Prevalence and Characteristics of Supernumerary Teeth in Israeli Orthodontic Patients.

BACKGROUND: Supernumerary teeth are one of the most common anomalies in the human dentition, found most frequently in the maxillary anterior region causing impaction or displacement of the adjacent permanent teeth. AIM: The purpose of this retrospective study was to determine the prevalence and characteristics of supernumerary teeth in orthodontically treated patients. STUDY DESIGN: Pre-treatment facial and intraoral photographs, study models, panoramic and periapical radiographs of 3,000 consecutively treated orthodontic patients (mean age 12.2 years) from the Department of Orthodontics Tel Aviv University, were examined to detect supernumerary teeth in both arches. They were recorded according to gender, age, number, location, position and morphology. RESULTS: Thirty-six patients, 22 (61%) males and 14 (39%) females with 50 supernumerary teeth, of which 42 (84%) were found in the maxillary anterior region, and 8 (16%) in the mandible, presenting a prevalence of 1.2%. CONCLUSIONS: A prevalence of 1.2% was found in our study. The most common supernumerary tooth is mesiodens located at the maxillary anterior region. The characteristics of supernumeraries were based on their morphology, location and position. The most frequent complications caused were rotations, displacement and arrested eruption of maxillary incisors.

Supernumerary Teeth in the Maxillary Anterior Region: The Dilemma of Early Versus Late Surgical Intervention.

Supernumerary teeth are the most common developmental dental anomalies in the maxillary anterior region causing interference to the developing permanent incisors resulting in poor dental and facial esthetics. Two different opinions regarding the timing for surgical removal of the supernumerary teeth are presented. In this case report, three brothers with supernumerary teeth in the maxillary anterior region are presented, their surgical and orthodontic management and outcome are discussed.

Pattern of maxillary and mandibular proximal enamel thickness at the contact area of the permanent dentition from first molar to first molar.

INTRODUCTION: Proximal enamel thickness (PET) at the mesial and distal contact areas of the complete permanent dentition has not been previously reported. Anatomic investigation of PET is essential for interproximal reduction treatment. Our objectives were to measure the PETs of the complete maxillary and mandibular dentitions at the contact areas, to compare the PETs of adjacent teeth, and to evaluate the vertical position of each contact area. METHODS: We evaluated 720 extracted teeth; of these, 109 intact teeth were selected. The mesial and distal contact areas were demarcated, and each tooth was embedded in transparent epoxy resin. Blocks were prepared so that the 2 demarcated contact areas were exposed, and 6 measurements were taken and statistically analyzed. RESULTS: Both jaws showed the same PET pattern characterized by 5 features: PET increased progressively from incisor (0.63 mm) to first molar (1.48 mm). Per tooth, mesial and distal PET did not differ. Total maxillary (26.86 mm) and mandibular (24.52 mm) PETs were similar. Paired PETs at the interproximal interface were similar, with the exception of the lateral incisor-canine interfaces. From incisor to first molar, the contact area becomes located farther gingivally. CONCLUSIONS: The existing guideline of maximal 0.5-mm interproximal reduction per 2 adjacent teeth should be kept in the anterior region and could be increased to 1 mm in the posterior region, when an equal amount is removed.

Dental Anomalies' Characteristics.

The aim of this study was to characterize dental anomalies. The pretreatment records (photographs and radiographs) of 2897 patients (41.4% males and 58.6% females) were utilized to detect dental anomalies. The dental anomalies studied were related to number, size and shape, position, and eruption. A Chi-square test was carried out to detect associations between dental anomalies, jaw, and sex. A total of 1041 (36%) of the subjects manifested at least one dental anomaly. The prevalence of all dental anomalies was jaw-dependent and greater in the maxilla, except for submerged and transmigrated teeth. The most frequently missing teeth were the maxillary lateral incisor (62.3%) and the mandibular second premolars (60.6%). The most frequent supernumerary teeth were the incisors in the maxilla (97%) and the first premolars in the mandible (43%). Dental anomalies are more frequent in the maxilla and mainly involve the anterior teeth; in the mandible, however, it is the posterior teeth. These differences can be attributed to the evolutionary history of the jaws and their diverse development patterns.

