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Generating Labial Bone for an Orthodontic Implant 

Orthodontics - February 15, 2014 - Vol. 28 - No. 2

Labial bone may be created for an implant by orthodontic lingual movement.

Background: In cases where nonrestorable teeth are to be replaced by implants and there is inadequate bone for the implants, orthodontics has been shown to be an effective method to enhance bone support. The technique of orthodontically extruding a nonrestorable tooth typically decreases the socket diameter and depth with bone apposition in the interproximal and periapical areas adjacent to the orthodontically extruded tooth. Extrusion has also been shown to increase the zone of attached keratinized gingival tissue. The end result is that a better environment is created for an immediate implant placement. At times, labial bone is lacking, and extrusion has not been shown to be effective in adding bone in that dimension. Is there a way to modify the orthodontics to enhance the alveolus labially?

Objective: To orthodontically develop bone apically and labially at the potential implant site.

Design/Methods: This was a clinical report of a single case in which the typical orthodontic extrusion technique was altered to apply both an extrusive force and a lingual force to the nonrestorable tooth. The subject was a 41-year-old male with a nonrestorable maxillary right central incisor. The unrestorable tooth was extruded and moved lingually with fixed appliances for 5 months. The tooth was extracted and an immediate implant was placed. A graft was also placed on the labial using guided bone regeneration techniques. Four years later, a cone beam CT was taken to evaluate the tissues surrounding the implant.

Results: The additional labial bone remained intact, and the implant was judged to have an excellent long-term prognosis. The increased gingival thickness on the labial aspect and the improved tissue biotype were also maintained.

Conclusions: The volume and height of the labial bone and labial gingival tissue and biotype were enhanced. The osseous site for a guided bone regeneration technique is improved by this technique.

Reviewer's Comments: Even though this was a single case report, the authors suggested that additional bone generation on the labial can occur by orthodontic movement to the lingual. This technique is potentially very useful clinically, as occasionally the alveolar bone is inadequate for proper implant placement. I look forward to additional and ideally long-term reports on this interesting technique.(Reviewer–John S. Kanyusik, DDS, MSD).

 © 2013, Oakstone Publishing, LLC

 Orthodontics - September 30, 2013 - Vol. 27 - No. 9

Autotransplantation is a technique that, when performed with established protocols, is a highly successful procedure that is well-accepted by the patient.

Article Reviewed: Survival and Success Rates of Autotransplanted Premolars: A Prospective Study of the Protocol for Developing Teeth. Plakwicz P, Wojtowicz A, et al: Am J Orthod Dentofacial Orthop; 2013;144 (August): 229-237.

Objective: To examine the predictability of the protocol for premolar autotransplantation when applied by an inexperienced surgeon.

Participants: 19 patients with 23 consecutively transplanted developing premolars.

Methods: In addition to the main objective, the hard and soft tissues of the transplanted teeth were compared to control premolars. Patients' perceptions of the procedure were also assessed following the surgical procedure. Mean patients age at surgery was 12 years 8 months (range, 9 years 10 months to 17 years). Mean observation time was 35 months (range, 6 to 78 months). Plaque accumulation, pocket depth, gingival recession, mobility, and pulp sensitivity were recorded for the transplanted and control teeth. Standardized radiographs were used to examine hard tissues and crown-to-root ratios. Questionnaires were used to register each patient's opinion about the treatment and its outcome.

Results: Survival rate of the transplanted premolars was 100%, and the success rate was 91.3%. Of transplanted teeth, 2 were categorized as not successful with 1 having a less than ideal crown-to-root ratio and the other was ankylosed. No significant differences in plaque accumulation, gingival height, mobility, and pocket depths were recorded between the autotransplanted teeth and controls. Electronic pulp testing the teeth did not find a significant difference between samples. Crown-to-root ratios were found to be 11% smaller in transplanted teeth than controls. Transplanted teeth generally exhibited various degrees of pulp obliteration and normal lamina duras on post-surgical evaluation. Patients' perceptions of the surgical management and treatment outcomes were favorable.

Conclusions: The protocol for autotransplantation of developing premolars in growing patients was successfully adopted. Soft and hard tissues of transplanted premolars were generally not significantly different than controls. Patients who had the procedure generally responded favorably when surveyed about the surgery and outcome.

Reviewer's Comments: Autotransplantation is a highly successful procedure provided proper established protocols are followed. The technique is not utilized as extensively in the U.S. as in Europe. The article did not elaborate on the protocols although they are referenced in the article. With a mean observation time of 35 months (range, 6 to 78 months) it would be interesting to evaluate these patients at longer intervals to determine if any differences between controls develop in time.(Reviewer–John Kanyusik, DDS, MSD).

 © 2013, Oakstone Publishing, LLC

Orthodontics - September 30, 2013 - Vol. 27 - No. 9

Unilateral functional crossbite causes facial asymmetry of the mandible, which becomes worse with time.

