Microanchor mediated upper molar intrusion in deep posterior bite after long-term edentulousness for prosthetic reconstruction with dental implants

Introduction

Long-term edentulousness can lead to elongation of antagonistic teeth, making prosthetic rehabilitation impossible. An interdisciplinary case is presented where elongated teeth were successfully intruded by micoranchor-mediated orthodontic movement.

Discussion

To the right mandible, implants had been inserted correspondingly to the alveolar process height. However, the patient waited over 1 year for prosthetic treatment. The antagonistic maxillary teeth had elongated considerably. On the left side, elongated upper molars occluded with previously crowned and in the meantime unprovided teeth 35 and 37. On the right side, two palatal, three vestibular microanchors of 8 mm length and 1.6 mm diameter were used, on the left side, two palatal and two vestibular microanchors to intrude the teeth 14 to 17 and 26. The screwheads were connected to individually model-casted splints for bodily intrusion of the molars.

Conclusion

This case illustrates how vertical tooth movements can be ventured by the use of orthodontic microscrews before either conventional or implant-borne prosthetic rehabilitation.     

Dentoalveoläre Traumen

Purpose

The purpose of this study was to evaluate the overall place of dental trauma in facial injuries. This was a retrospective investigation based on the analysis of a large amount of dentoalveolar injuries over a 10-year period.

Patients and methods

Between 1991 and 2000, 4763 of 9543 patients suffering from oral and maxillofacial injuries, sustained dentoalveolar trauma. Records of 6237 different dental injury patterns were reviewed according to the five main injury mechanisms: age, sex, type of injury, cause of accident, and frequency of dentoalveolar trauma. They were statistically analyzed using frequency distribution, chi-square test, t-test, Mann-Whitney U test, Kolmogorov-Smirnov test, and logistic regression analysis.

Results

Household and play (2117), sports (1533), traffic accidents (438), acts of violence (426), and work-related accidents (201) were noted. A total of 4763 patients had 2988 subluxations, 2356 showed crown fractures, 444 had avulsions, 176 root fractures, 154 intrusions, and 119 patients suffered from concussions. This number of patients accounts for the prevalence of 49.9% for dentoalveolar trauma among all facial injuries.

Conclusion

Only the analysis of a large number of injuries reveals the risk of suffering from dentoalveolar trauma. Due to this fact, preventive methods can be recommended and demanded more effectively.     

Space conditions and dental and occlusal features in patients with palatally impacted maxillary canines: an aetiological study

The aetiology of palatal canine impaction is unclear. The aim of this research was to investigate the occlusal features that could contribute to the aetiology of palatal maxillary canine impaction. The material consisted of the pre-treatment dental casts of 34 patients (27 female and seven male) with unilateral palatal canine impaction (impaction group). The average age of this group was 17.7 years (+/- 4.6). These were matched according to age, gender and type of malocclusion with a comparison group of pre-treatment dental casts from unaffected orthodontic patients. From the dental casts the following parameters were obtained: (1) dentoalveolar arch relationship, (2) missing or anomalous teeth, (3) the mesiodistal width of each maxillary tooth, (4) the upper arch perimeter, (5) the maxillary inter-premolar and inter-molar widths. The arch length-tooth size discrepancy was only calculated for subjects with no missing teeth. Palatal canine impaction occurred most frequently in subjects with a Class II division 2 malocclusion. There was an association between palatal canine impaction and anomalous lateral incisors (P = 0.01). The transverse arch dimension was significantly wider in the impaction group than in the comparison group (P < 0.01). There was no statistically significant difference in the mesiodistal width of maxillary teeth or in the arch length-tooth size discrepancy between the palatal canine impaction group and their matched comparisons (P > 0.05). These results suggest that the presence of an 'excess palatal width' and anomalous lateral incisor may contribute to the aetiology of palatal canine impaction.     

An 11-year review of dental injuries associated with maxillofacial fractures in Turin, Italy

Introduction

The aim of the study was to analyze the incidence, characteristics, and correlations between maxillofacial fractures and dental injuries in patients who were treated at a first-level trauma center in a metropolitan center in northwest Italy in the last 11 years.

