Combined orthodontic-periodontal treatment in periodontal patients with anteriorly displaced incisors

INTRODUCTION

Flared and elongated incisors are associated with different types of periodontal bone defects, usually horizontal. Combined orthodontic-periodontal treatment is being used in periodontal patients with anterior displacement of the incisors. The purpose of this study was to investigate the changes in periodontal health and the shape of bone defects in the incisors after such combined treatment.

METHODS

Fourteen adults were included in the study. In total, 56 elongated maxillary incisors with horizontal bone defects received orthodontic-periodontal treatment with circumferential supracrestal fibrotomy. To improve bone morphology, periodontal regenerative surgery and guided tissue regeneration were performed on the anterior teeth with angular bone defects after orthodontic treatment. Cone-beam computed tomography scans were taken before treatment (T0), at the end of the orthodontic intrusion (T1), and 6 months after the guided tissue regeneration surgery (T2). Probing pocket depth and clinical attachment loss were examined at T0, T1, and T2. The data were analyzed using paired t tests.

RESULTS

From T0 to T1, clinical attachment loss decreased significantly by 0.29 mm (P <0.05). The distance from the cementoenamel junction to the marginal bone crest decreased by 0.66 mm (P <0.05). The labial side of alveolar bone thickness increased by 0.54 mm (P <0.05), and the lingual side of alveolar bone thickness decreased by 0.46 mm (P <0.05). The shape of the bone defect was changed from horizontal to vertical on some teeth. From T1 to T2, both probing pocket depth and clinical attachment loss improved significantly, and the radiographic examinations showed bone redepositions of 2.15 ± 0.68 mm (P <0.05) vertically and 1.44 ± 0.92 mm (P <0.05) horizontally. The distance from the most apical point of the bone defect to the cementoenamel junction after combined treatment decreased by 2.11 ± 1.30 mm (P <0.05).

CONCLUSIONS

Combined orthodontic-periodontal treatment improved the periodontal conditions of the defective bone sites. Bone morphology, altered by orthodontic intrusion with fibrotomy, can improve the results of subsequent guided tissue regeneration.

Amelogenesis Imperfecta with Coronal Resorption: Report of Three Cases

Intracoronal resorption of the permanent dentition in cases of amelogenesis imperfecta (AI) is a rare finding which poses an added complication to the already complex management of this condition. This paper presents three cases of AI associated with delayed eruption of permanent teeth in which asymptomatic intracoronal resorption occurred. CPD/Clinical Relevance: This paper highlights the fact that teeth affected with amelogenesis imperfecta may undergo asymptomatic intracoronal resorption which is only identifiable radiographically.

The Ethics of Interproximal Reduction

Interproximal reduction (IPR) has become particularly popular with the use of removable aligners. Clinical and ethical factors concerning the use of interproximal reduction to facilitate orthodontic alignment are discussed. CPD/Clinical Relevance: An understanding of the aetiological factors of a malocclusion is essential to enable full discussion of the risks and benefits, or the alternatives to IPR.

Measurement of Incisor Overjet and Physiological Diastemata Parameters in Quarter Horse Foals

Cephalometric studies are important to quantify abnormalities of jaw length and positioning. In this study, 4 to 7-month-old Quarter horse foals (n = 51) were examined to determine overjet (horizontal overlap) prevalence and measure the size of the physiological diastemata. Results were analyzed in relation to age, sex, and lineage. Another aim of this study was to develop a simple field technique for measuring incisor malocclusion and physiological diastemata dimensions that could be used to monitor the growth of the rostral components of maxilla, incisive bone, and mandible. The overall prevalence of overjet lesions in these foals was 51%. Females were overrepresented (61.5%). Overjet occurred more commonly in show foals (50% prevalence) than other working (7.7%) and race (42.3%) lineage foals. Significant differences were found between maxillary and mandibular physiological diastemata lengths in foals of all ages and, as expected, there was a positive statistical correlation between age and maxillary and mandibular physiological diastemata measurements. Incisor overjet was present in 44.4% of 4-month-old foals, 45.5% of 5-month-old foals, 58.3% of 6-month-old foals, and 60% of 7-month-old foals. There was a weak positive correlation between age and the presence of incisor overjet. It was concluded that incisor overiet was common among Quarter horse foals, especially those from show and race lineages. The field technique for physiological diastema measurements was considered effective.

