Dental Arch Width Research Articles

Buccolingual inclination of posterior dentition in maxillary impacted canine patients using quadrant analysis - A cone-beam computed tomographic study

BackgroundTo examine the buccolingual inclination of maxillary posterior teeth, curve of Wilson, and transversal dimensions in palatally impacted maxillary canine patients, compared to controls by cone-beam computed tomography (CBCT).Materials and methodsPre-treatment images of 22 bilateral, 32 unilateral impacted maxillary canine patients and 30 controls were included. All patients had palatally impacted canines, with no posterior cross-bite. Data were reclassified in quadrants according to the presence of impaction, as the impaction quadrant (right and left quadrants of 22 bilateral impacted cases, and quadrants presenting impaction of 32 unilateral cases, n = 76), unaffected quadrant (quadrant without impaction in 32 unilateral cases, n = 32) and the control quadrant (right and left quadrants of 30 controls, n = 60) to evaluate the buccolingual inclination angle, transversal width, and arch perimeter. Additionally, comparisons were made regarding curve of Wilson and total arch perimeter among bilateral and unilateral impaction groups with the control group. Statistical analysis was performed by one-way ANOVA and Kruskal Wallis tests. Tukey or Dunn tests were used for comparisons between groups in pairs.ResultsNo significant difference was found for the buccolingual inclination of maxillary posterior teeth and curve of Wilson among groups. The buccolingual inclination of canines in the impaction quadrant was significantly lower than the other quadrants (p < 0.001). Basal bone width at the level of second premolars, and alveolar width at both premolars were significantly narrower in the impaction quadrant than in the unaffected quadrant (p < 0.05). Dental arch width at the level of first premolar was significantly decreased in the impaction quadrant compared to other quadrants (p < 0.05). Arch perimeter was significantly reduced in the impaction quadrant than in the unaffected quadrant (p < 0.05).ConclusionThe presence of bilateral or unilateral palatally impacted maxillary canines did not effect the buccolingual inclination of posterior teeth, and curve of Wilson. Transverse discrepancy was evident in the impaction quadrant even in the absence of posterior cross-bite. Quadrant analysis was particularly useful in evaluating asymmetry for basal bone and alveolar bone widths in the premolar region in patients with unilateral palatally impacted maxillary canine patients.

Credibility of Pont’s index in Egyptian population

BackgroundMany indices have been suggested to help orthodontists in predicting the ideal dental arch width. One of these was Pont’s index which was established by Pont. He suggested equations to predict the ideal maxillary dental arch width (interpremolar and intermolar) from the combined mesiodistal width of the maxillary incisors. This study aimed to test the applicability of Pont’s index as an orthodontic diagnostic tool in Egyptian population and to compare the results with those obtained from studies of different ethnic subjects.MethodsThis study was performed using dental casts of 184 Egyptian individuals (82 males and 102 females; age range, 19–24 years). The casts were divided into 46 casts with normal occlusion, 46 casts with class I, 46 casts with class II and 46 casts with class III malocclusion, according to Angle’s classification. Alginate impressions were taken for all patients and poured immediately using dental plaster. The real models were transformed into digital models using three-dimensional laser scanner to allow digital model analysis. Predicted arch widths were calculated using Pont’s equations. The predicted values were compared to the measured values.ResultsIntra class correlation coefficient (ICC) (absolute agreement) between measured and predicted arch widths was determined. Poor absolute agreement was found between measured arch width values and the corresponding values calculated according to Pont’s index.ConclusionAccording to the results of this study, Pont’s index is not a reliable method for predicting the ideal dental arch widths in Egyptian populations.

Genetic and environmental impact on variation in the palatal dimensions in permanent dentition: a twin study.