Material and methods

Between January 1, 2001 and December 31, 2011, 2,110 patients with maxillofacial fractures were admitted. Only dentulous patients with complete clinical records who presented with associated dental injuries were included in this study. Data on the age, gender, mechanism of injury, damaged tooth, type of dental injury, site of facial fractures, and concomitant injuries were recorded.

Results

On the whole, 267 patients (13.1 %), mainly males aged 20–29 years, presented with 759 dental injuries associated with maxillofacial fractures, especially following motor vehicle accidents. The maxillary teeth, most often the anterior elements with decreasing involvement from the incisors to the molars, were the teeth most frequently damaged overall. The main types of dental trauma in patients with maxillofacial fractures were luxations and dental fractures.

Discussion

Our findings show that patients with mandibular fractures were statistically and significantly associated with dental injury, and the teeth in the upper jaw were the most frequently injured teeth, exhibiting mainly luxations and crown fractures. Confirmation of the predominant impact site in patients with dental injuries associated with maxillofacial fractures comes from the 177 lacerations noted in the chin and lip regions in 267 patients.     

A retrospective study of the prevalence and characteristics of root dilaceration in a sample of the Turkish population

Objectives

We aimed to determine the prevalence and distribution of root dilaceration by tooth type and to investigate the relationship between trauma history and teeth with dilaceration in a large population of adult dental patients in Turkey.

Methods

Periapical radiographs of 9,406 permanent teeth from 5,504 patients were examined. Teeth were recognized as having mesial or distal root dilaceration if there was deviation of 90° or more from the normal long axis of the tooth. The patients’ biographic data, dilacerated and non-dilacerated teeth, and accidental trauma history were recorded. The Pearson Chi-square test was used to evaluate differences by sex and the Mann–Whitney U test was used to determine whether significant differences existed in the occurrence of dilaceration by age and side.

Results

In the 5,504 subjects (2,877 males and 2,627 females), 9,406 teeth (5,029 in males and 4,377 in females) were examined. The Mann–Whitney U test revealed no significant differences in root dilacerations by age (P = 0.6) The teeth most frequently observed with root dilaceration were mandibular third molars (10.7 %), followed by maxillary first molars (5.8 %), mandibular second molars (5.2 %), maxillary third molars (5.0 %), maxillary second molars (4.9 %), and mandibular third molars (4.9 %). Overall, there were 161 right and 156 left root dilacerations. In all patients, the root dilacerations were unilateral. Trauma occurred in 1 % (n = 59) of the population, and all cases were in the maxillary arch. Trauma involved 0.6 % of all teeth examined, and was most common in maxillary third molars (2.6 %), followed by maxillary first molars (1.9 %), maxillary second molars (1.3 %), and maxillary lateral incisors (1.3 %) (P > 0.05). In 252 of 317 dilacerated teeth (79 %), the dilaceration was observed in the apical third region.

Conclusions

Clinicians should consider the possibility of root dilaceration in teeth with trauma history. When other treatment (such as extraction, orthodontics) is required, identification of a dilaceration is important to ensure appropriate management. Periapical radiographs are the most appropriate way to diagnose the presence of root dilacerations.     

Complications and survival rates of teeth after dental trauma over a 5-year period

Objectives

The purpose of this study was to evaluate whether the current guidelines of the International Association of Dental Traumatology (IADT) for emergency care of traumatised teeth result in lower complication rates.

Materials and methods

Therapeutic strategies of 361 dental injuries in 291 patients treated at a university dental hospital over a 5-year period were investigated by evaluating the patients' records. Adherence to the guidelines of the IADT (Flores et al. Dent Traumatol 17:1–4, 2001; 49–52, 2001; 97–102, 2001; 145–148, 2001; and 193–196, 2001; Flores et al. Dent Traumatol 23:66–71, 2007; 130–136, 2007; and 196–202, 2007) was evaluated. Complications were also recorded according to the patients' records and analysed relative to the treatment and injury pattern. During follow-up visits, the teeth were inspected regarding pulp vitality and overall function of the injured tooth. The Kaplan–Meier survival analysis of pulps and teeth was performed for different injury categories.

