Maxillary Width Research Articles

Efficiency of Invisalign First® to promote expansion movement in mixed dentition: a retrospective study and systematic review.

The present study aimed: i) to retrospectively evaluate the expansion movement predicted by the Clincheck® software and the achieved expansion using Invisalign First® in children needing maxillary expansion to correct malocclusions; and ii) to critically compare these clinical results with the outcomes obtained for maxillary expansion using conventional removable and cemented expanders. The 3D digital models of the dental arches of 24 children undergoing orthodontic treatment exclusively with Invisalign First® aligners between 2018 and 2021 were sequentially selected for this study. Three digital models were analysed: pre-treatment (P0), the Clincheck®-predicted tooth positions (P1), and post-treatment (P2) models. The maxillary dental arch width and expansion efficiency were measured andcalculated. An in-depth review of the available literature on maxillary expansion was performed following PRISMA guidelines. Invisalign First® was able to achieve a total effectiveness of maxillary expansion of 62.6%, compared to the predicted movement. Similarly, the total effectiveness of mandibular expansion was 61.6%. Our data shows that Invisalign First® system can increase the arch width with maxillary expansion effectiveness, providing similar results to those achieved with conventional removable appliances. However, neither Invisalign First® aligners nor conventional removable expanders are as much efficient as cemented-retained appliances.

Treatment Plan and Discussions of Class I with Smilestream: A Case Report

The aim of the study was to present a Class I case and the treatment plan related to orthodontic diagnosis. The chief complaint of a patient and his parents are crowded teeth upper and lower and anterior crossbite. “@I’m looking like a crocodile” were the first words of the boy sitting on the dental chair. The main task was functional but also esthetics because it was from the first important to him. The treated malocclusion is characterized with a narrow maxillary width and prominence of the mandible. The maxilla was deficient in anteroposterior and transverse dimensions, causing a slightly concave and unpleasant profile, a crossbite relationship of lateral incisors and upper and lower anterior crowding. The use of mechanics was preferred and accepted as a better solution for the patient according to the idea to generate well directed growth. The patient was 12 year-old boy with Class I malocclusion and anterior crossbite. A molar and canine class 1 and correction of the malocclusion were obtained. The improvement of facial aesthetics and smile enlarging were also ensured.

Comparison of three-dimensional maxillary growth across spheno-occipital synchondrosis maturation stages

BackgroundThis study aimed to three-dimensionally compare the maxillary growth among the spheno-occipital synchondrosis (SOS) maturation stages in both genders.MethodsThis is a cross-sectional study of a retrospective type in which cone-beam computed tomography (CBCT) images of 500 patients aged 6 to 25 years (226 males and 274 females) were analyzed. The SOS was evaluated using the four-stage scoring system; completely open, partially fused, semi-fused, or completely fused. The SOS scoring and three-dimensional cephalometric measurements were analyzed by Invivo 6.0.3 software. Descriptive and analytical statistics were performed and a P-value < 0.05 was considered statistically significant.ResultsThere was a statistically significant difference in maxillary measurements among SOS maturation stages in both genders (P < 0.05). The mean differences in the maxillary growth among the SOS maturation stages between SOS stages 2 and 3 were higher than those between stages 1and 2 and stages 3 and 4 for maxillary length and height in both genders. However, the mean difference in the maxillary width was higher between SOS stages 1 and 2 than those stages 2 and 3 and stages 3 and 4. On other hand, there may be lesser maxillary growth between SOS stages 3 and 4 for maxillary width, length (in males), and height. The growth curves showed high active growth of the maxilla as the SOS was still fusing (especially stage 2 and 3) than those of the fused (stage 4). Moreover, the acceleration of growth occurred earlier in females than males regarding chronological age but not for SOS maturation stages.ConclusionsThe SOS maturation stages are valid and reliable maxillary skeletal maturation indicators for three-dimensional maxillary growth in both genders.

Rapid maxillary expansion treatment increases mid-facial depth in early mixed dentition.

