Correction of severe bimaxillary protrusion with first premolar extractions and total arch distalization with palatal anchorage plates

Correction of a severe protrusive soft tissue profile without orthognathic surgery can be challenging. This case report describes the treatment of a young woman with a severe bimaxillary protrusion. Orthodontic treatment included extraction of her 4 first premolars and total arch distalization of both arches using a palatal plate appliance. The total treatment time was 24 months. Her occlusion and facial appearance were significantly improved.

Mandibular changes secondary to serial extractions compared with late premolar extractions and controls

INTRODUCTION

Variations in treatment times for serial extraction and late premolar extraction patients may be due to differences in the time needed to flatten the occlusal curves. In this study, we compared tooth tipping and occlusal curves in patients treated by serial extractions or late premolar extractions with untreated controls.

METHODS

Mandibular dental casts and cephalometric radiographs were collected from 90 subjects (30 Class I control subjects, 30 patients with serial extractions, and 30 with late premolar extractions) at 3 time points: T0, baseline for the controls and serial extraction patients; T1, after natural drift and preorthodontics for the controls and the serial extraction patients, and pretreatment for the late premolar extraction patients; and T2, after comprehensive orthodontic treatment for the serial extraction and the late premolar extraction groups. The long axes of the central incisor, canine, and first molar to the palatal plane were measured on digitized headfilms to determine the direction and the amount of tipping between the time points. Three occlusal curves were measured by sphere fitting cusp-tip landmarks on digitized mandibular casts.

RESULTS

From T0 to T1, incisors and canines in the patients with serial extractions tipped distally. Molars at T1 in the patients with serial extractions were tipped forward more than in the late premolar extraction patients and the controls. From T1 to T2, canines and molars in the patients with serial extractions were uprighted.

CONCLUSIONS

Serial extractions produce steeper occlusal curves and distal tipping of the incisors and canines after drift (T1). Posttreatment (T2) occlusal curves in the patients with serial extractions are steeper than in the late premolar extraction patients and controls (except for the curve of Spee). After the serial extractions, orthodontic treatment included incisor and canine proclination, with molar uprighting and occlusal curve flattening.

Genotypic and phenotypic variation in six patients with solitary median maxillary central incisor syndrome

Solitary Median Maxillary Central Incisor occurs in 1 of 50,000 live births. It is the mildest manifestation of the holoprosencephaly spectrum and is genetically heterogeneous. Here we report six patients with solitary median maxillary central incisor, and a range of other phenotypic anomalies with different degrees of severity, varying from mild signs of holoprosencephaly to associated intellectual disability, and with different genetic background. Using array comparative genomic hybridization, pathogenic copy number variants were found in three of the six patients. Two patients had a deletion at the 18p11 chromosomal region that includes TGIF1 while the other patient had a deletion at 7q36, including the SHH gene. In one patient, a mutation in SIX3 was detected with exome sequencing, while in the two remaining patients all known holoprosencephaly genes were excluded using multiplex ligation-dependent probe amplification and sequencing, and remain unsolved. One of the two latter patients had isolated solitary median maxillary central incisor without other visible dentofacial anomalies, while the other had clinical features not part of the known holoprosencephaly spectrum.

Ritual tooth modification among the Baka pygmies in Cameroon

INTRODUCTION

Ritual tooth mutilation is a relatively understudied human body mutilatory practices. The purpose of the study was to examine the effects of ritual tooth modification, teeth cleaning measures and herbal medications for their oral health problems among the Baka pygmies in Cameroon.

MATERIALS AND METHODS

This cross-sectional study was conducted between January and March, 2012 using semi-structured questionnaire as the tool of data collection. Intra-oral examinations were carried out to determine the dental hard tissue loss using Smith and Knight Tooth Wear Index (TWI).

RESULTS

Fifty-six pygmies with ritual tooth modification made of 34 males (60.7%) and 22 females (39.3%) with a mean age of 31 years were interviewed and had oral health examination. The reported age at which the tooth modification was done was between 10 and 15 years with mean age as 12 ± 1.66 years. More than half (58.9%) of the participants reported the tooth filing as painful and nearly two-thirds (64.3%) of the participants reported having persistent pain afterwards. The upper right central and lateral incisors were the most commonly modified teeth. A total of 42.9%, 12.5% and 7.1% of the participants had Smith and Knight TWI scores of 2, 3 and 4 respectively. All the participants reported cleaning their teeth at least once-daily with about two-thirds (66.1%) of them doing so with chewing stick. The majority (67.9%) of the participants reported cleaning their teeth for cosmetic reasons [to remove dirt' (60.7%) and 'to remove stains' (7.1%)]. The oral health problems among the participants in form of tooth sensitivity, toothache and dental abscess were treated with plant-based traditional medicines from Irvingia gabonensis, Ricinodendron heudoletti, Pterocarpus soyauxii, Alchornea cordifolia and Piptadeniastrum africanum.