Results

The majority of injuries (322/361; 89.2 %) were treated according to the guidelines. When IADT guidelines were followed, complication rates were significantly lower than for cases treated without adherence to the guidelines. The most frequent complication was the loss of restoration, followed by pulp necrosis, abnormal mobility, and tooth loss. The overall survival analysis showed that in the permanent dentition, the loss of pulp vitality and tooth occurs within the first 6 months but may also occur later.

Conclusions

The results of this study indicate that traumatised teeth that were treated according to the recommendations had a lower complication rate. In addition, the majority of pulp necrosis and tooth losses in the permanent dentition occurred within the first 6 months after trauma. These results indicate that early follow-up visits are essential to promptly treat complications.

Clinical relevance

Adherence to the IADT guidelines for treatment of dental trauma may lead to more favourable outcomes when compared to cases treated without compliance to the guidelines.     

Evaluation of a possible association between a history of dentoalveolar injury and the shape and size of the nasopalatine canal

Objectives

Maxillary incisors (MI) are often affected by dentoalveolar injury resulting in tooth devitalization and apical periodontitis. The aim of the present study was to analyze any association between a history of dentoalveolar injury and the shape and size of the nasopalatine canal (NC) using cone beam computed tomography (CBCT).

Material and methods

Patients were allocated to the trauma group if they had a history of dentoalveolar injury and a root filling in at least one MI and/or one missing MI. As controls, 100 matched-controlled (age and gender) patients were selected. NC dimensions including length, width at midway, and diameter of incisal and nasal foramen were measured in sagittal and axial CBCT planes. Furthermore, an evaluation of NC bulging signs, apical osteolysis of MI, and its fusion with NC was performed.

Results

In the trauma group (n?=?96), 31.3 % had at least one missing MI, and 95.8 % had a root filling in a MI. The antero-posterior dimension of the incisive foramen (p?=?0.02) and of the NC at midway (p?= 0.04) was significantly larger in the trauma group. Significantly more cases with a bulging sign were found in the trauma (n?=?19) than in the control group (n?=?3, p?= 0.001). An apical osteolysis was identified in 5.1 % of MI, and 12/38 did show a fusion with the NC.

Conclusion

Wider dimensions of the NC and a bulging sign may suggest a former dentoalveolar injury to the anterior maxilla. Periapical osteolysis of central MI over 5 mm in diameter tends to fuse with the NC.

Clinical relevance

In patients with a history of dentoalveolar injury and/or apical periodontitis, the NC should be evaluated on available CBCT images. Any inflammatory processes in the neighboring teeth should be recognized and eliminated as they may initiate bulging of the NC and/or the formation of a nasopalatine duct cyst (NPDC). NC with bulging signs should be monitored clinically and radiographically to diagnose a NPDC in an early stage.

     

Maxillary osteonecrosis and spontaneous teeth exfoliation following herpes zoster

Background

Reports of osteonecrosis and spontaneous tooth loss following herpes zoster infection of the fifth cranial are extremely rare. Only 39 previously recorded cases of post-zoster osteonecrosis have been found in the literature. The unusual feature of the case of interest to the dental surgeon is a rare complication of tooth exfoliation and maxillary osteonecrosis.

Case report

This article reports a case of 52-year-old man with herpes zoster infection of the trigeminal nerve and related alveolar bone necrosis and teeth loss. The etiology and management of herpes zoster infection associated with destructive sequelae are discussed.

Discussion

Very few cases of osteonecrosis and spontaneous teeth exfoliation secondary to herpes zoster are found in the literature. The exact mechanism by which herpes zoster induces these destructive changes in the alveolar bone and teeth cannot be proposed. As Varicella zoster virus is an aneurotropic virus, the possible provoking factors may be the infection of the nerves innervating the periosteum or the chronic inflammatory changes in the form of adverse periodontal disease and delayed healing of the extraction sockets associated with compromised host resistance.     

