Ocular Hypertelorism: Principles and Management.

Background: Ocular hypertelorism (OH) was initially considered as un-differentiated congenital cranio-facial deformity, however, I.T Jackson mentioned it as teleorbitism, considering it as increase in the inter-canthal width, inter-pupillary as well as inter-orbital distance as a result of lateralization of the orbital complex in total. Furthermore, Sailer further refined it and included the distance from the lateral orbital wall, i.e. he denoted increased inter-orbital distance along with the distance between lateral orbital walls as true hypertelorism. This condition is rare and is seen in association with midline congenital defects affecting the cranio-facial region. Classification and review of cases: The ideal time for the OH correction is usually between 5 and 8 years of age. However, the management of OH is complex, and several techniques have been described in literature for the same. Here, we describe our classification of OH, along with the evolution of the surgical aspects, the key treatment principles we follow, together with the types of the osteotomies and their indications. Furthermore, we delineate the four main principles that we have set for OH management. Results: Though the improvement in appearance is seen immediately post-surgery, however, this challenging surgery faces a multitude and common postoperative complications which have been represented in this article. The surgeon needs both the technical expertise and an inclination towards aesthetics for the execution of such procedures. Conclusion: It is preferred that the management of OH should be individualized as per the stage of the craniofacial growth and the psychosocial needs of the patient and the parents.

Management of Tessier 30-Median Mandibular Cleft: 12-Year Follow-Up-A Case Report.

Midline clefts of mandible and lower lip are rare congenital facial deformities. Non-union of bone in the symphysis of the mandible, median cleft of the lower lip and tongue adherence in the midline to the floor of the mouth are the principle features of the anomaly. Early surgical correction of both hard and soft tissue defects resulted in excellent function such as mastication and speech. 12-yr follow-up shows total bony fusion of the symphysis and normal growth of mandible as per the chronologic age of patient.

Does the Timing of 1-Stage Palatoplasty With Radical Muscle Dissection Effect Long-Term Midface Growth? A Single-Center Retrospective Analysis.

OBJECTIVE: To evaluate the long-term effect of timing of 1-stage palatoplasty on midfacial growth in patients with cleft lip and palate (CLP). DESIGN: Retrospective observational cohort study. STUDY SETTING: Institutional hospital. PATIENTS: One hundred twelve patients with CLP who underwent palatoplasty and were divided into 3 groups: group I: operated between 9 and 11 months; group II: operated between 18 and 20 months; and group III: operated between 21 and 24 months. INTERVENTIONS: All patients underwent von Langenbeck palatoplasty technique, which was converted to a Bardach 2-flap technique in case of any technical difficulties. The patients were followed up between 8 and 9 years when they reported for secondary alveolar bone grafting. Postsurgical cephalometric and dental casts measurements were taken for midfacial growth analysis. MAIN OUTCOME MEASURES: The cephalometric measures were analyzed for midfacial growth and compared within the groups. RESULTS: Statistically significant difference (P < .01) was found on comparing the cephalometric parameters such as sella-nasion-A point angle (SNA), A point-nasion-B point angle (ANB), n toperpendicular to point A (N-perpA), condylon to point A (Co-A), anterior nasal spine to posterior nasal spine (ANS-PNS), nasion to Anterior nasal spine (N-ANS), nasion to menton (N Me), and witts appraisal (Witt (AO-BO)) in group I when compared to both group II and group III patients, implying deficient midfacial growth in group I. No statistical difference was found in the cephalometric values between group II and group III. Group II had better cephalometric measurements than group III, showing better growth in group II than group III. Overall, there was less incidence of midfacial hypoplasia in patients treated between 18 and 20 months (group II). CONCLUSION: We conclude that palatal closure carried out at 18 to 20 months and 21 to 24 months is associated with better midfacial growth when compared to closure at 9 to 11 months. The best time to operate would be between 18 and 20 months to avoid speech disturbances. Midfacial growth can be greatly influenced by the timing of 1-stage palatoplasty.