CONCLUSION

Ritual tooth modification is a painful mutilatory practice which is culturally significant for the Baka pygmies without health benefit. There is need for intervention to stop this harmful traditional practices among the pygmies. Further studies is recommended to elucidate the medicinal and pharmaceutical benefits of plants used for tooth sensitivity and other oral health problems by the pygmies.

Molar Incisor Hypomineralization of Eight- and 14-year-old Children: Prevalence, Severity, and Defect Characteristics

PURPOSE

To report on the prevalence, severity, defect location, and other characteristics of molar incisor hypomineralization (MIH).

METHODS

Representative samples of eight- and 14-year-old children (1,179 and 1,156, respectively) in three Greek cities were examined for MIH in the classroom using European Academy of Pediatric Dentistry criteria. MIH either mild or severe included the recording of defect color and location.

RESULTS

MIH prevalence was 21 percent (498 of 2,335 children), with a statistically significant difference in one city (16 percent) from the other two (23 percent, P=.007; and 23 percent, P=.002). In 46 percent of MIH cases, only permanent first molars (PFMs) were affected. MIH severity was associated with age (severe MIH eight-year-olds comprised 13 percent; 14-year-olds comprised 35 percent, P<.001) and with number of affected teeth per child (mild equals 2.44, severe equals 4.22, P<.001). The lingual surfaces of mandibular PFMs and palatal/lingual surfaces of all incisors were significantly less frequently affected (all less than 10 percent) than their buccal/labial counterparts (P<.0001).

CONCLUSIONS

Predominantly mild MIH was common in children's permanent teeth, with some intracountry variation. A surface predilection of MIH opacities was clearly revealed. The severity in 14-year-olds was threefold that of eight-year-olds.

Wear Fast, Die Young: More Worn Teeth and Shorter Lives in Iberian Compared to Scottish Red Deer

Teeth in Cervidae are permanent structures that are not replaceable or repairable; consequently their rate of wear, due to the grinding effect of food and dental attrition, affects their duration and can determine an animal's lifespan. Tooth wear is also a useful indicator of accumulative life energy investment in intake and mastication and their interactions with diet. Little is known regarding how natural and sexual selection operate on dental structures within a species in contrasting environments and how these relate to life history traits to explain differences in population rates of tooth wear and longevity. We hypothesised that populations under harsh environmental conditions should be selected for more hypsodont teeth while sexual selection may maintain similar sex differences within different populations. We investigated the patterns of tooth wear in males and females of Iberian red deer (Cervus elaphus hispanicus) in Southern Spain and Scottish red deer (C. e. scoticus) across Scotland, that occur in very different environments, using 10343 samples from legal hunting activities. We found higher rates of both incisor and molar wear in the Spanish compared to Scottish populations. However, Scottish red deer had larger incisors at emergence than Iberian red deer, whilst molars emerged at a similar size in both populations and sexes. Iberian and Scottish males had earlier tooth depletion than females, in support of a similar sexual selection process in both populations. However, whilst average lifespan for Iberian males was 4 years shorter than that for Iberian females and Scottish males, Scottish males only showed a reduction of 1 year in average lifespan with respect to Scottish females. More worn molars were associated with larger mandibles in both populations, suggesting that higher intake and/or greater investment in food comminution may have favoured increased body growth, before later loss of tooth efficiency due to severe wear. These results illustrate how independent selection in both subspecies, that diverged 11,700 years BP, has resulted in the evolution of different longevity, although sexual selection has maintained a similar pattern of relative sex differences in tooth depletion. This study opens interesting questions on optimal allocation in life history trade-offs and the independent evolution of allopatric populations.

Combined surgical-orthodontic treatment: how did it evolve and what are the best practices now?

It has been 50 years since the landmark presentation by Hugo Obwegeser at Walter Reed Army Hospital. At that conference, Professor Obwegeser offered American surgeons techniques to correct facial skeletal deformities with access through intraoral incisions. As important advances in surgical technique and anesthesia evolved for the surgical procedures, a major contribution by American orthodontists in collaboration with surgeons was the creation of a common diagnostic, planning, and treatment scheme for use by both clinician groups in the treatment of dentofacial deformities, the skeletal and dental problems of the most severely affected 5% of the population. This article summarizes what American orthodontists and surgeons have learned in the late 20th and early 21st centuries, and forecasts what might be the future of treatment for patients with dentofacial deformities.