The objective of this study was to assess the relative contributions of genetic and environmental factors to variation in palatal parameters in twins with completed maxillary growth. The subjects of this study comprised digital dental casts of 50 monozygotic and 35 dizygotic twin pairs. The subjects' average age was 17.95 ± 2.83years. Zygosity determination was carried out using 15 specific DNA markers and an amel fragment of the amelogenin gene. The interdental distances were measured between selected dental landmarks at the occlusal and gingival planes. The palatal height, surface area and volume were measured between the gingival plane and the midpalate suture. High heritability estimates were observed for all transverse intra-arch measurements. The palate height (a2 = 0.8), dental arch width in the molar area (a2 = 0.86), palatal surface area (a2 = 0.61) and palate volume (a2 = 0.69) were under strong additive genetic control. Moderate genetic dominance was observed for dental arch widths at the gingival line in the canine (d2 = 0.5) and premolar regions (d2 = 0.78-0.81). Sexual dimorphism was shown, with males exhibiting a greater arch width, palate surface area and volume than females (p < 0.01). The majority of palate parameters variation in twins was controlled by genetic effects, and most were highly heritable.

Relationship of buccolingual inclination between the alveolar bone and first molar in different vertical facial types: A CBCT study

BackgroundThis study aimed to investigate the differences in the buccolingual inclination and transverse width of maxillary and mandibular first molars among different vertical facial types. MethodsIn all, 78 samples were divided into three groups based on the GoGn-SN angle: the low-angle group (n = 26, mean age=24.21±5.11), average-angle group (n = 26, mean age=22.66±3.72), and high-angle group (n = 26, mean age=22.23±2.43). Cone beam computed tomography (CBCT) measurements were used to assess the buccolingual inclination of the axis of the maxillary and mandibular first molars, as well as the buccolingual inclination of the alveolar bone, the dental arch width, and the basal bone width. One-way ANOVA, the LSD test, and Pearson correlation analysis were performed. ResultsThe high-angle group showed significantly greater lingual inclination of the maxillary alveolar bone than the low-angle group and average-angle group (p < 0.001; p < 0.05). The difference in buccolingual inclination of the axis of the maxillary first molar and the alveolar bone was significantly greater in the high-angle group than in the low-angle group (p < 0.05). Both the maxillary and mandibular dental arch were significantly narrower in the high-angle group than in the other two groups. The mandibular basal bone was also significantly narrower in the high-angle group than in the low-angle group and average-angle group (p < 0.001; p < 0.01). ConclusionsThe alveolar bone of maxillary first molar in the high-angle group was more palatal inclined than that the low-angle group and the average-angle group, which suggests that orthodontists should pay more attention to the root-bone relationship in the high-angle group during expansion treatment to prevent bone fenestration and dehiscense.

Pont’s Index, is it Reliable and Applicable for Iraqis?

To facilitate the correct diagnosis and treatment planning, a range of diagnostic orthodontic indices have been developed. Pont’s index, as one of them, was documented to estimate the ideal maxillary dental arch widths from the sum of crown widths of maxillary incisors. This retrospective study aimed to evaluate the applicability of Pont’s index to Iraqi individuals. Fifty stone dental models for 25 females and 25 males were retrieved from the archives of the Department of Orthodontics in Baghdad College of Dentistry. The dental arch widths at the level of 1st premolar and molar areas in addition to the mesiodistal crown widths of all teeth were measured using an electronic vernier. The estimated arch widths were compared to the actual ones using paired sample t-test. The results showed highly significant differences between the actual and estimated maxillary inter-premolar and intermolar widths with over-estimated values in both genders. New formulas were developed to make Pont's index more reliable, and the newly estimated widths were non-significantly different from the actual one. The original Pont’s index is an unreliable and inapplicable method for arch width prediction. A specific modification of Pont’s index is developed and can be applied for more reliable results.

Effect of selective trimming of nasoavleolar molding on maxillary arch growth in patients with unilateral cleft lip and palate.

Presurgical Nasoalveolar molding (PNAM) is a technique used for cleft lip and palate patients prior to cheiloplasty. However, concerns exist regarding its negative impact on maxillary arch growth.This study aimed to assess the effect of selective trimming in NAM on maxillary arch growth in patients with unilateral cleft lip palate. The retrospective observational study analyzed the study casts of 30 patients before and after undergoing nasoalveolar molding treatment. Study casts which were repositories of the institute were analyzed and segregated as Group A: NAM given with selective trimming of the appliance, and Group B: NAM without selective trimming of the appliance. Pre and post-treatment casts were assessed digitally at L-L' (Intercleft segment width), C-C' (Intercanine width), T-T' (Alveolar arch width), L-TT' (Alveolar arch length from major cleft segment), and L'-TT' (Alveolar arch length from minor cleft segment) RESULTS: A notable significant difference between Group A's and B's mean Alveolar arch width and Intercleft segment width was seen. Whereas parameters such as intercanine width, and alveolar arch length as functions from major and minor segments showed no significant variance. Although NAM has been known to affect the growth of the maxillary arch, this study proposes that techniques such as selective trimming can help counteract this drawback.

