Segmental alveolar distraction for the correction of unilateral open-bite caused by multiple ankylosed teeth: a case report

How do teeth erupt?

The development of normal occlusion requires eruptive migration of teeth from their developmental position in the jaw into a functional position within the oral cavity. This process involves significant and coordinated movement in an axial direction and appropriate eruption through the gingival tissues. The mechanisms regulating these developmental events are poorly understood, and teeth retain eruptive potential throughout their lifespan. In recent years, the use of mouse models has helped to elucidate some of the underlying molecular and biological mechanisms of mammalian tooth eruption. Here, we outline our current understanding of tooth eruption mechanisms and discuss their relevance in terms of known human disorders of tooth eruption.

Camouflage Correction of Skeletal Class III Severe Open Bite with Tooth Ankylosis Treated by Temporary Anchorage Devices: A Case Report

Tooth ankylosis is a disorder characterized by the fusion of tooth and alveolar bone. This case report describes the treatment of a severe open bite due to tooth ankylosis. A 14-year-old female patient with a chief complaint of masticatory dysfunction was diagnosed with skeletal Class III severe anterior open bite and tooth ankylosis. She visited our university hospital with a chief complaint of an anterior open bite. After the surgical luxation of the ankylosed maxillary right central incisor, the tooth was orthodontically retracted using a nickel-titanium wire. The right mandibular lateral incisor and canine were luxated and retracted using intermaxillary elastics from a temporary anchorage device (TAD), which was inserted in the opposite jaw. During the treatment, skeletal Class III malocclusion deteriorated due to anterior growth of the mandible. Therefore, TADs were inserted into the retromolar pad on both sides of the mandible and retracted into the mandibular dental arch. Although the mandibular right canine was luxated several times, it could not be brought to the occlusal line, and was thus extracted; the extraction space was replaced with a prosthesis. Consequently, a normal overjet and overbite with a straight profile were achieved. Extrusion of ankylosed teeth by intermaxillary elastics from a TAD is a valid treatment option for patients with severe open bites.

Primary failure of tooth eruption: Etiology and management

Primary failure of eruption (PFE) is a rare disorder defined as incomplete tooth eruption despite the presence of a clear eruption pathway. PFE is known to be caused by rare variants in the parathyroid hormone 1 receptor gene (PTH1R). Although several PTH1R variants have been reported, the etiology of PFE remains unclear. However, important studies that help elucidate the pathology of PFE have recently been published. The purpose of this review is to summarize current treatment options, clinical symptoms or phenotypes for diagnosis, genetic information including solid evidence in mouse disease models and disease-specific induced pluripotent stem cells, thus approaching the etiology of PFE from the perspective of the latest research.

Miniscrew-assisted single-tooth distraction osteogenesis to align an ankylosed infraoccluded maxillary central incisor: A case report

The ankylosis of permanent incisors is usually caused by trauma. In a growing patient, the ankylosed tooth fails to move along with the vertical growth of the remaining alveolar process, which results in an infraoccluded tooth, gingival margin disharmony and unaesthetic smile.This case report presents an 23-year-old female patient whose maxillary right central incisor (tooth number 11) had been traumatised eight years earlier. A vertical discrepancy of about 4 mm was exhibited between teeth 11 and 12. To reposition the crown and gingival margins of the ankylosed tooth to an ideal level, single-tooth dento-osseous osteotomy and distraction of the block of bone containing the tooth was planned. In order to separate the roots of adjacent teeth for opening a space for osteotomy incision, fixed orthodontic treatment with multibracket appliances was initiated on her maxilla. After five weeks, a single-tooth dento-osseous osteotomy was performed using a piezoelectric device. To move the tooth in occlusal and buccal directions, two temporary anchorage devices (miniscrews) on her mandible and interarch elastics were applied. Approximately three weeks later, the ankylosed tooth successfully had an ideal position-relative to the adjacent teeth-and a harmonious gingival margin was achieved by minor gingivoplasty on all incisors.

Front-block technical note: dental and bone borne distractors

Orthognathic surgical technique of segmental osteogenesis distraction of the anterior mandible alveolar process (front-block) was introduced by Triaca and al. in 2001 [2] including lower incisors. The technical note describes distraction process used both, dental-borne distractor and bone-borne distractor. A genioplasty plate was used as a bone-borne distractor. The main point here is that distraction depends on two distraction vectors, a dental one and an alveolar one. It provides good stability and controlled segmental osteogenesis translation and allows sufficient alveolar segmental transport without loading the teeth too heavily.

Failure of eruption of permanent molars: a diagnostic dilemma

BACKGROUND

Limited studies have proposed protocols for the management of failure of eruption (FOE) of permanent molars with no clear consensus or guidelines. Accurate diagnosis is challenging but key for successful management.

AIMS

Confirm key diagnostic criteria that will aid diagnostic differentiation between primary failure of eruption (PFE) and mechanical failure of eruption (MFE) of permanent molars and identify successful management strategies.

DESIGN

Retrospective descriptive study. Patients diagnosed with FOE of permanent molars (excluding impaction) between January 2003 and December 2013 were identified. Patient details and clinical and radiological features of FOE were recorded. Two examiners analysed the data. A diagnosis of PFE or MFE was made based on a combination of current protocols. Management strategies for each were identified and reported as satisfactory/unsatisfactory.

