Maxillary Arch Form Research Articles

Morphometric Evaluation of the Maxillary Arch Using Cone Beam Computed Tomography

Objective: Anatomically, a dental arch is a result of natural teeth being positioned on the alveolar bone. The purpose of this study is to assess the morphological characteristics of various maxillary arch types using Cone Beam Computed Tomography (CBCT) and ascertain their prevalence. Methods: This retrospective study analyzed 200 randomly selected maxillary CBCT images from patients aged 18–65. Measurements were interpreted using various planes, and maxillary arch forms were classified according to the House dental arch classification in the axial region of the CBCT images. Results: Patients over 45 years old had significantly higher mean canine-palate and first molar-palate measurements compared to younger groups, particularly the 18–25 age group, which showed a higher hard palate–anterior mean than the 25–35 group. Class II cases had a significantly higher mean canine-palate than Class I and III cases. Class II cases also exhibited higher first molar-palate and canine-anterior means compared to Class I and III. In contrast, Class I cases had a higher canine-canine mean than the other classes. Conclusion: Morphologic measurements are crucial for guiding specialists in diagnosis and treatment, enhancing the ease and accuracy of clinical practice.

An in-vivo Analysis of the Positional Relationship of Palatal Rugae with Maxillary Teeth in Different Arch Forms Among Young Dentulous Gujarati Individuals-A Pilot Study

Background- The palatal rugae are transverse folds of tissue located in the anterior portion of the hard palate. They are considered to be reliable landmarks with manifold uses in the field of orthodontics and forensics. The current study was carried out with the aim of determining if a positional relationship of palatal rugae exists with the maxillary teeth in individuals with different maxillary arch forms. Material and method- The study was carried out in 100 participitants (87 females and 13 males) . Irreversible hydrocolloid impressions were made and casts were poured in Type 3 dental stone. The casts were divided according to arch forms as taper, ovoid and square. Palatal rugae on the casts were assessed digitally and the position of the most posterior rugae evaluated in relation with the adjacent maxillary teeth. Results –It was observed that the palatal rugae had a higly significant positional relationship with the maxillary posterior teeth(p value <0.0001) . In the ovoid and square arches, majority of the individuals had the most posterior rugae lying at the level of distal margin of 2nd premolar while in cases of taper dental arches, maximum number of individuals had the distal margin of 1st premolar coincide with the most posteriorly located rugae. Conclusion- Hence, it can be concluded that the most posterior limit of the rugae may serve as a reliable guide for the arrangement of the maxillary teeth in different arch forms. Key Words- Palatal Rugae, maxillary anterior teeth , denture aesthetics

Model analysis through two-dimensional evaluation of alveolar changes of untreated unilateral cleft lip and palate infants

The primary objective of therapeutic interventions for unilateral cleft lip and palate (UCLP) is to reestablish typical role and anatomy. The efficacy of nasoalveolar molding relies on the age at which it is initiated, thus early initiation is recommended. Evaluating the success of presurgical orthopedics involves assessing the after-treatment maxillary arch form and proportions in UCLP infants and comparing them to age-matched infants without clefts. Untreated UCLP cases exhibit various changes in the transverse and angular dimensions of the alveolar segment. Utilizing digital analysis of UCLP plaster casts through Photoshop software (version 24.0.0) can serve as an alternative method to predict changes in cleft width, arch width, and angular measurements in untreated cases.

Maxillary basal arch forms in operated adult patients with cleft lip and palate using root apices: A pilot study.