Vertical and transverse treatment effects of Invisalign First system compared to Hyrax maxillary expanders with fixed appliances in mixed dentition patients.

To compare vertical and transverse changes in mixed dentition patients treated with the Invisalign First System (IFS) to those treated with a banded hyrax expander with fixed appliances (Hyrax) and control groups, and to assess the efficiency rate of dental arch expansion with IFS. The study included 80 mixed dentition patients, with 40 in each group (IFS and Hyrax) and 40 controls from the American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection. Skeletal and dental vertical dimension changes and arch width changes between pretreatment (T1) and posttreatment (T2) were evaluated. Age at T1, time interval (T1-T2), sex, and Angle class did not significantly differ among the groups. Mandibular plane angle changes showed a similar reduction for the control and IFS groups, with no changes in the Hyrax group. However, the differences among the three groups did not reach statistical significance (P = .06). The Hyrax group showed significantly greater expansion in maxillary intermolar width compared to the IFS group, 4.4 vs 2.5 mm, respectively. The efficiency of maxillary expansion using IFS ranged from 52.3% to 76.87%. During the mixed dentition stage, no significant changes occurred in vertical dimensions among the control, Hyrax, and IFS groups. Although there was a trend suggesting a greater reduction in mandibular plane angle in the IFS group compared to the Hyrax group, this may not be clinically significant given the less than 1° difference. IFS can be a viable option for addressing mild arch width deficiencies, with a predictable increase in intermolar width of approximately 2.5 mm.

A Comparison of Dental Arch Width and Length on 3D Digital and Plaster Models

The aim of the study was to determine potential deviation in measurements of commonly used orthodontic variables, including intermolar width (IMW), intercanine width (ICW), and arch perimeter (AP), when measured on three-dimensional images compared to measurements performed on plaster models obtained from alginate impressions using a hand-held digital vernier caliper. A total of 120 sets of models were divided into four groups: plaster models made from an alginate impression, digitized plaster models made from an alginate and silicone impression, and digital models obtained via intraoral scan. The repeated measurements analysis of variance (ANOVA) with Sidak post-hoc test was applied to test differences in measurements between the four methods. The results show better agreement for intermolar and intercanine width (r = 0.468–0.967) and smaller measurement error (ME = 0.53–1.07) compared to arch length (r = 0.422–0.477; ME = 2.04–2.89). Better agreement levels were more frequently observed between plaster models with intraoral scans than between digitized plaster models. The deviations in intermolar and intercanine width measurements between the hand-held digital vernier caliper and digital analyses were found to be clinically insignificant. The observed difference in arch perimeter suggests that curved measurements may not be clinically acceptable.

A Comparative Analysis of Arch Widths in Class I and Class II Malocclusion: Extraction vs. Non-extraction Treatment.

This study aimed to assess and compare dental arch widths in the anterior and posterior regions among patients undergoing extraction and non-extraction treatments for Class I and Class II malocclusions. A total of 40 patients were selected, with 10 in each of the categorized groups based on malocclusion type and treatment status. Dental arch widths were meticulously measured using a digital Vernier caliper at the canine and molar regions to ensure precise data collection. Statistically significant differences were noted when comparing mean inter-canine and molar widths between pre- and post-treatment periods among extraction cases in Class I malocclusion (p < 0.001). Conversely, there were no significant changes observed in arch widths among non-extraction cases in Class I malocclusion. Similarly, significant changes were observed in both extraction and non-extraction cases of Class II malocclusion when comparing mean inter-canine and molar widths between pre- and post-treatment periods (p < 0.05). After treatment, both Class I and Class II extraction cases showed an increase in inter-canine arch width, while intermolar arch width remained unchanged, suggesting that the treatment did not significantly alter the buccal corridor. Additionally, there were no notable changes in inter-canine arch widths between pre- and post-treatment in Class I non-extraction cases. However, the Class II non-extraction group exhibited increased upper and lower inter-canine arch widths after treatment.

