Three-dimensional dental arch and palatal form changes after extraction and nonextraction treatment. Part 2. Palatal volume and height

Is palatal cavity volume affected by maxillary sinus pathologies? A CBCT study

AIM

This study uses cone beam computed tomography (CBCT) to determine whether pathology in the maxillary sinus (MS) affects the volume of the palatal cavity.

METHODS

188 individuals, 95 women and 93 men, aged between 17 and 63, were included in the study. MS pathology in the patients and the open-closed status of the maxillary sinus ostium (MSO) were recorded. Palatal volume measurements were performed using open-access ITK-SNAP via CBCT images. Statistical analysis of the study was conducted using SPSS v.21 software (IBM. Chicago. IL. USA), and p<0.05 was considered statistically significant.

RESULTS

The average palatal volume was 1375.29±313.38 mm3 in male patients and 1235.33±250.40 mm3 in females, and it was found to be statistically significant between genders (p=0.001). MS pathology was detected in 114 (60.6%) of the patients. It was determined that the most frequently observed pathology in both the right (n = 58, 30.9%) and left (n = 65, 34.6%) side MS of individuals was mucosal hypertrophy. It was determined that the mean palatal volume was higher when the MSO was closed (p = 0.000). As a result of the correlation analysis, it was shown that the presence of MS pathology had a positive effect in explaining palate volume by 38.6% (R2 = 0.386).

CONCLUSION

Palatal cavity volume was affected by maxillary sinus pathologies. Palatal cavity volume increases in the presence of MS pathologies and when MSOs are closed.

Palatal shape covariation in extraction versus nonextraction borderline patients: A geometric morphometric study

INTRODUCTION

This study aimed to evaluate changes in palatal shape after orthodontic treatment from a borderline sample of extraction and nonextraction patients with a Class I relationship.

METHODS

A borderline sample regarding premolar extractions was obtained through discriminant analysis and comprised 30 nonextraction and 23 extraction patients. The digital dental casts of these patients were digitized with 3 curves and 239 landmarks placed on the hard palate. Procrustes superimposition and principal component analysis were implemented to assess group shape variability patterns.

RESULTS

The success of the discriminant analysis in identifying a borderline sample regarding the extraction modality was validated using geometric morphometrics. Concerning palatal shape, no sexual dimorphism was found (P = 0.78). The first 6 principal components that were statistically significant accounted for 79.2% of the total shape variance. Palatal changes were 61% more pronounced in the extraction group, which exhibited a decrease in palatal length (P = 0.02; 10,000 permutations). In contrast, the nonextraction group showed an increase in the palatal width (P <0.001; 10,000 permutations). Intergroup comparisons indicated that the nonextraction group exhibited longer palates, whereas the extraction group exhibited higher palates (P = 0.02; 10,000 permutations).

CONCLUSIONS

Considerable changes in palatal shape were seen for the nonextraction and extraction treatment group, with the latter exhibiting more pronounced changes, mainly in terms of palatal length. Further investigations are needed to clarify the clinical significance of the palatal shape changes in borderline patients after extraction and nonextraction treatment.

Morphometric covariation between palatal shape and skeletal pattern in children and adolescents: a cross-sectional study

Objective

To assess shape covariation of the palate and craniofacial complex (CFC) in children and adolescents.

Methods

Pre-treatment lateral cephalometric radiographs and corresponding maxillary casts of 100 children (8-10 years) and 100 adolescents (15-20 years) were digitized. Exclusion criteria were previous orthodontic treatment, craniofacial syndromes, mouth breathing, finger sucking, crossbite, tooth agenesis, and tooth impaction. Palatal shape was described with 239 surface and curve semilandmarks and craniofacial shape with 10 fixed landmarks and 117 curve semilandmarks. Procrustes superimposition and principal component analysis were applied for evaluation of shape variability. Shape covariation between palate and CFC was assessed with partial least squares analysis.

Results

The first five principal components explained 77 per cent (palate) and 60 per cent (CFC) of total shape variability. The palate varied mainly in height (adolescent group) and width-length (both groups), whereas the CFC varied mainly in the vertical dimension. Significant covariation was found between the craniofacial and palatal components (RV coefficient: 0.27, children; RV: 0.23, adolescents). Variation of the CFC in the vertical and anteroposterior direction was mainly related to variation in the height-width and the width-length ratio of the palate, respectively.

Limitations

The use of lateral cephalometric radiographs eliminated the transverse dimension from the craniofacial shape analysis. The study was cross-sectional, so the observed intergroup differences should be interpreted with caution.

Conclusions

Covariation strength and pattern were similar in children and adolescents. The closer a subject was to the high-angle end of the variability spectrum, the higher and narrower was the palate, and conversely.

Dental Arch Dimensions of Nigerian Children with Hypertrophied Adenoids

OBJECTIVE

The study objective was to assess the effect of adenoid hypertrophy on the dental arch dimensions of children in Ile-Ife, Nigeria.