The purpose was to identify the maxillary basal arch forms utilizing the root apices and compare the maxillary basal arch form of groups with cleft lip and palate (CLP) and normal group. This study included 30 patients (21.8 ± 3.5 years old) with unilateral CLP (ULCP group) and 30 patients (20.9 ± 2.2 years old) with bilateral CLP (BCLP group). The normal group consisted of 30 non-cleft patients (21.2 ± 2.3 years old) with normal occlusion. Three-dimensional (3D) Cartesian coordinates of the root apices of each tooth were determined using cone-beam computed tomography. The 3D coordinates were projected onto the palatal plane to create the 2D coordinates. Thereafter, the basal arch forms were constructed by the Procrustes superimposition. Finally, For the basal arch form comparisons among groups, the inter-root widths were measured. Both CLP groups had a narrower inter-root width than the normal group. The BCLP group had significantly narrower premolar and molar widths than the UCLP group (P < .05). Especially, the inter-first molar width of the UCLP and BCLP groups was 3.7 ± 0.7 (P < .001) and 6.6 ± 0.8 (P < .001) mm smaller than that of the normal group, respectively. We used the root apices to identify the basal arch forms. The basal arch form of patients with CLP was narrower than that of the normal group. The basal arch form of patients with BCLP was narrower than that of patients with UCLP. Our findings may help clinicians better comprehend basal arch forms in patients with CLP and transverse discrepancies.

COMPARISON OF MAXILLARY AND MANDIBULAR ARCH FORM IN CLASS I, CLASS II AND CLASS III PATIENTS REPORTING FOR TREATMENT

Background: - Archforms play an important role in orthodontic diagnosis and treatment planning. Limitations for tooth movement, especially for incisor retraction arise from the basal bone where teeth are rooted. If teeth move excessively over the alveolar bone, periodontal complications and unstable treatment effects, even the tooth exfoliation may occur. The aim of this study is to compare the maxillary and mandibular arch forms of class I, class II, class III patients reporting for treatment in Saveetha dental college and hospitals, Chennai, Tamil nadu from June 2019 to January 2021.Materials and method: - It is a single centered retrospective study conducted in a private dental institution, Chennai. The data of patients reporting was collected from the dental hospital management system and the arch form was compared. Ethical clearance for this study was obtained from the Institutional review board. Statistical analysis was obtained using SPSS version 20.Results:-The results showed that there is no significant correlation in maxillary and mandibular arch forms among Angle’s Class I, Class II, and Class III malocclusion. Class I occlusal relationship was the most common class of malocclusion followed by Class II malocclusion. Ovoid arch was more common in class I, Class II, Class III malocclusion. Conclusion: - Within the study limits, it was concluded that Class I occlusal relationship was the most common class of malocclusion followed by Class II. Ovoid arch was more common in class I, Class II, Class III malocclusion followed by v-shaped and square arch forms in class I and class III and V-shaped arch was more prominent in class II patients.

Associations among the anterior maxillary dental arch form, alveolar bone thickness, and the sagittal root position of the maxillary central incisors in relation to immediate implant placement: A cone-beam computed tomography analysis.

PurposeThis study evaluated the associations of the dental arch form, age-sex groups, and sagittal root position (SRP) with alveolar bone thickness of the maxillary central incisors using cone-beam computed tomography (CBCT) images.Materials and MethodsCBCT images of 280 patients were categorized based on the dental arch form and age-sex groups. From these patients, 560 sagittal CBCT images of the maxillary central incisors were examined to measure the labial and palatal bone thickness at the apex level and the palatal bone at the mid-root level, according to the SRP classification. The chi-square test, Kruskal-Wallis test, and multiple linear regression were used for statistical analyses.ResultsSignificant differences were found in alveolar bone thickness depending on the arch form and SRP at the apex level. The square dental arch form and class I SRP showed the highest bone thickness at both levels of the palatal aspect. The taper dental arch form and class II SRP presented the highest bone thickness at the apex level of the labial aspect. No association was found between the dental arch form and SRP. Elderly women showed a significant association with thinner alveolar bone. Age-sex group, the dental arch form, and SRP had significant associations with alveolar bone thickness at the apex level.ConclusionThe patient’s age-sex group, dental arch form, and SRP were associated with alveolar bone thickness around the maxillary central incisors with varying magnitudes. Therefore, clinicians should take these factors into account when planning immediate implant placement.