Correlation between surgical protocols for palatoplasty and midfacial growth in cleft lip and palate patients: A long-term, single centre study.

To evaluate and compare the outcomes of two different surgical protocols for palatoplasty for midfacial growth in patients with cleft lip and palate. A retrospective observational cohort study was conducted in 80 patients with cleft lip and palate, who were divided into two groups. Group 1 comprised patients who underwent operation between 9 and 11 months of age using the Bardach two-flap technique without a palatal pushback. Group 2 comprised patients who had undergone operation between 18 and 20 months of age using either a Bardach two-flap technique with a palatal pushback or a von Langenbeck technique. Patient follow-up was done between 8 and 9 years of age when they reported to the centre for secondary alveolar bone grafting. Post-surgical cephalometric measurements were taken for midfacial growth analysis. Group 1 underwent palatoplasty at significantly younger ages than Group 2 (p < 0.01). A statistically significant difference(p < 0.01) was found between the two groups of patients on comparison of cephalometric parameters such as SNA, ANB, CoA, NperpA ANS-PNS, N-ANS, N-Me, Witt's (AO-BO). Group 2 had more positive cephalometric values as compared to Group 1, thereby implying that there was less incidence of midfacial hypoplasia in patients treated at the age of 18-20 months. Between the types of palatoplasty techniques within Group 2, i.e., Bardach two-flap and von Langenbeck, there was no statistical difference found in the post-opertative cephalometric values, i.e., SNA, ANB, CoA, ANS-PNS, N-ANS, N-Me, Witt's (AO-BO) except for Nperp-A, which showed a statistical difference (p = 0.03). Within the limitations of the study which is only a single center experience it seems that palatal closure should be carried out at 18-20 months of age for better midfacial growth, leading to decreased incidence of maxillary hypoplasia at a later stage in life. Repair at less than 18 months of age is also associated with mid-facial hypoplasia.

Association between ABO, Rh blood groups, lip and dermatoglyphic patterns, and nonsyndromic oral clefts: A case-control study.

OBJECTIVE: The objective of the study is to determine the association between nonsyndromic oral clefts (OC) in children and ABO, Rh blood groups, lip, and dermatoglyphic patterns of their unaffected parents. METHODS: This case-control study was conducted at a tertiary cleft center in Chennai, India, among 240 individuals comprising 80 units (40 cases and controls, respectively). Each unit (triad) was constituted by a child (0-12 years of age) either born with nonsyndromic OC (cases) or with no diagnosed congenital anomaly (control) and their unaffected parents (mother and father). ABO and Rh blood groups, specific lip print, fingerprint pattern, and palmar asymmetry were recorded for each individual. Strength of association of related factors was assessed by multivariable logistic regression reported as adjusted odds ratios and 95% confidence interval. RESULTS: A1-positive blood group was found to be considerably higher among case mothers (14.39 [1.57-32.27]). A higher odds of OCs were observed among case mothers with whorl lip pattern (1.51 [1.16-3.17]) and radial loop pattern in fingers (1.44 [1.09-2.31]) relative to controls. In addition, palmar asymmetry was distinctively higher among case parents compared to controls (P < 0.01). CONCLUSION: Findings indicate that A1-positive blood group, higher frequency of whorl lip, and radial loop finger patterns in mothers and higher ulnar loop pattern in fathers and palmar asymmetry in both parents increases odds of occurrence of OC among their offspring. These identifiable traits offer potential scope for better service planning among resource-constrained disadvantaged communities in India.

Distraction Osteogenesis Versus Orthognathic Surgery: Demystifying Differences in Concepts, Techniques and Outcomes.