To evaluate the effects of rapid maxillary expansion (RME) on mid-facial depth in early mixed dentition and to investigate the relationship between change in mid-facial depth and maxillary sinus and nasal cavity. A total of 35 patients with mixed dentition treated with a Haas expander were included in this retrospective study. All patients underwent a cone-beam computed tomography scan before and after rapid maxillary expansion. The Wilcoxon signed-rank test was performed to evaluate the changes in maxillary width, facial depth, maxillary sinus, and nasal cavity volume before and after expansion. Multiple linear regression analysis was applied to evaluate the correlations among them. The hard and soft tissue facial depth in the middle third increased significantly (P < 0.001). The gain on the outer sagittal plane (1.04-1.52 mm) was slightly bigger than that on the inner sagittal plane (0.91-1.30 mm). Maxillary width and nasal cavity width increased 3.42 ± 0.93 mm (P < 0.001) and 2.25 ± 0.77 mm (P < 0.001), respectively, after treatment. A gain was also achieved in both nasal cavity volume (2,236.15 mm3, P < 0.001) and maxillary sinus volume (1,227.33 mm3, P < 0.001). Multiple linear regression analysis showed that with the increase in maxillary sinus volume, the facial depth increased as well (B = 0.455-0.683, P < 0.05). Also, statistically significant correlations were found between nasal width and nasal cavity volume (B = 0.384, P < 0.05). The depth of the middle third face increased significantly. The facial depth increase was related to the enlargement of maxillary sinus volume, while the nasal cavity volume gain was related to the nasal width increase. This indicated that RME might enhance the fullness of the mid-face and facilitate the patency of nose breathing.

Comparison of patients with different cervical spine bone ages before and after arch expansion treatment based on cone-beam computed tomography.

The changes of maxillary basal arch width, molar angle, palatal suture width and nasal cavity width were analyzed in patients with different cervical bone ages before and after maxillary rapid arch expansion treatment, providing more reference for orthodontic design and treatment in the future. A total of 45 patients with maxillary lateral, insufficient development that underwent arch expansion treatment in Jiaxing Second Hospital between February 2021 and February 2022 were selected for the study. Patients were retrospectively grouped based on the cervical vertebra bone age, and divided into the pre-growth (15 cases), mid-growth (15 cases) and post-growth groups (15 cases). All patients had oral cone-beam computed tomography (CBCT) and lateral cranial radiographs taken before and after the treatment. Maxillary basal arch width, palatal suture width, nasal cavity width and molar angle were measured and analyzed using paired samples t-test, ANOVA and least significant difference test (LSD-T). The maxillary basal arch width, palatal suture width, nasal cavity width and molar angle in the three groups were significantly changed after arch expansion treatment (p<0.05). There was no statistically significant difference in all measurement indexes between patients in the pre-growth and the mid-growth groups (p>0.05), but there was statistically significant difference between patients in the pre-growth and the late-growth groups (p<0.05). There were statistically significant differences in all measurement indexes between the middle-growth and the late-growth group (p<0.05). Rapid expansion of arch can be used to enlarge the width of palatal suture, maxillary basal arch, and nasal cavity in adolescent patients of different bone ages. With the increase of cervical bone age, the bony effect of expansion of arch gradually decreases, while the dental effect increases. Appropriate overcorrection should be made during arch expansion in late growth and excessive tooth tilt should be avoided to conceal bony width irregularities.

Estimation of human somatype using inter-canine and inter-premolar distances of the maxillary arch.