Comparison of maxillary anterior mathematical proportions among 3 dental arch forms

Statement of problemRace and sex differences in the mathematical proportions of maxillary anterior teeth have been evaluated. However, studies exploring the relationship between the mathematical proportion of maxillary anterior teeth and maxillary dental arch form are lacking. PurposeThe purpose of this clinical study was to determine if a correlation exists between the mathematical proportions of maxillary anterior teeth and 3 dental arch forms. Material and methodsThree hundred young participants were recruited according to predefined criteria, and images and maxillary casts were obtained. The perceived width and length of the maxillary anterior teeth were measured on the images by using a software program, and mathematical proportions, including width ratios and width-to-length ratios, were calculated for each. The casts were used to categorize each specimen into tapered, ovoid, or square groups by using a specific classification method, and the width ratios and width-to-height ratios of the 3 dental arch forms were compared. Statistical analysis was performed by using analysis of variance (ANOVA) or the Kruskal-Wallis H test to compare the mathematical proportions of maxillary anterior teeth among the 3 dental arch forms (α=.05). The intraclass correlation coefficient (ICC) was used to test the reliability of the investigators. ResultsExcept for the width-to-length ratios of the central incisor, mathematical proportions were affected by the dental arch form. The perceived width ratios of the maxillary lateral incisor-to-central incisor gradually increased from the tapered arch to the ovoid arch and from the ovoid arch to the square arch, with mean ±standard deviation values of 0.71 ±0.04, 0.73 ±0.05, and 0.79 ±0.06, respectively. For the maxillary perceived width ratios of canine-to-lateral incisor, the ovoid arch had the maximum perceived width ratios (0.86 ±0.10), followed by the tapered (0.82 ±0.10) and square arches (0.77 ±0.11). The width-to-length ratios of the central incisor were not affected by the arch form (P=.075), and the width-to-length ratios of the lateral incisor increased as the arch form became flat, with respective values of 0.70 ±0.10, 0.74 ±0.10, and 0.76 ±0.10. For the width-to-length ratios of the canine, the ovoid arch had the maximum perceived width ratios (0.58 ±0.10), followed by the tapered (0.53 ±0.10) and square arches (0.52 ±0.10). ConclusionsThe mathematical proportions varied among the 3 dental arch forms, and the dental arch form should be considered during the prosthodontic design of maxillary anterior teeth.

Correlation of Three Dimensions of Palate with Maxillary Arch Form and Perimeter as Predictive Measures for Orthodontic and Orthognathic Surgery.

Hard palate is regarded as an important part of the human skull, which contributes to the separation of the oral and nasal cavities. The aims of the study were to investigate the morphology of the hard palate in order to create a general guideline of three-dimensional values of the palate in a Kurdish sample in the city of Sulaimani as well as determining the possible correlations between different palatal parameters in class I malocclusion with the maxillary arch form and perimeter. A retrospective study design was adopted by collecting 100 study models of orthodontic patients aged 16–24 years old attending different private dental clinics in the city of Sulaimani seeking orthodontic management. In this study, three-dimensional palatal measurements including depth, length, and width were measured in an attempt to discover their correlation with each maxillary arch form and perimeter. Additionally, measurements of inter-molar width, inter-canine width, and arch perimeter were carried out. About two-thirds of those seeking orthodontic treatment were females. Nearly 80% of the study sample had narrow palate followed by 15 and 5% of intermediate palate and broad palate, respectively. In regard to arch form, almost 90% of subjects were with tapered maxillary arch form and 10% of them with oval arch form. Males had increased dimensions compared to females, with significant differences, except in palatal depth in the molar area, and palatine height index, in which females showed increased dimensions than males but the differences were statistically non-significant. A strong positive correlation was observed between arch form and canine depth. In regard to arch perimeter, a strong negative correlation was found with molar depth and a medium positive correlation with each of canine depth, palatal width, and palatal length.

