Thesis (PhD(Dentistry))--University of Limpopo (Medunsa Campus), 2010 / Open bite deformity is a dentofacial anomaly characterised by a space between the upper and lower teeth when the jaws are brought together. When the posterior teeth are in contact and there is separation between the upper and lower incisal edges, the condition is referred to as an anterior open bite (AOB). Anterior open bite occurs more commonly among the Black African race groups, and unless recognised and intercepted early in life, treatment of the condition can become complicated, extended and expensive. Some of the aetiological factors cited in the development of the condition include, an unfavourable growth pattern, finger sucking habits, enlarged tonsillar lymphoid tissue, abnormal tongue and orofacial muscular activity and hereditary factors. Morphologically AOB can involve only the dentoalveolar regions of the craniofacial anatomy, in which case the AOB is said to be a dental AOB; it may be the result of a disproportion between the jaws and is then referred to as a skeletal AOB, or it may be a mixture of the two. The aetiology and structural components of AOB would largely determine the mode of treatment, which can be orthodontic treatment, orthognathic surgery or a combination of the two. Previous studies into the prevalence of AOB in South Africa have reported it to be as high as 27%. Since a major percentage of the patients seen at the School of Dentistry of the University of Limpopo are of the South African Black race group it became relevant to investigate the prevalence of AOB at this institution and to develop a fresh assessment method with standardised values for this population sample. A retrospective study was therefore undertaken among patients visiting the School of Dentistry of the University of Limpopo to determine the prevalence of AOB over a 15-year time period from 1992 to 2006. All xvii patients with an AOB were documented with regard to age, gender, severity and aetiology. The criteria for determining open bite was a measure of at least 1 mm vertical separation between the incisal edges of the upper and lower incisors when the posterior teeth are in occlusion, as determined from the lateral cephalograms and confirmed by the study models. A review of the literature pertaining to craniofacial growth, the aetiology, pathogenesis, clinical presentation and treatment of AOB is also presented as well as investigative techniques for the assessment of AOB. A revised lateral cephalometric assessment method proposed as the Dawjee Analysis was designed and developed and is introduced. It consists of 12 measurements of which nine have never been previously mentioned in the literature and are being defined and described for the first time in this proposed analysis. These parameters are measured against existing and tested anatomical landmarks and planes, combined with the introduction of one new landmark and seven new measuring planes that have not been cited or described in other established analyses. These landmarks, planes and measurement parameters of the analysis are presented and its utility is described. A case study of a patient with AOB is included with an assessment of pre-treatment and post-treatment changes using this analysis. In order to establish standardised values for this population sample, the proposed Dawjee analysis was applied to a control group consisting of 50 adult male and 50 adult female subjects whose cephalometric analysis conformed to the standardised values for this race group. The analysis was also applied to an AOB sample from the retrospective study consisting of 46 male and 59 female cephalograms. Based on the amount of incisor separation this group was divided into mild, moderate and severe AOB. All subjects in both the AOB and control samples were in their permanent dentition stage, having their first permanent molars in a Class I relation. xviii In testing the validity of the proposed Dawjee Analysis, 20 cephalograms from the control group and 20 from the AOB group were also evaluated using other established cephalometric methods and the results thereof were compared to the findings of the proposed Dawjee Analysis From the 15-year retrospective investigation this study found the prevalence of AOB to be 9.67% with the male to female ratio of 46:54. The condition appears to be more common before the age of 13 years than after 13 years with a ratio of 68:32. The aetiology of the AOB in order of rank was found to be thumb or finger sucking, hereditary, nasal obstruction and unknown causes. Over the 15-year period the number of AOB patients attending the Orthodontic Department, School of Dentistry of the University of Limpopo, decreased from 16% to 8%. While this could be due to the realization that the principal cause (thumb or finger sucking) carries a social stigma, a concerted effort must be made to educate communities so that this detrimental habit can be minimised and eradicated. Standardised values for the proposed Dawjee Analysis are presented and potential flaws are outlined. When comparisons are drawn between the control and AOB group it was found that the latter differs from the control sample in 8 of the 12 of the parameters, namely: 1. Incisor separation 2. Anterior cranial base inclination 3. Posterior maxillary position 4. Posterior mandibular position 5. Interalveolar angle 6. Point B position 7. Apex of the maxillary triangle 8. Apex of the mandibular triangle The null hypothesis, which states there are no difference in the cephalometric values of the proposed Dawjee Analysis between AOB xix subjects and a control group for this population sample, was therefore rejected. These morphological differences were supported by the findings of other established analysis that were tested on the AOB and control groups. The difference of the proposed Dawjee Analysis from other cephalometric methods lies in its capability to identify and separate the skeletal from the dental components of an AOB for this study sample. Diagnosis involves a comparison to population standards and the aim of cephalometrics is to describe the standardised morphology of a population. To this end standardised values for the proposed Dawjee Analysis in a South African Black population sample have been determined which focuses on identifying the morphological basis of an AOB.

