Effects of impacted maxillary canines on root resorption of lateral incisors : A cone beam computed tomography study.

OBJECTIVES: The aim of this study was to analyze the amount of root resorption of maxillary lateral incisors by relating the position, location, and angulation of the impacted canine using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The study sample consisted of panoramic and CBCT radiographs of 46 patients with a unilateral impacted canine (16 males and 30 females; mean age: 19.53 ± 6.66 and 19.44 ± 5.77 years, respectively). Sector location and canine angulation were measured in panoramics. All tomographs were obtained using CBCT (NewTom 5G, QR, Verona, Italy) and three-dimensional (3D) reconstructions of the maxillary laterals assessed by Mimics 14.01 image analysis software. RESULTS: Upper lateral incisor volume was smaller on the impacted side (401.95 ± 83.69 mm3) than on the nonimpacted side (433.54 ± 92.6 mm3, P < 0.05). There were no significant differences of lateral root resorption volume when comparing the impacted canines being on the labial or palatal sides (P > 0.05), but impacted canine angulation was significantly steeper on the labial side (70.85°) than on the palatal side (46.09°, P < 0.05). The volume of root resorption of laterals when comparing the various positions of the canine in different sectors or canine angulation in 30o intervals was not statistically significantly different (P > 0.05). CONCLUSIONS: The impacted canines caused root resorption of lateral incisors. The angulation of the canine was steeper on the labial side than on the palatal side but root resorption of adjacent laterals was not different. There were no statistically significant differences in the amount of root resorption of the laterals when the canine was evaluated according to localization and angulation.

Comparison of arch forms between Turkish and North American.

OBJECTIVE: The aim of this study was to clarify the morphological differences in the mandibular arches of Turkish and North American white subjects. METHODS: The sample included 132 Turkish (34 Class I, 58 Class II, and 40 Class III) and 160 North American (60 Class I, 50 Class II, and 50 Class III) subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of patients' mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The subjects were grouped according to arch form types (tapered, ovoid and square) in order to have frequency distribution compared between ethnic groups in each Angle classification. RESULTS: The Turkish group showed significantly lower molar depth and more significant molar width-depth (W/D) ratio in all three Angle classifications. On the other hand, the Turkish group also showed a significantly larger intercanine width in Class III malocclusion and intermolar width in Class II malocclusion. The most frequent arch forms seen were the ovoid arch form in the Turkish group and the tapered form in the white group. CONCLUSIONS: Our results demonstrate that when treating Turkish patients, one should expect to use preformed ovoid arch form orthodontic wires in a significant percentage of patients.

Comparison of arch forms between Turkish and North American

ABSTRACT Objective: The aim of this study was to clarify the morphological differences in the mandibular arches of Turkish and North American white subjects. Methods: The sample included 132 Turkish (34 Class I, 58 Class II, and 40 Class III) and 160 North American (60 Class I, 50 Class II, and 50 Class III) subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of patients' mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The subjects were grouped according to arch form types (tapered, ovoid and square) in order to have frequency distribution compared between ethnic groups in each Angle classification. Results: The Turkish group showed significantly lower molar depth and more significant molar width-depth (W/D) ratio in all three Angle classifications. On the other hand, the Turkish group also showed a significantly larger intercanine width in Class III malocclusion and intermolar width in Class II malocclusion. The most frequent arch forms seen were the ovoid arch form in the Turkish group and the tapered form in the white group. Conclusions: Our results demonstrate that when treating Turkish patients, one should expect to use preformed ovoid arch form orthodontic wires in a significant percentage of patients.

RESUMO Objetivo: o objetivo deste estudo foi avaliar as diferenças morfológicas entre as arcadas dentárias inferiores de indivíduos turcos e indivíduos norte-americanos leucodermas. Métodos: a amostra incluiu 132 indivíduos turcos (34 Classe I, 58 Classe II e 40 Classe III) e 160 norte-americanos (60 Classe I, 50 Classe II e 50 Classe III). A porção mais vestibular de 13 áreas de contato proximal foi digitalizada a partir de imagens impressas das arcadas dentárias inferiores dos pacientes. Os pontos de colagem dos braquetes foram calculados, para cada dente, com base em dados referentes à espessura dos dentes inferiores. Quatro medidas lineares e duas proporcionais foram obtidas. Os indivíduos foram classificados de acordo com o formato da arcada (triangular, oval e quadrada), permitindo que a frequência de cada formato fosse comparada entre os grupos étnicos, e dentro de cada classificação de Angle. Resultados: o grupo composto por indivíduos turcos apresentou profundidade da arcada na região dos molares significativamente menor, além de uma proporção largura/profundidade da arcada na região dos molares maior em todas as classificações de Angle. Em contrapartida, esse mesmo grupo mostrou maiores distâncias intercaninos nos pacientes Classe III e intermolares nos pacientes Classe II. A arcada oval foi a mais frequente no grupo composto por indivíduos turcos, enquanto a arcada triangular foi a mais frequente no grupo composto por indivíduos norte-americanos leucodermas. Conclusões: os resultados obtidos mostram que, ao tratar pacientes turcos, o profissional deve prever o uso de arcos ortodônticos pré-conformados ovais em um percentual significativo dos pacientes.

Effects of cleft lip and palate on the development of permanent upper central incisors: a cone-beam computed tomography study.

