Effects of Rapid Maxillary Expansion on the Temporomandibular Joint: A Bone Scintigraphy Study.

OBJECTIVE: The purpose of this study is to assess the effects of rapid maxillary expansion on metabolic activity in the temporomandibular joints of young adult patients using scintigraphy. METHODS: The images belonging to temporomandibular joints were obtained from the retrospective scintigraphic records taken from 17 adult females (16.1 and 18.8 years of age and the mean age was 17.3±0.86 years) who had non-functional bilateral posterior crossbite, deep palatal vault and dental crowding, and had been treated with rapid maxillary expansion. Bone scintigraphy images were collected at three-time intervals: at the beginning of treatment (T1), during the opening of the mid palatal suture (T2), and at the end of screw activation (T3). Alteration in bone activity in the temporomandibular joint regions were evaluated in sagittal and transaxial slices. To determine the differences between the intervals, repeated analysis of variance and Bonferroni multiple comparison tests were applied. RESULTS: In the right and left temporomandibular joint regions, significantly increased metabolic activity was exhibited between T1-T2 (p<0.001). At the time of opening the maxillary mid-palatal suture, the metabolic activity increased approximately 60% compared to the initial status. At the end of the active expansion period (T3), the change in metabolic activity was approximately 20% reduced compared to T2. CONCLUSION: Metabolic activity intensification occurs in the regions of interest in the temporomandibular joint during rapid maxillary expansion. After mid-palatal suture opening, activity noticeably decreased (T2-T3). This decrease in bone activity suggests that the temporomandibular joint complex adapts to rapid maxillary expansion forces.

Heritability of facial proportions and soft-tissue profile characteristics in Turkish Anatolian siblings.

INTRODUCTION: The purpose of this study was to determine the possible effects of genetic factors on facial proportions and soft-tissue profile characteristics in Turkish Anatolian siblings. METHODS: The material consisted of lateral and posteroanterior cephalometric head radiographs of 138 siblings (70 women, 68 men) living 15 years or more in the province of Erzurum in eastern Turkey. The subjects were required to have completed their pubertal growth spurts and to have received no previous orthodontic or prosthodontic treatment. The heritability assessments of craniofacial and soft-tissue measurements were undertaken according to narrow-sense heritability. For the calculation and evaluation of heritability estimate values, the mixed-model least-squared and maximum likelihood computer program model type II was used for statistical analysis. RESULTS: According to the narrow-sense heritability estimate values, the measurements of total depth index, soft-tissue chin thickness, soft-tissue facial angle, Merrifield angle, and Holdaway angle showed the highest heritability coefficients (P <.001). Total height index, anterior height index, facial width index, upper to lower facial height index, and lower lip-E line measurements demonstrated moderate heritability values (P<.01). The upper depth index had a low but statistically significant heritability value (P <.05). However, no statistically significant heritability coefficient in upper lip-E line measurement was found. CONCLUSIONS: Turkish Anatolian siblings have similar facial features regarding facial proportions and soft-tissue measurements.

Cervical headgear effects on the morphology of the cervical vertebrae and cervical posture.

OBJECTIVE: To test the hypothesis that use of cervical headgear has an important effect on the morphology of the cervical vertebrae and cervical posture. MATERIALS AND METHODS: The material consisted of pretreatment and posttreatment lateral cephalograms and initial hand-wrist films of 30 subjects who were receiving cervical headgear therapy. Preobservation and postobservation control cephalograms and preobservation hand-wrist films of 15 untreated subjects served as controls. The average treatment time for the treatment group was 9.06 +/- 1.02 months, and the average observation period for the control group was 10.0 +/- 1.1 months. A paired t-test was applied to compare the changes occurring during the examination and observation periods in both groups. In addition, Student's t-test was performed to assess the differences between the groups. RESULTS: The results of the paired t-test showed that within each group there were statistically significant differences in the majority of measurements concerning the morphology of the cervical vertebrae, whereas the measurements concerning cervical posture showed no significant changes in either group. According to the results of the Student's t-test, however, no statistically significant changes between the treatment and control group were present except with regard to two measurements. CONCLUSIONS: Changes in the cervicovertebral morphology in the treatment group were achieved more by growth than by cervical headgear treatment. Although high individual variations were found in postural variables, cervical posture did not change over a period of 9 months either in the treatment group or in the control group.