Maxillary sinus aplasia

Purpose

A case of unilateral aplasia is reported. Associated anatomical anomalies and review of the literature is described, and a comparison with maxillary sinus hypoplasia is made.

Patient

A 40-year-old male was complaining of an esthetic “defect” in his face. There was an antero-posterior depression in the left infraorbital region. Computed tomography showed absence of the left maxillary antrum, uncinate process, and maxillary infundibulum. The ipsilateral orbit was increased in volume inferiorly, and the inferior margin was immediately adjacent to the root of the inferior turbinate. The left inferior and middle turbinate was hyperplastic. The nasal septum was a little dislocated to the ipsilateral side. There was no history of antecedent sinusitis or surgery, and no evidence of systemic disease. An appositional en bloc autogenous bone graft was placed on the left infraorbital depression.

Conclusions

With precise computed tomography assessments, a maxillary sinus hypoplasia or aplasia can be diagnosed and distinguished from other maxillary sinus anomalies, and may help the surgeon to plan his surgical procedure and identify the limits of dissection accordingly. The condition can also “cause” an esthetical deficit in the infraorbital/zygomatic region, which can be resolved with an appositional graft.     

Satisfaction with the dentition related to dental functional status and tooth replacement in an adult Bulgarian population: a cross-sectional study

Objectives

The purpose of this study is to assess satisfaction with the dentition in general, dental esthetics, and chewing function related to dental functional status and tooth replacement in subjects, dentate in both jaws.

Materials and methods

Dentitions of subjects (n?=?2,437) aged ≥20 years were categorized in a hierarchical functional classification system, with and without tooth replacements, according to four dental conditions: ‘≥10 teeth in each jaw’, ‘complete anterior regions’, ‘sufficient premolar regions’ (≥3 occluding pairs), and ‘sufficient molar regions’ (bilaterally ≥1 occluding pair). Likelihood ratios (LR) were used to express the ability of these conditions to discriminate between satisfied and not satisfied subjects. Odds ratios (OR) were calculated to evaluate associations between satisfaction, the four dental conditions separately, and tooth replacement.

Results

In the hierarchical system, subjects having ‘<10 teeth’ were more likely of being not satisfied with their dentitions (LR 4.09), esthetics (LR 3.51), and chewing (LR 5.49). As a separate condition, ‘≥10 teeth’ was significantly associated only with satisfaction with chewing. The conditions ‘complete anterior regions’ and ‘sufficient’ premolar and molar regions’ were associated with all satisfaction variables (ORs 1.47–2.96, p values ≤0.012). When dental conditions were determined on the basis of natural teeth only, having teeth replaced was positively correlated with satisfaction; when determined on the basis of natural plus replaced teeth, subjects having teeth replaced tended to be less satisfied than their counterparts with natural teeth only.

Conclusions

Satisfaction was strongly associated with dental functional status.

Clinical relevance

Dental configurations comprising both natural and artificial teeth were less likely to provide the same level of satisfaction as equivalent dental configurations comprising natural teeth only.     

Surgical repositioning of a traumatically intruded permanent incisor in a patient with rheumatic fever: case report

Abstract –  Intrusive luxation of permanent teeth is a relatively uncommon type of injury to the periodontal ligament. However, it is one of the most severe types of dentoalveolar trauma. By definition, intrusive luxation consists of the axial displacement of the tooth into the alveolar bone, accompanied by comminution or fracture of the alveolar bone. Here we report the treatment management of a traumatically intruded immature permanent central incisor by surgical repositioning undertaken in a 10-year-old child with rheumatic fever 10 days after sustaining a severe dentoalveolar trauma. The intraoral examination showed the complete intrusion of the permanent maxillary right central incisor and the radiographic examination revealed incomplete root formation. Prophylactic antibiotic therapy was prescribed and the intruded tooth was surgically repositioned and endodontically treated thereafter. The postoperative course was uneventful, with both clinically and radiographically sound conditions of the repositioned tooth up to 3 years and 2 months of follow-up. These outcomes suggest that surgical repositioning combined with proper antibiotic prophylaxis and adequate root canal therapy may be an effective treatment option in cases of severe intrusive luxations of permanent teeth with systemic involvement.     