INTRODUCTION: The popularity and interest evoked by orthognathic surgery and distraction osteogenesis are undisputed in the field of oral and maxillofacial surgery. However, questions regarding the individual identities of either of them with clarity in their concepts, techniques and outcomes have remained unanswered. The aim of this review is to shed light on these questions. METHODS: This review is structured as a narrative review of thirty years of literature available in the specialities of orthognathic surgery and distraction osteogenesis. CONCLUSION: The authors present a review of existing literature combined with contrasting experience gained over the years in providing an overview of the merits and demerits of the two surgical techniques which will aid the clinician in justifying the use of one technique over the other.

Retrospective analysis of a TMJ ankylosis protocol with a 9 year follow up.

OBJECTIVE: Temporomandibular joint ankylosis (TMJa) is a debilitating condition that causes difficulty in mastication, speech and mouth opening. Its treatment poses surgical and rehabilitative challenges along with a high incidence of reankylosis. This study was designed to assess the long-term outcomes with a new two phase physiotherapy protocol following conservative resection of the ankylotic mass. MATERIALS AND METHODS: 143 patients who were treated for TMJa were initially recruited, among whom 98 were inducted into the study and retrospectively evaluated using clinical records and 3-dimensional computed tomography. All the patients underwent a minimal pre auricular incision and conservative interpositional gap arthroplasty with collagen membrane. This was followed by the new two phase physiotherapy protocol with the use of a bite block. The primary outcome measures were the maximum interincisal distance, vertical ramus height and complications. The patients were followed up at monthly intervals during the first year, quarterly intervals during the second year, and at intervals of 6 months during subsequent follow-up years. The mean follow up period was 6.38 ± 2.36 years after ankylotic release. Paired student t test was used for statistical analysis. RESULTS: The mean scores for mouth opening at T1, T2 and T3 were statistically significantly different at all intervals (p < 0.0005). The mean scores for ramal length were statistically significantly different at T1 and T2 interval (p < 0.0005) and insignificant at T2 and T3 interval. No reankylosis was observed in patients who followed the physiotherapy protocol. CONCLUSIONS: In the management of TMJa, the success of the conservative surgical technique with interpositional arthroplasty is less dependent on the longevity and rigidity of the interpositional material but more indebted to the patient compliance in following the proposed physiotherapy protocol.

Does Sphenopalatine Ganglion Block Improve Pain Control and Intraoperative Hemodynamics in Children Undergoing Palatoplasty? A Randomized Controlled Trial.

PURPOSE: Children undergoing cleft palate repair have pain, dysphagia, and wound irritation in the immediate postoperative phase that may compromise surgical outcomes. This trial evaluates the efficacy of the sphenopalatine ganglion block (SPGB) in optimizing intraoperative hemodynamics and postoperative analgesia in children undergoing primary palatoplasty. MATERIALS AND METHODS: The study was designed as a prospective, double-blind, randomized controlled trial comparing the use of SPGB with general anesthesia (GA) (study group) versus the use of only GA (control group). Routine preoperative documentation included type of cleft, patient weight, hemoglobin (Hb%), packed cell volume (PCV), blood pressure, and echocardiogram. Intraoperative monitoring included heart rate, blood pressure, and surgical field assessment. Postoperatively, the pain score, pain-free duration, and need for rescue analgesics were recorded. Postsurgical changes in Hb% and PCV values were assessed. Data analysis of collected variables was performed using SPSS software (version 16; IBM, Armonk, NY). Quantitative data were assessed for normality using the Shapiro-Wilk test and analyzed using the independent-sample t test, and the Fisher exact test was used for comparison of the binary variable (gender). The outcome variables were compared between the study and control groups after adjustment for confounding variables. P < .05 was considered statistically significant. RESULTS: We randomized 100 patients undergoing primary palatoplasty under GA into the control group (n = 49) and study group (SPGB) (n = 51). Three patients were excluded from the control group because of changes in intraoperative anesthetic protocol. The results showed statistically significant differences in the postsurgical pain-free duration (19.46 minutes vs 87.59 minutes) and mean blood loss (105.5 mL vs 62 mL) in favor of the study group. Surgical field and postoperative reduction of Hb% and PCV were also significantly favorable for the study group. CONCLUSIONS: SPGB is a potent pre-emptive technique offering excellent perioperative analgesia, hemodynamic stability, and a clear surgical field.