Maxillary and mandibular dental arch forms in a Jordanian population with normal occlusion

BackgroundEthnic background has been claimed to affect arch form. The purpose of this study was to describe and elucidate the maxillary and mandibular arch forms in Jordanian population and to develop a classification method for these forms which could be employed to construct orthodontic archwires accordingly.MethodsThe sample was comprised of study casts of five hundred and twenty subjects (231 males and 289 females with a mean age of 15.4 ± 1.02 years). All subjects had permanent dentition with normal occlusion. A mathematical method associated with a polynomial function of 6th degree was employed to assess the dental arch forms. The resultant arch forms were classified into 5 groups for both the maxilla and mandible utilizing a computer software with special code designed for this study. Each group was subdivided into 3 subgroup sizes namely: small, medium, and large.ResultsCatenary arch form was found in 47% and 41.2% (p ˂ 0.01) of maxilla and mandible arch forms, respectively. Form 2 (which is halfway between ellipse and U-shaped arch form) was found in 27.7% and 26.7%. Medium size arch form was found in 55.4% of the maxillary and 65.6% of the mandibular arch forms.ConclusionCatenary arch form was the most prevalent arch form, followed by wide elliptical form. The other forms, which included tudor arch, tapered equilateral and quadrangular forms were less frequent. Regarding size, the medium size was the most prevalent among the studied samples.

ASSESSMENT OF MEAN DISTANCE BETWEEN CENTRAL INCISOR AND INCISIVE PAPILLA WITH RESPECT TO STANDARDIZED ARCH FORM IN DENTATE SUBJECTS

BACKGROUND &amp; OBJECTIVE: Edentulous patients require accurate positioning of artificial maxillary anterior teeth in complete dentures to recover the esthetic and phonetic characteristics. This positioning is guided by measuring distance between central incisor (CI) and incisive papilla (IP) in dentate subjects which varies according to the ovoid, square and tapered maxillary arch forms.&#x0D; Objectives: 1- To determine the frequency of three different arch forms in dentate patients;&#x0D; 2- To assess the mean distance between central incisor and incisive papilla in each of the three maxillary arch forms.&#x0D; METHODOLOGY: 130 cases were selected by non-probability consecutive sampling, which included both genders and age range of 20-40 years. Impressions of maxillary arches were recorded and their casts photocopied. Arch form template was used to standardize the assessment of arch forms by best-fit method on the photocopies. The distance between mesio-incisal edge of CI and posterior border of IP was measured with digital verniercalipers (SparkFun,Colorado).&#x0D; RESULTS: Out of 130 subjects, 54 males and 76 females were present. The ovoid arch form was the most frequent form recorded at 67% (n=87) while the tapered arch was the least at 14% (n=18). The overall mean distance between central incisor (CI) and incisive papilla (IP) was 11.34mm (7.58mm - 16.45mm). The mean distance was the highest for ovoid arch form (11.58mm) and lowest for square (10.49) with a statistically significant difference (p=0.016) between the two arch forms.&#x0D; CONCLUSION: The ovoid arch was the most frequent arch form found in dentate subjects. The mean distance recorded was highest for ovoid arch followed by tapering arch and least for square arches.

Accuracy of three different customized lingual orthodontic appliance systems in achieving predicted results on maxillary anterior teeth: A Retrospective Cohort Study.

OBJECTIVE:To comparatively evaluate the ability of three different customized lingual appliance systems in achieving predicted results with respect to the mesiodistal crown tip, labiolingual crown inclination, in–out position of Maxillary permanent anterior teeth, and Maxillary arch form.METHODS:Three commercial houses: Incognito, iLingual 3D, and Lingual matrix were analysed in this study. The final sample size consisted of 42 cases. Fourteen digital prediction and posttreatment models of the maxillary arch were provided by three orthodontic offices each using a different system. Discrepancies between the prediction and posttreatment model in mesiodistal tip, labiolingual inclination, in–out position of anterior teeth, and arch form were analyzed.RESULTS:Incognito displayed the highest accuracy in all parameters except for in–out positioning. Lingual Matrix showed greater precision in achieving planned mesiodistal positions than labiolingual inclination while it was just the opposite for iLingual 3D. All three systems proved to be clinically reliable in achieving the predicted in–out positions of permanent Maxillary anterior teeth.CONCLUSION:These systems were considerably accurate in achieving planned treatment goals with minute deviations from the predicted value.