Midline correction by asymmetric reciprocal torque: a pilot study

Objective

Can we correct dental midline discrepancies by systematic torque bends on all canines and premolars without extraction and mesiodistal tooth movement?

Patients and methods

Eight orthodontic patients (4?males, 4?females, mean age 31?years) presented a dental midline discrepancy of 2–4?mm, moderate deviation of the chin, no skeletal asymmetry, and a horizontal orientation of the occlusal plane in the frontal aspect. On the side where the mandible was shifted medially, asymmetric torque bends moved the antagonist canine and both premolar crowns buccally, while palatal crown torque was used on the maxillary canine and premolars on the other side. Lingual crown torque corrected the medially shifted canine and premolars in the mandibular dental arch, and buccal crown torque the laterally shifted lower canine and premolars.

Results

On average, torque effects altered the canine guidance by 6.5?±?4.7°, the first premolar guidance by 7?±?4.1°, and the second premolar guidance by 6.3?±?3.7°. Correction of the dental midline shift averaged 1.6?±?0.8?mm after the torque, and eliminated the midline discrepancy completely (n?=?2) or partly (n?=?6).

Conclusion

In this pilot study, asymmetric reciprocal torque represented a treatment option for midline corrections of approximately 2–4?mm and improvement in the chin position without mesiodistal tooth movement or extraction.     

The role of unfinished root canal treatment in odontogenic maxillofacial infections requiring hospital care

Objectives

The aim of this study was to evaluate clinical and radiological findings and the role of periapical infection and antecedent dental treatment of infected focus teeth in odontogenic maxillofacial abscesses requiring hospital care.

Materials and methods

In this retrospective cohort study, we evaluated medical records and panoramic radiographs during the hospital stay of patients (n?=?60) admitted due to odontogenic maxillofacial infection originating from periapical periodontitis.

Results

Twenty-three (38 %) patients had received endodontic treatment and ten (17 %) other acute dental treatment. Twenty-seven (45 %) had not visited the dentist in the near past. Median age of the patients was 45 (range 20–88) years and 60 % were males. Unfinished root canal treatment (RCT) was the major risk factor for hospitalisation in 16 (27 %) of the 60 cases (p?=?.0065). Completed RCT was the source only in 7 (12 %) of the 60 cases. Two of these RCTs were adequate and five inadequate.

Conclusions

The initiation of inadequate or incomplete primary RCT of acute periapical periodontitis appears to open a risk window for locally invasive spread of infection with local abscess formation and systemic symptoms. Thereafter, the quality of the completed RCT appears to have minor impact. However, a considerable proportion of the patients had not received any dental treatment confirming the importance of good dental health. Thus, thorough canal debridement during the first session is essential for minimising the risk for spread of infection in addition to incision and drainage of the abscess. If this cannot be achieved, tooth extraction should be considered.

Clinical relevance

Incomplete or inadequate canal debridement and drainage of the abscess may increase the risk for spread of endodontic infection.     

A retrospective study on the influence of maxillary canine impaction on premolar root morphology

Objectives

The root morphology of the maxillary first premolar differs from the other premolars by presenting a high incidence of separated roots. This study addressed the spatial conditions during root development as a possible influencing factor. Therefore, maxillary computed tomographic (CT) scans of patients with regularly erupted or impacted permanent canines were evaluated on the root morphology of the premolars.

Methods

The following parameters were retrospectively analysed in 250 maxillary CT scans (100 patients with regular erupted permanent canines, 150 patients with at least one impacted permanent canine): sex, status of the canines (erupted/impacted), position of the impacted canines (buccal/palatal; vertically inclined inside/outside the dental arch/horizontally inclined) and root morphology of the premolars.

