Clinical Guidelines for the Surgical/Orthodontic Management of Impacted Maxillary Central Incisors Based on a Decision Tree.

Maxillary central incisors are critical to occlusal function, smile esthetics, and even one's self-image. Furthermore, their impaction at an early age could have harmful psychological consequences on the individual. Maxillary central incisors can be impacted due to early dentoalveolar trauma to the upper anterior region that displaces the incisor in formation and, in rare instances, tooth germs are deformed. The aftermath of trauma during primary dentition is seen later during mixed dentition. Other causes are either an impediment in the eruption pathway of the maxillary central incisor due to the presence of odontomas or supernumerary teeth, an insufficient eruption space, or, very rarely, syndromic and/or other general medical conditions. Diagnosis is completed through a detailed medical/dental history, clinical evaluation, and appropriate imaging. Arch width increase, space opening, removal of obstructions if present, suitable soft-tissue management, well-designed orthodontic traction mechanics, and long-term periodontal follow-up are all essential elements in resolving cases of impacted maxillary central incisors.

Quantification of the apical palatal bone index for maxillary incisor immediate implant assessment: A retrospective cross-sectional study.

BACKGROUND: Apical palatal bone is important in immediate implant evaluation. Current consensus gives qualitative suggestions regarding it, limiting its clinical decision-making value. OBJECTIVES: To quantify the apical palatal bone dimension in maxillary incisors and reveal its quantitative correlation with other implant-related hard tissue indices to give practical advice for pre-immediate implant evaluation and design. MATERIAL AND METHODS: A retrospective analysis of immediate implant-related hard tissue indices in maxillary incisors obtained by cone beam computed tomography (CBCT) was conducted. Palatal bone thickness at the apex level (Apical-P) on the sagittal section was selected as a parameter reflecting the apical palatal bone. Its quantitative correlation with other immediate implant-related hard tissue indices was revealed. Clinical advice of pre-immediate implant assessment was given based on the quantitative classification of Apical-P and its other correlated immediate implant-related hard tissue indices. RESULTS: Apical-P positively correlated with cervical palatal bone, whole cervical buccal-palatal bone, sagittal root angle, and basal bone width indices. while negatively correlated with apical buccal bone, cervical buccal bone, and basal bone length indices. Six quantitative categories of Apical-P are proposed. Cases with Apical-P below 4 mm had an insufficient apical bone thickness to accommodate the implant placement, while Apical-P beyond 12 mm should be cautious about the severe implant inclination. Cases with Apical-P of 4-12 mm can generally achieve satisfying immediate implant outcomes via regulating the implant inclination. CONCLUSIONS: Quantification of the apical palatal bone index for maxillary incisor immediate implant assessment can be achieved, providing a quantitative guide for immediate implant placement in the maxillary incisor zone.

Micro-CT assessment of the shaping ability of four root canal instrumentation systems in oval-shaped canals.

AIM: To compare the shaping ability of four root canal instrumentation systems in oval-shaped canals using micro-computed tomographic analysis. METHODOLOGY: Forty anatomically matched mandibular incisors were scanned and assigned to four groups (n = 10), according to the canal preparation protocol: BioRace, Reciproc, Self-Adjusting File (SAF) and TRUShape systems. After canal instrumentation, the specimens were rescanned, and the registered pre- and postoperative datasets were examined to evaluate the percentages of accumulated hard-tissue debris, untouched canal walls and dentine removed. Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction were used to compare the variables in the groups (α = 5%). RESULTS: The preparation techniques did not affect the percentage of accumulated hard-tissue debris (P = 0.126). The percentage of untouched canal areas was significantly higher for BioRace (32.38%)compared to Reciproc (18.95%) and SAF (16.08%) systems (P < 0.05). Reciproc removed significantly more dentine (4.18%) than BioRace (2.21%) and SAF (2.56%) (P < 0.05). The TRUShape system had intermediate results for both untouched canal walls (19.20%) and dentine removed (3.77%), with no significant difference compared to BioRace, Reciproc and SAF systems. CONCLUSIONS: The preparation techniques resulted in the same level of accumulated hard-tissue debris. Compared to the other tested systems, BioRace was associated with more untouched canal walls and Reciproc produced the greatest amount of removed dentine. Although it touched more of the root canal walls, the SAF system removed less dentine, whereas TRUShape had intermediate results for these same parameters. None of the systems tested were able to provide optimal shaping ability in oval-shaped canals.

Improvement in Peer Assessment Rating scores after nonextraction, premolar extraction, and mandibular incisor extraction treatments in patients with Class I malocclusion.