[Lingual treatment of an anterior open bite case]

One of the benefits of the orthodontic lingual technique is the complete discretion it provides, preserving acceptable facial esthetics throughout treatment. Nevertheless, it is a fact that the treatment of open bites with this technique inevitably poses a challenge for the practitioner. The patient we present in this article displayed a skeletal and dental Class II with anterior open bite. The difficulty with this case was to control the incisal torque during open bite closure, given that this constitutes a critical factor in the lingual technique. Consequently, we will emphasize above all our diagnostic procedures as well as our treatment strategies designed to achieve our objectives while controlling the incisal torque.

Fixed functional appliances show definite skeletal and dental changes in the short term

A meta-analysis of the literature on fixed functional appliances found nine unique data sets (n= 418 patients, mean age = 13.2 years) that fulfilled the criteria. Small but statistically significant changes in SNA, SNB, and ANB occurred, with larger changes in the incisor angulations. The results are compared with a previous meta-analysis on the effects of removable functional appliances by the same team and discussed in regard to their implications for clinical practice.

An Update on Crown Lengthening. Part 2: Increasing Clinical Crown Height to Facilitate Predictable Restorations

This is the second paper in this two-part series. Paper one provided an overview of managing gingival tissue excess and paper two will focus on increasing clinical crown height to facilitate restorative treatment. Crown lengthening is a surgical procedure aimed at the removal of gingival tissue with or without adjunctive bone removal. The different types of procedure undertaken will be discussed over the two papers. In order to provide predictable restorations, care must be taken to ensure the integrity of the margins. If this is not taken into account it can lead to an impingement on the biologic width, which may in turn lead to chronic inflammation resulting in recession or the development of periodontal problems which can be hard to manage. Clinical Relevance: This paper aims to reinforce the need for thorough diagnosis and treatment planning and provides an overview of the various procedures that can be undertaken.

Functional crown lengthening surgery in the aesthetic zone; periodontic and prosthodontic considerations

Crown lengthening surgery aims to increase the amount of supragingival tooth tissue by resection of the soft and/or hard tissues to enable otherwise unrestorable teeth to be restored by increasing the retention and resistance forms of the teeth. Restoration of the worn dentition may require significant prosthodontic knowledge and skill. A prosthodontist should be involved from the beginning of the management of the patient. A number of key stages should be considered for correct management. Although the periodontist may guide the prosthodontist with regards to what may or may not be possible surgically, the overall treatment plan should be prosthodontically driven. Clinical Relevance: Toothwear of the anterior dentition provides a unique challenge to restore not only function but also to manage the aesthetic demands of the patient. To ensure that the correct outcome is reached, clinicians should be familiar with the normal anatomical proportions and relationships to enable planning and treatment to take place.

Fibre-reinforced composite (FRC) bridge--a minimally destructive approach

Replacing missing teeth is an integral part of the clinical services of the dental practitioner. The fibre-reinforced composite (FRC) bridge is a relatively new method for replacing missing teeth. This article will explain and discuss this alternative treatment option. Practical instructions on how to construct a FRC bridge will be given, by means of a clinical case. Different technique options will be illustrated to provide the reader with a good understanding of the most practical way to use the FRC strips. The fibre-reinforced composite provides a non-destructive, aesthetically pleasing and cost-effective way to restore missing teeth. Clinical Relevance: Minimally invasive options should always be considered and destruction of healthy enamel and dentine during the preparation phase of a replacement treatment should be avoided as much as possible.

[Maxillary canine impaction increases root resorption risk of adjacent teeth: A problem of physical proximity]

INTRODUCTION

Our objectives were to investigate the prevalence, resorption location and extent, and potential risk factors for impacted canine-associated root resorption (ICARR) in Chinese patients, who, unlike white patients, have predominantly buccal maxillary canine impactions.

METHODS

Pretreatment cone-beam computed tomography scans of 170 Chinese subjects (ages, 12-30 years; mean, 14.5 years) with impacted maxillary canines (101 buccal and 69 palatal impactions) and 170 age- and sex-matched subjects without impactions were used. All cone-beam computed tomography records were evaluated in software programs by 1 rater. The prevalence, location, and extent of ICARR at the maxillary lateral incisor, central incisor, and first premolar were analyzed. To identify risk factors for ICARR, the subjects with impacted canine were divided into 2 groups (with and without root resorption). Measurements of 10 variables were individually compared between the groups and then tested together by using binary logistic regressions for each tooth.