Objective: To determine the magnitude of soft tissue changes in subjects with different facial patterns following Class II correction. Materials/Methods: A retrospective sample of 80 subjects exhibiting Class II malocclusions was used. Subjects were categorized into facial types according to pre-treatment values of MPA and Y-axis, which yielded 20 brachycephalic, 40 mesocephalic, and 20 dolichocephalic subjects. Data collection included digital analysis on the pre-treatment (T0) and post-treatment (T1) cephalometric radiographs. A paired t-test statistic was used to investigate the differences between the three facial groups at T0 and T1. Conclusions: There are differences in the soft tissue effects observed in patients treated with the XbowTM appliance which are related to the pre-existing facial pattern (p<0.05): The mesocephalic group showed increased retrusion of the upper lip to E-Plane compared with brachycephalic, and dolichocephalic groups. The dolichocephalic group showed significantly more flattening of the mentolabial fold compared to the mesocephalic group.

OBJECTIVES: The aim of this project is to develop a novel 3D cephalometric analysis using anatomical landmarks that cannot be easily viewed on a planar film but on a CBCT image and study the reliability of these measurements between different examiners. METHODS: Fifty CBCT images of patients with normodivergent, Class I skeletal patterns and without any noticeable craniofacial deformities were screened and included in the study based on the lateral cephalograms generated from CBCT data using the Roth/Jarabak Analysis. Fifteen predetermined landmarks that found to be reliable in another associated study were used to define six planes. Measurements were also completed on a human dry skull to confirm accuracy. Eleven different cephalometric measurements were performed by three operators three times using landmarks and planes in 3D. Descriptive statistics (mean and standard deviation) and intra-class correlation coefficient for intra- and inter-examiner reliability was performed. RESULTS: The measurements showed that the means and standard deviations of all three measurers are: for Mandibular A/P: 14.49mm ±2.26; Mandibular deviation: 1.63mm, ±1.19; Maxilla/Mandibular divergence: 24.51°, ±3.85; Maxillary deviation: 0.94mm ±0.5; Pitch (Mandibular Plane), 50.38° ±2.8; Pitch (Maxillary Plane): 74.66° ±3.53; Roll (Mandibular Plane): 87.66° ±2.38, 0.05; Roll (Maxillary Plane): 87.70° ±1.85; Yaw (Maxillary Plane): 4.41°± 2.11; Yaw (Mandibular): 3.61°± 2.43; Maxillary A/P: 2.96mm ±2.26. An interclass correlation was calculated at a range from 0.53 to 0.95. CONCLUSIONS: The means and standard deviations of the measurements can be used as a reference to study. Amongst the operators, we indicate between moderate and excellent reliability. The highest reliability was with measurement mandibular pitch. Lowest reliability was with measurement mandibular roll.

Magister Scientiae Dentium - MSc(Dent) / The Tip-Edge and edgewise techniques are the main techniques that are mostly used in orthodontics, and are applicable to the treatment of any type of malocclusion from the most simple to the most complex. The edgewise bracket wire combination produces bodily tooth movement simultaneously or separately in all three planes of space and hence permits correction of the most extreme tooth malpositions. On the other hand Tip-Edge offers a differential tooth movement (just like the previously used Begg technique) within an edgewise based bracket system (Parkhouse 2003). When treating patients using the Tip-Edge technique, it is recommended that a specialized archwire i.e. Australian stainless steel wire be used. This wire can be described as a round austenitic stainless steel wire that is heat-treated and cold-drawn to its proper diameter. This was done in order to produce its special and needed properties such as toughness, resiliency and tensile strength (Kesling, 1985). It is used in conjunction with light (2oz) class II elastics. The aim of this study was to compare cephalometric changes in skeletal and dento-alveolar parameters in cases treated by these two different orthodontic techniques. This was to be established by calculating and comparing the pre- and post-treatment cephalometric variables of cases treated with these techniques by looking at the skeletal and dento-alveolar measurements. Thirty Tip-Edge and thirty edgewise treated cases that had class II malocclusion, had extraction of four premolars and were treated with Class II elastics were selected. The gender distribution between the Tip-Edge and the edgewise techniques were 47% and 60% respectively for females. For males it was 53% in Tip-Edge and 40% in the edgewise techniques.