Results

Of the patients, 68 % with at least one impacted canine were female; the canine was impacted palatally in 75.6 % and in a horizontally inclined position in 58.4 %. In patients with an impacted canine, the number of first and second premolars with separated roots was significantly reduced on the ipsilateral as well as on the contralateral side (all p values?<?0.01).

Conclusions

The present study detected an influence of maxillary canine impaction on the root morphology of all premolars, in that impaction and the associated surplus of space resulted in decreased root separation. This supports the hypothesis that root development is at least partly influenced by increased spatial conditions of the dental arch. However, root development can be regarded as a multifactorial event, influenced by space, direct mechanical interferences, as well as genetic predetermination. The retrospective nature of this observational study did not allow for conclusive differentiation between these factors. Alternatively, root separation and the mesial concavity of the first premolar may represent a path for canine eruption similar to the lateral incisor.

Clinical relevance

A single-rooted maxillary first premolar might represent an additional risk factor for canine impaction.     

Extraction of Permanent Maxillary Teeth by Only Buccal Infiltration of Articaine

Objective

The aim of this study is to demonstrate whether articaine hydrochloride administered alone as a single buccal infiltration in maxillary tooth removal, can provide favourable palatal anesthesia as compared to buccal and palatal injection of lidocaine.

Study Design

The study population consisted of 30 patients who were undergoing orthodontic treatment, and who required bilateral extraction of maxillary permanent premolars as per their orthodontic treatment plan. On the experimental side, 4 % articaine/HCl was injected into the buccal vestibule of the tooth to be extracted. On the control side, 2 % lignocaine HCl was injected both into the buccal and the palatal side of the tooth to be extracted. Following tooth extraction all patients completed a 100-mm visual analogue scale (VAS) and faces pain scale (FPS) to rate the pain on extraction.

Results

According to the VAS and FPS scores, the pain on extraction between buccal infiltration of articaine and the routine buccal and palatal infiltration of lignocaine was statistically insignificant.

Conclusions

The routine use of a palatal injection for the removal of permanent maxillary premolar teeth may not be required when articaine/HCl is used as the local anesthetic.     

Mesiodistal tooth size in non-syndromic unilateral cleft lip and palate patients: a meta-analysis

Objectives

To evaluate, using meta-analysis methodology, mesiodistal tooth dimensions in non-syndromic unilateral cleft lip and palate (CLP) patients.

Materials and methods

A literature search was conducted using PubMed, Medline, Google Scholar Beta, EMBASE Excerpta Medica, CINAHL, Web of Science, and the Cochrane Collaboration, identifying English and non-English articles reporting on mesiodistal tooth dimensions on the cleft and non-cleft side of non-syndromic unilateral CLP patients. Additional studies were identified by searching reference lists of articles consulted. Only studies with a suitable control group were included. Two examiners independently performed the literature search and data extraction. Using meta-analysis software, data extracted from each selected study were statistically combined using the fixed-effects model. Weighted mean differences, 95 % confidence intervals, and heterogeneity were calculated for each measurement.

Results

Four articles fulfilling the inclusion criteria were located and included in the meta-analysis. Maxillary incisors and first molars were found to be significantly larger on the non-cleft side while mandibular incisors and premolars were larger on the cleft side, in non-syndromic unilateral CLP patients. On the cleft side, maxillary premolars and second molars were larger in cleft than control patients while incisors were smaller, whereas all mandibular teeth were larger in cleft patients. On the non-cleft side, all maxillary teeth except for the central incisors were larger in the cleft than control patients, while all mandibular teeth were larger in the cleft patients except for lateral incisors.

Conclusions

Non-syndromic unilateral CLP patients tend to have larger posterior but smaller anterior teeth compared with the general population. Comparing sides, unilateral CLP patients tend to have smaller maxillary but larger mandibular teeth on the cleft than on the non-cleft side.