The establishment of a correlation between tooth dimensions and body size is crucial within the realm of forensic odontology. While numerous investigations have focused on the association between tooth morphology or width and stature, limited reports exist regarding the correlation between overall body structure or build and odontogenic parameters. This study focuses on finding a correlation between inter-arch dimensions and the body build of an individual. This study aimed to examine the potential correlation between an individual's somatotype (body build) and the measurements of inter-canine and inter-premolar maxillary arch widths. Dayananda Sagar College of Dental Sciences. A cross-sectional study. The sample size of the study was 153 individuals aged 18-25 years. Impressions for the maxillary arch were taken, study models were made and inter-arch measurements were taken using a digital Vernier calliper. For body build measurements, Heath-Carter somatotype measuring technique was used. The collected data were entered into an Excel sheet, and statistical analysis was done. Principal component analysis. On using principal component analysis, it was seen that there exists no correlation between body build of an individual when compared to inter-canine and inter-premolar distances. While no positive correlation has been seen between the odontometric parameters and specific body type, it can be argued that this can be due to the cited limitations of the study. Hence, we conclude with the note that a more detailed study would offer more viable and credible results.

Comparative Study of Maxillary Growth in Patients With Unilateral Cleft Treated With and Without Pre-Surgical Orthopedics.

Compare the maxillary growth of patients with Unilateral Cleft treated with pre-surgical Functional Maxillary Orthopedic (FMO) and that of who underwent a surgical procedure with no previous use of appliances. Prospective study, the patients were divided into 2 groups. G1, was composed of 12 patients who received no pre-surgical intervention and cheilorhinoplasty at 6 months of age and G2, included 12 patients treated using Pre-Surgical Funtional Maxilary Orthopedic; they underwent no surgery during the study. Measurements were taken at three times: before the first month of life, at 6 months and between 9-12 months of age. Cleft distance (anterior, medium and posterior), maxillary width (anterior, medium and posterior) and minor and major segment width were analyzed. Alveolar Cleft decrease was 79.82% in G1 and 52% in G2. Posterior Cleft decrease was 24.1% in G1 and 41.77% in G2. Greater Segment Width increase was 24.53% for the patients in G1, and 37.47% for the patients in G2. As for Inter Canine Width, a decrease of 5.16% in G1 and an increase of 9.19% in G2 were found. Medium Arch Width only increased in a statistically significant manner in G2 9.02%. Surgery allowed for the closure of the alveolar cleft. FMO made it possible to close the anterior and the posterior clefts through the growth of the maxillary segments, increased the transverse growth of the maxilla and could prevent maxillary collapse. Each team must individually evaluate whether to indicate or not the use of preoperative orthopedics.

Analysis of maxillary arch morphology and its relationship with upper airway in mouth breathing subjects with different sagittal growth patterns

ObjectiveThis three-dimensional cone beam computed tomography(CBCT) study assessed pharyngeal airway and maxillary arch in mouth breathing subjects with different skeletal classifications and analyzed the factors associated with the upper airway morphological variations in mouth breathing (MB) and nasal breathing (NB) subjects. MethodsOne hundred and five subjects (52 MB and 53 NB children), divided into three skeletal groups: Class I (1° ≤ ANB° ≤ 5°), Class II (ANB° >5°), and Class III (ANB°<1°). An independent t-test and one-way ANOVA test were utilized in the group analysis of normal distributed data. The linear multiple regression test was applied to create a model for the airway volumes based on the maxillary arch parameters in different skeletal groups. ResultsIn three skeletal groups, NB individuals had greater oropharyngeal airway volume (OPV) and total pharyngeal airway volume (TPV) than MB. Maxillary arch parameters of intermolar width (IMW), intercanine width (ICW), and maxillary width of canines (MWC) were larger in NB participants than in MB subjects. In the MB group, we discovered that Class II individuals had lower NPV (nasopharyngeal airway volume) than Class I and Class III. MWC was lower in Class II subjects compared to Class I and Class III in both the NB and MB groups. ConclusionNB individuals had greater pharyngeal airway and maxillary arch parameters than MB subjects. Our model equation revealed that the inter-molar width (IMW) and palatal area (PA) parameters were the strongest predictors of total pharyngeal airway volume (TPV) in the skeletal Class II and Class I groups.

