Joe Rebellato

Skeletal and dental contributions to posterior crossbites.

The objective of this retrospective study was to compare skeletal and dental arch morphology of children with posterior crossbites with a control group of children without posterior crossbites. The study included 93 patients with a posterior crossbite (33 boys and 60 girls) and 97 patients without a posterior crossbite (50 boys and 47 girls). Skeletal and dental characteristics between the two groups were compared using measurements of dental casts, and lateral and posteroanterior cephalograms. Univariate analyses revealed that seven characteristics were significantly different between the crossbite and non-crossbite groups: mandibular plane angle, lower face height, skeletal maxillary to mandibular width ratio, maxillary intermolar width, mandibular intermolar width, maxillary to mandibular intermolar width ratio, and mandibular unit length. Using maxillary to madibular intermolar width ratio as the outcome measure, a stepwise variable selection technique, analyzed all 190 patients and found only two variables significantly associated with this measure: skeletal maxillary to mandibular width ratio and lower face height. The coefficient of multiple determination for this model was only 13%, indicating that these two variables accounted for only a small portion in the variation of the ratio between the maxillary and mandibular intermolar widths.

CONDYLAR POSITIONAL CHANGES AFTER MANDIBULAR ADVANCEMENT SURGERY WITH RIGID INTERNAL FIXATION

The purpose of this retrospective investigation was to describe condylar positional changes in patients after mandibular advancement surgery. By superimposing on clearly identifiable cephalometric landmarks (ie, mandibular symphysis and rigid fixation screws), condylar positional changes from immediately after surgery to orthodontic appliance removal were extrapolated. Although the mandibular symphysis generally moved in either an anterior or posterior direction after surgery, condylar movements were exclusively in an upward vertical direction. Correlations were found between several measured variables, including a tendency for increased superior postsurgical movement of the condyles with increasing magnitudes of surgical advancement of the mandible. This long-term instability of skeletal relationships may be caused by a wide variety of interacting factors and events.

Treatment of a patient with an impacted transmigrant mandibular canine and a palatally impacted maxillary canine.

Very few people have seen transmigrant mandibular canines and little has been presented in the literature about this rare phenomenon. In this case report, identification techniques and treatment options are presented along with the treatment results of a patient diagnosed with a transmigrant mandibular canine. This rare condition usually requires extraction of the involved tooth because orthodontic forces are seldom successful at erupting these teeth into their proper location. The treatment protocol for this patient involved a combination of orthodontic procedures, surgical extractions, gingivectomy and frenectomy, and implant replacement of the impacted transmigrant tooth. Through a collaborative effort of a team made up of an orthodontist, periodontist, prosthodontist, and oral surgeon, these techniques were used to achieve an excellent esthetic and functional outcome.

Congenitally missing mandibular second premolar: treatment outcome with orthodontic space closure.

Orthodontic treatment for patients with congenitally missing mandibular second premolars can be challenging. Treatment options include keeping the deciduous second molar, extracting the molars and allowing the space to close spontaneously, autotransplantation, prosthetic replacement, and orthodontic space closure. Space closure with orthodontic appliances is demonstrated in this case report.