Comparison of maxillary basal arch forms using the root apex in adult women with different skeletal patterns: A pilot study

This study aimed to establish maxillary basal arch forms using the root apices and to determine the differences in the basal arch forms in adult women with different sagittal skeletal patterns. This retrospective study included 91 adult women, with either a Class I (n=24), Class II Division 1 (n=22), Class II Division 2 (n=23), or Class III (n=22) malocclusion, who underwent cone-beam computed tomography. Three-dimensional coordinates of the root apices were determined using the multiplanar reformation mode of OnDemand3D software (Cybermed Inc, Seoul, South Korea). Two-dimensional coordinates were converted from acquired 3-dimensional coordinates via projection on the palatal plane, and the Procrustes superimposition method was used to build the basal arch form. Finally, interroot width measurements were performed for basal arch form comparisons. There were significant differences among the 4 groups (P<0.05) with respect to the intercanine width. The intercanine width of Class II Division 1 group was significantly narrower than that of the other groups. The Class II Division 1 and Class II Division 2 groups tended to have tapered arch forms and squared arch forms, respectively. We established maxillary basal arch forms using the root apices. The Class II Division 1 group had a significantly narrower intercanine distance. The use of the root apex to depict the basal arch form seems reasonable.

Comparison of Mesiodistal Width of Maxillary Anteriors with Arch Form in Various Malocclusions: A Retrospective Study

This study was conducted for evaluating and comparing the mesiodistal width of upper anteriors in different malocclusions and its relation with various arch forms. In total, 60 subjects with different malocclusions were examined. Mesiodistal width was measured for the anterior teeth using digital vernier caliper. 3M Unitek arch form template and two-dimensional (2D) model were superimposed to find out primarily the relation of arch form in specific malocclusion to the sum the mesiodistal width of the maxillary of anterior teeth and secondarily the relation of sum of the mesiodistal width of the maxillary anterior tooth with different arch forms. The ovoid arch form was common in class I malocclusion with mean mesiodistal width of 50.43 mm. The tapered arch form was the common type in both class II and class III malocclusion with mean mesiodistal width of 49.96 and 45.15 mm, respectively. The mean of anterior mesiodistal width for Angle's class III individuals was 45.15 mm considerably less than that of class II subjects and class I subjects, which signifies that the tooth material was more in the anterior region of the subject of class I followed by class II and class III malocclusions. The performed study presents various maxillary dental arch forms observed in various malocclusions (Angle's class I, class II, and class III). The ovoid and tapered arch forms exhibited the common occurrence, while the square form was the rarest.

Semi-automatic and robust determination of dental arch form in dental cone-beam CT with B-spline approximation

Background and objectiveThe dental arch form is generally used as a base for planning orthodontic treatments. It is, therefore, vital to determine the proper individual dental arch form for more accurate orthodontic treatment. We aimed to develop and validate a robust algorithm for semi-automatic determination of the dental arch form in dental cone-beam CT (CBCT) images with the cubic B-spline approximation. MethodsOur algorithm consists of tooth segmentation, determination of an occlusal plane, and generation of intersection points between the teeth and the offset plane from the occlusal plane in CBCT images. By fitting a curve to the intersection points using the cubic B-spline curve approximation, the dental arch form was finally determined. The accuracy of the dental arch forms was evaluated by comparison with gold standards determined by an expert orthodontist. ResultsThirteen dental CBCT scans from nine subjects were enrolled in this study. From the CBCT scans, 13 maxillary arch forms and 11 mandibular arch forms with Class I occlusion were determined by our proposed algorithm and evaluated for validation. The mean error between the dental arch forms of gold standards and our method using the cubic B-spline was 0.413 ± 0.092 mm (range, 0.264–0.587 mm). ConclusionsOur proposed method showed reliable accuracy of determining the dental arch forms for the maxilla and mandible. These results suggested that this method might be used for planning automatic tooth setup for individual patients.

