Changes in mandibular shape after early treatment in subjects with open bite: a geometric morphometric analysis

Gingivectomy with Diode Laser Versus the Conventional Scalpel Surgery and Nonsurgical Periodontal Therapy in Treatment of Orthodontic Treatment-Induced Gingival Enlargement: A Systematic Review

Background and objective: Some studies support the superiority of diode laser gingivectomy to scalpel surgery and nonsurgical treatments. However, a systematic review on this topic is lacking. This study aimed to compare gingivectomy with diode laser versus the conventional scalpel surgery and nonsurgical periodontal therapy (NSPT) in the treatment of orthodontic treatment-induced gingival enlargement (GE). Materials and methods: In this systematic review, an electronic search of the relevant literature was conducted in Web of Science, Medline/PubMed, Scopus, Cochrane Central Register of Controlled Trials, and ProQuest with no language restriction. Randomized clinical trials published between 1985 and 2020 on comparative treatment of orthodontic treatment-induced GE by diode laser gingivectomy and scalpel surgery or NSPT regarding intraoperative and postoperative bleeding and/or pain were included. Risk of bias was assessed by the Cochrane 1 tool. Results: Of the initially retrieved 288 articles, 40 were duplicates and excluded; 236 articles were excluded following title and abstract screening, and 5 others were excluded following full-text assessment. Finally, 7 studies underwent systematic review. In the risk-of-bias assessment, 5 studies scored 2, and 2 studies scored 3 out of 6. Intraoperative and postoperative bleeding and pain were found to be significantly lower in the laser group. Conclusions: Within the limitations of this systematic review and with respect to the quality of evidence, the present results revealed lower level of pain and bleeding in diode laser gingivectomy compared with the conventional scalpel surgery and NSPT for treatment of orthodontic treatment-induced GE.

Mandibular morphometric analysis in open bite early treatment relapse subjects: a retrospective observational pilot study

BACKGROUND

The purpose of this retrospective study was to evaluate the mandibular shape differences between a group of success and a group of failure Anterior Open Bite (AOB) malocclusion early orthodontic treatment in growing subjects, in order to identify mandibular features of relapse.

METHODS

Twenty three patients (7 males, 16 females, 9.3 years ±1,5 years) were enrolled from the Department of Orthodontics at the University of Rome Tor Vergata. Inclusion criteria were: white ancestry, overbite < 0 mm, mixed dentition phase, end-to-end or Class I molar relationship, first skeletal class assessed on lateral cephalograms (0° < ANB < 4°), cervical skeletal maturation CS1-CS2, no previous orthodontic treatment, no congenital diseases. Pre-treatment (T1) lateral cephalograms were acquired. Each patient underwent early orthodontic treatment with Rapid Maxillary Expander (RME) and Bite Block (BB) or Quad-Helix Crib (QHC) until open bite correction. Radiographic records were recollected at T2 (permanent dentition, skeletal cervical maturation CS3-CS4). Mean interval time T2-T1 was 4.2 years ±6 months. According to treatment stability, a Relapse Group (RG 11 patients, 3 M, 8F; 13.7 years ±8 months, 7 subjects treated with RME/BB, 4 with QH/C) and a Success Group (SG, 12 patients, 4 M, 8F; 13.4 ± 10 months, 7 subjects treated with QH/C, 5 with RME/BB) were identified. On the lateral radiographs the mandibular length (Co-Gn), the inferior gonial angle (NGo^GoMe) and the antegonial notch depth (AND) were analyzed. Then the mandibular Geometric Morphometric analysis (GMM) was applied. Intergroup statistically significant differences were found using student's t-tests. Procrustes analysis and principal component analysis (PCA) were performed for the GMM.

RESULTS

At T1 no statistically significant differences were found between RG and SG, however higher values of antegonial notch depth were found in RG. T2-T1 comparison showed in RG statistically significant increases in Co-Gn (p = 0.04), NGo^GoMe angle (p = 0.01) and antegonial notch depth (p = 0,04). PC1 confirmed the increase in the antegonial notch depth in RG when compared to SG at T2.

CONCLUSIONS

The increased antegonial notch depth associated with the increased mandibular length and the increased gonial angle could be responsible of relapse of early orthodontic treatment in open bite growing subjects.

Evaluation of the Upper Arch Morphological Changes after Two Different Protocols of Expansion in Early Mixed Dentition: Rapid Maxillary Expansion and Invisalign® First System

Background: The objective of this retrospective study was to analyze the morphological changes of the upper arch after two protocols of expansion, the Invisalign® First system and rapid maxillary expansion (RME), in mixed dentition by means of geometric morphometric analysis (GMM). Methods: Digital dental casts of 32 children treated either with RME (RME group: 17 subjects; mean age 8.1 years) or the First system (First group: subjects; mean age 8.4 years) were collected. For both the RG and FG, pre-(T1) and post-treatment(T2) digital models were created. A total of 14 landmarks were digitized and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. Results: The PC1 resulting from the T2–T1 comparison in the RG g showed statistically significant morphological changes in the posterior region of the upper arch shape, without significant variations in the anterior region. The comparison of the T2–T1 changes in the FG showed an increase in the transverse dimension at the level of the canine and the first deciduous molar widths, with morphological variation in the anterior region due to frontal teeth alignment. Conclusions: The First system induced shape modifications of the upper arch during expansion in contrast to RME. The FG presented an improvement in the maxillary arch shape, while the RG maintained the initial triangular shape.

Palatal vault morphometric analysis of the effects of two early orthodontic treatments in anterior open bite growing subjects: a controlled clinical study

Background

The purpose of this study was to evaluate the palatal morphological changes in Anterior Open Bite (AOB) pre-pubertal subjects treated with Rapid Maxillary Expansion and Bite-Block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Analysis (GMM).

Methods

AOB group (AOBG) included 30 subjects (20 females, 10 males, mean age 8.1 ± 0.8ys) with dentoskeletal AOB. AOBG was divided in two subgroups according to the treatment strategy: RME/BB group (RME/BBg) included 15 subjects (10 females, 5 males, QH/C group (QH/Cg) comprised 15 subjects (10 females, 5 males). The two subgroups were compared with a CG of 15 subjects (10 females, 5 males) matched for sex, age, vertical pattern, and observation period. Digital upper dental casts were collected before treatment (T1) and at the end of the active treatment (T2). Landmarks and semilandmarks were digitized on dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed.

Results

At T2, RME/BBg when compared with QH/Cg evidenced no statistically significant differences. Instead, RME/BBg showed an increased maxillary transverse dimension and a decreased palatal depth when compared with CG. The comparison QH/Cg vs. CG demonstrated a slight transversal maxillary expansion.

Conclusions

RME/BBg showed significant changes in the transversal and vertical dimensions with a clear maxillary expansion and a decrease of the palatal depth when compared with QH/Cg and CG. QH/Cg showed a significant slight maxillary expansion and no variation in vertical and sagittal planes when compared with CG.

Application of the diode laser for soft-tissue surgery in orthodontics: Case series

Referral to an oral surgeon for soft-tissue surgery before, during or after orthodontic treatment is not uncommon. This process may delay treatment and could potentially increase the risk of complications. In addition, seeing multiple specialties in different environments may demotivate paediatric or anxious patients from pursuing orthodontic treatment and could also adversely affect patient compliance and satisfaction. The development of laser technology provides a safe and effective alternative, allowing the orthodontic clinician to perform soft-tissue surgery. To date, there are no laser exposure protocols or UK guidelines regarding the use of laser surgery in orthodontics. This case series reports four clinical cases that demonstrate potential advantages of using a diode laser for the management of soft tissue in the field of orthodontics.