Neocondyle distraction osteogenesis in the management of temporomandibular joint ankylosis: Report of five cases with review of literature.

INTRODUCTION AND OBJECTIVES: Management of temporomandibular joint (TMJ) ankylosis is a challenging and rather daunting task owing to complex abnormal anatomy and its sequel to craniofacial structures. Various autogenous grafts and alloplastic materials have been tried with variable success for creation of a near-normal joint. In recent years, neocondyle distraction has added a new dimension to the management of TMJ ankylosis. The aim of this paper is to describe the role of neocondyle distraction in TMJ ankylosis. MATERIALS AND METHODS: Neocondyle distraction was carried out in five patients with TMJ ankylosis following gap arthroplasty. Computed tomogram scans were taken before surgery and 1-year postdistraction for surgical planning and postoperative assessment, respectively. The intraoral distractors (KLS Martin, Jacksonville, FL, USA) were used in this study. RESULTS: All five patients reported with adequate mouth opening and functional jaw movements. The procedure was well tolerated by all the patients. None of the patients underwent reankylosis following neocondyle distraction. CONCLUSION: With proper surgical planning and distraction protocol, neocondyle distraction is an effective and safe technique for TMJ reconstruction and preventing reankylosis.

Mid-Face Degloving: An Alternate Approach to Extended Osteotomies of the Midface.

Extended osteotomies for mid-face advancement require generous exposure of the anterior maxilla, nasal bones, infraorbital rims, orbital floor, zygoma, and the anterior third of the zygomatic arches. This cannot be obtained with an exclusive transoral approach. Hence, the surgeon is usually compelled to utilize supplemental cutaneous incisions that are a compromise on the purpose behind a cosmetic surgery. In order to alleviate the need for such compromise, the authors advocate the mid face degloving approach for extended osteotomies at Lefort II and Lefort III levels. Mid face degloving involves a combination of circumvestibular incision, with inter cartilaginous and transfixation components from a nasal incision. The authors have utilized this technique for 9 patients and documented favorable results. The purpose of this paper is to focus the utility of this approach in orthognathic surgery and promote this as a viable alternative to traditional approaches in surgery of the mid face because of the absence of external scars.

Impact of mandibular distraction osteogenesis on the oropharyngeal airway in adult patients with obstructive sleep apnea secondary to retroglossal airway obstruction.

AIM: To evaluate the impact of mandibular advancement by distraction osteogenesis on the oropharyngeal airway in adult patients with retroglossal airway obstruction using two different techniques of mandibular distraction. MATERIALS AND METHODS: 13 adult patients with mandibular hypoplasia secondary to TMJ ankylosis with OSAS and radiographic, CT and polysomnographic evidence of OSAS were included in the study. MDO was performed (corpus distraction in 8 cases and morphometric distraction in 5 patients). Post-operatively the patients were followed up by radiographs, CT and polysomnography after 1 month and 6 months. RESULTS: There was an increase in the linear dimension of mandible by 11.07 mm, the volume by 19.3% and a decrease in AHI from 44.8 to 13.2. CONCLUSION: Mandibular distraction (corpus and orthomorphic-equivocal results) is an effective method of relieving the retroglossal airway obstruction in adult patients with OSAS.

Reconstruction of Nasal Cleft Deformities Using Expanded Forehead Flaps: A Case Series.