Differences in dentofacial morphology in children with sleep disordered breathing are detected with routine orthodontic records

BackgroundResidual snoring in children with obstructive sleep disordered breathing (SDB) may continue post-adenotonsillectomy. This study aims to identify baseline dentofacial differences in children with SDB using routine orthodontic records that might aid effective early intervention for the upper airway to prevent continued obstruction. MethodsChildren (6–16 years) with clinically diagnosed SDB from a paediatric Otolaryngology Clinic who required adenotonsillectomy were participants (n = 10). The control group (n = 9) comprised healthy non-snoring children from the community. Baseline overnight polysomnography (PSG), standardised frontal and right profile photographs and alginate impressions were taken of all children. Facial width, length, depth, convexity and mandibular position were measured from the photographs. The occlusion, arch width, arch depth, maxillary arch form, palatal height and volume were recorded from digitised dental models. Inter-group differences were compared. ResultsSDB patients had a significantly increased lower face height, maxillo-mandibular angle (1.73°; 95% CI 0.45–3.0) and a narrower maxillary arch in the upper posterior region. There was a trend towards a decreased palatal volume, increased posterior crossbite and Class II molar relationship. ConclusionDentofacial phenotypic differences between children with SDB and controls can be detected using facial photographs and dental models. Increased awareness of these features may help to identify children who to continue to snore post adenotonsillectomy.

Correlation of maxillary and mandibular arch form and tooth size ratio in ethnic Javanese malocclusion patient

Aims: Arch form is one of the important components that can relapse after orthodontic treatment. The relationship is between arch form and tooth size ratio (TSR) need to be evaluated that could help to determine extraction or nonextraction treatment in malocclusion. The aim of this study was to analyze the correlation of maxillary and mandibular arch forms with TSR in ethnic Javanese Malocclusion Patient at Airlangga University Dental Hospital. Materials and Methods: This study was an observational, analytical study with cross-sectional and total sampling method. The samples consisted of 135 model study were chosen according to the inclusion criteria and distributed into malocclusion Class I, Class II, and Class III Angle's classification. All the samples were analyzed using Bolton's anterior and overall ratio, and the maxillary and mandibular arch forms were detected using mathematical ratio using (canine depth/molar depth (MD))/(canine width [CW]/molar width [MW]). Statistical Analysis: The correlation of maxillary and mandibular arch form with clinically significant TSR using Bolton's analysis is interpreted using Pearson correlation test (P 0.05) was found. While the anterior TSR in Class I Angle's malocclusion has a significant correlation with inter-CW in mandibular arch (P < 0.05). Conclusions: TSR was not affected by types of arch form either in maxillary or mandibular while the anterior TSR in Class I Angle's malocclusion did.

Comparison of short-term effects of presurgical nasoalveolar molding and Hotz’s plate on maxillary arch form in unilateral cleft lip and palate

ObjectiveTo compare the short-term effects of presurgical nasoalveolar molding (PNAM) and Hotz’s plate treatment on maxillary arch form in patients with unilateral cleft lip and palate (UCLP). Materials and MethodsThis retrospective study included patients with non-syndromic UCLP who received orthopedic treatment with PNAM (the PNAM group; n = 27) or Hotz’s plate (the Hotz’s group; n = 29) before lip repair. Maxillary dental casts obtained at first visit and at the time of lip repair were scanned, and the two groups were compared for maxillary form by superimposition of palatal rugae. ResultsBy the time of lip repair, the PNAM group exhibited significantly greater posterior movements of the incisal and cleft-edge points of the major segment than did the Hotz’s group; additionally, the incisal point had moved laterally to the cleft side. Moreover, the PNAM group exhibited significant smaller alveolar cleft width and alveolar arch length than the Hotz’s group at the time of lip repair. ConclusionSince PNAM induces rotation of the major segment to the cleft side, it could contribute to the formation of a more symmetrical maxillary arch. However, it might also decrease alveolar arch length before lip repair.