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Made available in DSpace on 2014-06-11T19:35:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-15Bitstream added on 2014-06-13T18:46:21Z : No. of bitstreams: 1 takeshita_dcri_me_sjc.pdf: 1226654 bytes, checksum: e9d097b585b998e5d383e3db8a960dd7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente , a cefalometria passa po questionamentos com relação a sua precisão em avaliar o grau e a localizaçãoda deformidade a ser tratada. a abtenção das radiografias cefalométricas, de forma padronizada, pela metodologia da postura natural de cabeça(PNC) tem pouca popularidade no Brasil, talvez pelos poucos estudos existentes sobre o tema. Sendo assim, o objetivo no presente estudo foi verificar se havia diferença nos valores da análise cefalométrica do perfil tegumentar, tendo como base a Análise facial de Arnett, realizada em radiografias cefalométricas em norma lateral, digitalizadas, obtidas pelas técnicas convencional e me PCN. àra tal propósito 100 radiografias cefalométricas, pertencentes ao arquivo digital da disciplina de radiologia da Faculdade de odontologia de São José dos Campos da Universidade Estadual Paulista Julio de Mesquita Filho - UNESP foram utilizadas e as medidas foram realizadas duas vezes com um intervalo de 15 dias entre elas. Não encontramos significâncias entre os dias. Utilizamos o teste ANOVA para comparar o resultado médio entre os sexos para cada uma das linhas e concluimos que não houve diferença média estatisticamente significante entre os sexos. Fizemos também uso do T-Student Pareado para comparar os resultados entre as linhas LVV e perp PHF para todos os parâmetros. Concluímos que houve diferença média estatisticamente significante entre as duas metodologias estudadas, e assim não devemos substituar a linha LVV pela linha perp PHF. / Currenty , the cephalometry passes for questionings with regard to its precision in evaluating the degree and the localization of the deformity to be treted . The obtainment of the cephalometric lateral x-rays, of standardized form, for the methodology of the natural head posture has little popularuty in Brazil, perhaps for the few studies on the theme. Being thus, the aim in the present study was verif IF it hás difference in the on Arnett's facial analysis, carried through in digitalizided cephalometrics x-rays gotten by the conventional and with natural head posture techniques, For such a purpose 100 cefalomretic X-rays, pertaining to the digital archive of the discipline of Radiology of the Faculty of Dentistry of Saint José of the Fields of the State University of São Paulo Julio de Mesquita Filho UNESP went used and the measures were carried out two times with an interval of 15 days between them. We do not find significations between the days. we use the test ANOVA to compare the middle result between the sexs for each one ofthe lines and end that there was no statistically significant middle difference between the sexs. We did also use of the T-Student Pareado in order that LVV compared the results between the lines and perp PHF for all the parameters. It was concluded that there was statiscally significant middle difference between both methods studied, so we should not switch the LVV line for perp PHF line.