OBJECTIVE: The aim of this study was to evaluate 1. the differences among the cleft sides of unilateral cleft lip and palate (UCLP) patients, non-cleft sides of the same UCLP patients and well matched control patients in the root development and position of permanent upper central incisors and 2. possible gender differences. MATERIALS AND METHODS: The study sample consisted of 40 patient (20 males and 20 females; mean age: 14.84±3.2 years) with non-syndromic UCLP patients, and 40 control patients (20 males and 20 females; mean age: 13.38±1.6 years). Cone-beam computed tomography (CBCT) images were taken off from all patients. All tomographs were obtained in supine position by using CBCT (NewTom 5G, QR, Verona, Italy). RESULTS: Significant smaller root volume of central incisor was observed on the cleft side than on the non-cleft side of UCLP patients (P < 0.05). No significant difference in the root development and position of the central incisors was found between the non-cleft side of the UCLP and the control group (P > 0.05). There were no statistically significant gender differences in any linear, angular, or volumetric measurements (P > 0.05). Only the root volume of the cleft side was smaller in females than in males (P < 0.05). CONCLUSIONS: In general, root volumes of central incisors on the cleft side were 12.15 per cent smaller than non-cleft side. Root development of the central incisor was much more influenced by the cleft in females than in males.

Assessment of pharyngeal airway volume in adolescent patients affected by bilateral cleft lip and palate using cone beam computed tomography.

OBJECTIVE: To test the null hypothesis that there were no significant differences for pharyngeal airway volumes between the adolescent patients affected by bilateral cleft lip and palate (BCLP) and well-matched controls using cone beam computed tomography. MATERIALS AND METHODS: The study sample consisted of 16 patients (11 female and 5 male; mean [SD] age 14.1 [2.1] years) affected by BCLP and 16 patients (10 female and 6 male; mean [SD] age 13.4 [2.0] years) as age- and sex-matched control group. Craniofacial measurements and pharyngeal airway dimension, area, and volume measurements of patients in both groups were calculated and statistically examined using Student's t-test and multiple linear regression analyses. RESULTS: Statistically significant differences were found between the BCLP and control groups for SNB (P < .05), SN-GoGn (P < .05), Co-A (P < .05), PAS (P < .01), minAx (P < .01), and oropharyngeal airway volume (P < .05). The most predictive variables for oropharyngeal airway volume were found as PAS (r  =  .655 and P  =  .000) and minAx (r  =  .787 and P  =  .000). CONCLUSIONS: The null hypothesis was rejected. Oropharyngeal (P < .05) and total (P > .05) airway volumes were found to be less in the BCLP group, and thus the treatment choice in these patients should have positive effects on the pharyngeal airway.

Condylar and ramal vertical asymmetry in adolescent patients with cleft lip and palate evaluated with cone-beam computed tomography.

INTRODUCTION: The aims of this study were to evaluate condylar and ramal mandibular vertical asymmetry in a patient group affected by unilateral (UCLP) and bilateral (BCLP) cleft lip and palate, and to compare the findings with a well-matched control group with normal occlusion. METHODS: The study groups included 20 UCLP patients (12 male, 8 female), 21 BCLP patients (12 male, 9 female), and a control group of 21 subjects with normal occlusion (10 male, 11 female). Measurements of condylar, ramal, and condylar plus ramal heights and asymmetry indexes were examined on cone-beam computed tomography images. One-way analysis of variance was used to determine potential statistical differences among the groups for condylar, ramal, and condylar plus ramal asymmetry index measurements. The post-hoc Tukey HSD test was used to determine individual differences. RESULTS: No investigated group showed a statistically significant sex difference for any asymmetry index (P >0.05). There was a statistically significant difference between the normal and cleft sides in the ramal height and ramal plus condylar height measurements in the UCLP group (P = 0.004 and P = 0.006, respectively). The Tukey HSD test showed a statistically significant difference between the UCLP and BCLP groups in terms of ramal asymmetry index values (P = 0.018). CONCLUSIONS: The ramal height and ramal plus condylar height measurements were significantly lower in the cleft side in the UCLP patients, and there was a statistically significant difference in ramal asymmetry index values between the patients affected by UCLP and BCLP.

Comparision of orofacial airway dimensions in subject with different breathing pattern.

OBJECTIVE: To test the null hypothesis that there is no significant difference in the craniofacial morphology and orofacial airway dimensions between mouth breathing (MB) and nasal breathing (NB) subjects. MATERIALS AND METHODS: Lateral cephalometric radiographs of 34 MB subjects (mean age: 12.8±1.5 years; range: 12.0-15.2 years) and 33 NB subjects (mean 13.9±1.3 years; age range: 12.2-15.8 years) with Class I occlusion were examined. Totally, 34 measurements (27 craniofacial and 7 orofacial airway) were evaluated. Group differences were statistically evaluated by independent samples t-test at p<0.05 levels. RESULTS: Statistical comparisons showed that SNA (p<0.01), ANB (p<0.01), A to N perp (p<0.05), convexity (p<0.05), IMPA (p<0.05) and overbite (p<0.05) measurements were significantly lower in MB group when compared to NB group. However, SN-MP (p<0.01) and PP-GoGn (p<0.01) from angular measurements and S-N (p<0.05) and anterior facial height (p<0.05) from linear measurements were significantly higher in MB subjects. Among orofacial airway measurements, only upper posterior airway space was found significantly higher(p<0.001) in MB than NB subjects. CONCLUSIONS: The null hypothesis was rejected. Mouth breathing affects craniofacial morphology and orofacial airway dimensions.