Surgically assisted palatine expansion in adult patients: evaluation of a conservative technique

Linear analysis of the nasal septum in patients treated with surgically assisted rapid maxillary expansion

INTRODUCTION

Surgically assisted rapid maxillary expansion is a widely used surgical procedure for resolving transverse maxillary occlusal changes in patients with bone maturity. However, few studies about the postoperative morphologic alterations in the nasal cavity in its inferior portion and the nasal septum positioning exist.

METHODS

The linear nasal septum measurements of 26 adult patients treated with surgically assisted rapid maxillary expansion from 2009 to 2013 were assessed through a retrospective analysis of cone-beam computed tomographies, in Digital Imaging and Communications in Medicine files, through the Dolphin Imaging program (Dolphin Imaging and Management Solutions, Chatsworth, Calif), aimed to identify significant changes during 3 time periods of the treatment: preoperative, immediately after the palatal expansion device locking (immediate postoperative), and 6-months postoperative (late postoperative). The analyses were performed in the inferior third of the nasal septum, from 4 equidistant points in anteroposterior position and height, using fixed cranial references for lateral measures of displacement.

RESULTS

No significant difference was found between preoperative, immediate postoperative, and late postoperative measurements in the 4 fixed nasal septum measurements, applying the analysis of variance test with a significance level of 5%. Comparing the surgical times alone, we found no statistically significant difference between the right and left sides applying the Student t test, which also showed symmetry in the nasal septum.

CONCLUSIONS

The measurements of the nasal septum did not change in the different surgical times throughout their inferior extension, and they remained symmetrical throughout patients' follow-up period.

Transverse changes after surgically assisted rapid palatal expansion

The aim of this retrospective study was to investigate the amount of skeletal and dental expansion in patients submitted to surgically assisted rapid palatal expansion (SARPE). The sample consisted of 21 patients (14 female and seven male) with a mean age of 25.4 years (range 17.4-41.8 years). Postero-anterior (PA) cephalograms were taken pre-expansion (T1), immediately after expansion (T2), and at post-expansion retention of 120 days (T3). SARPE promoted significant transverse skeletal changes, which were maintained from T2 to T3. Dentoalveolar expansion and dental tipping were also observed in the region of the first molars and first premolars; however the net effect at the first molars was significantly less than that at the first premolars. No statistically significant effect on the width of the nasal cavity was observed. The findings indicate that peculiarities inherent to dental effects may influence the clinical options for SARPE. Skeletal expansions with SARPE were significant and stable. Dental changes were different between molars and premolars. The transverse changes after SARPE should be observed for future procedures related to the retention and the completion of orthodontic treatment.

Photoelastic analysis of stress distribution of surgically assisted rapid maxillary expansion with and without separation of the pterygomaxillary suture

PURPOSE

The aim of this study was to evaluate in vitro the mechanical effect over teeth and bone structures of surgically assisted rapid maxillary expansion (SARME) in photoelastic analogs by observing stress produced during Hyrax-type and Haas-type appliances activation.

MATERIALS AND METHODS

Two photoelastic analogs were fabricated by use of birefringent materials to simulate an adult skull that contained teeth, bone, and maxillary sinus. Hyrax-type and Haas-type appliances were applied to the anchor teeth and incrementally activated. SARME was simulated by subsequent cuts of the lateral maxillary wall and midpalatine suture and separation of the pterygomaxillary junction. After each osteotomy, the appliances were activated. Resulting stress patterns were recorded photographically in the field of a plane polariscope.

RESULTS

Before any osteotomy, the activation of the appliances distributed stress through the anchoring teeth to the zygomaticomaxillary walls, concentrating at the zygomaticomaxillary and zygomaticofrontal sutures and at the midline of the maxilla. After midpalatal and maxillary wall osteotomies, a marked reduction of the stress at the zygomaticomaxillary walls was observed. With successive activations, the stresses increased in intensity at the molars, maxillary tuberosity, and pterygoid plates. After pterygomaxillary separation, the stress intensity at the molar area, maxillary tuberosity, and pterygoid plates decreased considerably. With successive activations, stress increased in intensity around the molars and maxillary tuberosity. There were no differences between stresses produced by the 2 appliances.

CONCLUSIONS

In this biomechanical model, sectioning of all maxillary articulations, including separation of the pterygomaxillary junction, caused a decrease in stress over anchorage teeth. These data cannot be completely extrapolated to the clinical situation but indicate that electing to perform the SARME technique should be based on periodontal health and amount of expansion necessary for each case.

Surgical treatment of maxillary transverse deficiency: retrospective study of 14 patients

INTRODUCTION

The diversity of the proposed techniques in the treatment of maxillary transverse deficiency in adults reflects the conflicting opinions about the primary area of resistance to maxillary expansion in the craniofacial skeleton. In order to evaluate the efficiency of the surgical expansion in which no osteotomies of the pterygomaxillary junction were made, we have carried out a retrospective study with 14 patients with maxillary transverse deficiency, who were treated from 2003 to 2006.

MATERIAL AND METHODS

In the study, models were made prior to and after surgery, and the intercanine and intermolar distances and the improvement of the interocclusal relationships were analyzed. Breathing function and the complications that occurred during and after the surgeries were also analyzed.

RESULTS

All expansions were carried out according to pre-surgical planning so that expansion completely corrected the crossbite, resulting in the desired final occlusion for all patients. Intraoperative complications were limited to one Hyrax appliance deformation. Two patients had minor postoperative complications that included wound dehiscence and pain. Improvements in nasal breathing were observed in all patients that complained of breathing problems prior to the surgery.

CONCLUSION

The satisfactory results obtained turns the surgical protocol described in this study recommended for the treatment of maxillary transverse deficiency in adults. Importantly, we found that pterygomaxillary osteotomy is not essential for maxillary expansion. The morbidity of the procedure was low with fairly minor complications, and surgically assisted rapid maxillary expansion was shown to improve nasal breathing.