INTRODUCTION: Different treatment protocols implemented for correction of Class I malocclusion aim at achieving ideal occlusal characteristics. This study was planned to evaluate the improvement in the occlusal characteristics of Class I patients treated with nonextraction (NE), all first premolar extractions (PME), and mandibular incisor extraction (MIE) as assessed by the percentage of improvement in Peer Assessment Rating (PAR) scores. METHODS: This retrospective cross-sectional study was conducted on the pretreatment and posttreatment dental casts of 108 subjects with Class I malocclusion. The total sample was divided into 3 equal groups according to the treatment protocol implemented: NE, PME, and MIE. The mean pretreatment and posttreatment PAR scores, and the percentages of improvement were compared among the 3 treatment modalities using Kruskal-Wallis and post-hoc Dunnett T3 tests. RESULTS: The mean percentages of improvement in the PAR score were 75.8% ± 25.8% in the NE group, 73.1% ± 19.4% in the PME group, and 70.6% ± 24.1% in the MIE group. There was no significant difference (P = 0.351) in the percentages of improvement in PAR scores among the 3 treatment modalities. However, the mean pretreatment and posttreatment PAR scores varied significantly (P <0.001) in the 3 groups. The average pretreatment and posttreatment PAR scores were highest in the MIE group and lowest in the NE group. CONCLUSIONS: The comparable percentages of improvement in PAR scores among the 3 groups denote that equivalent occlusal corrections were achieved in Class I patients treated with the NE, PME, and MIE protocols.

Micro-computed Tomography Assessment of Dentinal Micro-cracks after Root Canal Preparation with TRUShape and Self-adjusting File Systems.

INTRODUCTION: The aim of the present study was to evaluate the percentage frequency of dentinal micro-cracks observed after root canal preparation with TRUShape and Self-Adjusting File (SAF) systems by means of micro-computed tomography imaging analysis. A conventional full-sequence rotary system (BioRace) and a single-file reciprocation system (Reciproc) were used as reference techniques for comparison because of their known assertive cutting efficiency. METHODS: Forty anatomically matched mandibular incisors were selected, scanned at a resolution of 14.25 µm, and assigned to 4 experimental groups (n = 10), according to the preparation protocol: TRUShape, SAF, BioRace, and Reciproc systems. After the experimental procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 70,030) were screened to identify the presence of dentinal micro-cracks. RESULTS: Overall, dentinal defects were observed in 28,790 cross-section images (41.11%). In the TRUShape, SAF, BioRace, and Reciproc groups, dentinal micro-cracks were visualized in 56.47% (n = 9842), 42.38% (n = 7450), 32.90% (n = 5826), and 32.77% (n = 5672) of the slices, respectively. All dentinal defects observed in the postoperative data sets were already present in the corresponding preoperative images. CONCLUSIONS: None of the preparation systems induced the formation of new dentinal micro-cracks.

In vitro assessment of retention and resistance failure loads of two preparation designs for maxillary anterior teeth.

STATEMENT OF PROBLEM: Parallel labiolingual walls and the preservation of the cingulum in anterior tooth preparations have been advocated. However, their contribution to retention and resistance form has not been evaluated. PURPOSE: The purpose of this in vitro study was to evaluate the retention and resistance failure loads of 2 preparation designs for maxillary anterior teeth. MATERIAL AND METHODS: Forty metal restorations were fabricated and paired with 40 cobalt-chromium prepared tooth analogs. Twenty of the specimens had parallel buccolingual walls at the cervical part (group PBLW; the control group), whereas the remaining 20 had converging buccolingual walls (group CBLW; the experimental group). The restorations were cemented to the tooth analogs with a resin-modified glass ionomer luting agent. Ten specimens from each group were subjected to tensile loading with a universal testing machine; the rest were subjected to compression loading until failure. Descriptive statistics and the independent t test (α=.05) were used to determine the effect of failure loads in the tested groups. RESULTS: The independent t test revealed statistically significant differences between the tested groups in tensile loading (P<.001) and in compressive loading (P<.001). The PBLW group presented a higher tensile failure load than the CBLW. On the contrary, the PBLW group presented a smaller compression failure load than the CBLW. CONCLUSIONS: Parallelism of the buccolingual axial walls in anterior maxillary teeth increased the retention form but decreased the resistance form.

Patients' attitude towards anterior teeth extraction an prosthetic replacement at the UPTH Dental Center, Port Harcourt.

