Eruption Of Posterior Teeth Research Articles

Three years of follow-up of otodental syndrome in 3-year-old Chinese boy: a rare case report

BackgroundOtodental syndrome is an exceptionally rare autosomal dominant condition characterized by a delayed eruption of posterior teeth, globodontia, lisping, and sensorineural hearing loss. In this case report, we reported a 3-year-old Chinese boy with the otodental syndrome.Case presentationA 3-year-old Chinese boy was referred to our hospital with complaint of no eruption of primary canines and molars. Three years follow-up showed lately erupted bulbous primary canines with hypoplastic enamel spot, globe-shaped primary molars and sensorineural hearing loss at 4 and a half-year-old age. We diagnosed otodental syndrome in the patient’s mother with hearing loss at 16-year-old age. Gene sequencing and analysis of deafness-related genes GJB2, GJB3, SLC26A4, and mtDNA did not reveal any mutation or SNPs in the patient and his mother.ConclusionsThis case report highlights the importance of detailed medical, dental, and family history examination, as well as multi-disciplinary teamwork for diagnosis and treatment of otodental syndrome.

Eruption of posterior teeth in the maxilla and mandible for age determination of water deer

ObjectiveEruption of posterior teeth, including premolars and molars in the mandible rather than in the maxilla, is accepted as an accurate reference for age determination of deer. In water deer, Hydropotes inermis, the eruption age of mandibular molars has been described in two studies, but the ages were inconsistent with each other. In this study, we aimed to confirm the eruption age of mandibular posterior teeth for the accurate age determination of water deer and to evaluate the efficacy of maxillary posterior teeth for the age determination of deer. DesignThe eruption of mandibular and maxillary posterior teeth was investigated in the dry skulls of individual wild water deer of both sexes, up to an age of about 15 months. ResultsThe eruption age of mandibular molars in water deer was consistent with that of a previous study. The eruption age of posterior teeth was almost the same in the maxilla and mandible of individual water deer. The deciduous mandibular fourth premolar and the permanent maxillary fourth premolar were two easiest teeth to be identified for the age determination. ConclusionsThe former controversial eruption age of mandibular posterior teeth in water deer was confirmed. Our study first presented the eruption age of maxillary posterior teeth in water deer. It is suggested that posterior teeth not only in the mandible but also in the maxilla are useful indicators for the age determination of water deer.

Failure of eruption of posterior teeth

Failure of eruption of posterior teeth is rare but has significant clinical implications. There has been a recent re-classification of failure of eruption based on aetiology and presentation. Primary failure of eruption (PFE) affects all teeth distal to the affected tooth and can result in a significant posterior open bite. Mechanical failure of eruption (MFE) is due to ankylosis and the teeth distal to the affected tooth are not affected. Early diagnosis and differentiation between PFE and MFE is essential to ensure that the correct treatment is provided. Two cases are shown that demonstrate MFE. Clinical Relevance: This article reviews the aetiology for non-eruption and identifies the differences between PFE and MFE.

Severe anterior open-bite case treated using titanium screw anchorage.

Anterior open bite is often caused by a downward rotation of the mandible and/or by excessive eruption of the posterior teeth. In such cases, it is difficult to establish absolute anchorage for molar intrusion by traditional orthodontic mechanics. This article reports the successful treatment of a severe skeletal anterior open-bite case using titanium screw anchorage. A female patient 33 years eight months of age had open bite of -7.0 mm and increased facial height. The titanium screws were implanted in both the maxilla and the mandible, and an intrusion force was provided with elastic chains for 13 months. After active treatment of 19 months, her upper and lower first molars were intruded about 3.0 mm each, and good occlusion was achieved. Her retrognathic chin and convex profiles were improved by an upward rotation of the mandible. Our results suggest that titanium screws are useful for intrusion of molars in anterior open-bite cases.