AIMS: The aims of this study were to examine the cephalometric and airway measurements on children with Sleep Related Breathing Disorders (SRBD) and without SRBD, and to investigate the impact of maxillary expansion on these measurements. MATERIALS AND METHODS: This observational study utilized data from Boston University Orthodontics Department between 2016 and 2020. Lateral cephalograms, acoustic rhinometry and pharyngometry were obtained at two time points. SRBD was determined by a score of 0.33 or higher according to the Pediatric Sleep Questionnaire. Mann–Whitney U test and Spearman correlation analysis were used to analyze the data. Statistical significance was set at <0.05. RESULTS: A total of 163 children (61 male, 102 female) were included in this study. Certain airway measurements (Ph Volume p=0.02, Rh air resistance p=0.05, Rh minimum resistance p=0.001) were significantly higher in SRBD group compared to non-SRBD group. In the SRBD group there was a significant negative correlation between Ph Min Distance and SNA (p=0.001), SND (p=0.05), mandibular arc (p=0.03), U1-SN (p=0.02), U1-Apo (p=0.03). Positive. correlations were observed between Ph Volume with L1-NB (p=0.05) and Rh Min Distance Left with Pog- NB (p=-0.5), mandibular arc p=0.05, L1-NB (p=0.01), L1-Apo (p=0.01). Rh Min Cross-sectional left was positive correlated with overbite (p=0.03) and Rh Min cross-sectional right with posterior face height (p=0.05). Certain airway measurements and cephalometric measurements were statistically different across expansion and non-expansion groups (RhVolumeRt p=0.003. RhMinCrossSectionalLft p=0.03, RhMindistanceRt p=0.03, RhAirResistanceRt p=0.05, ANB p=0.0058, S-N (mm) p=0.05, U1 - NA (mm) p=0.04, U-Incisor Protrusion p=0.01, nterincisal Angle p=0.01, Upper Lip - S Line p= 0.005, Upper Lip to E-Plane p=0.01 CONCLUSION: Airway measurements and cephalometric measurements differ significantly between SRBD and non-SRBD subjects. Significant correlations were observed between cephalometric measurements and airway measurements in the SRBD children. Maxillary expansion can be a treatment option for improving certain airway and cephalometric values among those with sleep-disordered breathing.

The lateral cephalometric radiography is an essential tool in clinical practice, especially in the area of orthodontics, allows measurements to investigate the development and growth of the facial skeleton , aiding in the diagnosis and treatment plan for each patient. The first type of radiography was the conventional were used and the development of technology has evolved to be digital . The purpose of this study was to compare the geometric distortion of digital lateral cephalometric with conventional cephalometric in human cadaver skulls . The sample was taken for convenience and was composed of 21 human cadavers dry skulls, three markers were placed on each skull lead. The first marker was at the level of the junction of the sutures sphenofrontal, coronal , flaky and sphenosquamosa and parallel to the Frankfort plane . The second one below the frontozygomatic suture and the last at the branch level of the jaw and positioned in the concave part of the line above and parallel to the Frankfort plane . No significant differences were found when comparing the measurements of conventional and digital plates in the upper and middle third, but when the last third was analyzed differences were found between conventional and digital images . All the images presented distortion when they were compared with the gold standard. / La telerradiografía lateral es una herramienta esencial en la práctica clínica especialmente en el área de ortodoncia, nos permite realizar mediciones para investigar el desarrollo y crecimiento del esqueleto facial, ayudando en el diagnóstico y plan de tratamiento de cada paciente. El primer tipo de radiografía utilizada fueron las convencionales y con el desarrollo de la tecnología, fue evolucionando hasta ser digital. El propósito de este estudio fue comparar la distorsión geométrica de la telerradiografía lateral digital con la telerradiografía convencional en cráneos de cadáveres humanos. La muestra fue tomada por conveniencia, siendo conformada por 21 cráneos secos de cadáveres humanos, se le colocaron tres marcadores de plomo a cada cráneo. El primer marcador estuvo a nivel de la unión de las suturas esfenofrontal ,coronal, escamosa y esfenoescamosa y paralelo al plano de Frankfort. El segundo debajo de la sutura frontocigomática y el último a nivel de la rama de la mandíbula y posicionado en la parte más cóncava de la línea anterior y paralela al plano de Frankfort. No se hallaron diferencias significativas al comparar las medidas de las placas convencionales y digitales en el tercio medio y superior, pero al analizar el tercer tercio si se hallaron diferencias entre las imágenes convencionales y digitales. En cuanto a la comparación con el gold standard, todas las placas presentaron distorsión. PALABRAS CLAVES: telerradiografía lateral, distorsión, telerradiografía convencional, telerradiografía digital / Tesis