Machine learning in 3D auto-filling alveolar cleft of CT images to assess the influence of alveolar bone grafting on the development of maxilla

BackgroundMachine learning based auto-segmentation of 3D images has been developed rapidly in recent years. However, the application of this new method in the research of patients with unilateral cleft lip and palate (UCLP) is very limited. In this study, a machine learning algorithm utilizing 3D U-net was used to automatically segment the maxilla, fill the cleft and evaluate the alveolar bone graft in UCLP patients. Cleft related factors and the surgery impact on the development of maxilla were analyzed.MethodsPreoperative and postoperative computed tomography images of 32 patients (64 images) were obtained. The deep-learning-based protocol was used to segment the maxilla and defect, followed by manual refinement. Paired t-tests and Mann-Whitney tests were performed to reveal the changes of the maxilla after surgery. Two-factor, two-level analysis for repeated measurement was used to examine the different trends of growth on the cleft and non-cleft sides of the maxilla. Pearson and Spearman correlations were used to explore the relationship between the defect and the changes of the maxillary cleft side.ResultsOne-year after the alveolar bone grafting surgery, different growth amount was found on the cleft and non-cleft sides of maxilla. The maxillary length (from 34.64 ± 2.48 to 35.67 ± 2.45 mm) and the alveolar length (from 36.58 ± 3.21 to 37.63 ± 2.94 mm) increased significantly only on the cleft side while the maxillary anterior width (from 11.61 ± 1.61 to 12.01 ± 1.41 mm) and posterior width (from 29.63 ± 2.25 to 30.74 ± 2.63 mm) increased significantly only on the non-cleft side after surgery. Morphology of the cleft was found to be related to the pre-surgical maxillary dimension on the cleft side, while its correlation with the change of the maxilla after surgery was low or not statistically significant.ConclusionThe auto-segmentation of the maxilla and the cleft could be performed very efficiently and accurately with the machine learning method. Asymmetric growth was found on the cleft and non-cleft sides of the maxilla after alveolar bone graft in UCLP patients. The morphology of the cleft mainly contributed to the pre-operation variance of the maxilla but had little impact on the maxilla growth after surgery.

Morphologic variations in the craniofacial structures in Japanese adults and their relationship with sex differences

The morphology of the human face varies broadly, with genetic and environmental factors determining these variations. Examining variations in the 3-dimensional (3D) craniomandibular morphology and identifying related factors (eg, sex differences) are important in orthodontic clinics. This study observed shape variations in the 3D facial morphology of Japanese adults showing skeletal Class 1 malocclusion and examined the association of sexual dimorphism with shape variations. Sixty cone-beam computed tomography images of Japanese adults (30 males and 30 females) with skeletal Class I malocclusion were employed. In each cone-beam computed tomography image, wire mesh fitting was conducted as previously described. A principal component (PC) analysis after Procrustes registration and the PC clustering method was conducted to observe the shape variations. A PC regression analysis was conducted to determine the sexual morphologic characteristics. Nine PCs depicting 62% of the morphology were determined. Four typical phenotypes were found, mainly related to mandibular protrusion (PC1) and the vertical divergence of the face (PC2). PCs related to sex determination were PC3 (robustness of the mandibular angle in males), PC5 (greater size and shape of the coronoid and mastoid processes in males), and PC7 (greater maxillary width in males), accounting for 16% of total variations. The major shape variations in skeletal Class 1 subjects were related to nonsexual dimorphic characteristics (ie, mandibular protrusion and facial divergence). Sexual dimorphic characteristics were evaluated in detail and accounted for 16% of total morphologic variations.

Assessment of sexual dimorphism in Maharashtrian young adults using maxillary intercanine, interpremolar, and intermolar widths: A morphometric study.