INTRODUCTION: Reconstruction of the nasal clefts is a challenging task considering the nasal anatomic complexity and their possible association with craniofacial defects. The reconstruction of these defects needs extensive amounts of soft tissue that warrant the use of forehead flaps. Often presence of cranial defects and low hairline compromise the amount of tissue available for reconstruction warrenting tissue expansion. AIM: To evaluate the efficacy of tissue expansion in reconstruction of congenital nasal clefts. SUBJECTS AND METHODS: 9 patients with congenital nasal clefts involving multiple sub units were taken up for nasal reconstruction with expanded forehead flaps. The average amount of expansion needed was 200 ml. The reconstruction was performed in 3 stages. RESULTS: Expanded forehead flaps proved to be best modality for reconstruction providing the skin cover needed for ala, columella and dorsum with minimal scarring at the donor site. CONCLUSION: Expansion of the forehead flap is a viable option for multiple sub unit reconstruction in congenital nasal cleft deformities.

A paradigm shift in orthognathic surgery? A comparison of navigation, computer-aided designed/computer-aided manufactured splints, and "classic" intermaxillary splints to surgical transfer of virtual orthognathic planning.

PURPOSE: Advances in computers and imaging have permitted the adoption of 3-dimensional (3D) virtual planning protocols in orthognathic surgery, which may allow a paradigm shift when the virtual planning can be transferred properly. The purpose of this investigation was to compare the versatility and precision of innovative computer-aided designed and computer-aided manufactured (CAD/CAM) surgical splints, intraoperative navigation, and "classic" intermaxillary occlusal splints for surgical transfer of virtual orthognathic planning. MATERIAL AND METHODS: The protocols consisted of maxillofacial imaging, diagnosis, virtual orthognathic planning, and surgical planning transfer using newly designed CAD/CAM splints (approach A), navigation (approach B), and intermaxillary occlusal splints (approach C). In this prospective observational study, all patients underwent bimaxillary osteotomy. Eight patients were treated using approach A, 10 using approach B, and 12 using approach C. These techniques were evaluated by applying 13 hard and 7 soft tissue parameters to compare the virtual orthognathic planning (T0) with the postoperative result (T1) using 3D cephalometry and image fusion (ΔT1 vs T0). RESULTS: The highest precision (ΔT1 vs T0) for the maxillary planning transfer was observed with CAD/CAM splints (<0.23 mm; P > .05) followed by surgical "waferless" navigation (<0.61 mm, P < .05) and classic intermaxillary occlusal splints (<1.1 mm; P < .05). Only the innovative CAD/CAM splints kept the condyles in their central position in the temporomandibular joint. However, no technique enables a precise prediction of the mandible and soft tissue. CONCLUSIONS: CAD/CAM splints and surgical navigation provide a reliable, innovative, and precise approach for the transfer of virtual orthognathic planning. These computer-assisted techniques may offer an alternate approach to the use of classic intermaxillary occlusal splints.

Tessier 30 symphyseal mandibular cleft: early simultaneous soft and hard tissue correction - a case report.

A symphyseal mandibular facial cleft (Tessier 30) is a rare congenital abnormality. Nonunion of bone in the symphysis of the mandible, median cleft of the lower lip and tongue adherence in the midline to the floor of the mouth are the principle features of the anomaly. A satisfactory result can be achieved with early surgical correction of both hard and soft tissue defects in the age of 6 months. More than 3 years follow-up shows total bony fusion of the symphysis and normal lower lip function. There were only left deciduous central incisor and the ipsilateral tooth bud of the permanent central incisor missing.

Intraoperative vascular anatomy, arterial blood flow velocity, and microcirculation in unilateral and bilateral cleft lip repair.