Relationship between dental arch width and vertical facial morphology in untreated Indian population

Introduction: Facial growth pattern is an important factor in planning orthodontic treatment properly. Knowledge of arch forms is important for an orthodontist, as it is related to future treatment outcome. Factors such as age, sex, and ethnicity are also important. The purpose of present study was to evaluate the dental arch dimensions in a different facial pattern in regional population, to evaluate correlation in the facial pattern with dental arch width to evaluate the differences in dental arch width between male and female subjects. Materials: The present study was conducted on 120 untreated subjects comprising of 60 males and 60 females aged between 16 to 38 years. The Jarabak’s ratio (posterior facial height/anterior facial height) was measured on cephalograms of each patient. Maxillary and mandibular inter-canine, first inter-premolar, second inter-premolar and first inter-molar widths were measured on study models of each patient. Results: There was no significant correlation between dental arch width and vertical facial pattern in regional population. In males, arch width is greater in canine, premolar and molar region than females. Conclusion: It was concluded that dental arch width is not associated with the vertical facial pattern but it is associated with gender. Thus, using individualized arch wires according to gender is suggested during orthodontic treatment. Bangladesh Journal of Medical Science Vol.23 (Special Issue) 2024 p.S26-S31

Comparison between basal arch width in normal occlusions and class Ⅱ malocclusions by using cone-beam computed tomography

ObjectiveThe purpose of this research was to investigate the measurements of maxillary and mandibular basal arch width in male and female with normal occlusion, and to compare dental arch width difference between normal occlusion and ClassⅡ malocclusion groups could be helpful in orthodontic diagnosis and treatment planning. MethodsCone-beam computed tomography (CBCT) images from 133 individuals (76 males and 57 females) with normal occlusion and 64 (25 males and 39 females) with skeletal Class II malocclusions were evaluated. The distances between canines, first molars (basal arch widths: BAW) and second molars were measured from CRs (center of resistance) of the teeth and the projection of first molars on buccal bones (WALA distance) were measured. ResultsThere were significant differences in male and female maxillary and mandibular dental transverse widths. The normal range of the maxilla and mandible basal bone widths differences were −2 mm–2 mm (−0.05 ± 2.17 mm). The normal occlusion and Class Ⅱ groups exhibited significant differences in the width of the intercanine and first molars. Sella-nasion-A point angle (SNA) and Sella-nasion-B point angle (SNB) in the Class Ⅱ male group were positively correlated with the width between the maxillary canines. For individuals with normal occlusions, the width of the mandible at the second molar was greater than that of the maxilla, so more attention should be paid to the width of the second molar when considering clinical treatment. ConclusionMeasuring the width of the maxilla and mandible basal bones from the resistance center of the first molar was a feasible and repeatable method can be used in clinical practice. The data could serve as a reference for orthodontic treatment planning. More consideration should be paid to the horizontal dental problems of the treatment plan for Class Ⅱ patients. And the width of the mandible at the second molar was greater than that of the maxilla, so more attention should be paid during treatment.

Dental and Alveolar Arch Widths in Normal Occlusion and Class II Division 1 Malocclusion

This study was to evaluate and compare dental arch and alveolar widths of patients with Class II division one malocclusion with group of untreated normal occlusion subjects. This study was performed using measurement on dental casts of 30 normal occlusion and 30 Class II division 1 malocclusion of Iraqi sample aged 15-22 years. T-test was applied for comparing the groups , the finding of this study indicated that maxillary interpremolar width, maxillary canine, maxillary premolar and maxillary first molar and mandibular premolar and molar alveolar widths were found significantly narrower in the Class II division 1 group when compared with the normal occlusion sample (P&lt;.001). The maxillary and mandibular intermolar and mandibular intercanine alveolar widths were statistically significantly larger in the Class II division 1 group ( P&lt;.01) . Maxillary molar teeth in subjects with Class II division 1 malocclusion tend to incline to the buccal to compensate the insufficient alveolar base therefore rapid maxillary expansion rather than slow maxillary expansion should be considered during treat ment of Class II division 1 patients. The results of our study sugg ested that transverse discrepancy in Class II division one maloccl usion originated from upper posterior teeth and maxillary alveolar base.