Sexual dimorphism practically involves differences in size and appearance of the same species which does not involve the difference in sexual organs. A significant variation also occurs with the tooth size, shape, etc., which plays a critical role in sex determination. Forensic investigations are used in defining the number of missing people whose skeletal remains are unknown. Depending on the available bones and their state, a variety of methods with varying degrees of reliability are available for identifying unknown remains. Fifty male and 50 female patients in the age group 20-30 years were randomly selected after taking a detailed history. All maxillary impressions were made with alginate and poured into a dental stone. These casts were measured for intercanine width, interpremolar width, and intermolar width using a digital vernier caliper, and findings were correlated with sexual dimorphism. Intercanine width between the tips of right and left maxillary canine was measured in males and females at 36.08 ± 2.04 mm (Range: 30.05-41.64 mm) and in females, the mean intercanine width was 34.31 ± 1.75 mm (Range: 28.35-39.01 mm), respectively. Interpremolar width between the distal pits of right and left first premolars was measured in males and females at 38.97 ± 2.10 mm (Range: 33.94-45.21 mm) and in females, the mean interpremolar width was 36.92 ± 1.87 mm (Range: 31.34 mm), respectively. Intermolar width between the central fossae of right and left first molars was measured in males and females at 50.43 ± 2.25 mm (Range: 44.16-56.84 mm) and in females, the mean intermolar width was 47.90 ± 2.06 mm (Range: 42.66-54.63 mm), respectively. In males, the mean value of the combination of intercanine, interpremolar, and intermolar widths was 125.47 ± 5.61 mm (Range: 108.15-141.86 mm) and in females, it was 119.12 ± 5.05 mm (Range: 103.25-134.36 mm). Mean values of all combinations were larger in males than in females. Thereby, maxillary arch widths contribute to accuracy in determining the gender of the individual.

Gender determination using dental arch characteristics among a south Indian pediatric population: A morphometric study

Aim: To establish the normative data of dental arch characteristics and use them to determine the gender among a pediatric population of south India. Methods: Three hundred children aged 3 to 5 years were selected. The intra oral examination of each child was carried-out using a sterile disposable mouth mirror and a CPI probe. To receive maximum illumination, the oral examination was done in adequate natural daylight seating the child in upright positioning on a chair. Following, the molar and canine relationship was recorded. The investigators prepared the maxillary and mandibular impression of teeth and their dental casts. The intercanine width, intermolar width, dental arch form, arch length and arch perimeter was measured. The descriptive analysis of all the explanatory and outcome parameters was done using frequency and proportions for categorical variables, whereas in Mean &amp; SD for continuous variables. To compare the selected dental arch parameters between genders, Independent Student t-test Chi-Square test were used. P≤0.05 was set as the level of significance. Results: The mesial step molar relationship and Class I canine relationship were found be more common among males compared to females, however it was not statistically significant (p&lt;0.26). Although, the ovoid arch form was commonly seen especially among males followed by square and tapered, it was not statistically significant (p=0.14). The intercanine width, intermolar width, arch length and arch perimeter was greater in males than females. (p&lt;0.001) Conclusions: Sexual dimorphism was observed among the studied dental arch parameters. Dental arch dimensions like intercanine width of the maxillary arch, intermolar width, and arch perimeter of both maxillary and mandibular arches showed to be an indicator for gender determination with an accuracy of 100%. Keywords: Dental Arch; Primary Teeth, Sexual Dimorphism

Artificial Neural Network as a Predictive Tool for Gender Determination using Volumetric and Linear Measurements of Maxillary Sinus CBCT: An Observational Study on South Indian Population

Introduction: Determination of age and gender using bones of skull is central aspect of forensic odontology. Maxillary sinuses in this regard have shown high accuracy in predicting gender. Aim: To identify gender using the volumetric and linear measurements of maxillary sinuses obtained from a Cone Beam Computed Tomography (CBCT) by using Artificial Neural Network (ANN) based tool. Materials and Methods: A retrospective study was conducted on 80 volumes of CBCT (derived from n=80 patients) with equal gender distribution. The CBCT images were analysed for eight linear and two volumetric measurements namely the maxillary sinus height, maxillary sinus length, maxillary sinus width, distance between infraorbital foramen and distance between maxillary sinus. The data from these parameters were reported by two experts and subjected to discriminant analysis and McNemars test for gender determination. The same data was also fed to the ANN software and the accuracy of its gender prediction was analysed by Receiver Operating Characteristics Curve (ROC) and Area Under the Curve (AUC). Results: The ROC test and AUC (ANN –test) had shown high accuracy for prediction of gender form the data of the CBCT parameters for maxillary sinuses. McNemars test showed that the difference in proportion between the actual gender and ANN predicted gender was not significant (p-value=0.687) and the agreement between the actual gender and ANN in measuring the gender was 84.6%. The male sex was predicted correctly upto 89.7% and female sex upto 94.9%. Conclusion: This study has found ANN to have an encouraging predictive power in gender determination based on linear and volumetric measurements of maxillary sinus obtained from CBCT