Effects of early loss of permanent first molars on the development of third molars.

INTRODUCTION: The aim of this study was to evaluate whether early loss of the permanent first molars has an effect on the developmental stages and eruptive conditions of the third molars. METHODS: Panoramic radiographs and dental casts of 165 adolescent patients (103 boys, 62 girls) with unilateral early loss of a permanent first molar were used to assess the developmental stages of the third molars. The formation stages of third molars on the extraction sides were evaluated, and the formative conditions of the contralateral teeth were used as controls. The Mann-Whitney U test was used to assess sex differences in formation stages of the third molars. The Kruskal-Wallis analysis of variance (ANOVA) was used to determine whether there were significant differences in the developmental stages of the third molars between the various extraction quadrants. In addition, the Wilcoxon signed rank test and the paired t test were used to compare the differences in the developmental stages and eruptive conditions of the third molars between the extraction and control sides. RESULTS: The Mann-Whitney U test showed no significant sex differences for the formation stage of the third molars. Therefore, the data from both sexes were pooled. No statistically significant differences were found in the developmental stages of the third molars between the various extraction quadrants in the same jaw and between those in the mandible and maxilla. However, statistically significant differences were found in developmental stages (P <.001) and eruptive conditions (P <.05) of the third molars between the extraction and control sides. The development of the third molars on the extraction side was significantly accelerated compared with the contralateral teeth. CONCLUSIONS: Early loss of the permanent first molars might have an accelerating effect on the development of the third molar on the extraction side compared with the contralateral teeth. Therefore, emergence of the third molars on the extraction side might be hastened, and these teeth might erupt earlier than the contralateral teeth.

Nonsurgical rapid maxillary expansion effects on craniofacial structures in young adult females. A bone scintigraphy study.

OBJECTIVE: To evaluate the skeletal effects of nonsurgical rapid maxillary expansion (RME) on craniofacial structures with bone scintigraphy in young adult female subjects. MATERIALS AND METHODS: The material of the present study consists of scintigraphic records taken from 17 early adult females treated with RME. All patients had a bilateral posterior crossbite, transverse maxillary deficiency, deep palatal vault, and dental crowding at the beginning of the treatment. The age range of the patients was 16.1 to 18.8 years, and the mean age was 17.3 +/- 0.86 years. Bone scintigraphy records were obtained before RME (T1), during the splitting of the midpalatal suture (T2), and after the end of active widening period (T3). Repeated measure analysis of variance was used to assess the differences between the periods. In addition, Bonferroni multiple comparison tests were applied to the measurements at which F values were found to be statistically significant. RESULTS: According to the statistical analysis, significant activity changes were found in all regions studied and in all slices. The metabolic activity in all regions showed significant increases up to the separation of the midpalatal suture (T1-T2), whereas the metabolic activity exhibited a remarkable decrease (T2-T3) after the opening of the midpalatal suture. CONCLUSIONS: Scintigraphic records revealed an increase in the regions of interest scores during RME in all regions and all slices. Therefore, it can be speculated that RME has had not only dental effects but also skeletal effects on young adult patients.

Using a modified nutrition plate for early intervention in a newborn infant with Pierre Robin sequence: A case report.

Pierre Robin sequence is a triad of micrognathia, glossoptosis, and cleft palate that results in upper airway obstruction and feeding problems. It is a serious condition with potentially severe, life-threatening airway obstruction. Approaches for treatment of airway obstruction among neonates with Pierre Robin sequence include prone positioning of the infant, tongue-lip adhesion, mandibular distraction, and tracheostomy. This case report describes a modified nutrition plate and a baby treated using this appliance.