Duration and anchorage management of canine retraction with bodily versus tipping mechanics.

OBJECTIVE: To compare tipping mechanics (TM) and bodily mechanics (BM) with respect to duration, angulation, and anchorage loss during canine retraction. MATERIALS AND METHODS: TM and BM brackets were bonded to the upper right and left canines, respectively, of 14 subjects requiring maxillary first premolar extractions. The upper canines were retracted with variable nickel titanium closed coil springs (F = 0.50 or 0.75 N) attached posteriorly to a Nance anchorage appliance through the first molars. Panoramic radiographs and dental casts were taken at five time points. Canine angulation was assessed with custom metallic jigs inserted into the vertical slots of the canine brackets prior to radiographic exposure. RESULTS: The canine crown contacted the second premolar after 102.2 +/- 106 and 99.0 +/- 80.0 days, and achieved root uprighting in 72.0 +/- 31.3 and 37.2 +/- 42.7 additional days with the TM and BM groups, respectively. Only the uprighting stage differed significantly between the two mechanics (P < .05). During retraction, tooth angulation differed significantly (P < .001) between the TM (6 degrees ) and BM (-0.8 degrees ) groups. Anchorage loss, as assessed by mesial molar movement, was 1.2 +/- 0.3 mm and 1.4 +/- 0.5 mm for the TM and BM groups, respectively. CONCLUSIONS: Bodily canine retraction occurred faster (38 days) than tipping due to a shorter duration of root uprighting. Anchorage loss (17%-20%) was similar for both retraction methods, ie, maximum anchorage could not be provided by the Nance appliance. Both TM and BM brackets had inadequate rotational control of the retracted canine.

Management of excessive gingival display following adult orthodontic treatment: a case report.

A common cause for the condition described as excessive gingival display is the phenomenon known as altered passive eruption, a coronally situated gingival complex that failed to recede normally during eruption of an otherwise healthy and normal dentition. Orthodontic movement in such conditions may set the stage for additional coronal growth of hyperplastic gingival complex. The objective of this article is to describe, through a detailed case presentation, the surgical methods used to achieve healthy and aesthetic gingival contours in such conditions.

Effects of buccal versus lingual surfaces, enamel conditioning procedures and storage duration on brackets debonding characteristics.

OBJECTIVES: To determine the influence of two enamel conditioning techniques on buccal and lingual tooth surfaces at two different times on debonding strength and tooth damage. METHODS: The study included 50 premolars. Buccal and lingual surfaces of 10 teeth were scanned using SEM before (N=4) and after enamel conditioning by either acid etching or sandblasting prior to acid etching (N=6) for their morphology. The remaining 40 teeth were divided into 2 equal groups, differing in enamel conditioning prior to metallic bracket bonding on the buccal and lingual surfaces. Each group was equally subdivided into short-term (48h) or long-term (12m) water storage. Debonding strength was measured followed by SEM and EDAX for adhesive remnant index (ARI) and calcium remnant index (CRI) left on bracket bases. ANOVA with repeated measures was applied to the results. RESULTS: The buccal enamel was rougher than the lingual one. The surface morphology after the two types of conditioning showed a different pattern. A significantly higher debonding strength was needed to debond the buccal brackets compared to the lingual ones (p<0.05). A significantly higher ARI (p<0.002) and higher CRI (p<0.005) were found in the lingual surface compared with the buccal. No differences were found in debonding strength ARI or CRI regarding the different conditioning or storage duration. CONCLUSIONS: Lingual bonding leads to higher ARI and CRI than buccal bonding. Sandblasting prior to etching does not improve bonding strength for lingual or buccal bonding.