RESULTS

Compared with the control subjects and the side of nonimpaction, root resorption was significantly more prevalent in the canine-impaction subjects and the side of impaction (P\0.01), with overall prevalence rates of 27%, 18% and 10% at the maxillary lateral incisor, the central incisor, and the first premolar, respectively. Predominantly affecting the apical third of all teeth, ICARR, if present, reached the pulp of the maxillary lateral incisor, the central incisor, and the first premolar at rates of 36%, 57%, and 0%, respectively. Individually, variables reflecting the proximity to the impacted maxillary canine had different measurements (P\0.05) between the impaction sites (maxillary quadrants) with and without root resorption for each tooth, whereas the canine development stage factor was only significant for the maxillary central and lateral incisors. No significant difference of ICARR prevalence was found between subjects with buccal and palatal impactions. Combined, the contact relationship was the dominant predictor for ICARR at all teeth, with "in contact" (\1 mm separation) having the largest and most significant increase of root resorption likelihood compared with "out of contact" ($1 mm separation); odds ratios were 9.9, 3.7 and 5.9 for the maxillary lateral incisor, the central incisor, and the first premolar, respectively.

CONCLUSIONS

Maxillary canine impaction increases the risk of root resorption at adjacent teeth (incisors and first premolars). Physical proximity (\1 mm) between the impacted canine and an adjacent root is the most important predictor for root resorption, and this characteristic is largely similar in Chinese patients to that in white people.

Periodontal consequences of mandibular incisor proclination during presurgical orthodontic treatment in Class III malocclusion patients

OBJECTIVE

To test the hypothesis that periodontal changes are similar between proclined and minimal-changed mandibular incisor position groups during presurgical orthodontic treatment for Class III orthognathic surgery.

MATERIALS AND METHODS

The following measurements were performed before and after presurgical orthodontic treatment of 75 patients (proclination group, 39 subjects; minimal-change group, 36 subjects): clinical crown length, sulcus and bone probing depths, and width of attached gingiva from clinical examination; infradentale-to-MP (perpendicular distance of infradentale to mandibular plane) from examination of lateral cephalograms; and the distance between the cementoenamel junction and alveolar crest from examination of periapical radiographs. Data were compared between the two groups, and a regression analysis was performed to investigate factors affecting the periodontal changes.

RESULTS

In both groups, clinical crown length and bone probing depth increased during presurgical orthodontics (P < .05). Infradentale-to-MP and the width of attached gingiva decreased more in the proclination group than in the minimal-change group (P < .05). Proclination and protrusion of the mandibular incisors, and treatment duration affected the periodontal changes.

CONCLUSIONS

The null hypothesis was rejected. Proclination of the mandibular incisors for decompensation in Class III surgery patients seems to result in labial alveolar bone recession and a decrease in width of attached gingiva. However, the amount of the periodontal recession appeared to be clinically insignificant.

Conservative orthodontic-prosthodontic approach for excessive gingival display: A clinical report

A differential diagnosis of excessive gingival display is critical in determining appropriate treatment options and sequence. Anterior tooth malposition for patients with deep vertical overlap has been suggested as one of the 3 main causes of excessive gingival display. Specifically, patients with Angle class II, division 2 malocclusions show an occlusal scheme that might be responsible for additional anterior tooth wear when compared with individuals without malocclusion. In the long term, this condition can cause dentoalveolar compensation and overeruption of maxillary incisors with concomitant coronal movement of the gingival margin with excessive gingival display. A combined orthodontic and restorative treatment was proposed as a conservative treatment to reposition maxillary anterior teeth and their gingival margins to a more ideal position and create the necessary interocclusal restorative space to restore worn teeth with ceramic restorations, enhance dental and facial esthetics, and reestablish anterior guidance.

EFFECT OF INCISOR INCLINATION CHANGES ON CEPHALOMETRIC POINTS A AND B

BACKGROUND

The position of cephalometric points A and B are liable to be affected by alveolar remodelling caused by orthodontic tooth movement during incisor retraction. This study was conducted to evaluate the change in positions of cephalometric points A and B in sagittal and vertical dimensions due to change in incisor inclinations.

METHODS

Total sample of 31 subjects were recruited into the study. The inclusion criteria were extraction of premolars in upper and lower arches, completion of growth and orthodontic treatment. The exclusion criteria were patients with craniofacial anomalies and history of orthodontic treatment. By superimposition of pre and post treatment tracings, various linear and angular parameters were measured. Various tests and multiple linear regression analysis were performed to determine changes in outcome variables. Statistically significant p-value was < or = 0.05.

RESULTS

One-sample t-test showed that change in position of only point A was statistically significant which was 1.61 mm (p<0.01) in sagittal direction and 1.49 mm (p<0.01) in vertical direction. Multiple linear regression analysis showed that if we retrocline upper incisor by 10 degrees, the point A will move superiorly by 0.6 mm.

CONCLUSIONS

Total change in the position of point A is in a downward and forward direction. Total Change in upper incisors inclinations causes change in position of point A only in vertical direction.