Mandibular Second Premolars Research Articles

Intrabony migration of impacted teeth.

Intrabony migration of impacted teeth is a rare dental anomaly, which occurs only in the permanent dentition of the lower jaw. The teeth involved in this phenomenon are the mandibular lateral incisor, canine, and second premolar. Migration of the lateral incisor is usually in a distal direction, resulting in transposition with the canine. Migration of the canine is most frequently in a mesial direction, resulting in transmigration across the mandibular symphysis to the opposite side of the dental arch. The second premolar most often migrates distally, sometimes past the gonial angle and as far as the coronoid process. Surgical and orthodontic treatment options are presented for the three intrabony migrating teeth.

An occlusal and cephalometric analysis of maxillary first and second premolar extraction effects.

The purpose of this study was to examine dimensional changes in the maxillary arch following the extractions of maxillary first or second premolars. Pre- and posttreatment records of 71 patients treated by one experienced orthodontist were randomly selected from completed premolar extraction cases. Forty-five patients involved the extraction of maxillary first premolars; of these, 15 also had extractions of mandibular first premolars and 30 had extractions of mandibular second premolars. Twenty-six patients involved the extraction of maxillary second premolars, and all of these also had extractions of mandibular second premolars. Pretreatment factors that seemed to suggest a basis for the extraction choice in this sample included incisal overjet, molar relationship, and maxillary incisor protrusion. Mean reductions with treatment in the anteroposterior arch dimension were similar within all premolar extraction groups. There was evidence of greater mean maxillary intermolar-width reduction following the extractions of maxillary second premolars than following extractions of maxillary first premolars. Greater mean maxillary incisor retraction was found in the maxillary first premolar extraction group than in the maxillary second premolar group. A wide range of individual variation in incisor and molar changes did, however, accompany treatment involving both maxillary premolar extraction sequences.

Clinical study of dens evaginatus cases with pulpal involvement.

The objective of the present study was to investigate the incidence, clinical findings, diagnosis and treatment of evaginated teeth with pulpal involvement. Five hundred and three cases requiring endodontically treated premolars were studied at Kaohsiung Medical College Hospital. We observed 23 (4.6%) evaginated teeth with pulpal involvement out of the 503 samples studied here. Of the 23 teeth, mandibular second premolars comprise the largest portion. Clinically, all tubercles of pulpally involved evaginated teeth had been worn down by attrition and all these teeth showed negative response in vitality tests. The study indicated that 17 cases had sinus tracts, 1 tooth had discoloration in crown portion, 1 case had facial asymmetry and 6 teeth had a painful history. Radiographs confirmed that 21 cases had apical or lateral rarefaction, 1 tooth had thickened periodontal ligament and 8 teeth had incomplete root formation. Clinical diagnosis included pulp necrosis (23 cases), acute apical periodontitis (3 cases), chronic apical periodontitis (4 cases), suppurative apical periodontitis (17 cases)and Garrer' osteomyelitis (1 case). After the treatment, 13 teeth showed satisfactory results. The treatment on 2 teeth was failed, 1 tooth had root fracture and 7 teeth had loss of follow-up. We conclude that the evaginated teeth can hence be preserved even if they are pulplly infected and have an incomplete root apex.

Inversion, rotation and ectopic eruption of a mandibular second premolar

Summary. This case illustrates complete inversion, rotation and ectopic extra-oral eruption of a mandibular right second premolar and the congenital absence of the contralateral tooth. As far as can be ascertained, the simultaneous expression of these four abnormalities in one patient has not been reported before. Resume. Ce cas illustre l'inversion complete, la rotation, l'eruption en position ectopique d'une seconde premolaire mandibulaire droite et l'absence congenitale de la dent contra-laterale. Pour autant que nous le sachions, l'expression simultanee de ces quatre anomaies chez le meme patient n'a jamais ete rapportee jusqu'a maintenant. Zusammenfassung. Dieser Fall wird die Inversion, Rotation und der ektopische Durchbruch eines zweiten Pramolars im Unterkiefer beschreiben sowie die congenitale Nichtanlage des kontralateralen Zahnes. Soweit bekannt wurden das simultane Auftreten von diesen vier Abnormalitaten an einem Patienten bis anhin nicht beschrieben. Resumen. Este caso ilustra la inversion completa, rotacion, y erupcion ectopica del segundo premolar mandibular derecho y la ausencia congenita del diente contralateral. Por lo que se puede determinar, la expresion simultanea de estas cuatro anormalidades en un solo paciente no ha sido reportado.

