Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations

Bilateral mandibular tooth transposition is a relatively rare dental anomaly caused by distal migration of the mandibular lateral incisors and can be detected in the early mixed dentition by radiographic examination. Early diagnosis and interceptive intervention may reduce the risk of possible transposition between the mandibular canine and lateral incisor. This report illustrates the orthodontic management of bilateral mandibular canine-lateral incisor transposition. Correct positioning of the affected teeth was achieved on the left side while teeth on the right side were aligned in their transposed position. It demonstrates the outcome of good alignment of the teeth in the dental arch

Prevalence and Characteristic Features of Mandibular Second Molar Impaction in Chinese-American School Children

Svrha: Željeli su se odrediti rasprostranjenost i svojstva zaglavljenja (impakcije) drugoga donjočeljusnog kutnjaka (mandibularnog molara) u velikom etničkom uzorku kinesko-američkih ortodontskih pacijenata. Materijali i metode: Analizirano je tri tisuće ortopantomograma kinesko-američke djece podvrgnute ortodontskoj terapiji. Pozornost je bila usmjerena na impakciju drugoga mandibularnog molara, njegov anatomski položaj i nagib u odnosu na susjedne zube. Sve su te vrijednosti zabilježene. Rezultati: Uočene su 103 jednostrane i obostrane (unilateralne i bilateralne) impakcije drugoga kutnjaka u donjoj čeljusti kod 71-og kinesko-američkog pacijenta, pa je učestalost iznosila 2,36 posto. Gotovo svi zubi (89%) bili su nagnuti mezijalno. Uglavnom su zabilježeni zaglavljeni zubi u posteriornom mandibularnom dijelu, a nerazvijeni treći molari locirani su u području korijena drugih molara. To je na dvodimenzionalnom ortopantomogramu ostavljalo dojam preklapanja. Zaključak: U slučaju kinesko-američkih ortodontskih pacijenata zabilježena je impakcija drugih mandibularnih molara od 2,36 posto. Većina tih zuba bila je nagnuta mezijalno u posteriorno zbijenom području pokraj trećeg kutnjaka u razvoju. Mogući krivac za zaglavljenost jest dominantni mezijalni nagib, vjerojatno uzrokovan različitom brzinom razvoja korijena (distalni korijen je razvijeniji od mezijalnog). Preuzak posteriorni prostor nije toliko važan te se smatra sekundarnim uzrokom. Kako bi se postigao najbolji mogući klinički ishod, preporučuje se rano otkrivanje i odgovarajuća ortodontska terapija.Objectives: To determine the prevalence and characteristic features of mandibular permanent second molar impaction in a large sample of ethnic Chinese-American orthodontic patients. Materials and methods: Panoramic radiographs of 3000 consecutively orthodontically treated Chinese-American school children aged 11-15 years were studied for mandibular second molar impaction. Their anatomic position and angulation relative to the adjacent teeth were recorded and evaluated. Results: A total of 103 mandibular second molar impactions both unilateral and bilateral were detected in 71 Chinese-American patients with a prevalence of 2.36%. The significant majority of the mandibular second molar impactions (89%) were mesially inclined. Posterior mandibular crowding was detected in most of these impactions and the developing third molars were located along the root of the second molars, giving an impression of an overlap on the twodimensional panoramic radiographs. Conclusions: Chinese-American orthodontic patients present a prevalence rate of 2.36% in mandibular second molar impactions, most of them mesially inclined in posteriorly crowded arches and in close proximity of the developing third molars. A possible mechanism for their impaction is the predominant mesial angulation, possibly caused by the different stages of root development (distal root more developed than the mesial root). The posterior space deficiency appears to be less critical, thus a secondary factor. Early detection and an appropriate orthodontic treatment are recommended for best clinical outcome

Prevalence and Patterns of Permanent Tooth Agenesis among Orthodontic Patients—Treatment Options and Outcome