An application of a splint purposeful resin-bonded fixed partial denture after orthodontic treatment: a case report.

An adult male patient who had lost his maxillary left central incisor seven years ago in a traffic accident presented with a chief complaint about his unaesthetic appearance associated with the loss of his maxillary left central incisor space, a Class III molar occlusion, and an anterior open bite malocclusion due to tongue-thrust swallowing. Fixed orthodontic treatment was rendered following fan-type expansion of the maxilla. A Maryland bridge as a minimally invasive dentistry approach was used as a retention appliance and the patient's aesthetic appearance was restored.

The effect of heritability on Bolton tooth-size discrepancy.

The purpose of this study was to determine the possible effect of genetic factors on Bolton tooth-size discrepancy. Subjects who applied for orthodontic treatment and their siblings (106 females and 78 males) were included in the study. The ages of the subjects ranged from 13 to 21 years. The siblings were grouped according to gender: male-male (24 pairs), female-female (38 pairs) and male-female (30 pairs). Mesio-distal tooth size was measured using a pair of dividers with fine tips, and Bolton anterior and overall ratios were calculated. The effect of heritability on Bolton ratios was studied by means of Harvey's mixed model least-squared and maximum likelihood computer program (LSMLMW) model type II. Statistical analysis showed that heritability was effective on Bolton tooth-size discrepancy in all groups except the male-female group. Siblings of the same gender showed high heritability for anterior and overall ratios, but no statistically significant difference was observed in the siblings of different gender.

Longitudinal posteroanterior changes in transverse and vertical craniofacial structures between 10 and 14 years of age.

Longitudinal growth changes in the transverse and vertical craniofacial dimensions occurring between 10 and 14 years of age were evaluated in 22 female and 23 male subjects. All subjects were healthy, had a clinically acceptable occlusion, and had not received orthodontic or orthopedic therapy before. Serial cephalometric radiographs were taken at ages 10, 11, 12, and 14 years. In studying the P-A cephalograms, seven transverse and five vertical measurements were used. The effects of age and sex on the transverse and vertical growth of the craniofacial structures were investigated by means of analysis of variance and Bonferroni multiple comparison test. The results of the study revealed that all measurements studied were affected by age, and cranial, facial, nasal, and maxillary widths were affected by sex. The most pronounced age-related increases occurred in the mandibular width for transverse measurements and in the total facial height for vertical measurements in both sexes during this study.

Investigation of the changes in the positions of upper and lower incisors, overjet, overbite, and irregularity index in subjects with different depths of curve of Spee.

The aim of this study was to investigate the relationship between the depth of the curve of Spee and positions of upper and lower incisors, overjet, overbite, and anterior lower crowding. The material consisted of lateral head films and dental casts of 137 untreated adolescent subjects, 76 girls and 61 boys, aged 13 to 16 years. The subjects were divided into three groups with normal Spee, flat Spee, and deep Spee and were compared with one another. Differences between the Spee groups and between sexes were assessed by means of analysis of variance and a post hoc multiple comparison test. In addition, correlation coefficients between the depth of curve of Spee and other variables were calculated. Finally, cephalometric measurements for all subjects were subjected to a multiple regression analysis, with the depth of curve of Spee as the dependent variable. The results showed that there were no statistically significant differences in the positions of upper and lower incisors and anterior lower crowding among the Spee groups. However, overjet and overbite demonstrated significant differences among the groups. Statistically significant correlations were found between the depth of curve of Spee and overjet and overbite. Multiple linear regression analysis revealed that chronological age and all other variables used in the study could account for only 28.7% of the total variance of the curve of Spee. The overbite alone explained 17.3% of the total variance of the curvature.

An investigation of maxillary and mandibular morphology in different overjet groups.