Article Reviewed: Three-Dimensional Evaluation of Facial Asymmetry in Association With Unilateral Functional Crossbite in the Primary, Early, and Late Mixed Dentition Phases. Primozic J, Perinetti G, et al: Angle Orthod; 2013;83 (March): 253-258.

Background: When a child presents with a unilateral posterior crossbite and functional shift of the mandible, an orthodontist must decide whether to treat that problem early, thus producing 2 phases of orthodontic treatment, or to simply wait and treat the crossbite when all permanent teeth have erupted. Is there any advantage to preventing further asymmetry of the face by treating the child earlier?

Objective: To consider the degree of facial asymmetry using 3-dimensional laser scanning methodology in growing subjects according to their dentition phase when a unilateral functional crossbite is present.

Design: Observational study.

Methods: The authors assembled a sample of 234 Caucasian children between ages 4 and 12 years. One-third of the sample had posterior unilateral functional crossbites with a shift of the mandible. The other two-thirds of the sample had no malocclusion. They were divided into dentition stages of primary, early mixed, and late mixed dentition. The authors used 3-dimensional laser scanning technology to produce a color map of the face of each child to determine the position and amount of facial asymmetry. They then quantitatively compared the degree of facial asymmetry at these different stages of dental development.

Results: Facial asymmetry of the mandible was prominent and prevalent at all dentition stages. Interestingly, asymmetry of the middle portion of the face, the maxilla, was apparent and more prominent after the primary dentition and in the early mixed dentition.

Conclusions: Facial asymmetry of the mandible is consistently present in patients who have a functional crossbite; however, asymmetry of the maxilla begins to occur in the early mixed dentition.

Reviewer's Comments: My conclusions from this study are that if one wants to avoid compensatory changes in the maxilla from a functional crossbite, then one should resolve the crossbite and eliminate the functional shift before the patient gets to be late mixed dentition. This would suggest that children with posterior functional crossbites should receive an early phase of treatment to correct the crossbite and avoid alterations in the maxilla that can occur with time.(Reviewer–Vincent G. Kokich, Sr, DDS, MSD).

 © 2013, Oakstone Publishing, LLC

Current Evidence for Ethical Treatment of TMD

Diagnosis and Treatment of Temporomandibular Disorder: An Ethical Analysis of Current Practices.

Reid KI, Greene CS:

J Oral Rehabil 2013; 40 (July): 546-561

The current literature supports conservative and reversible treatment for temporomandibular disorders, with expensive and invasive changes to the occlusion and jaws showing no additional benefits in most patients.

Article Reviewed: Diagnosis and Treatment of Temporomandibular Disorders: An Ethical Analysis of Current Practices. Reid KI, Greene CS: J Oral Rehabil; 2013;40 (July): 546-561.

Background: Clinical management for temporomandibular disorders (TMDs) varies widely based on the training and treatment philosophies of different dentists, ranging from inexpensive and conservative techniques to costly and invasive treatment for the same symptoms.

Objective: To suggest an ethical framework for the treatment of TMDs based on current scientific literature.

Design: Retrospective review.

Methods: The methodology for article selection was not described, but 131 current scientific articles found on PubMed (November 9, 2009) were included.

Results: The current literature has repeatedly shown that TMDs are often self-limiting and generally not progressive (although symptoms may fluctuate over time). Cases most frequently occur in women between 15 and 45 years of age. Occlusion, maxillomandibular relationships, condylar position, and other structural factors generally do not cause TMD. Additional diagnostic aids such as electromyography and electronic jaw tracking have not been found to have the sensitivity and specificity to add diagnostic value. Many patients have been shown to have significant improvement in TMD solely by proper explanation of the issue, good pain management, home self-care, and possibly splint therapy. This biopsychosocial medical model for treatment differs greatly from many older invasive treatment techniques, such as occlusal equilibration, orthodontic treatment, bite opening, prosthodontic treatment, or surgical intervention. These techniques are based on the belief that static and dynamic occlusion relationships are the primary etiological factors of TMD, which is not supported by the current literature.

Conclusions: Multiple systematic review articles have shown that conservative and reversible management of TMDs can successfully treat most cases. There is no evidence to justify routine initial treatments that are invasive, irreversible, and expensive. With this evidence, the ethical principles of respect for patient autonomy and non-malfeasance support proper patient education about current scientific evidence and providing conservative, reversible initial treatment for TMD.

Reviewer's Comments: As orthodontists, we routinely work to create ideal occlusion, and it can be difficult to see a malocclusion and not associate it with a patient's TMD. This article has some very nice tables summarizing the evidence of multiple systematic reviews. When considering this evidence, it is hard to justify orthodontic treatment as a first line of care in cases in which TMD is the only concern.(Reviewer–Brent E. Larson, DDS, MS).

© 2013, Oakstone Publishing, LLC