AIM: The purpose of this study was to assess the attitude of patients towards anterior teeth extraction and prosthetic replacement of same at the Dental center of the University of Port Harcourt Teaching Hospital (UPTH). METHODS: A retrospective review of the data of patients who presented for anterior teeth extraction and prosthetic replacement or anterior teeth extraction only over a two-year period was done using the records of the oral surgery and prosthetic clinics of UPTH Dental centre. Demographic and clinical information were retrieved and analyzed using the SPSS version 15.0 (SPSS Inc., Chicago, IL, USA). RESULTS: Ninety-two patients comprising 58 males(63%) and 34 females (37%), giving a male to female ratio of 1.7:1, were involved. The age range was 6 to 86 years with a median age of 34.5 years. Forty- three patients (46.7%) had both extraction and replacement within the study period while 49 patients (53.3%) had extraction without replacement. Trauma was the major cause of anterior tooth loss, especially among males and young individuals. Plastic removable partial denture was the main type of replacement offered. Fifty percent of the females (17/34) had replacement compared to 44.8% of the males (26/58). Among those who had both extraction and replacement, majority (74.4%, 32/43) requested for replacement within a month post extraction. Also, 86.2%t of the patients below 40 years either had immediate dentures or replacement within a month compared to 50% of those above 40 years. CONCLUSION: Most of the patients, surprisingly, tolerated anterior edentulousness. However, it appears that anterior edentulousness was more abhorent to female patients and younger individuals.

Morphological assessment of dentine and cementum following apicectomy with Zekrya burs and Er:YAG laser associated with direct and indirect Nd:YAG laser irradiation.

OBJECTIVES: This study aimed to assess the apical surface morphology of maxillary central incisors resected 3.0 mm from the tooth apex using Zekrya burs or Er:YAG laser, with or without subsequent direct Nd:YAG laser irradiation (apical and buccal surfaces) and indirect irradiation (palatal surface). STUDY DESIGN: Forty maxillary central incisors were instrumented and obturated. The roots were divided into 4 groups according to the root resection method (Zekrya bur or Er:YAG laser - 1.8 W, 450 mJ, 4 Hz, 113 J/cm(2)) and further surface treatment (none or Nd:YAG laser - 2.0 W, 100 mJ, 20 Hz, 124 J/cm(2)). The teeth were prepared for SEM analysis. Scores ranging from 1 to 4 were attributed to cut quality and morphological changes. The data were analyzed by the Kruskal-Wallis test and by Dunn's test. RESULTS: SEM images showed irregular surfaces on the apical portions resected with Zekrya burs, with smear layer and grooves in the resected dentine and slight gutta-percha displacement and plasticization. On the other hand, apicectomies carried out with Er:YAG laser showed morphological changes compatible with ablated dentine, with rough surfaces and craters. In spite of the presence of plasticized gutta-percha, with the presence of bubbles, an irregular adaptation of the filling material to the root walls was also observed. Direct Nd:YAG laser irradiation of the apical and buccal surfaces of the resected roots resulted in areas of resolidification and fusion in the dentine and cementum, with a vitrified aspect; indirect Nd:YAG laser irradiation of the palatal surfaces yielded a lower number of changes in the cementum, with irregular resolidification areas. CONCLUSIONS: There were no differences in terms of cut quality between the use of burs and Er:YAG laser or between the 2 surfaces (apical and buccal) treated with Nd:YAG laser with direct irradiation. However, morphological changes were significantly less frequent on surfaces submitted to indirect irradiation (palatal) when compared with those directly irradiated.

Using the support immersion endoscope for socket assessment.

BACKGROUND: The purpose of this study was to determine the indications, efficacy, and advantages of the support immersion endoscope (SIE) method for extraction socket assessment. METHODS: Twelve patients (four women and eight men; mean age: 28 years) in need of extraction with implant placement participated in the study. The teeth extracted included eight upper central incisors and six upper lateral incisors. Extraction sockets were evaluated with a conventional extraction site evaluation (CESE) method alone or with CESE + SIE. CESE includes: visual evaluation; periodontal probing; ridge mapping with calipers, dental mirror, and orthopantomogram; and diagnostic wax-up. RESULTS: CESE + SIE had significantly better accuracy in examining extraction socket labial plate vertical position, labial plate thickness, and bone quality compared to CESE alone. The results obtained from CESE assessment were inconsistent because of poor visualization. CONCLUSION: The SIE can be used as an adjunct tool in assessing extraction socket morphology and bone conditions without flap elevation.

Replantation of avulsed primary incisors: a risk benefit assessment.

Parents of preschool children with avulsed primary incisors may request replantation. Although dental textbooks uniformly recommend that primary teeth not be replanted, some case reports advocate the procedure. This review of case reports identifies a number of pathological outcomes of replantation and provides information for clinicians and parents on the risks that may accompany replantation.