BACKGROUND: Cleft lip repair aims to normalize the disturbed anatomy and function. The authors determined whether normalization of blood circulation is achieved. METHODS: The authors measured the microcirculatory flow, oxygen saturation, and hemoglobin level in the lip and nose of controls (n = 22) and in patients with unilateral and bilateral cleft lip-cleft palate. The authors measured these parameters before lip repair (n = 29 and n = 11, respectively), at the end of lip repair (n = 27 and 10, respectively), and in the late postoperative period (n = 33 and n = 20, respectively). The arterial flow velocity was measured in unilateral groups at the same time points (n = 13, n = 11, and n = 12, respectively). Statistical differences were determined using analysis of variance. RESULTS: Before surgery, the arterial flow velocities and microcirculation values were similar on each side of the face and between groups. The microcirculatory flow was significantly higher in the prolabium of bilateral patients than in the philtrum of controls. All circulation values in unilateral and bilateral patients in the late postoperative period were within the range of controls and of those before surgery. Intraoperatively, the authors consistently found a perforating artery on the superficial side of the transverse nasalis muscle. CONCLUSIONS: There appears to be no intrinsic circulatory deficit in unilateral and bilateral cleft lip-cleft palate patients. The increased flow in the prolabium indicates a strong hemodynamic need in this territory, compelling its vascular preservation. Whether surgical preservation of the nasalis perforator artery is of long-term benefit should be addressed in future studies. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Computer-assisted orthognathic surgery: feasibility study using multiple CAD/CAM surgical splints.

OBJECTIVE: We present a virtual planning protocol incorporating a patented 3-surgical splint technique for orthognathic surgery. The purpose of this investigation was to demonstrate the feasibility and validity of the method in vivo. MATERIALS AND METHODS: The protocol consisted of (1) computed tomography (CT) or cone-beam computed tomography (CBCT) maxillofacial imaging, optical scan of articulated dental study models, segmentation, and fusion; (2) diagnosis and virtual treatment planning; (3) computed-assisted design and manufacture (CAD/CAM) of the surgical splints; and (4) intraoperative surgical transfer. Validation of the accuracy of the technique was investigated by applying the protocol to 8 adult class III patients treated with bimaxillary osteotomies. The virtual plan was compared with the postoperative surgical result using image fusion of CT/CBCT dataset by analysis of measurements between hard and soft tissue landmarks relative to reference planes. RESULTS: The virtual planning approach showed clinically acceptable precision for the position of the maxilla (<0.23 mm) and condyle (<0.19 mm), marginal precision for the mandible (<0.33 mm), and low precision for the soft tissue (<2.52 mm). CONCLUSIONS: Virtual diagnosis, planning, and use of a patented CAD/CAM surgical splint technique provides a reliable method that may offer an alternate approach to the use of arbitrary splints and 2-dimensional planning.

Incidence of cleft Lip and palate in the state of Andhra Pradesh, South India.

OBJECTIVE: To assess the incidence of cleft lip and palate defects in the state of Andhra Pradesh, India. DESIGN SETTING: The study was conducted in 2001 in the state of Andhra Pradesh, India. The state has a population of 76 million. Three districts, Cuddapah, Medak and Krishna, were identified for this study owing to their diversity. They were urban, semi-urban and rural, respectively. Literacy rates and consanguinity of the parents was elicited and was compared to national averages to find correlations to cleft births. Type and side of cleft were recorded to compare with other studies around the world and other parts of India. RESULTS: The birth rate of clefts was found to be 1.09 for every 1000 live births. This study found that 65% of the children born with clefts were males. The distribution of the type of cleft showed 33% had CL, 64% had CLP, 2% had CP and 1% had rare craniofacial clefts. Unilateral cleft lips were found in 79% of the patients. Of the unilateral cleft lips 64% were left sided. There was a significant correlation of children with clefts being born to parents who shared a consanguineous relationship and those who were illiterate with the odds ratio between 5.25 and 7.21 for consanguinity and between 1.55 and 5.85 for illiteracy, respectively. CONCLUSION: The birth rate of clefts was found to be comparable with other Asian studies, but lower than found in other studies in Caucasian populations and higher than in African populations. The incidence was found to be similar to other studies done in other parts of India. The distribution over the various types of cleft was comparable to that found in other studies.

Non-surgical risk factors for condylar resorption after orthognathic surgery.