Influence of presurgical nasoalveolar molding (PNAM) treatment in maxillary dental arch width and nasolabial symmetry in patients with unilateral complete cleft lip and palate.

Unilateral complete cleft lip and palate (UCCLP) is one of the most severe clinical subphenotypes among nonsyndromic cleft lip and/or palate (NSCL/P), that complicates surgical repair operations. Presurgical nasoalveolar molding (PNAM) is a technique used to reshape the nose, lip and alveolar bone of infants with UCCLP before surgery (the modified Mohler rotation advancement cheiloplasty and two flap palatoplasty), with the potential to facilitate surgical repair. However, the effectiveness of PNAM treatment is still a matter of debate. In this paper, the 3Shape scanning system and 3dMD stereophotography were used to assess the short-term and long-term effects of PNAM treatment on the dental arch morphology and nasolabial features of patients with UCCLP, respectively. The findings indicated that PNAM treatment negatively affects both short-term and long-term dental arch shape compared to the treatment without PNAM, particularly in terms of limiting the transverse width of the maxillary canine-to-midline. Regarding the nasal and labial symmetry, PNAM improves the symmetry of the nasal alae in patients over 7 years old and the symmetry of the lip in patients under 7 years old. Moreover, UCCLP patients who received PNAM treatment exhibited a shorter and wider shape of the nostril on the cleft side compared to those without PNAM treatment. In clinical practice, the multidisciplinary team should carefully consider the advantages and disadvantages of the outcomes of PNAM treatment when treating infants with cleft lip and palate.

Evaluation of Buccal Corridors in Patients Seeking Orthodontic Treatment in Different Types of Malocclusion at Tertiary Care Hospital

There are many factors that make an appealing smile, and the buccal corridor is one of the most crucial smiling characteristics. Objective: To evaluate the width of buccal corridors in patients with different types of malocclusions seeking orthodontic treatment at tertiary care hospital LUMHS Jamshoro/Hyderabad. Methods: 93 subjects were studied. Patients were asked to smile fully to measure buccal corridor width with a vernier caliper. The buccal corridor was estimated by multiplying the maxillary interproximal width by the inner lip corner distance by 100. They were divided into 5 modes by buccal corridor percentage. i-e: Buccal corridor 2% (wide smile), Buccal corridor 10% (nearly a wide smile), Buccal corridor 15% (mediocre smile), Buccal corridor 22% (nearly a narrow smile), Buccal corridor above 22% (narrow smile). Angle's malocclusion classification classified all patients. Results: The mean age was 19.18. Males were 34.4% and females were 65.6%. With various types of buccal corridors among them, 37 participants were in a class I malocclusion, 43 were in the class II and 13 were in the class III malocclusion. 14 participants belongs to medium narrow buccal corridors (15.1%), 18 belongs to the medium buccal corridors (19.4%), 47 belongs to the medium broad buccal corridors (50.5%), and 14 belongs to broad buccal corridors (15.1%). The results showed that there was no significant association between these two variables having p-value 0.207. Conclusion: Medium broad buccal corridors were seen more frequently in various types of malocclusion

The Relationship between Unilateral Palatal Maxillary Canine Impaction and the Morphology of the Maxilla: A CBCT Study in Eastern Province of Saudi Arabia.