(1) Background: tooth agenesis is a very common dental anomaly of the human dentition most often affecting the maxillary anterior region, mandibular and maxillary premolar regions. (2) Purpose: the present study was aimed to evaluate the prevalence and patterns between bilateral and unilateral tooth agenesis among orthodontic individuals and to illustrate the treatment options for missing teeth and the outcome. (3) Materials and methods: Pre-treatment records, photographs and radiographs, of 3000 consecutively treated orthodontic individuals from the post-graduate clinic of Tel Aviv University were surveyed to detect permanent tooth agenesis in either dental arch. The data was recorded according to gender, and location and quantified between unilateral and bilateral agenesis. Descriptive and comparative statistical analysis were performed with t-test and Chi-square test (p < 0.05). (4) Results: permanent teeth agenesis, excluding third molars, was found in 326 individuals (11%), 139 males (43%) and 187 females (57%). Of them, 59% were missing in the maxilla and (41%) were missing in the mandible. A higher prevalence rate of bilateral missing lateral incisors in the maxilla (62 cases), followed by bilateral missing second premolars in the mandible (44 cases) compared with unilateral missing teeth. (5) Conclusions: this study found an overall prevalence of missing permanent teeth in orthodontic patients to be 11%. The female: male prevalence ratio was roughly 3:2, with a greater tendency in the maxilla than in the mandible. A higher prevalence of bilateral missing maxillary lateral incisors and mandibular second premolar than unilateral missing teeth

Mandibular Second Molar Impaction-Part II: Etiology and Role of the Third Molar

(1) Introduction: Mandibular second molar (MM2) impaction is a relatively rare dental anomaly, but its early detection is imperative for orthodontic diagnosis and treatment. This study evaluates early radiographic characteristics of MM2 in the process of its impaction and the role of the third molar (MM3) in this process. (2) Materials and Methods: Panoramic radiographs of orthodontic patients of Chinese-American origin (n = 5575), age 9&ndash;15 years (mean 13.13) were examined for MM2 impactions and the presence of MM3. (3) Results: A total of 151 patients with 212 impacted MM2s were detected in the Chinese-American study group. Unilateral impactions were found more than bilateral and were distributed equally between the left and right sides. Mesial angulation of the impacted teeth was present in 92.7% of the cases, and MM3s were found adjacent to the impacted MM2s in 97.4% of the cases. (4) Conclusions: MM2 differential root developments with deficient mesial root lengths appeared to be the primary cause for MM2 impaction. Posterior crowding and arch length deficiency were contributing factors causing MM2 impaction. This impaction occurred early, before the third molar bud was developed. It sometimes occurred even when the third molar was congenitally missing. Nevertheless, the possible involvement of the third molar in MM2 impaction needs further investigation

Mandibular Symmetrical Bilateral Canine-Lateral Incisors Transposition: Its Early Diagnosis and Treatment Considerations

Bilateral mandibular tooth transposition is a relatively rare dental anomaly caused by distal migration of the mandibular lateral incisors and can be detected in the early mixed dentition by radiographic examination. Early diagnosis and interceptive intervention may reduce the risk of possible transposition between the mandibular canine and lateral incisor. This report illustrates the orthodontic management of bilateral mandibular canine-lateral incisor transposition. Correct positioning of the affected teeth was achieved on the left side while teeth on the right side were aligned in their transposed position. It demonstrates the outcome of good alignment of the teeth in the dental arch

Mandibular Second Molar Impaction-Part II: Etiology and Role of the Third Molar

(1) Introduction: Mandibular second molar (MM2) impaction is a relatively rare dental anomaly, but its early detection is imperative for orthodontic diagnosis and treatment. This study evaluates early radiographic characteristics of MM2 in the process of its impaction and the role of the third molar (MM3) in this process. (2) Materials and Methods: Panoramic radiographs of orthodontic patients of Chinese-American origin (n = 5575), age 9–15 years (mean 13.13) were examined for MM2 impactions and the presence of MM3. (3) Results: A total of 151 patients with 212 impacted MM2s were detected in the Chinese-American study group. Unilateral impactions were found more than bilateral and were distributed equally between the left and right sides. Mesial angulation of the impacted teeth was present in 92.7% of the cases, and MM3s were found adjacent to the impacted MM2s in 97.4% of the cases. (4) Conclusions: MM2 differential root developments with deficient mesial root lengths appeared to be the primary cause for MM2 impaction. Posterior crowding and arch length deficiency were contributing factors causing MM2 impaction. This impaction occurred early, before the third molar bud was developed. It sometimes occurred even when the third molar was congenitally missing. Nevertheless, the possible involvement of the third molar in MM2 impaction needs further investigation