Australian Orthodontic Journal最新文献

Aim: This case report describes the treatment of a patient of African descent with bilateral congenitally missing mandibular incisors and a 10 mm overjet.

Methods: The article discusses the incidence of tooth agenesis and the different approaches to treating patients with bilateral congenitally missing lower incisors. The current treatment involved lower canine substitution for the lower lateral incisors and upper premolar extractions because of malformation. Temporary micro-implants were placed to augment anchorage and to resolve the excessive overjet by the retraction of the upper anterior teeth while preserving a Class I molar relationship.

Results: The Bolton disharmony created by the incisor agenesis and the extraction pattern proved to be a challenge and although an acceptable result was achieved, it was expectedly less than ideal.

Objective: This case report presents short and long-term treatment results of a unilateral cleft lip and palate patient treated with a modified intra-oral tooth-bone borne distraction appliance.

Materials and methods: The chief complaints of a 16 year-old, unilateral cleft lip and palate patient were poor facial aesthetics, crowding and a fistula. Severe maxillary retrognathism was treated via distraction osteogenesis of the maxilla and performed using an intra-oral tooth-bone borne appliance. Treatment continued to completion with a multibracket system. At an eight-year review following the distraction procedure, the short and long-term results were determined cephalometrically.

Results: Following the distraction, A-point advanced 7 mm, 2 mm of which relapsed during fixed appliance treatment. At the end of the active treatment, the patient's skeletal and dental Class III relationship improved to Class I, which was preserved at the long-term review. The profile was markedly improved by the distraction osteogenesis.

Conclusion: In cases of severe maxillary retrognathism as a result of a cleft lip and palate, maxillary distraction osteogenesis provides a viable alternative to orthognathic surgery.

Objective: The purpose of this study was to evaluate the effects of four premolar extractions and orthodontic treatment on changes to the lips and vermilion height during a posed smile.

Methods: Fifteen female patients who were diagnosed with bimaxillary protrusion and treated with four premolar extractions were selected. The control group consisted of 25 female volunteers with a normal occlusion. Frontal photographs of the patients during a posed smile were taken before and after orthodontic treatment. Thirty-five landmarks on the upper and lower lips were identified and used to generate measurements of lip area and vermilion height. Linear and angular cephalometric measurements were also obtained.

Results: The mean values for vermilion height and lip form before orthodontic treatment were significantly larger in the treatment group compared with those of the control group. Following treatment, values significantly decreased to the extent that there was no significant difference in the vermilion height and lip form between the post-treatment and control groups. Only three and four significant correlations were found between the changes in incisor position and changes in vermilion height and lip area for the upper and lower lips, respectively.

Conclusions: The vermilion height and lip area in patients with bimaxillary protrusion approached comparative and normal values as a result of four premolar extractions and orthodontic retraction.

Introduction: The impaction of permanent teeth poses a challenge to orthodontists, especially when posterior teeth are involved. Multiple impacted posterior teeth without associated with systemic conditions/syndromes is an uncommon clinical occurrence which leads to a posterior open bite and severely compromised function.

Aim: The present article reports the clinical management of an impacted maxillary second premolar, mandibular premolars and mandibular first and second molars on the right side.

Method: The premolars were guided into occlusion by orthodontic traction. Disimpaction and uprighting of the mandibular first molar were achieved using a Begg uprighting spring while a T-loop was used to correct the second molar. Absolute anchorage in the form of miniscrews was not required as anchorage demands were minimal. The total treatment time was 24 months.

Results: Orthodontic mechanics resolved a demanding clinical problem and eliminated the need for prosthetic replacements. An acceptable occlusion with a Class I molar relationship, normal function and a healthy periodontium were achieved.

Conclusion: The results indicated the benefits of uprighting multiple impacted teeth through orthodontic treatment.

Measuring tooth widths is a key component of orthodontic treatment planning. Over recent decades, many methods have been proposed to achieve this purpose. The current review highlights and describes the initial techniques. The evidence behind their use is presented along with a brief discussion of their benefits and shortfalls. With knowledge and understanding of the accuracy and limitations of the various measurement methods, the clinician may be better informed and therefore able to select the most appropriate method for clinical practice.

Aim: The mesiodistal widths of the maxillary and mandibular teeth and anterior and overall tooth size ratios were measured by CBCT and conventional orthodontic plaster methods, compared, and correlation coefficients for both methods determined.

Material and methods: The records of 26 patients (14 males and 12 females) between the ages of 18 and 28 years were randomly selected from the archives of the Oral Diagnosis, Radiology and Orthodontic Departments at the Karadeniz Technical University. The mesiodistal diameters of the maxillary and mandibular permanent teeth from first molar to first molar were measured on the patient's plaster models and also on CBCT arch renditions. Anterior and overall Bolton ratios were calculated for each method. Comparisons were performed using Pearson's correlation coefficient (PCC).

Results: The measurements of the mesiodistal widths of most maxillary and mandibular teeth were similar and consistent between the conventional and CBCT methods. PCC values ranged from 0.637 (mandibular right second premolar) to 0.916 (maxillary right canine). PCC values for anterior and overall ratios were 0.756 and 0.781, respectively, indicating that correlations between conventional and CBCT methods were acceptable.

Conclusion: Dental measurements and anterior and overall Bolton ratios calculated on CBCT showed acceptable PCC values indicating that CBCT measurements could be used instead of those obtained from conventional plaster models.

It is suggested that lingually-positioned lower lateral incisors in young children are anatomically correct and not a symptom of crowding. Primary canines with intact periodontal attachments have an important role to play as proprioceptors to encourage growth of the alveolar arch. Extractions of primary cuspids would deprive the alveolus of important growth stimuli. Clinical evidence suggests that serial extraction is counter-productive. The early extraction of primary cuspids will invariably result in crowding of the permanent cuspids. It is a common belief that serial extraction corrects the crowding of lower incisors but the procedure is not evidence based. In reality, the problem is maintained and the 'crowding' shifts to involve the permanent cuspids. Let us not forget the most basic canon of the health profession which is 'first do no harm, and if it is not broken, do not try to fix it'.

The essential feature of paediatric sleep-disordered breathing (SDB) is increased upper airway resistance during sleep presenting clinically as snoring. Paediatric SDB is a continuum ranging from primary snoring (PS), which is not associated with gas exchange abnormalities or significant sleep fragmentation, to obstructive sleep apnoea (OSA) with complete upper airway obstruction, hypoxaemia, and obstructive hypoventilation. Adenotonsillar hypertrophy, obesity and craniofacial disharmonies are important predisposing factors in the development and progression of paediatric SDB. Clinical symptoms are significant and domains affected include behaviour, neurocognition, cardiovascular morbidity and quality of life. Overnight polysomnography is the current diagnostic gold standard method to assess SDB severity while adenotonsillectomy is the recommended first line of treatment. Other treatments for managing paediatric SDB include nasal continuous airway pressure, the administration of nasal steroids, dentofacial orthopaedic treatment and surgery. However, there are insufficient long-term efficacy data using dentofacial orthopaedics to treat paediatric SDB. Further studies are warranted to define the characteristics of patients who may benefit most from orthodontic treatment.