Fall IJO Abstracts
(Click title to read full article)
Background and aim: The tooth size discrepancy (TSD) is crucial in determining and predicting treatment outcomes. The Bolton analysis, which measures the mesiodistal width of the mandibular and maxillary teeth, is essential for this process. This study aims to evaluate the Bolton anterior and overall tooth size ratios and to analyze their association with various classes of dental malocclusion, as defined by Angle’s classification.
Methods: In this retrospective cross-sectional study, 150 patients with complete permanent dentition and no dental anomalies were randomly selected. After excluding unsuitable casts, samples were divided into Class I, II, and III malocclusion groups. Anterior and overall Bolton ratios were measured and analyzed across groups, and gender differences were also evaluated.
Results: The present study showed that skeletal Class III patients had significantly higher anterior Bolton ratios than Class II patients. However, this difference was not statistically significant in the CLI group, although it was greater. The differences in overall Bolton ratios between different malocclusion groups were not statistically significant. Statistical analysis showed that there was a weak correlation between these parameters and anterior Bolton ratios. About 30% of patients had significant anterior tooth size differences (more than 1 standard deviation from the Bolton standard). In this study, there was no significant difference in anterior and overall Bolton ratios between the male and female groups.
Conclusion: This study revealed that skeletal Class III patients had a significantly higher anterior Bolton ratio than Class II patients. There was no significant difference in overall Bolton ratios between different malocclusion groups, and there was no significant difference in anterior and overall Bolton ratios between males and females in general.
Keywords: Bolton Analysis, Esthetics, Macrodontia, Microdontia, Tooth Size Discrepancy.
Conflict of Interest: None
This case report presents a multidisciplinary approach in treatment planning for a patient with hypodontia and spacing. The patient’s chief complaint was multiple diastema on both anterior and posterior regions, unfavorable smile and sensitivity of the lower front teeth. Having had braces for seven (7) years, with a constant opening up of spaces or relapse, the patient requested for an esthetic and restorative solution. A comprehensive diagnostic evaluation confirmed hypodontia, resulting in generalized spacing across the maxillary and mandibular arches.
To address the malocclusion and restore optimal dental and skeletal balance, a combination of functional and fixed orthodontic appliances was employed. Treatment objectives focused on correcting the asymmetric molar relationship, managing the effects of hypodontia, improving incisor angulation, and resolving the deep bite, creation of appropriate spaces for prosthetic replacement of missing teeth and esthetic rehabilitation of lower anterior teeth with attrition. Additional goals focused on improving vertical dimension, mandibular position based on phonetics and functions and achieving stability to manage bruxism.
Keywords: hypodontia, multiple diastema, attrition, bruxism, deep bite, vertical dimension, ortho-esthetics
Conflict of Interest: None
Correcting the appearance of a gummy smile has long been a challenge, particularly when attempting non-surgical methods. Historically, intruding posterior teeth without skeletal anchorage has been unfeasible, while traditional orthodontic intrusion of anterior teeth often exerts an extrusive force on the posterior teeth. Furthermore, the mechanics involved in space closure can produce undesirable side effects, potentially exacerbating the appearance of the gummy smile. This case report describes the non-surgical correction of a gummy smile through the intrusion of the entire maxillary dentition using skeletal anchorage, along with its long-term retention.
Keywords: gummy smile; intrusion; case report; mini-implants; center of resistance
Conflict of Interest: None
Background: The displaced maxillary permanent canine is a common clinical problem that can be associated with multiple complications including external root resorption (ERR) of adjacent teeth. Objectives: This retrospective crosssectional observational study investigated ERR associated with teeth adjacent to displaced permanent maxillary canines using cone-beam computed tomographic (CBCT) imaging.
Materials and Methods: The study sample comprised all patients diagnosed with displaced maxillary canine teeth with CBCT imaging available of the anterior maxilla, who attended a tertiary orthodontic-oral surgery treatment planning clinic within a 24-month period between 2018-2020 at Guy’s and St Thomas’ NHS Foundation Trust, UK. CBCT imaging was analysed to localise the buccalpalatal, vertical and mesio-distal position of the displaced maxillary canines and quantify ERR associated with adjacent teeth. Severity of ERR was assessed based on proximity to the pulp and graded as slight, moderate or severe. Descriptive statistics and logistic regression were used to examine the relationship between canine location and ERR associated with adjacent teeth.
Results: One hundred and nineteen displaced canines were analysed from 92 CBCT scans (41 buccal displaced canines (BDC), 16 in the line of the arch (LOA) and 62 palatal displaced canines (PDC)). ERR was associated with n=44 (37%) displaced canines, with 18.2% of these involving resorption of two adjacent teeth. The teeth most frequently affected by ERR were lateral incisors (73.1%), followed by central incisors (23.1%), and first premolars (3.9%). Interestingly, amongst maxillary central incisor teeth affected by ERR, 58% were classified as severe. BDC were significantly associated with ERR (P=0.011), whilst other factors significantly associated with ERR of neighbouring teeth included patient age ≤18 years (P=0.005) and apical position of the canine crown tip (P=0.03). Conclusions: BDC were associated with an increased incidence and severity of root resorption associated with adjacent teeth in the maxilla compared to LOA and PDC.