BACKGROUND: Growth of the cranial base and its structures are of particular interest to the orthodontic community. The midface and nasal bones have a significant influence on facial esthetics and thus pattern recognition of facial growth from parental data can influence orthodontic treatment plans. We aimed to determine if there is a similarity in midface and nasal bone and soft tissue growth between a child and either parent. MATERIALS AND METHODS: This cross-sectional study was comprised of forty-seven western European families from the Forsyth/Moorrees Twin Study. The lateral cephalograms of each parent and post pubertal child, who were at least 2 years past peak growth (age ≥ 16 yrs for females and ≥ 17 yrs for males) were evaluated on fourteen cephalometric variables. The radiographs were digitized and analyzed using the Mimics™ software program (Materialise, Leuven, Belgium) by a single investigator. A linear regression analysis was used to correlate linear and angular measurements to one another. An ANOVA with multiple comparisons (TUKEY) was performed to test for the differences between family members controlling for the effect of the individual family (as each family has a trend within itself). Age and gender interactions were tested for in the models. Statistical significance was set at p < 0.05. RESULTS: Twenty-five male and twenty-two female children and their parents were studied. When comparing the fourteen parameters between the mean of the child and both parents, a significant difference (p < 0.05) was found between the child and the father but not the mother in six measurements. These included the ratio of nasal height to total face height, angle of nasal bone to SN, distance from rhinion to pronasale (mm), distance from ANS to pronasale (mm), projection of nose (mm) and nasal length (mm). A significant difference was also found between the child and the mother, but not the father for rhinion to ANS (mm). A significant difference was found between the child and both parents for nasal height (mm). When controlling for family and isolating the gender of the child, males and females were not significantly different from their fathers for ratio of nasal height to total face height. For angle of nasal bone (S-N-Rh) and nasal length (N’-vertical line from Pro), females but not males were significantly different from the father. Both girls and boys were still significantly different from the father in the rhinion to pronasale and ANS to pronasale distances, projection of nose and nasal heights. Only males showed a significant difference from the mother for rhinion to ANS and nasal height when isolated for by gender. CONCLUSION: Statistically significant differences were found between the child and father and not the mother for six out of our fourteen measurements of interest. Two measurements of interest showed a difference between the child and the mother and not the father and one showed a significant difference from both parents. From this study we conclude that children tend to be morphologically less similar to their fathers when comparing midface and nasal soft and hard tissue parameters.

O objetivo nesta pesquisa foi o de avaliar quantitativamente as variações na determinação de 7 pontos cefalométricos e analisar o quanto que estes erros podem influenciar no planejamento e progressão da terapêutica ortodôntica. Foram utilizados 14 crânios macerados onde fora colocadas esferas metálicas para a demarcação dos pontos cefalométricos escolhidos. Estes crânios foram radiografados com e sem as esferas metálicas, e as grandezas cefalométricas avaliadas estatisticamente. Os resultados mostraram que a média de erro na localização dos pontos foi de 57,5% e que este desvio em termos numéricos podem levar a equívocos de planejamento que podem comprometer seriamente o resultado do tratamento com desvios em algumas medidas cefalométricas de até 4mm. As mensurações relacionadas aos pontos espinha nasal anterior, pogonio e gônio foram as que tiveram maior reprodutibilidade, porém, as medidas cefalométricas relacionadas ao ponto A mostraram que as diferenças encontradas então em torno de 4,3mm, e que a avaliação do comprimento mandibular obtida pela localização do ponto condílio, também gerou diferenças de 2,8mm em média, alterando assim substancialmente as avaliações para diagnóstico e tratamento ortodôntico e cirúrgico. / The aim of this study were to evaluate quantitatively the variations on the determination of 7 cephalometric landmarks and to analyze how these differences may influence the planning and outcome of the orthodontic treatment. Small steel balls were glued on specific sites of 14 dry skulls to represent the true anatomical landmarks. The skulls were radiographed with and without the steel balls, and the cephalometric values were submitted to statistical analysis. Results showed that the error in the localization of the landmarks was in average 57,5%. This high deviation, that reaches up to 4mm in certain cephalometric measurements, could lead to errors in treatment planning and compromise the result of any orthodontic treatment. Measurements of the Anterior Nasal Spine, Pogonion and Gonion showed the highest reproducibility, while point A showed the lowest (4,3mm). The evaluation of the mandibular length through the identification of Condyle also showed high discrepancies (2,8mm), which may alter the evaluations for orthodontic and/or surgical diagnosis and treatment.