Evaluation of maxillary arch morphology in children with unilaterally impacted incisors via three-dimensional analysis of digital dental casts: a controlled study

OBJECTIVE

The purpose of this work was to analyze variations in maxillary arch dimensions in subjects presenting unilaterally impacted maxillary permanent central incisors compared with a control group of subjects without eruption anomalies.

METHODS

A group of 23 Caucasian children [8 females and 15 males, mean age 9.7 years, standard deviation (SD) 1.6 years] displaying unilaterally impacted maxillary permanent central incisors (impacted incisor group: IIG) were compared with a control group (CG) of 23 subjects (9 females; 14 males, mean age 8.8 years, SD 1.9 years) presenting no eruption disorders. Pretreatment dental casts were taken from each subject and the upper arch was scanned using a three-dimensional scanner. Linear measurements were taken on each digital model to analyze maxillary arch dimensions. Significant between-group differences were tested with the Student's t test (p < 0.05).

RESULTS

The transverse and sagittal upper-arch measurements were significantly smaller in the IIG than in the CG. In particular, the anterior arch was 1.35 mm shorter in the IIG, while intercanine width was decreased by 2.51 mm on the impacted side.

CONCLUSION

Children revealing unilaterally impacted maxillary central incisors demonstrated a significantly constricted maxillary transverse width and shorter arch on the impacted side compared with subjects with no eruption disorders.

Inhibition of Notch Signaling During Mouse Incisor Renewal Leads to Enamel Defects

The continuously growing rodent incisor is an emerging model for the study of renewal of mineralized tissues by adult stem cells. Although the Bmp, Fgf, Shh, and Wnt pathways have been studied in this organ previously, relatively little is known about the role of Notch signaling during incisor renewal. Notch signaling components are expressed in enamel-forming ameloblasts and the underlying stratum intermedium (SI), which suggested distinct roles in incisor renewal and enamel mineralization. Here, we injected adult mice with inhibitory antibodies against several components of the Notch pathway. This blockade led to defects in the interaction between ameloblasts and the SI cells, which ultimately affected enamel formation. Furthermore, Notch signaling inhibition led to the downregulation of desmosome-specific proteins such as PERP and desmoplakin, consistent with the importance of desmosomes in the integrity of ameloblast-SI attachment and enamel formation. Together, our data demonstrate that Notch signaling is critical for proper enamel formation during incisor renewal, in part by regulating desmosome-specific components, and that the mouse incisor provides a model system to dissect Jag-Notch signaling mechanisms in the context of mineralized tissue renewal.

Class II Division 1 Malocclusion Treated with a Cervical-Pull Headgear: A Case Report

Orthodontic treatment for skeletal Class II malocclusion was undertaken with the aim ofachieving orthopedic correction by modifying the growth pattern. A case of Class II, Division 1 malocclusion in the late mixed dentition was corrected to a Class I molar relationship by primarily using cervical-pull headgear. Cephalometric analysis indicated a reduction in the maxillo-mandibular discrepancy (ANB°) due to the correction of a skeletal Class II malocclusion to a Class I occlusion. The superimposition demonstrated that this was achieved by favorable growth of the mandible, control of maxillary first molars in an antero-posterior direction and retraction of maxillary incisors. Proclination of mandibular incisors was reduced. Significant improvement in the soft-tissue profile was noted.

Surgically Assisted Orthodontics: Use of Piezocision in a Case of Oligodontia to Accelerate the Rate of Tooth Movement

Conventionally the use of surgical assisted tooth movement is to hasten orthodontic tooth movement. In this article, a case of 13 year-old male with oligodontia has been described in whom piezocision has been used to improve bone turnover and remodeling in long standing edentulous spaces which have less medullary bone and more cortical bone.