Skeletal and dental effects of function-generating bite appliance compared to rapid palatal expander and untreated controls.

Maxillary expansion is a fundamental interceptive orthodontic treatment, which can be achieved through either a rapid expansion protocol or functional devices. However, no data exist about the efficacy of functional devices in achieving skeletal expansion. Therefore, the aim of this study was to compare the effects of the rapid palatal expander (RPE) and the function-generating bite type M (FGB-M) on the transversal dimension of the maxilla, and on the maxillary and mandibular dental arch width. One hundred eighty-one skeletal Class I patients, aged between 6 and 12 years and with a cervical vertebral maturation stage II or III, with maxillary transversal deficiency were retrospectively enrolled; among these 55 were treated with FGB-M, 73 were treated with RPE and 51 were untreated subjects retrieved from historical databases. The pre-treatment (T0) and post-treatment (T1) frontal cephalograms were retrieved, and the maxillary and mandibular widths, and the distance between upper and lower first molars were measured. T1-T0 interval was of 17.3 months (RPE), 24.6 months (FGB-M) and 18.2 months (controls). The statistical analysis showed that there were no statistically significant differences between the RPE and FGB-M groups regarding skeletal and dental expansion, while the untreated control group differed significantly from the other two groups. The comparison between patients treated with RPE and FGB-M showed that there were no statistically significant differences between the RPE and FGB-M groups regarding the amount of skeletal expansion and dental arch width, suggesting that both appliances can be used to achieve similar results.

Changes in the arch width and buccal corridor after fixed orthodontic treatment with Damon self-ligating system: premolar extraction vs. non-extraction.

Extraction vs. non-extraction is a crucial decision in orthodontic therapy. The aim of the present study was to investigate the changes in the dental arch width and buccal corridor after orthodontic treatment using extraction and non-extraction therapy with Damon self-ligating system. This retrospective study consisted of 35 patients (20 female and 15 male patients with median age of 12.5 years), treated by extracting 4 or 2 premolars, and 37 patients (16 female and 21 male patients with the median age of 12.8 years), treated without premolar extraction. Both groups were treated with Damon self-ligating system. Plaster models before (T0) and after (T1) treatment were measured, and the arch width values were determined at the level of the first molars, second premolars, canines and palatal rugae. Buccal corridor width was measured using the extraoral images at T0 and T1. Paired t-test was used for the analysis of the normally distributed data, and Wilcoxon Mann-Whitney U test was used for the data with non-normal distribution. Values of p<0.05 were set as statistically significant. The upper intercanine width increased significantly in both groups (p<0.01). In the non-extraction group, the arch width increased significantly in the maxillary second premolar and first molar region (p<0.01) as well as in the region of the canines (p=0.04), second premolars (p=0.01) and first molars (p<0.01) of the mandible. The buccal corridor decreased significantly in the non-extraction group (p<0.01). Premolar extraction in combination with Damon self-ligating system did not lead to reduction of the dental arch width in the maxilla, nor did it increase the size of the buccal corridors.

The Effect of Cleft Width on Maxillary Morphology in Newborn with Unilateral Cleft Lip and Palate

