Evaluation of the Soft Tissue Changes after Rapid Maxillary Expansion Using a Handheld Three-Dimensional Scanner: A Prospective Study

Comparison of the effects on facial soft tissues produced by rapid and slow maxillary expansion using stereophotogrammetry: a randomized clinical trial

OBJECTIVE

To compare the effects on facial soft tissues produced by maxillary expansion generated by rapid maxillary expansion (RME) versus slow maxillary expansion (SME).

MATERIALS AND METHODS

Patients in the mixed dentition were included with a transverse discrepancy between the two arches of at least 3 mm. A conventional RME screw was compared to a new expansion screw (Leaf expander) designed to produce SME. Both screws were incorporated in a fixed expander. The primary outcome was the difference of the facial tissue changes in the nasal area measured on facial 3D images captured immediately before application of the expander (T0) and after one year of retention, immediately after the expander removal (T1). Secondary outcomes were soft tissue changes of other facial regions (mouth, lips, and chin). Analysis of covariance was used for statistical analysis.

RESULTS

Fourteen patients were allocated to the RME group, and 14 patients were allocated to the SME group. There were no dropouts. Nasal width change showed a difference between the two groups (1.3 mm greater in the RME group, 95% CI from 0.4 to 2.2, P = 0.005). Also, intercanthal width showed a difference between treatments (0.7 mm greater in the RME group, 95% CI from 0.0 to 1.3, P = 0.044). Nasal columella width, mouth width, nasal tip angle, upper lip angle, and lower lip angle did not show any statistically significant differences. The Y-axis (anterior-posterior) components of the nasal landmark showed a statistically significant difference between the two groups (0.5 mm of forward displacement greater in the RME group, 95% CI from 0.0 to 1.2, P = 0.040). Also, Z-axis (superior-inferior) components of the lower lip landmark was statistically significant (0.9 mm of downward displacement in favor of the RME group, 95% CI from 0.1 to 1.7, P = 0.027). All the other comparisons of the three-dimensional assessments were not statistically significant.

CONCLUSIONS

RME produced significant facial soft tissue changes when compared to SME. RME induced greater increases in both nasal and intercanthal widths (1.3 mm and 0.7 mm, respectively). These findings, though statistically significant, probably are not clinically relevant. Trial registration ISRCTN, ISRCTN18263886. Registered 8 November 2016, https://www.isrctn.com/ISRCTN18263886?q=Franchi&filters=&sort=&offset=2&totalResults=2&page=1&pageSize=10.

Orthodontic program design based on aesthetic

Orthodontics is a discipline that is based on aesthetics. It coordinates the relationship among nose, lip, and chin through the movement of teeth and the adjustment of jaw relationship. Orthodontists need to fully analyze the patient's soft tissue profile before treatment. They also need to analyze the existing problems and those that may be solved or caused during orthodontics to guide the design of orthodontic treatment and effectively improve the clinical effect of orthodontics. This article reviews the aesthetic preconditions that guide the design of orthodontic treatment from the perspective of orthodontists.

Application of three-dimensional reconstruction technology in dentistry: a narrative review

BACKGROUND

Three-dimensional(3D) reconstruction technology is a method of transforming real goals into mathematical models consistent with computer logic expressions and has been widely used in dentistry, but the lack of review and summary leads to confusion and misinterpretation of information. The purpose of this review is to provide the first comprehensive link and scientific analysis of 3D reconstruction technology and dentistry to bridge the information bias between these two disciplines.

METHODS

The IEEE Xplore and PubMed databases were used for rigorous searches based on specific inclusion and exclusion criteria, supplemented by Google Academic as a complementary tool to retrieve all literature up to February 2023. We conducted a narrative review focusing on the empirical findings of the application of 3D reconstruction technology to dentistry.

RESULTS

We classify the technologies applied to dentistry according to their principles and summarize the different characteristics of each category, as well as the different application scenarios determined by these characteristics of each technique. In addition, we indicate their development prospects and worthy research directions in the field of dentistry, from individual techniques to the overall discipline of 3D reconstruction technology, respectively.

CONCLUSIONS

Researchers and clinicians should make different decisions on the choice of 3D reconstruction technology based on different objectives. The main trend in the future development of 3D reconstruction technology is the joint application of technology.

What is the impact of miniscrew-assisted rapid palatal expansion on the midfacial soft tissues? A prospective three-dimensional stereophotogrammetry study

OBJECTIVES

To evaluate the midfacial soft tissue changes of the face in patients treated with miniscrew-assisted rapid palatal expansion (MARPE).

MATERIALS AND METHODS

3D facial images and intra-oral scans (IOS) were obtained before expansion (T0), immediately after completion of expansion (T1), and 1 year after expansion (T2). The 3D images were superimposed and two 3D distance maps were generated to measure the midfacial soft tissue changes: immediate effects between timepoints T0 and T1 and overall effects between T0 and T2. Changes of the alar width were also measured and dental expansion was measured as the interpremolar width (IPW) on IOS.