Conditional Knockout of the MicroRNA 17-92 Cluster in Type-I Collagen-Expressing Cells Decreases Alveolar Bone Size and Incisor Tooth Mechanical Properties

To test the role of the miR17-92 (miR) cluster in dental bones, we evaluated the incisor tooth phenotype by micro-CT in 5- and 12-week-old conditional knockout (CKO) mice deficient in the miR17-92 cluster in type-I collagen-expressing cells and bone strength by finite element analysis. The incisor teeth of CKO mice showed a 23-30 % reduction in tissue volume and bone volume. Accordingly, the stiffness and failure load of incisor teeth assessed by finite element analysis showed an 18-40 % decrease in CKO compared to wild-type mice. A positive correlation between bone parameters and strength data suggests that the decreased mechanical properties of incisor teeth are due to decreased tissue volume and bone volume. Subsequently, we found that the width of alveolar bone was reduced by 25 % with a 16 % increase in periodontal ligament space, suggesting that the CKO mice are more susceptible to tooth movement. Since alveolar bone is populated primarily by osteoblast lineage cells, it is likely that the reduction in periosteal expansion of alveolar bone in the lower jaw of CKO mice results from decreased periosteal bone formation. Overall, our phenotype analysis demonstrates that the miR17-92 cluster is essential for development and maintenance of tooth strength by regulating its tooth size.

Intrusion of Lower Incisors in Deep Overbite Cases with Mini-screws

OBJECTIVES

To evaluate the dentoskeletal effects of intrusion of the lower incisor teeth by mini-screws.

MATERIAL AND METHODS

Ten patients were selected from the outpatient clinic of the Department of Orthodontics, Faculty of Dentistry, Mansoura University with Angle's Class II division I malocclusions. Age ranged from 15 to 18 years (15.4 year mean) with deep overbite (more than 1/3 the crown height of the lower incisors covered) requiring intrusion of the lower incisors. After alignment of the first molars, the second premolars ,and canines without inclusion of the lower four incisors, the cuspids were retracted on 16x22 inch stainless steel wire. For each patient, two mini-screws were inserted for anchorage for the lower incisors segment intrusion between the lateral incisor and the cuspid--one in each side and connected to a utility arch wire.

RESULTS

The mean of overbite correction was 4.2 mm (p<. 05, and lower incisors were intruded significantly by a mean of 3.55 mm (p<.05).

CONCLUSION

The mandibular incisors were effectively intruded by using mini-screws as orthodontic anchorage with no significant counteractive movements in the molars.

[Incisor repositioning: a new approach in orthodontics]

Lower incisors axis has a "key" position in different cephalometric analysis. However, several critics are directed towards the cephalometric profile and cephalometric landmarks (point, line and angle). The published norms and the cephalometric standards recommended for the optimal positioning of incisors could only be used as general clinical guidelines. Incisor repositioning to achieve optimal facial aesthetics requires taking into consideration the hard and soft tissues of the face, the profile, the muscular dynamics as well as the facial growth. In this work, we propose a new approach of incisor repositioning taking into account the variability of periodontal, functional and aesthetic factors.

Dental Abrasion of Incisor caused by a Babies' Dummy Clip: A Case Report

Tooth surface loss (TSL), the non-carious loss of tooth tissue, is considered pathological if the teeth involved experience sensitivity and pain, are functionally compromised or they detract from the patient's appearance. TSL is a common clinical finding in many patient groups, although differences between the primary and permanent dentition contribute to TSL occurring at a faster rate and with worse outcomes in the primary dentition. This case report presents localized abrasion and associated apical periodontitis affecting a single primary tooth in a 2-year-old infant following the misuse of a babies' dummy clip whilst teething. Abrasion is rare in the primary dentition. CPD/CLINICAL RELEVANCE: This article highlights an unusual presentation of dental abrasion affecting the primary dentition caused by a previously unreported foreign object; abrasion in this case was a side-effect of soothing the discomfort of teething.

[Orthodontic tooth movement through the maxillary sinus in an adult with multiple missing teeth]

This case report describes the successful orthodontic tooth movement through the maxillary sinus in an adult patient. A 41-year-old Asian woman had severe lip protrusion and multiple missing posterior teeth. Her orthodontic treatment included the extraction of two teeth, maximum retraction of the incisors using the extraction spaces and the existing spaces from the missing molars, and closure of all remaining spaces. Even though the treatment time was extended because of the anatomic and biologic challenges associated with moving posterior teeth over a long distance through the maxillary sinus, a successful outcome was obtained, with significant bone modeling of the maxillary sinus. The results demonstrate that a carefully selected force system can overcome the anatomic limitations of moving tooth against the cortical bone of the maxillary sinus wall in adult patients.