Morphological and functional peri-oral changes during early treatment of Class II division 1 malocclusions using EF Line ® functional education devices

The aim of this article was to assess the impact of a flexible functional education splint for interceptive treatment of Class II division 1 dysmorphoses. An observational, prospective, multi-center non-comparative EGIDYS study was conducted in 81 children with a Class II division 1 malocclusion presenting one or several functional disorders. Patients wore a flexible splint in the EF Line® range for a minimum of two hours per day and all night over 12 months in combination with educational exercises depending on the case. Patients were followed at one month, four months and twelve months of treatment. Ventilation, lingual position, labial peri-oral muscle tension, arch forms and dentoskeletal cephalometric measurements were assessed at initiation and completion of the functional education. Functional examination on inclusion showed that the majority of children displayed a low tongue position at rest, oral or mixed ventilation, abnormal labial and peri-oral muscle tone and, in many cases, a narrow maxilla. Initial cephalometric examination recorded the following parameters: overjet, deep bite, and inclination of the lower incisors relative to the A-Pog line, and the SNA, SNB and ANB angles. After twelve months of functional education with a flexible EF Line® splint, improvement was observed in the orofacial functions as shown by correction of the tongue position at rest as well as the lingual index indicating the position of the tongue against the palate, reduced tension of both the lower lip and the buccinator muscles at rest and in function, increased nasal breathing ability and a more rounded maxillary arch form. In addition, a major reduction in overjet and deep bite were visible as well as a significant reduction of the ANB angle due to its increased SNB component. This first stage in the orthodontic treatment plan resulted in a 73% improvement of Class II division 1 malformations. Correction of the malocclusion and functional disorders correlates significantly with compliant wearing of the EF Line® splints. This study demonstrates that the design of EF Line® flexible functional education devices effectively corrects functional disorders linked to poor tongue position and triggers positive dentoskeletal changes, as compared with no treatment. From the clinical viewpoint, flexible EF Line® splints can contribute to orthopedic and orthodontic treatment of Class II division 1 malformations.

Correlation between maxillary central incisor crown form and maxillary dental arch form: A Model-Based morphometric, cross-sectional study

The crown form of maxillary central incisor tooth is one of the vital phenomenon for a person's esthetics. Its crown form has been compared with other anatomical parameters such as arch form and facial form. Three different classes of tooth forms which relate to square, tapered, and ovoid forms are identified. The aim of this study was to morphometrically evaluate the correlation between maxillary dental arch form and the maxillary central incisor crown form. Dentate cast models of fifty male and fifty female normal occlusion controls in the age group of 18–23 years were analyzed. The mesiodistal (MD) dimensions of the maxillary central incisors were measured at incisal (MD_I) and at gingival (MD_G) levels. The transverse widths of maxillary casts were measured at the first molar and at the first premolar levels. The measured data were statistically analyzed using the SPSS software. The MD dimensions of maxillary central incisor were significantly greater in males than females. The ratio between the two MD dimensions also varied significantly among genders. The intermolar width (IMW) and inter first premolar width (IPmW) between males and females were highly significant (P

Effects of pre-surgical nasoalveolar moulding on maxillary arch and nasal form in unilateral cleft lip and palate before lip surgery.

To investigate the effects of pre-surgical nasoalveolar moulding (PNAM) on the maxillary arch and nasal form in patients with unilateral cleft lip and palate (UCLP). This is a retrospective case series study. The subjects were infants with complete UCLP who were treated with PNAM (n=18) at Kagoshima University Medical and Dental Hospital (Japan) between 2006 and 2013. Maxillary dental casts and facial photographs were taken at the time of the first visit and immediately prior to lip surgery to evaluate the maxillary arch and nasal form changes. The dental casts were scanned with a laser scanner, and changes in the 3-Dimensional coordinates of anatomical landmarks and alveolar cleft width were analysed. Moreover, we investigated the correlation between the changes in the maxillary alveolar arch and nasal form. Regarding the maxillary alveolar arch form, the anterior points of the major segment had moved significantly to the cleft side just prior to the time of lip repair, and the alveolar cleft width was significantly decreased. For nasal form, the inclination and displacement of the columella were significantly improved. The improvement of columella inclination was moderately correlated with the posterior movement of the anterior points of the major segment. These findings indicate that PNAM for infants with UCLP enhanced symmetry in the maxillary alveolar arch and nasolabial form. In addition, the posterior movement of the anterior points of the maxillary alveolar arch was correlated with the improvement of columella deformation.