Objective: This study aims to investigate the impact of cleft width on maxillary morphology in newborns with unilateral cleft lip and palate (UCLP). Materials and Methods: Plaster models from 35 newborns with unilateral cleft lip and palate (UCLP) (17 boys, 18 girls) and 35 newborns with isolated soft palate cleft (CP) (16 boys, 19 girls) were examined. The measured parameters included C-C' , T-T', arch circumference, arch length, G-L, a-a', and b-b'. Statistical analyses were conducted using an independent samples t-test and Mann–Whitney U test for normally and non-normally distributed data, respectively. Pearson Correlation assessed the correlation between G-L and other measurements. The analysis was performed at a significance level of 0.05 using R software, version 4.0.5. Results: Statistically significant differences were found in C-C' (p &lt; 0.001) and T-T' (p &lt; 0.05) between the two groups. UCLP newborns showed a significant increase in arch length (28.4 ± 2.9 mm) compared to CP (25.0 ± 2.6 mm, p &lt; 0.001). Both (a-a') and (b-b') demonstrated a significant increase in UCLP (p &lt; 0.001). A significant correlation was observed between (G-L) and (C-C') and (a-a') (p &lt; 0.01), and between (T-T') and (a-a') and (b-b') (p &lt; 0.01). The correlation between arch circumference and (b-b') was significant at the 0.05 level. Conclusion: In UCLP newborns with increased anterior cleft width, the anterior alveolar arch width increases, affecting maxillary morphology. While early orthopedic and surgical interventions prove effective in managing severe clefts, the initial severity of the cleft width significantly influences dental arch relationships and treatment outcomes. Consequently, initiating maxillary expansion and protraction interventions during the early primary dentition period becomes crucial.

Correlation of dental arch width and alveolar arch width with facial divergence

Dentofacial skeletal anomalies occur as a result of a differential growth of the lower facial skeleton to upper facial skeleton resulting in malocclusion in transverse, vertical and sagittal plane. To correlate different Vertical facial types with Dental arch width and Alveolar arch width for the patients in North Indian sub population. Lateral cephalograms and study models of 150 untreated adults were selected and divided into 3 groups: Group I (Normodivergent), Group II (Hypodivergent) and Group III (Hyperdivergent) on the basis of (SN-MP angle, FMA, Gonial angle &amp; Jarabak’s ratio). Dental arch width and Alveolar arch width were measured on maxillary and mandibular casts by using digital caliper. All the 3 groups were compared by using ANOVA followed by Post Hoc Turkey HSD test. Significant (p&amp;#60;0.05) correlation was seen for parameters of Dental arch width and Alveolar arch width in both maxillary and mandibular arches with Facial divergence. Dental and Alveolar arch width were maximum in hypodivergents followed by normodivergents and minimum in hyperdivergents in both maxillary and mandibular arches. Therefore, during orthodontic treatment it is suggested to use individualized arch wires according to each patients pretreatment arch form and widths.

Efficiency and Predictability of Coronal Maxillary Expansion Repercussion with the Aligners System: A Retrospective Study.

The tooth movement tables of 75 previously selected cases were analyzed in terms of dental-arch width and expansion efficiency, through the Invisalign® platform, considering the pre-treatment (T0), planned treatment (TP) and post-treatment models (T1) using ClinCheck Pro® 6.0 software. All patients were treated by an orthodontic specialist and Invisalign® Diamond Provider in a private practice (T.P.). Difference between T1 and T0: for each maxillary and mandibular measurement, there was a statistically significant difference between pre- and post-aligner treatment values. The greatest amount of expansion occurred in both the upper and the lower premolars. Difference between TP and T1: for each maxillary measurement, statistically significant differences were verified for the molar and canine. At the mandibular level, statistically significant differences were only verified in the first molar. The Invisalign® clear aligners are effective for simultaneous intra-arch expansion in both jaws.

Assessment of early dental arch growth modification with removable maxillary expansion by cone-beam computed tomography and lateral cephalometric radiographs: a retrospective study