Is the value of oral health related to culture and environment, or function and aesthetics?

OBJECTIVE

To examine the disutility of tooth loss. It compared how people value their teeth in two countries which are culturally similar in order to explore the effect of culture on self-perceptions of oral health.

BASIC RESEARCH DESIGN

Cross sectional study.

PARTICIPANTS

Participants were recruited from subjects attending two hospitals in Turkey and in Iran.

INTERVENTIONS

Nineteen descriptions of mouths with varying degrees and types of tooth loss were presented to the participants. They were shown mouth models of partially edentate dentitions and the teeth missing were explained in relation to the participants own mouth. The participants were specifically asked to consider the role their teeth played in function (chewing), communication (speech) and aesthetics (looks) along with "all the other things that make your mouth important".

MAIN OUTCOME MEASURES

The participants were asked to indicate on a visual analogue scale how they would value the health of their mouth if they lost the tooth/teeth described and the resultant space was left unrestored.

RESULTS

Overall 152 subjects participated, 78 in Turkey and 74 in Iran with 83 being female and 69 male. Their mean age was 29.5 years (SD 9.3), 62.5% had experienced tooth loss and 37.5% had complete (or completely restored) dentitions. Although there were no differences between the two countries in the degree of utility people attached to anterior teeth, Turkish participants attached significantly more disutility than Iranians to the loss of premolar and molar teeth (p < 0.003).

CONCLUSION

Country of origin had an influence on the value placed on certain parts of the dentition and this effect is independent of the number of missing teeth, gender and age. This implies that attitudes to oral health are influenced by prevalent cultural attitudes more than by function.

Interactions of hard tissues, soft tissues, and growth over time, and their impact on orthodontic diagnosis and treatment planning

The approach to orthodontic diagnosis has changed gradually but steadily over the past 2 decades. The shift away from diagnosis based entirely on hard tissue evaluations has been a result of a broadened recognition of the importance of facial and smile appearance to our patients, and how they change over time. The purpose of this article is to describe and illustrate the integration of the new soft tissue paradigm into long-term treatment planning, with a focus on the esthetic goals of treatment.

[Dentoalveolar compensation in skeletal Class III patients treated with orthognathic surgery]

OBJECTIVE

To investigate the compensation of the upper and lower incisors in skeletal Class III patients treated with orthodontic-surgical approach.

METHODS

The samples consisted of 54 skeletal Class III patients treated with orthodontic-surgical approach from November 2011 to January 2015. Lateral cephalograms were taken before treatment. The differences between the samples and the norms from Peking University normal occlusion sample library were assessed using independent-sample t test. Correlation analyses were performed to find associations between skeletal and dental parameters. According to skeletal anteroposterior discrepancy/vertical type (ANB/SN-MP), the samples were allocated into group A (ANB < -4°, SN-MP ≤ 37.7°, n = 11), group B (ANB ≥ -4°, SN-MP ≤ 37.7°, n = 16), group C (ANB < -4°, SN-MP > 37.7°, n = 14), and group D (ANB ≥ -4°, SN-MP > 37.7°, n = 13). After measurement of variables, one-way ANOVA with SNK multiple comparison test were performed.

RESULTS

The maxillary incisors were more proclined and the mandibular incisors more retroclined in skeletal Class III patients compared with norm values (P < 0.01). Both skeletal anteroposterior discrepancy and vertical type were correlated with the position of upper and lower incisors (P < 0.01). According to skeletal anteroposterior discrepancy/vertical type, no significant differences were found in the upper incisors' inclination among the four groups, while patients in group A and group D exhibited significant difference in lower incisor compensation.

CONCLUSIONS

Different skeletal anteroposterior discrepancy/vertical type resulted in varied incisors' compensation. Therefore, decompensation should be treated differently.