RESULTS

Twenty-nine patients (22 women, 7 men, mean age 25.9 years) were enrolled. The soft tissue in the regions of the nose, left of philtrum, right of philtrum, and upper lip tubercle demonstrated a statistically significant anterior movement of 0.30 mm, 0.93 mm, 0.74 mm, and 0.81 mm, respectively (p < 0.01) immediately after expansion (T0-T1). These changes persisted as an overall effect (T0-T2). The alar width initially increased by 1.59 mm, and then decreased by 0.08 mm after 1 year, but this effect was not significant. The IPW increased by 4.58 mm and remained stable 1 year later. There was no significant correlation between the increase in IPW and alar width (r = 0.35, p = 0.06).

CONCLUSIONS

Our findings indicate that MARPE results in significant but small changes of the soft tissue in the peri-oral and nasal regions. However, the clinical importance of these findings is limited.

CLINICAL RELEVANCE

MARPE is an effective treatment modality to expand the maxilla, incurring only minimal and clinically insignificant changes to the midfacial soft tissues.

The Facial Characteristics of Individuals with Posterior Crossbite: A Cross-Sectional Study

Facial morphology is known to be influenced by genetic and environmental factors. Scientific evidence regarding facial parameters in patients with posterior crossbite is lacking. This study aimed to investigate the association between posterior crossbite and facial parameters. This cross-sectional study included 34 adolescents with and 34 adolescents without posterior crossbite in the age range from 13 to 15 years. Facial surface scans were acquired with a 3dMD imaging system, and landmark-based analysis was performed. Data were analyzed using the Mann-Whitney U test and Spearman's correlations. Individuals in the control group had lower face heights (females: p = 0.003, r = 0.45; males: p = 0.005, r = 0.57). The control group females presented with smaller intercanthal width (p = 0.04; r = 0.31) and anatomical nose width (p = 0.004; r = 0.43) compared with the crossbite group females. The males in the control group had wider nostrils. In the control group, significant correlations among different facial parameters were more common, including the correlations between eye width and other transversal face measurements. On the contrary, the facial width was correlated with nasal protrusion (r = 0.657; p < 0.01) and the morphological width of the nose (r = 0.505; p < 0.05) in the crossbite group alone. In both groups, the philtrum width was linked with the anatomical and morphological widths of the nose. Conclusions: Patients with posterior crossbites have increased face height and different patterns of facial proportions compared with individuals without crossbites.

Anthropometric assessment of microtia patients' normal ears and discussion on expander selection in auricular reconstruction surgery

The tissue expansion technique is the most suitable procedure for Chinese patients with microtia. However, it is difficult to determine whether the expanded flap is sufficient, and there are no clear or objective guidelines for determining the volume of the expander for different sizes of auricles. One hundred patients with unilateral microtia who visited our department in 2021 were randomly selected for auricular data collection using 3D scanning. The auricle length, width, projection, perimeter, and surface area were measured. Eight different volumes of expanders underwent CT and the surface areas of these expanders were measured. The surface areas of the auricles and expanders were compared and the correlation between them was explored. The average auricle parameters were calculated. The scatter plot showed a linear relationship between auricle length and auricle surface area (R² = 0.9913), which demonstrated that the auricle area was approximately equal to the auricle length multiplied by 76.921. Additionally, the surface area of the expanders was measured and made into a table for selection against the surface area of the auricles. Using our equation, the auricle surface could be estimated by simply measuring the non-defective auricle length; therefore, the suitable volume of the expander could be determined.

Effect of treatment of transverse maxillary deficiency using rapid palatal expansion on oral health-related quality of life in children: A randomized controlled trial

INTRODUCTION

This trial aimed to longitudinally evaluate the effect of the treatment of transverse maxillary deficiency using rapid palatal expansion (RPE) on self-perceived oral health-related quality of life (OHRQOL) in children.

METHODS

Eighty participants aged 8-10 years with transverse maxillary deficiency and bilateral posterior crossbite were randomly assigned to 2 groups (n = 40 each): a group treated with RPE using hyrax-type appliances and a nontreated control group. OHRQOL was assessed by using the Child Perceptions Questionnaire for 8-10-year-olds at 4 times: before RPE, during RPE (T₁), at the end of RPE (T₂), and 1 month after the appliance removal (T₃). Generalized mixed models were used for data analysis (α = 0.05).

RESULTS

Both groups exhibited similar demographic characteristics and OHRQOL scores at baseline. All participants completed the study. RPE had a time-dependent effect on OHRQOL. At T₁ and T₂, this therapy is expected to increase the overall OHRQOL scores by 1.17 times (ie, ∼17% increase; T₁ 95% confidence interval [CI], 1.08-1.26; T₂ 95% CI, 1.09-1.27; P = 0.001). In contrast, the overall OHRQOL scores at T₃ are expected to be 0.28 times the baseline scores (ie, ∼72% reduction; T₃ 95% CI, 0.26-0.31; P = 0.001). All individual domains of the OHRQOL evidenced a positive impact of treatment at T₃ (P = 0.001). Only the oral symptoms and social well-being domains showed a significantly negative impact of the treatment at T₁ and T₂.

CONCLUSIONS

Correction of the transverse maxillary deficiency by RPE in children aged 8-10 years improves OHRQOL. There is a temporary worsening of OHRQOL during the treatment of this condition using RPE.

REGISTRATION

This trial was not registered.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil, Financing Code 001.