Clinical relevance

Given that obtaining a stable, functional, and esthetic occlusion requires a thorough evaluation of tooth size, knowledge about trends in tooth size variations in CLP patients can help with dental and orthodontic treatment planning.     

Relationship between maxillary sinus pathologies and maxillary posterior tooth periapical pathologies

Objectives

To determine the prevalence of odontogenic maxillary sinus pathologies and their relationship with periapical pathologies in the maxillary posterior teeth using cone-beam computed tomography (CBCT).

Method

Maxillary posterior CBCT scans of consecutive patients aged 20–77 years were evaluated retrospectively. Patients with at least one maxillary posterior tooth were included. Patients with edentulous maxillae or having one or more maxillary implants were excluded. Finally, 461 CBCT images were evaluated. Demographic data, such as age and sex, and pathologic findings of the right and left maxillary sinuses and adjacent teeth were recorded. Statistical analyses were performed using the Chi square test and binary logistic regression.

Results

The prevalence of right and left odontogenic maxillary sinusitis was 59.5 and 64 %, respectively. Maxillary sinus pathology was more common in males, and there was no relationship with age. Regarding the maxillary sinus pathology, 64 % had mucosal thickening, 19 % had partial opacification, 5 % had total opacification, and 12 % had polypoidal mucosal thickening. Right and left maxillary sinus pathologies were approximately twice as prevalent in patients with periapical pathology in at least one maxillary posterior tooth. Periapical pathologies in the right maxillary first molar and left maxillary first and second molars significantly increased the risk of maxillary sinus pathology with odds ratios of 2.53, 1.83, and 3.12, respectively.

Conclusions

Odontogenic maxillary sinus pathologies were present in >50 % of the study population. Periapical pathologies in the maxillary first and second molar teeth significantly increased maxillary sinus pathologies.

     

Simultaneous presence of a congenitally missing premolar and supernumerary incisor in the same jaw: report of case

Supernumerary teeth and hypodontia can be regarded as opposite developmental phenomena. An eight-year-old girl presented a concomitant occurrence of a supernumerary tooth and two congenitally missing teeth. The supernumerary tooth was found in the left maxillary incisor region, while the left second premolar in the maxilla and the left lateral incisor in the mandible were congenitally missing. The supernumerary tooth showed a similar color and morphology to those of the maxilla lateral incisor, and the lateral incisor on the mesial side was diagnosed as a supernumerary tooth from dental age, eruption time, and mesiodistal crown dimension. The supernumerary incisor was guided labially to cure an anterior cross-bite, and the lateral incisor, canine, and first premolar were guided distally to compensate for the space left by the congenitally missing left second premolar.     

Comparison of digital dental images yielded by digital dental casts,cone-beam computed tomography,and multislice computed tomography for measurement of dental area

Objectives

We investigated and compared the errors generated by multislice computed tomography (MSCT), cone-beam computed tomography (CBCT), and digital dental casts when used to provide digital data about dental structures.

Methods

Ten A20 skull models were scanned with MSCT and CBCT, and dental plaster cast models were optically scanned in three dimensions. The maxillary dental area was then compared. The distance between the three-dimensional scan data of the skull and each set of digital dental data were measured. Reference data were then overlapped with the experimental digital model using surface-based registration. The distance of errors was measured with the shortest distance measurement function. The distances between each experimental digital model and the reference scan data were measured, and error values were determined for all maxillary teeth and each tooth surface area. Errors were measured for all teeth from the central incisors to the second molar on both the left and right sides. Errors were measured from the mesial, distal, and labial surfaces and the tooth cusp tip area for each tooth.

Results

The digital dental casts had the smallest error (p < 0.001). The error in the digital dental casts (mean ± standard deviation) was 0.10 ± 0.12 mm. The CBCT error was 0.34 ± 0.38 mm, which was significantly greater than the MSCT error (0.19 ± 0.16 mm) (p < 0.001).

Conclusions

We recommend the use of digital dental casts with digital dental imaging for three-dimensional measurement of the dental area because this technique had the smallest errors.