BACKGROUND: It has been suggested that overjet may be related to the form of the maxilla and mandible. AIMS: The aims of this study were to compare the gender differences in the maxillary and mandibular morphology in different overjet groups, and to determine the associations between overjet and craniofacial morphology in the same subjects. METHODS: The material consisted of lateral cephalometric radiographs of 80 untreated subjects 140 boys, 40 girls), aged 13 to 15 years, selected from records held in the Orthodontic Department, Atatürk University. The subjects were divided into four overjet groups. Thirteen linear, one angular, and three area measurements were used to assess maxillary and mandibular form in the male and female subjects. RESULTS: The results showed that there were statistically significant differences in the maxillary anterior and posterior dentoalveolar heights (MxAABH, MxPABH), effective mandibular length (Cd-Gn), corpus length (Go-Gn), and ramus width (RW) between the overjet groups. In 15 out of 17 measurements the males were significantly larger than the females. There were no gender differences in antegonial notch depth (AND) and the gonial angle. Furthermore, significant negative correlations were found between overjet and Cd-Gn, and between overjet and Go-Gn in the girls. Significant positive correlations were found between overjet and MxAABH, and overjet and RW in the boys. CONCLUSIONS: Evaluation of the maxillary dentoalveolar heights and some mandibular parameters, such as Cd-Gn, Go-Gn and RW, in different overjet patterns may be useful in the analysis of the malocclusion, and prediction of treatment success.

An investigation of cervicovertebral morphology in different sagittal skeletal growth patterns.

The purpose of the present study was to examine and compare cervicovertebral morphology in subjects with different sagittal skeletal patterns. The material comprised lateral head films of 90 untreated subjects, 45 girls and 45 boys, aged 13-15 years. The radiographs were obtained in the natural head position using a fluid level method. The subjects were divided into three groups according to ANB angle: ANB angle between 1 and 5 degrees (skeletal Class I), larger than 5 degrees (skeletal Class II), and smaller than 1 degree (skeletal Class III). Each ANB group consisted of 30 subjects, 15 girls and 15 boys. Twenty-nine linear and four area measurements were used to assess cervicovertebral morphology. Differences between the ANB groups and between genders were assessed by means of analysis of variance and the least significant difference test. In addition, cephalometric measurements for all subjects were subjected to discriminant analysis. The results of the analysis of variance showed that there were statistically significant differences in the measurements of the lumen length of C1, inferior depths of C2 and C4, anterior intervertebral spaces of C2 and C3, posterior intervertebral space of C3, and anterior and posterior body heights of C4 among the ANB groups. The total length of C1, inferior depths of C2-C5, anterior intervertebral spaces of C2-C4, posterior intervertebral space of C2, anterior body heights of C4 and C5, and posterior body heights of C3-C5 demonstrated significant gender differences. The results of the discriminant analysis indicated that 54.4 per cent of the original grouped cases were correctly classified in the total sample. The final discriminant model was able to classify correctly 20 of the 30 Class I subjects (66.7 per cent), 17 of the 30 Class II subjects (56.7 per cent), and 12 of the 30 Class III subjects (40.0 per cent).

Longitudinal cephalometric changes in incisor position, overjet, and overbite between 10 and 14 years of age.

The purpose of this study was to evaluate the longitudinal growth changes in the incisor position, overjet, and overbite between 10 and 14 years of age. Serial cephalometric radiographs of 63 subjects (31 boys and 32 girls) were taken at the ages of 10, 11, 12, and 14. The effects of age and gender on the incisor positions, overjet, and overbite were investigated by means of variance analysis and least square difference (LSD) tests. The results show that the measurements of overbite, upper incisor-NA (mm), lower incisor-NB (mm), upper incisor-NA (angle), and the interincisal angle were affected by age. The results also show that the measurements of overbite, upper incisor-NA (mm), upper incisor-NA (angle) and upper incisor-SN (angle) were affected by gender.