This study aimed to examine the correlation between the morphology of the maxilla and unilateral palatally impacted maxillary canine (PIMC) among the Saudi population in the Eastern Province of Saudi Arabia. In this retrospective study, 36 patients' records [(17 PIMC, 8 male, 9 female, mean age 16.75 ± 2.12 years) (19 control; 9 male,10 female, mean age: 17.16 ± 2.12 years)] were included from a teaching dental hospital. On cone-beam computed tomographic images, measurements of maxillary arch length (MAL), palatal vault depth (PVD), intermolar width, sum of widths of 4 maxillary incisors, available arch space (AAS), palatal maxillary width (PMW) in the molar and premolar regions, nasal cavity width (NCW), maxillary arch shape (MAS) (arch length/intermolar width x 100), and palatal vault shape (PVS) (the PVD/intermolar width x100) were performed. Data were analyzed by SPSS-20.0. p-value less than or equal to 0.05 reflected statistical significance. This study's findings depicted that AAS (p = 0.012), PVD (p = 0.028), and PMW in the molar and premolar regions at the level of the alveolar crest (p = 0.002 and p = 0.034) and mid-root (p = 0.004 and p = 0.022) were significantly higher in the control compared to the PIMC group. PVS showed a significant difference between the PIMC and control groups (p = 0.037). However, regarding MAS, no significant difference was observed (p = 0.707). MAS was narrower in PIMC compared to the control group. The control group had a deeper palatal vault and greater AAS compared to the PIMC group. However, no significant difference was observed between groups regarding tooth size or NCW.

Skeletal and dentoalveolar characteristics of maxillary lateral incisor agenesis patients: a comparative cross-sectional study

BackgroundThe aim of the study was to evaluate the cephalometric and dentoalveolar characteristics of maxillary lateral incisor agenesis patients, and to compare the findings to a matched control group without tooth agenesis, excluding third molars, from the same population.MethodsThe pre-orthodontic records of 72 non-growing patients, who were treated at the Orthodontic Department, Faculty of Dentistry, Alexandria University, were used to address the aim of this retrospective study. Patients having unilateral or bilateral maxillary lateral incisor agenesis, with no history of previous orthodontic treatment, congenital craniofacial malformations, facial trauma, or surgeries were divided into two test groups based on the pattern of maxillary lateral incisors agenesis (group I: unilateral (UMLIA), group II: bilateral (BMLIA)). A control group (group III (CTRL)) having a complete set of permanent dentition (excluding third molars), and having no dental anomalies was age-matched with the test groups. Measurements were performed on the pre-orthodontic lateral cephalometric radiographs and the pre-orthodontic digital dental casts. The measured variables were compared between the groups using one-way ANOVA and Kruskal Wallis tests according to the normality of the variable. In case of significant results, both tests were followed by multiple pairwise comparisons using Bonferroni adjusted significance level. Significance level was set at P < 0.05.ResultsBMLIA group showed a smaller SNA angle and maxillary length, a more negative ANB angle and Wits appraisal, and a larger Maxillo-mandibular differential than UMLIA and/or CTRL group. The dental and soft tissue cephalometric measurements did not show any significant differences between the groups. Dentoalveolar cast measurements showed that BMLIA patients presented with significantly smaller maxillary inter-canine width than UMLIA and CTRL patients.ConclusionsCephalometric analysis has shown that subjects with BMLIA have a statistically significant reduced ANB and maxillary length. Tooth eruption may play a role in the development of the maxillary arch.

The Analysis of Facio-Dental Proportions to Determine the Width of Maxillary Anterior Teeth: A Clinical Study.