Comparative evaluation of pulpal blood flow during incisor intrusion

AIM

The aim of the present study was to evaluate and compare changes in pulpal blood flow (PBF) as a result of maxillary incisor intrusion achieved by one of two methods (utility arches or mini-implants).

MATERIALS AND METHODS

Thirty subjects were divided into three groups, the first of which underwent maxillary incisor intrusion using utility arches (UA) and a second group, intrusion via mini-implants (MI). The third group acted as a control. An intrusive force of 100 g was applied to the upper incisors in the treatment groups, whereas no force was applied to the anterior teeth in the control group. A laser Doppler flowmeter (LDF) was used to measure PBF at baseline (T0) and during incisor intrusion at 24 hours (T1), three days (T2), seven days (T3) and three weeks (T4). Statistical changes in PBF were assessed by the Wilcoxon Signed Rank and Mann-Whitney U tests, with significance set at p < 0.05.

RESULTS

The mean PBF in the UA and MI groups decreased significantly from T0 to T1 (p < 0.001), slightly increased at T2 and continued to increase gradually at T3. PBF attained levels similar to those measured prior to intrusion at T4. No significant changes in PBF were observed in the control group over the course of the study. The only statistically significant difference between the UA and MI groups were at T1 and T2, at which time the MI group had lower PBF values (p < 0.001).

CONCLUSIONS

Despite slight regressive changes in pulpal tissue observed over the short-term, PBF values tended to return to initial levels within three weeks, indicating that changes observed in PBF with the UA and MI intrusion methods are reversible. Although the changes in PBF could not be directly related to the method of intrusion employed, in general, a more severe drop in PBF was observed in the MI group during the first three days of intrusion.

A study of Class III treatment: orthodontic camouflage vs orthognathic surgery

AIM

To evaluate the differences in pretreatment and post-treatment characteristics of Class III patients treated with orthodontic camouflage or orthognathic surgery, and to compare the range of skeletal, dental and soft tissue changes that are likely to occur with treatment, with particular reference to the influence of extractions on the resultant incisor angulations.

METHOD

Pretreatment and post-treatment cephalograms of 31 Class III orthodontically-camouflaged patients and 36 Class III surgical patients (without genioplasty) were obtained from one specialist practice. From the surgical group, 26 pre-surgical lateral cephalograms were also obtained. Inclusion criteria for the two groups were at least three of the following: (1) an ANB angle of 1 degree or less, (2) a Wits appraisal less than -4 mm, (3) an incisal overjet ≤ 0 mm, and (14) a Class III molar relationship. All lateral cephalograms were traced and digitised and a number of skeletal, dental and soft tissue variables were measured. The camouflage and surgical groups were also divided into premolar extraction and non-extraction subgroups to allow for a specific analysis of extraction effects.

RESULTS

Before treatment, the surgical group demonstrated, on average, a more severe skeletal discrepancy and increased dental compensations, compared with the orthodontically camouflaged group. After treatment, the mean SNA angle was greater, the ANB angle was more positive, the Wits appraisal was closer to ideal and the lower incisors were less retroclined in the surgery group. There was a small mean reduction in horizontal chin projection in the surgery group compared with a small increase in the camouflage group. The mentolabial fold and the lower lip curve were deeper, on average, and the lips less retrusive after surgery. There was a mean increase in upper incisor proclination during treatment in both the surgical and camouflage groups with a greater increase in the camouflage group. There was a significant reduction in upper incisor proclination and a subsequent greater increase in the ANB angle associated with upper premolar extractions in the surgical group compared with the non-extraction group. Lower premolar extractions in the camouflage group resulted only in a deeper mentolabial fold compared with those treated without lower extractions.

CONCLUSIONS

Class III patients selected for surgical treatment are likely to have more severe pretreatment dental and skeletal discrepancies than those selected for camouflage treatment. Surgical treatment is associated with significant decompensation of the lower incisors but, ultimately, not the upper incisors. Class III patients treated with either camouflage or surgery treatment are likely to finish with slightly proclined upper incisors. Generally, surgical treatment results in greater skeletal change, involving normalisation of the skeletal base relationship, a reduction in chin prominence, fuller lips, and a more favourable lip and chin contour.