METHODS

Ninety patients aged 3-12 years attending the Otorhinolaryngology Clinic at Obafemi Awolowo University Teaching Hospital Ile-Ife diagnosed as having hypertrophied adenoids and 90 children from the Child Dental Health Clinic were recruited as adenoid and control subjects respectively. Arch and palatal vault dimensions, including total arch length; inter-canine, inter-premolar, and inter-molar widths; palatal length; and palatal heights measured at three levels and palatal volume were determined for both groups from dental casts.

RESULTS

Maxillary arch dimensions were shorter in the adenoid group than the control group; however, only total maxillary arch length was significantly shorter (p=0.049). Mandibular arch dimensions with the exception of inter-molar width were significantly shorter in the adenoid group (p<0.05). Adenoid subjects had significantly increased palatal heights at canine, premolar, and molar levels and reduced palatal volume compared to the control subjects (p<0.05).

CONCLUSION

Adenoid subjects demonstrated shorter maxillary and mandibular arch dimensions compared with control subjects, with the differences being more evident in the lower arch. They also exhibited increased palatal heights at all levels and reduced palatal volume compared with control subjects.

Long-term stability of maxillary anterior alignment in non-extraction cases

OBJECTIVE: The purpose of this retrospective study was to evaluate long-term stability of maxillary incisors alignment in cases submitted to non-extraction orthodontic treatment. METHODS: The sample comprised 23 patients (13 female; 10 male) at a mean initial age of 13.36 years (SD = 1.81 years), treated with fixed appliances. Dental cast measurements were obtained at three different time points (T1 - pretreatment, T2 - posttreatment and T3 - long-term posttreatment). Variables assessed in maxillary arch were Little Irregularity Index, intercanine, interpremolar and intermolar widths, arch length and perimeter. The statistical analysis was performed by one-way ANOVA and Tukey tests when necessary. Pearson' correlation coefficients were used to investigate possible associations between the evaluated variables. RESULTS: There was no significant change in most arch dimension measurements during and after treatment, however, during the long-term posttreatment period, it was observed a significant maxillary incisors crowding relapse. CONCLUSION: The maxillary incisors irregularity increased significantly (1.52 mm) during long-term posttreatment. None of the studied clinical factors demonstrated to be predictive of the maxillary crowding relapse.

Three-dimensional longitudinal evaluation of palatal vault changes in growing subjects

OBJECTIVE

To evaluate palatal vault change in children and to assess the reliability of two palatal parameters in assessing growth modifications.

SUBJECTS AND METHODS

A group of 26 healthy white children aged 5.3 ± 0.3 years (15 boys, 11 girls) were randomly selected. Impressions of the upper dental arches were obtained at baseline and at 12, 18, and 30 months follow-up. Three-dimensional digital images of study casts were obtained using a laser scanning device. Palatal surface area and palatal volume were measured on the digital study casts at each time point. Effect size (ES) coefficients were calculated for both parameters as indices of diagnostic reliability in individual subjects when at least equal to 1.0.

RESULTS

Significant increases in palatal surface area and volume were seen over the observation period (P < .001). ES coefficients for palatal surface area were greater than those for palatal volume. However, even for the former parameter, only the value taken at 30 months was above the threshold.

CONCLUSIONS

Growth of the palatal vault was significant during the observation period, which coincides with primary and mixed dentition stages. Palatal surface area appears to be more reliable than palatal volume in assessment of growth modifications in individual subjects.

Palatal configuration in Class II Division 1 malocclusion: a longitudinal study

INTRODUCTION

The purpose of this study was to evaluate palatal contours in nonextraction orthodontic treatment and long-term stability in patients with Class II Division 1 malocclusions.

METHODS

Data were obtained from maxillary study models before treatment, after treatment, and at least 5 years postretention. Data were collected with a digital pantograph in the canine, second premolar, and first molar regions. Palatal width, base width, palatal height, and alveolar angle were evaluated.

RESULTS

During treatment, the canine region was stable; in the premolar and molar regions, there were statistically significant increases in transverse (palatal and base widths) and palatal height measurements, whereas the alveolar angle decreased. In the postretention evaluation, the canine region showed the greatest modifications, except for alveolar angulation, which was stable. The premolar region showed stability, but, in the molar region, palatal width and alveolar angulation decreased.

CONCLUSIONS

In analyzing alterations in the geometry of palatal configuration, we concluded that a favorable transverse gain of the palatal base, from growth or orthodontics, was important for stability. The transverse gain of palatal base width during Class II treatment is important to compensate for the expected transverse loss in the cervical region and the decrease of alveolar angle in the long term.

Long-term stability of orthodontic treatment and patient satisfaction. A systematic review

OBJECTIVE

To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment.

MATERIALS AND METHODS

Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies.

RESULTS

The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective.

CONCLUSIONS

This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.

Three-dimensional dental arch and palatal form changes after extraction and nonextraction treatment. Part 3. Transversal and sagittal palatal form

The purpose of this study was to investigate changes in the palatal form in patients treated with and without premolar extractions. Records collected at pretreatment, at bracket removal, at the end of retention, and 5 years out of retention were examined. Stone casts were mounted on an articulator with an anatomic face-bow and a central wax record, and measurements were made with a 3-dimensional digitizer. The hypothesis that orthodontic treatment with premolar extractions changes the palatal form was verified.