An ortho-surgical approach to severe impaction using bone crestal bridge: a case report.

Impaction of both mandibular canine and lateral incisor is a rare clinical finding which is often treated by way of surgical extraction. This decision is often taken because of the anatomical limitations presented by the mandible, and the horizontal position of the impacted teeth, which have occasionally transmigrated, placing them in close proximity to the roots of neighboring teeth and with a high risk for causing their resorption. In addition, this condition significantly increases the likelihood that the area involved will undergo gingival recession and loss of crestal bone if an unsophisticated ortho-surgical approach is undertaken. The present report describes a novel ortho-surgical technique which maintains the alveolar crestal bone and utilizes a lingual arch attached to the first molars with traction through tunneling with super-elastic springs. This combined approach eliminated the need for extraction of the impacted teeth, and accomplished their full alignment without any of the aforementioned side effects. Every dentist (general practitioners as well as specialists) should be aware of this procedure and refer patients to a specialist.

Skeletal and dental response to rapid maxillary expansion with 2- versus 4-band appliances.

PURPOSE: Banding a rapid palatal expansion (RPE) appliance to the 2 first molars has been proposed as an equivalent to the conventional 4-band RPE appliance. However, the dentoskeletal response to this treatment has not been evaluated. MATERIAL: Twenty-eight subjects (aged 8-20 years) who required maxillary expansion were matched by age and randomly assigned to either a 2-band or a 4-band RPE group. Skeletal and dental responses were measured from standardized anteroposterior cephalometric and occlusal radiographs and dental casts before treatment (T1), at the end of expansion (T2), and at 1 year postexpansion (T3). RESULTS: At T2, suture expansion was 2.5 times greater and arch perimeter was 6-fold larger in the 4-band than in the 2-band group. Both appliances displayed the typical "V" expansion of the suture and "reverse V" expansion of the dental arch. At T3, remineralization reduced the suture opening by 75%, but 95% to 99% of the dental reaction was maintained. The 2-band group demonstrated a significant inverse age-dependent correlation ( r = -0.795), with treatment failure beyond 12 years of age, whereas the 4-band group was age-independent. CONCLUSIONS: The greater the skeletal resistance, the smaller the sutural response but the greater the dental response to RPE therapy. Four-band RPE is indicated when severe anterior crowding is accompanied by a tapered arch form, and 2-band RPE is recommended in the mixed dentition when mild crowding occurs with posterior constriction.

Unequal outer and inner bow configurations: comparing 2 asymmetric headgear systems.

INTRODUCTION: Asymmetric headgear is used when different molar distalization forces (MDF) are needed on the right and left sides of the jaw to correct a Class II molar relationship. METHODS: We investigated 2 asymmetric headgear configurations, the outer-bow and the inner-bow, on cervical-pull headgear. In the first configuration, 5 hooks were soldered on 1 side of the outer bow at 10-mm intervals, making this side shorter; in the other, 4 stops (1.5 mm) were added to 1 side of the inner bow, making this side longer. The right and left MDF and the extraoral force (EF) were measured simultaneously with 2 fork transducers and a testing machine, respectively. RESULTS: A 40-mm difference between the long and short outer bows resulted in a 2.17-fold greater MDF on the long-side molar (7:3 ratio). The 3-4 stop configuration provided the optimal inner-bow arrangement, with stop/no-stop MDF ratios of 7:3 and 10:0, respectively, at 10 N EF. At low-to-medium EF levels, a unilateral MDF developed on the stop side with zero MDF on the no-stop side. The sum of the right and left MDF nearly equaled the EF in the outer-bow asymmetry and was 60% in the inner-bow setting; this suggests strong lateral forces in the latter. CONCLUSIONS: Clinically, for a bilateral unequal Class II relationship, the system of choice is outer-bow asymmetric headgear. For a unilateral Class II relationship with 1 side in a Class I molar relationship (Class II subdivision), inner-bow asymmetric headgear is recommended.