The present study aimed to analyze mid horizontal facial third proportions, those being the interpupillary, inner intercanthal, and bizygomatic distance modified with golden proportion, The Preston proportion, golden percentage and 70% recurring esthetic dental proportion were used for determining maxillary anterior teeth width. A total of 230 participants took part in this study. The front dental and facial photographs along dental stone cast which were converted to three-dimensional (3D) models were used for evaluation. The mid horizontal facial third proportions showed no significant relationship with maxillary anterior teeth width without modification with dental proportions. Whereas, with modification, no statistically significant difference was found between inner-intercanthal distance by golden percentage and width of central incisors. The bizygomatic distance was greater than intercanine distance. While the interpupillary distance by golden proportion was found to be consistent with intercanine distance in female participants. The modified anterior teeth width was significantly different from measured values, when determined by using the three mid facial proportions with Preston and 70% recurring esthetic dental (RED) proportion. Furthermore, the measured width of maxillary anterior teeth showed no difference when plaster dental casts widths were compared with 3D models. The interpupillary, inner-intercanthal, and bizygomatic distance should not be directly used to determine maxillary anterior teeth width. While maxillary anterior teeth width can be determined by modifying the inner inter-canthal distance with golden percentage and interpupillary distance with golden proportion. Moreover, the midfacial third proportions modified with Preston and 70% recurrent esthetic dental proportion were found to be unreliable for the determination of maxillary anterior teeth widths.

Should Mandibular Symphyseal Distraction Osteogenesis be considered in OSA Surgery?

Surgical maxillary expansion for the treatment of obstructive sleep apnea (OSA) has become common place. To maximize airway improvement, over-expansion of the maxilla can occur, resulting in an excessively widened maxilla that creates a mismatch to the mandible. Therefore, mandibular symphyseal distraction osteogenesis (MSDO) to widen the mandible along with maxillary expansion is being increasingly advocated in OSA surgery. The authors discuss their 20-year experience with MSDO and surgical maxillary expansion. They also analyze the airway impact between Distraction Osteogenesis Maxillary Expansion (DOME) and Endoscopically-Assisted Surgical Expansion (EASE) based on currently available computational fluid dynamic (CFD) data, which has implications in whether MSDO needs to be considered. The goal of surgical maxillary expansion is to enlarge the nasal cavity and reduce the airway resistance. CFD data demonstrates that EASE results in a much greater reduction in airway resistance as compared to DOME. EASE achieved a 12-fold reduction in nasal airway resistance compared to 3-fold reduction by DOME; a 12-fold reduction of retropalatal airway resistance as compared to 3-fold reduction by DOME; a 10-fold reduction of oropharyngeal airway resistance as compared to a 3-fold reduction by DOME, and an 8-fold reduction of hypopharygeal airway resistance as compared to a 3-fold reduction by DOME. Because there is no physiologic basis or data that demonstrates mandibular widening improves OSA, an airway centric surgical expansion technique such as EASE can achieve a much greater airway impact without needing excessive maxillary widening, thus eliminating the necessity MSDO.

Effectiveness of low-level laser therapy in facilitating maxillary expansion using bone-borne hyrax expander: A randomized clinical trial.

The objective of this randomized clinical trial was to study the skeletal and dental effects of low-level laser therapy (LLLT) along with a miniscrew-assisted expander (Hyrax) after six months of retention. After sequence generation, concealed allocation, and implementation, 24 female patients were randomly divided (1:1) into two-groups: bone-borne rapid palatal expansion (BBE) without LLLT (n = 12) and BBE with LLLT (n = 12). Eligibility criteria included female patients aged 10-13 years old with bilateral posterior crossbites. Intraoral and extraoral photographs, cone-beam computed tomography images, and digital study models were obtained before expansion and six months after retention. The 7 mm Hyrax appliance was anchored to four palatal mini-screws, which were activated twice daily for 15 days, then locked and kept in place as a retainer. LLLT was performed in the laser group during expansion and retention, according to the guidelines provided. The records of 24 patients were analyzed. According to the post-retention measurements, both groups showed a significant increase in nasal and maxillary widths and total facial height. In the laser group, the Sella-Nasion-Point A and Point A-Nasion-Point B angles and the interpremolar apical distance were significantly increased. Within the limitations of this study, the results suggest that the parameters and protocol of LLLT do not clinically affect the efficiency of BBE in prepubertal and pubertal patients.