortodoncia Correctiva/instrumentación , Niño , Humanos , Ortodoncia Correctiva/métodos , Evaluación de Procesos y Resultados en Atención de Salud , Planificación de Atención al Paciente , Estudios Prospectivos , Factores de Tiempo

RESUMEN

The aim of this study was to evaluate the correlation between timing of emergence of the permanent teeth and sagittal occlusal changes in children enrolled in a prospective clinical trial of Class II, division 1 treatment. The children, ages 7.2-13.3 years, met strict inclusion criteria and were assigned at random to treatment with either a headgear or a Fränkel functional appliance. Relationships between maxillary and mandibular first molars and canines, as well as overjet, were measured with digital calipers on casts made every 2 months and mounted on a SAM II articulator. The emergence of a permanent tooth was scored on a scale from 1 to 3, depending on the eruptive level of the tooth from cutting through the gingiva (1) to reaching the occlusal table (3). Specifically, emergence of the second premolars (PM2) and permanent second molars (M2), the most adjacent teeth to the first molars, was evaluated as it interacted with the development of the sagittal occlusion. Treatment of the distocclusion was as effective in late childhood as in mid-childhood. Within each appliance group, the emergence of PM2 and M2 did not affect the amount of progress toward Class I significantly (p > 0.05), indicating that improvement from distocclusion to neutrocclusion with each appliance is not influenced by the timing of emergence of these teeth. Although these findings support a one-phase treatment starting in the late mixed dentition, earlier intervention in mid-childhood may be required in the presence of several developmental conditions, or when the dental and skeletal development deviate significantly in the individual patient.

Asunto(s)

Maloclusión Clase II de Angle/terapia , Diente Molar/fisiología , Ortodoncia Correctiva/métodos , Adolescente , Factores de Edad , Diente Premolar/fisiología , Diente Premolar/fisiopatología , Niño , Dentición Mixta , Femenino , Humanos , Masculino , Desarrollo Maxilofacial , Diente Molar/fisiopatología , Erupción Dental , Diente Primario

RESUMEN

Norms available for the posteroanterior (PA) cephalometric analysis yield different information. The material used to generate these standards is not clearly defined. The purpose of this study was to use data from the Bolton-Brush Growth Study to generate new norms for the PA analysis. The Bolton material is recognized as a controlled longitudinal record of growing children. The assumption that growth in the transverse dimension is the first to be completed is challenged by finding that increments in maxillary and mandibular width vary, like sagittal and vertical growth, according to gender and chronologic age.

Asunto(s)

Cefalometría , Desarrollo Maxilofacial , Adolescente , Factores de Edad , Cefalometría/estadística & datos numéricos , Niño , Preescolar , Femenino , Humanos , Maxilares/diagnóstico por imagen , Estudios Longitudinales , Masculino , Variaciones Dependientes del Observador , Radiografía , Valores de Referencia , Caracteres Sexuales