BackgroundThis study evaluated the skeletal and dental changes of patients brought by early removable maxillary expansion (ERME) treatment to explore the clinical treatment effect of ERME on early dental arch growth modification.MethodsSubject children aged 6–10 years with a maxillary transverse deficiency received ERME treatment, cone-beam computed tomography (CBCT) and lateral cephalometric radiographs were measured before and after treatment, and statistical differences in the measured items were evaluated with corresponding statistical methods to explore the skeletal and dental changes.ResultsAfter ERME treatment, there was a statistical increase in the maxillary basal bone arch width, nasal cavity width, maxillary alveolar bone arch width, and maxillary dental arch width. A buccal inclination of the maxillary alveolar bone and a buccal inclination and buccal movement in the alveolar bone of maxillary first molars were found. The maxillary skeletal expansion was statistically greater than the dental expansion. Increases in the mandibular alveolar bone arch width and dental arch width happened after treatment. A decrease in angle ANB and an increase in Ptm-A, U1-SN, U1-PP, L1-MP, and L6-MP were found after treatment. No statistical changes in the growth pattern-related measured items were observed.ConclusionsERME could expand the maxillary basal bone arch width, nasal cavity width, maxillary alveolar bone arch width, and maxillary dental arch width. The maxillary skeletal expansion was greater than the dental expansion. Secondary increases in the mandibular alveolar bone and dental arch widths would happen after ERME. ERME would result in a mandibular advancement, a labial inclination of maxillary anterior teeth, and an increase of maxillary sagittal length, and would not change the patient’s growth pattern.Trial registrationThis study was approved by the Institutional Review Board of the West China Hospital of Stomatology, Sichuan University. (WCHSIRB-D-2020–446).

Analysis of the Facial Measurements and Dental Arch Dimensions for the Construction of Dental Prostheses among Adult Yemenis.

To investigate the dental arch dimension (width, length, and height) and facial measurements including inner-canthal width (ICW), bizygomatic width (BZW), inter-alar width (IAW), and mouth width (MW), and to assess the correlation between these facial measurements and dental arch width (canine width [CW], inter-first premolar width [I1PW], and inter-first molar width [I1MW]), to establish a preliminary reference for artificial teeth selection in Yemeni adult. The study included 80 individuals (40 males and 40 females) with symmetrical faces and normal class I occlusion ranging in age from 20 to 35. Maxillary and mandibular stone casts were made for each individual. The dimensions of dental casts and facial measurements, including ICW, BZW, IAW, and MW, were assessed using a digital caliper. The collected data were analyzed by using the SPSS software program. The descriptive statistics for each measurement were made. Differences between males and females were tested using an independent-sample t-test with p-values below 0.05 considered significant. Pearson correlation coefficient between facial measurements and dental arch width was also done. Most dental arch dimensions and facial measurements exhibited larger mean values in the male than in the female group, with the greatest significant difference in the maxillary dental arch width and the lowest in mandibular dental arch length. A highly significant correlation is observed between ICW and maxillary canine width (CW) (r = 0.318, p = 0.004). In contrast, no significant correlation between dental arch width and BZW, IAW, and MW is shown. Within this study's limitations, the ICW can determine the ideal dimension of the artificial teeth in the anterior maxillary arch. While the other facial parameters, including BZW, IAW, and MW, cannot be used for artificial teeth selection in Yemeni populations. The findings of this study established a reference database of facial measurements and their correlation to dental arch and teeth width in Yemeni populations. So, it can be implemented in artificial teeth and dental prostheses design and construction.

Evaluation of First Molar Buccolingual Angulations and Dental Arch Parameters in Adolescents with Bilateral Posterior Crossbite.

This study aimed to compare the maxillary and mandibular transverse dental arch widths and buccolingual inclinations of the molar teeth in patients with and without bilateral posterior crossbite (BPC) divided into different age groups. The study included dental models from 120 patients (age: 12-18 years), including 60 with BPC (32 boys and 28 girls) and 60 without BPC (controls; 30 boys and 30 girls), who were divided into three age groups (12-14, 14-16, and 16-18 years). The centroid and lingual transverse arch widths, dental arch perimeters, dental arch depths, and buccolingual angulation of the molar teeth in the maxillary and mandibular regions were evaluated using scanned three-dimensional dental models. Dental arch parameters and buccolingual molar angulation did not significantly differ between the different age groups in either the patients with BPC or the controls (p>0.05). However, several dental arch width parameters differed significantly between sexes in both groups, with higher values in boys than in girls (p<0.05). The difference in the upper and lower molar buccolingual angulation between patients with BPC and controls was greater at the age of 16-18 years than the age of 12-14 years (p<0.05). Patients with BPC have smaller maxillary dental arch widths and larger mandibular intermolar widths than those without BPC. The difference in the molar buccolingual angulation between them increases with advancing age.