RESULTS

Thirty-one patients met the inclusion criteria. Fifteen were classified as PFE and 14 as MFE. One patient was too young to confirm diagnosis, and one patient had delayed eruption. A total of 26% of cases were misdiagnosed which led to unsuccessful orthodontic management.

CONCLUSION

We propose a protocol based on the results of this study coupled with existing protocols in the form of a simple flow diagram to aid accurate diagnosis and management of this rare and challenging clinical problem.

Algorithm for the differential diagnosis of posterior open bites: two illustrative cases

PURPOSE

Posterior open bites can result from several causes: trauma, degenerative changes, tongue thrust habits, single-tooth ankylosis, multiple-tooth ankylosis, and/or condylar hyperplasia. Occasionally, posterior open bites are secondary to a combination of condylar hyperplasia and dental ankylosis, which can be difficult to diagnose and treat because of the large array of causative problems.

MATERIALS AND METHODS

This article presents 2 unusual cases of posterior open bite secondary to multiple etiologies in adolescent male patients. A useful method of algorithmic diagnosis, treatment, and protocol is presented that was used for these cases.

RESULTS

The 2 cases were successfully diagnosed and treated using the formulated algorithm for posterior open bites.

CONCLUSIONS

The algorithms presented facilitate the differential diagnosis of posterior open bites with ambiguous etiology.

Ankylosis of permanent first molars: genetics or environment? A case report of a discordant twin pair

The rare condition of secondary retention has been reported in the literature as being of genetic origin, with some authors suggesting an autosomal dominant pattern. We report the unusual case of two monozygotic biamniotic, bichorionic male twins, who were discordant for permanent first molar secondary retention, involving ankylosis. Twin A showed normal occlusion and eruption patterns, whereas Twin B displayed a left open bite, in relation with a totally submerged primary second molar leading to retention of the underlying premolar (35), and severe infraocclusion of the adjacent permanent molar (36). After orthodontic failure to close the open bite, ankylosis of 36 was confirmed, whereas 26 became severely infraoccluded.The mother had a history of bilateral molar ankylosis and presented reduced posterior alveolar height. Discordance in this twin pair demonstrates that environmental influences, in addition to epigenetic and local factors, may play a role in secondary retention, which is difficult to diagnose and challenging to treat.

Orthosurgical treatment including anchorage from a palatal implant to correct an infraoccluded maxillary first molar in a young adult

Tooth ankylosis during adolescence and early adulthood can lead to infraocclusion and several interrelated, adverse sequelae at the intra-arch and interarch levels. An orthosurgical treatment modality that includes surgical luxation and immediate orthodontic traction is recommended as a conservative approach in many patients. The key to success in this approach is the timely delivery of relatively heavy and continuous forces to the luxated tooth to prevent its reankylosis. Because high reactive forces are inevitably generated, it is crucial to create a reliable source of anchorage. This report describes the successful use of an osseointegrated orthodontic implant to reinforce the anchorage during the orthosurgical repositioning of an infraoccluded molar in a young adult.

Vertical periodontal ligament distraction--a new method for aligning ankylosed and displaced canines

OBJECTIVE

In the course of a clinical pilot study we tested the vertical periodontal ligament (V-PDL) distraction as a means of aligning ankylosed upper canines. The objective of this study was to analyze the appropriateness und effectiveness of this method.

METHOD AND MATERIALS

The ankylosed upper canines of five female patients aged between 16 und 19 years were surgically exposed, luxated, and after a latency period of 5 to 7 days, distracted at a rate of 0.5 mm per day. The installed distractors were borne by the periodontal-mucosa, the periodontal-mucosa and the bone, or by the bone exclusively. We evaluated the distraction distance and time and degree of hard and soft tissue generation present in the region surrounding the distracted teeth.

RESULTS

All canines were aligned after a mean distraction period of 43.2 days (+/- 3.6 days). The mean distraction distance was 10.8 mm. Three canines had defects at the cemento-enamel junction, and one canine had to be extracted due to a large defect at the root.

CONCLUSIONS

Vertical PDL distraction is a minimally-invasive therapy to align ankylosed impacted canines. Even if the long-term prognosis of distracted canines with defects is uncertain, the patient benefits from the vertical PDL distraction because both hard and soft tissues are generated in the vicinity of the distracted canine.

Severe lateral open bite caused by multiple ankylosed teeth: a case report

Multiple ankylosed teeth in a dental arch is rare and occasionally causes severe open bite. This article describes a case of severe lateral open bite caused by multiple ankylosed teeth. The patient was a 31-year-old female and her chief complaint was inadequate masticatory function on the right side. All the maxillary right teeth exhibited infraocclusion. The maxillary right first molar showed partial impaction and the maxillary and mandibular right second molars were completely impacted, although on the left side these teeth had fully erupted. CT images revealed unclear periodontal space between the alveolar bone and roots of the maxillary teeth from the incisor to the first molar on the right. To improve the masticatory function, a removable prosthetic appliance was applied to the maxillary arch. Prosthetic rehabilitation may be an effective alternative to surgical procedures such as distraction osteogenesis of the alveolar bone and subluxation of the ankylosed teeth.