Mandibular second premolar extraction--postretention evaluation of stability and relapse.

The dental casts and cephalometric radiographs of 46 patients, treated with mandibular second premolar extraction and edgewise orthodontic mechanotherapy, were evaluated for changes over a minimum 10-year postretention period. The sample was divided into two groups: early (mixed dentition) extraction of mandibular second premolars and late (permanent dentition) extraction of mandibular second premolars. Results showed no difference in long-term stability between the two groups. Arch length and arch width decreased with time and incisor irregularity increased throughout the postretention period. No predictors or associations could be found to help the clinician in determining the long-term prognosis in terms of stability. The sample was regrouped according to the postretention degree of incisor irregularity. Statistically significant differences in cephalometric measurements were found between the minimally crowded group and the moderately to severely crowded group.

Case report AE. Non-surgical correction of a severe Class II malocclusion (Brodie syndrome)

With a great deal of growth and cooperation over a period of 57 months it was possible to correct a severe Class II malocclusion (Brodie Syndrome) without surgical intervention. Initially, occlusal function was provided with a biteplate while the mandibular dentition was expanded. Following extraction of maxillary first and mandibular second premolars a fixed appliance (Edgewise) was used to complete all tooth movement. Through the treatment of this case the importance of function, growth and development was recognized.

Vertical changes in high mandibular plane cases following enucleation of second premolars.

The records of 23 patients who underwent mandibular second premolar enucleation in the early mixed dentition were studied. The patients were selected at random from a group which had mandibular plane angles in excess of 38 degrees to SN and had not worn headgear prior to mechanical orthodontic therapy. Pre- and posttreatment measurements were compared to measurements made in an earlier study by Isaacson et al. and a significant decrease in lower anterior face height was found.

Extreme distal migration of the mandibular second bicuspid. A variant of eruption.

A five-year study of 26,264 panoramic radiographs found distal positioning of the mandibular second bicuspid associated with a missing adjoining first molar in one of every 505 patients. Following early removal of the first molar, there is a 5% to 10% chance that the second bicuspid will migrate distally. It usually continues until it contacts the root of the second molar, and then rotates up into occlusion adjacent to the parallel with that tooth. Mesial drift seldom occurs in this circumstance; the resulting space between lower first and second bicuspids remains. Early conservative management can be very important in these cases, making periodic x-ray examination advisable whenever a molar has been lost and the adjoining bicuspid has not yet erupted.

Caries experience in orthodontically treated individuals.

The caries ecperience in 26 girls and 26 boys living on an island outside. Bergen, who had received orthodontic treatment with fixed appliances, was examined 1.5 to 2 years after the end of treatment. The children were then between 1l and 17 years old. The remaining children of the same age group, 58 girls and 53 boys, served as controls. The orthodontic patients had received repeated hygiene instructions during the treatment period and were expected to rinse their mouth with 0.05% sodium fluoride daily. The percentage distribution of DMF-surfaces indicated somewhat less caries experience in the treated group. A chi-square test showed significantly more intact surfaces on the maxillary first molars, second premolars, canines and central incisors, and mandibular molars and second premolars in treated than in untreated children, and also demonstrated significantly fewer new lesions in the upper second molars at the time of examination in the treated groups. A comparison of the caries experience of the different surfaces revealed significantly more intact surfaces in the treated group and significantly fewer new lesions on the mesial and distal surfaces in treated in untreated children at the time of examination.

The mandibular second premolars: morphologic variation and inheritance.

The mandibular second premolars: morphologic variation and inheritance.