Keywords: Impacted maxillary permanent canines; Buccal canines; Palatal canines; Displaced canines; Root resorption; CBCT imaging
Conflict of Interest: None
Objectives: Bracket bond failure is a common issue in orthodontics, especially with composite restorations. The shear bond strength of metal brackets that are bonded to composite surfaces using Single Bond 2 and Single Bond Universal Adhesive is compared in this study. Also, it evaluates the effects of surface preparation with diamond burs.
Methods: In this experimental study, 48 composite specimens were prepared and randomly assigned into four groups (n = 12) based on adhesive type and whether surface preparation with a diamond bur was performed. MBT metal brackets were bonded to composite surfaces. Shear bond strength and failure patterns were evaluated after 50,000 thermocycling cycles. A stereomicroscope was used to determine the mode of failure and adhesive remnant index (ARI) score. Data were analyzed using SPSS version 23, two-way ANOVA, and the Kruskal-Wallis test.
Results: The strength of the shear bond was significantly greater in Single Bond Universal Adhesive groups than in those treated with Single Bond 2 (P = 0.001). Bond strength did not significantly change after preparing the surface with a diamond bur (P = 0.913). The single bond universal groups had the most frequently observed Adhesive Remnant Index (ARI) score (score 4).
Conclusions: Bonding orthodontic brackets to composite restorations is more effective with universal adhesives, which improve bond strength, reduce clinical chair time, and guarantee reliable bracket retention throughout treatment.
Keywords: Bracket bond failure, Composite restoration, Orthodontic bracket, Shear bond strength, Universal adhesive.
Conflict of Interest: None
Objectives: To report the orthodontic treatment of monozygotic twins presenting Class II skeletal malocclusion, treated with extra-alveolar mini-implants in the infrazygomatic crest (IZC) and mass distalization of the maxillary teeth. Methods: Monozygotic twins (Patient 1, 11 years and 11 months, mixed dentition; Patient 2, same age, permanent dentition) presented with the main complaint of protruding teeth, convex facial profile, severe excess and Class II skeletal relationship. Comprehensive fixed orthodontic appliances were bonded to both archwires. Stainless steel wires were inserted into the maxilla, and IZC mini-implants were installed bilaterally. An elastic chain delivering approximately 350 gf on each side was extended from the IZC units to the mesial hooks of the maxillary canines. The force’s line of action was designed to pass directly through the maxillary center of resistance to prevent unwanted tilting or rotation of the occlusal plane. Results: Post-treatment clinical and cephalometric evaluations revealed successful correction of Class II skeletal malocclusion for a Class I ratio. Both patients achieved total overjet and overbite correction, optimal intercuspation with the molars and canines in Class I, and a significant reduction in ANB angle (4° in Patient 1 and 3.5° in Patient 2). Structural overlaps confirmed 3 mm of true distalization of the maxillary body molars without vertical impairment or adverse rotation of the occlusal plane, resulting in a balanced mesofacial biotype and a passive and competent lip seal. Conclusions: The integration of fixed orthodontic appliances with IZC mini-implants is a highly effective, predictable, and minimally invasive biomechanical approach to mass-correct sagittal skeletal discrepancies in growing individuals, ensuring excellent three-dimensional dental control and facial profile harmony.
Keywords: Orthodontic Anchorage Procedures; Malocclusion, Angle Class II; Twins, Monozygotic; Tooth Movement Techniques; Orthodontics
Conflict of Interest: None
Shape memory polymers (SMPs) are stimuliresponsive biomaterials with potential for patientspecific craniofacial and orthodontic applications. This review summarizes advances in biocompatible SMP design, functionalization, and 3D/4D printing, emphasizing adaptive devices and regenerative scaffolds. Current evidence, translational limitations, and priorities for clinical research are critically discussed.
Keywords: Shape memory polymers; biocompatible polymers; orthodontics; craniofacial applications; 3D printing; 4D printing; biomaterials
Conflict of Interest: None
From a legal perspective, it is only because of the existence of a doctor patient relationship that a doctor is required to conform to a given standard of care. While this special relationship is easy to establish, it is difficult to terminate unless specific protocols are followed. If the steps to legally dismiss a patient from one’s practice are not adhered to, the doctor may be found liable for having abandoned his patient.
Keywords: Formation and Termination of the Doctor Patient Relationship, Patient Abandonment
Conflict of Interest: None
The IAO is taking its Annual Meeting to Sydney, Australia, and this is a milestone you won’t want to miss!
I have spent 36 years in practice watching orthodontics reinvent itself, and I am convinced the next decade will bring sharper change than anything we have seen so far.
Looking back, three threads explain how we arrived here, and they will keep shaping how we diagnose, plan and deliver care: the precision engineering of our appliances, the digital revolution that now sits under almost everything we do, and the recurring cycle of trend-driven therapies that test our judgement. Here is where I believe each is heading, and, more importantly, what will not change no matter how good the technology becomes.