BACKGROUND: Condylar resorption following orthognathic surgery is an important cause of late skeletal relapse. However, its pathogenesis is not well understood. The purpose of this study was to find non-surgical risk factors for condylar resorption after orthognathic surgery. PATIENTS: In this retrospective study, 17 patients (Group I) who developed postoperative condylar resorption were selected. These patients were compared with 22 patients (Group II) without postoperative condylar resorption, but who showed mandibular hypoplasia with a preoperative high mandibular plane angle of more than 40 degrees. METHODS: Possible non-surgical risk factors were sought by analysing clinical and radiological data collected preoperatively and immediately, 6 weeks, and 1 and 2 years postoperatively. RESULTS: There was no significant difference of gender distribution between the two groups. Patients in Group I were significantly younger (p=0.02) than those in Group II. The incidence of temporomandibular joint dysfunction in both groups was similar preoperatively, but was significantly higher (p=0.001) postoperatively in Group I. The posterior inclination of the condylar neck in Group I was also significantly greater (p<0.001). The preoperative mandibular plane angle in Group I (mean value: 49.4 degrees ) was significantly greater (p=0.005) than in Group II (mean value: 44.9 degrees ). The preoperative SNB angle, overbite, and posterior facial height and ratio (posterior/anterior facial heights) in Group I were significantly smaller (p<0.05). CONCLUSION: The present study suggests that the posteriorly inclined condylar neck should be considered as a relevant non-surgical risk factor.

Effect of rhBMP-2 on guided bone regeneration in humans.

The aim of the present clinical study was to test whether or not the addition of recombinant human bone morphogenetic protein-2 (rhBMP-2) to a xenogenic bone substitute mineral (Bio-Oss) will improve guided bone regeneration therapy regarding bone volume, density and maturation. In 11 partially edentulous patients, 34 Brånemark implants were placed at two different sites in the same jaw (five maxillae, six mandibles) requiring lateral ridge augmentation. The bone defects were randomly assigned to test and control treatments: the test and the control defects were both augmented with the xenogenic bone substitute and a resorbable collagen membrane (Bio-Gide). At the test sites, the xenogenic bone substitute mineral was coated with rhBMP-2 in a lyophilization process. Following implant insertion (baseline), the peri-implant bone defect height was measured from the implant shoulder to the first implant-bone contact. After an average healing period of 6 months (SD 0.17, range 5.7-6.2), the residual defects were again measured and trephine burs were used to take 22 bone biopsies from the augmented regions. The healing period was uneventful except for one implant site that showed a wound dehiscence, which spontaneously closed after 4 weeks. Later at reentry, all implants were stable. At baseline, the mean defect height was 7.0 mm (SD 2.67, range 3-12 mm) at test and 5.8 mm (SD 1.81, range 3-8 mm) at control sites. At reentry, the mean defect height decreased to 0.2 mm (SD 0.35, range 0-1 mm) at test sites (corresponding to 96% vertical defect fill) and to 0.4 mm (SD 0.66, range 0-2 mm) at the control site (vertical defect fill of 91%). Reduction in defect height from baseline to reentry for both test and control sites was statistically significant (Wilcoxon P<0.01). Histomorphometric analysis showed an average area density of 37% (SD 11.2, range 23-51%) newly formed bone at test sites and 30% (SD 8.9, range 18-43%) at control sites. The fraction of mineralized bone identified as mature lamellar bone amounted to 76% (SD 14.4, range 47.8-94%) at test compared to 56% (SD 18.3, range 31.6-91.4%) at control sites (paired t-test P<0.05). At BMP-treated sites 57% (SD 16.2, range 29-81%) and at control sites 30% (SD 22.6, range 0-66%) of the surface of the bone substitute particles were in direct contact with newly formed bone (paired t-test P<0.05). It is concluded that the combination of the xenogenic bone substitute mineral with rhBMP-2 can enhance the maturation process of bone regeneration and can increase the graft to bone contact in humans. rhBMP-2 has the potential to predictably improve and accelerate guided bone regeneration therapy.